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Hill EB, Mastny-Jensen C, Loch C. Before and after: COVID-19 impacts on dental students' well-being, clinical competency and employment opportunities. Eur J Dent Educ 2024; 28:522-529. [PMID: 38009831 DOI: 10.1111/eje.12977] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Revised: 08/27/2023] [Accepted: 10/18/2023] [Indexed: 11/29/2023]
Abstract
INTRODUCTION The onset of COVID-19 challenged dental schools worldwide, impacting clinical training. In Australasia, New Zealand adopted a COVID-19 'elimination strategy', involving nationwide lockdowns that halted face-to-face education. The 'elimination strategy' adopted at the pandemic onset, which permitted return to 'normal life' in 2021, allowed the pandemic impacts and those related workforce transition to be teased out. This study aimed to evaluate perceived impacts of the COVID-19 pandemic on health and well-being, clinical competency and employment opportunities of dental students. MATERIALS AND METHODS Two surveys were distributed to final year dental students (n = 94; age range 20-35): one during their final semester and the second six months following graduation. Surveys included open and closed ended questions on participants' self-perceived impacts of COVID-19 on health and well-being, clinical competency and employment opportunities. Average percentages were calculated and descriptive statistics performed. RESULTS Pre-graduation, participants reported COVID-19 negatively impacted their mental and social health. Slightly lower scores on all dimensions of health post-graduation were likely due to transitioning to the workforce. Pre-graduation, less than half of participants felt prepared to provide the full scope of dental treatment; post-graduation most felt confident to do so. Most participants expected COVID-19 would negatively impact employment opportunities for their cohort, despite all participants being employed when the second survey was conducted. CONCLUSION Participants self-rated health and clinical competency scores were lower post-graduation when NZ returned to 'normal life', meaning lower scores were related to workforce transition. Dental schools need to be prepared to provide alternative forms of dental education and help mitigate mental health impacts of future major course disruptions.
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Affiliation(s)
- Eva Barron Hill
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin, New Zealand
| | - Chevvy Mastny-Jensen
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin, New Zealand
| | - Carolina Loch
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin, New Zealand
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Towle I, Loch C. Variation in enamel prism size in primate molars. Arch Oral Biol 2024; 160:105895. [PMID: 38266424 DOI: 10.1016/j.archoralbio.2024.105895] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Revised: 01/10/2024] [Accepted: 01/13/2024] [Indexed: 01/26/2024]
Abstract
OBJECTIVE This study examines whether larger enamel prism diameters accommodate a greater enamel volume from the enamel-dentine junction (EDJ) to the outer-enamel surface (OES) in primate molars, and how prism size relates to enamel thickness and crown location. DESIGN We assessed variation in enamel prism diameter in relation to crown location and enamel thickness in catarrhine lower molars (n = 14 species) and one platyrrhine. Prism diameter and enamel thickness were recorded in four locations (lingual lateral; lingual cuspal; buccal cuspal; buccal lateral), using a buccal-lingual section through the centre of the mesial cusps. Ten prism diameter readings were collected at inner (near the EDJ), outer (near the OES) and middle (between the two locations) enamel for each location. RESULTS Mean prism diameter values for each species were similar (range: 4.06 µm to 5.81 µm). Prism diameter enlarged from inner to outer enamel, suggesting larger prisms help accommodate the increase in enamel volume from the EDJ to the OES. Average prism diameter does not associate with enamel thickness. Instead, cuspal positions had significantly smaller prism diameter at the EDJ than lateral positions, and larger prism sizes at the OES, leading to an overall similar prism diameter mean for all positions (Lingual lateral: 5.11 µm; Lingual cuspal: 5.04 µm; Buccal cuspal: 4.78 µm; Buccal lateral: 4.99 µm). CONCLUSIONS Our study revealed consistent average enamel prism diameters in various crown locations of lower primate molars, potentially contributing to the mechanical integrity and functional optimization of enamel in primates.
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Affiliation(s)
- Ian Towle
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin 9054, New Zealand; Centro Nacional de Investigación sobre la Evolución Humana (CENIEH), Paseo Sierra de Atapuerca 3, 09002 Burgos, Spain.
| | - Carolina Loch
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin 9054, New Zealand
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Nath SJC, Fu Y, Li KC, Loho T, Loch C, Ekambaram M. A Comparison of the Enamel Remineralisation Potential of Self-Assembling Peptides. Int Dent J 2024; 74:187-194. [PMID: 37743135 PMCID: PMC10988264 DOI: 10.1016/j.identj.2023.07.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 06/19/2023] [Accepted: 07/04/2023] [Indexed: 09/26/2023] Open
Abstract
BACKGROUND The aim of this research was to compare the efficacy of the remineralising potential of self-assembling peptides (SAPs): Curodont Repair (P11-4), P26, and leucine-rich amelogenin peptides (LRAP) with the standard 5% NaF varnish (Duraphat) on early enamel caries lesions (EECLs). METHODS A demineralising solution (DS) was used to create artificial EECLs in human dental enamel specimens, which were randomly allocated to treatment groups: P11-4; P26 solution; LRAP solution; 5% NaF varnish; and deionised water (DIW). Each specimen was subjected to 8 days of pH cycling. Specimens from each test group were subjected to microcomputed tomography (micro-CT) and nanomechanical testing to assess mineral density (MD), hardness (H), and elastic modulus (EM) properties of sound, demineralised, and treated enamel. RESULTS The mean MD percentage gain was highest in the P26 and P11-4 groups, followed by the LRAP, 5% NaF varnish, and DIW groups. There were statistically significant differences amongst groups. In the outer layer of EECLs, the EM and H were highest in P26 and P11-4 groups, followed by the LRAP and 5% NaF varnish. In the inner layer of EECLs, the EM and H were highest in P11-4 and P26 groups, indicative of enhanced penetration and remineralisation of the deeper parts of the artificial EECLs. CONCLUSIONS P26 and P11-4 SAPs are more effective than 5% NaF varnish in remineralising the depth of EECLs.
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Affiliation(s)
- Suneil Jason Chand Nath
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin, New Zealand
| | - Yipeng Fu
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin, New Zealand; The Fifth Outpatient Department, Nanjing Stomatological Hospital, Medical School of Nanjing University, Nanjing, Jiangsu, People's Republic of China
| | - Kai Chun Li
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin, New Zealand
| | - Thomas Loho
- Faculty of Engineering, Chemical and Materials Engineering, University of Auckland, New Zealand
| | - Carolina Loch
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin, New Zealand
| | - Manikandan Ekambaram
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin, New Zealand.
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Aziz S, Loch C, Li KC, Anthonappa R, Meldrum A, Ekambaram M. Remineralization potential of dentifrices with calcium sodium phosphosilicate and functionalized tri-calcium phosphate in the deeper incipient carious lesions: An in vitro study. Clin Exp Dent Res 2024; 10:e876. [PMID: 38506322 PMCID: PMC10952118 DOI: 10.1002/cre2.876] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Revised: 02/04/2024] [Accepted: 02/25/2024] [Indexed: 03/21/2024] Open
Abstract
OBJECTIVES This study evaluated the remineralization potential of calcium sodium phosphosilicate and functionalized tri-calcium phosphate (f-TCP) dentifrices in deeper incipient carious lesions (ICLs). MATERIALS AND METHODS Artificial ICLs were created by placing premolars into demineralizing solutions. Teeth were randomly assigned into four groups: calcium sodium phosphosilicate (Group 1), f-TCP (Group 2), 1450 ppm fluoride (Group 3), and distilled water (Group 4), which were subjected to 10-day pH cycling. Mineral density (MD) was assessed using microcomputed tomography (Micro-CT), while hardness (H) and elastic modulus (EM) were assessed using nanomechanical testing. RESULTS MD % gain was higher in Groups 1-3 than in Group 4. In addition, Groups 1 and 2 exhibited significantly higher MD % gain than Group 3. Also, Groups 1-3 showed significantly higher EM and H values than Group 4 in the outer enamel area; yet, Groups 1 and 2 displayed significantly higher EM and H values than Groups 3 and 4 in the inner enamel. CONCLUSIONS The MD, EM, and H of ICLs significantly increased with the addition of calcium sodium phosphosilicate or f-TCP to fluoridated dentifrices compared to standard fluoride dentifrices. The added active ingredients remineralized the deeper parts of the ICLs, while remineralization at the lesion surface was similar between tested dentifrices.
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Affiliation(s)
- Shafiq Aziz
- Sir John Walsh Research Institute, Faculty of DentistryUniversity of OtagoDunedinNew Zealand
| | - Carolina Loch
- Sir John Walsh Research Institute, Faculty of DentistryUniversity of OtagoDunedinNew Zealand
| | - Kai Chun Li
- Sir John Walsh Research Institute, Faculty of DentistryUniversity of OtagoDunedinNew Zealand
| | - Robert Anthonappa
- Paediatric Dentistry, UWA Dental SchoolThe University of Western AustraliaPerthAustralia
| | - Alison Meldrum
- Sir John Walsh Research Institute, Faculty of DentistryUniversity of OtagoDunedinNew Zealand
| | - Manikandan Ekambaram
- Sir John Walsh Research Institute, Faculty of DentistryUniversity of OtagoDunedinNew Zealand
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Towle I, Borths MR, Loch C. Tooth chipping patterns and dental caries suggest a soft fruit diet in early anthropoids. Am J Biol Anthropol 2024; 183:e24884. [PMID: 38093580 DOI: 10.1002/ajpa.24884] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Revised: 11/07/2023] [Accepted: 11/21/2023] [Indexed: 01/25/2024]
Abstract
OBJECTIVES Fossils from the Fayum Depression, Egypt, are crucial for understanding anthropoid evolution due to the abundance of taxa and the time interval they represent (late Eocene to early Oligocene). Dietary and foraging behavioral interpretations suggest fruits were their dominant food source, although hard foods (e.g., seeds and nuts) and leaves could have been important dietary components for particular groups. In this study, we compare dental chipping patterns in five Fayum primate genera with chipping data for extant primates, to assess potential hard object feeding in early anthropoids. MATERIALS AND METHODS Original specimens were studied (Aegyptopithecus: n = 100 teeth; Parapithecus: n = 72, Propliopithecus: n = 99, Apidium: n = 82; Catopithecus: n = 68); with the number, severity, and position of chips recorded. Dental caries was also recorded, due to its association with soft fruit consumption in extant primates. RESULTS Tooth chipping was low across all five genera studied, with a pooled chipping prevalence of 5% (21/421). When split into the three anthropoid families represented, chipping prevalence ranged from 2.6% (4/154) in Parapithecidae, 6% (12/199) in Propliopithecidae, and 7.4% (5/68) in Oligopithecidae. Three carious lesions were identified in Propliopithecidae. DISCUSSION The chipping prevalence is low when compared to extant anthropoids (range from 4% to 40%) and is consistent with a predominantly soft fruit diet, but not with habitual hard food mastication. The presence of caries supports consumption of soft, sugary fruits, at least in Propliopithecidae. Our results add support for low dietary diversity in early anthropoids, with soft fruits as likely dominant food sources.
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Affiliation(s)
- Ian Towle
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin, New Zealand
| | - Matthew R Borths
- Duke Lemur Center Museum of Natural History, Duke University, Durham, North Carolina, USA
| | - Carolina Loch
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin, New Zealand
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Beckett DM, Vaz Viegas S, Broadbent JM, Wheeler BJ, Bērziņš K, Fraser-Miller SJ, Gordon KC, Drummond BK, Mahoney EK, Loch C. An Exploration of Mineral Density, Elemental and Chemical Composition of Primary Teeth in Relation to Cord-Blood Vitamin D, Using Laboratory Analysis Techniques. J Bone Miner Res 2023; 38:1846-1855. [PMID: 37877440 DOI: 10.1002/jbmr.4928] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Revised: 09/22/2023] [Accepted: 10/06/2023] [Indexed: 10/26/2023]
Abstract
Postnatally, severe vitamin D deficiency commonly results in rickets as well as potential defects in tooth mineralization. The effects of milder deficiency on oral health outcomes later in life are still unclear. This study used micro-computed tomography (μCT), energy dispersive X-ray analysis (EDX), and Raman spectroscopy to investigate mineral density, total density, and elemental composition of enamel and dentine in 63 exfoliated primary incisors from participants with known 25-hydroxyvitamin D levels (25-OHD) at birth. No differences in mineralization and chemical composition using μCT and EDX analysis were observed irrespective of 25-OHD status. Subtle structural differences were observed via Raman spectroscopy, with more crystalline enamel observed in those with sufficient 25-OHD at birth. Although subtle, the differences seen suggest further attention should be given to children with known milder levels of vitamin D deficiency in early life. © 2023 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).
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Affiliation(s)
- Deanna M Beckett
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin, New Zealand
| | - Shaun Vaz Viegas
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin, New Zealand
| | - Jonathan M Broadbent
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin, New Zealand
| | - Benjamin J Wheeler
- Paediatric Endocrinology, Te Whatu Ora Southern, Dunedin, New Zealand
- Department of Women's and Children's Health, University of Otago, Dunedin, New Zealand
| | - Kārlis Bērziņš
- Department of Pharmacy, University of Copenhagen, Copenhagen, Denmark
- Department of Chemistry, University of Otago, Dunedin, New Zealand
| | | | - Keith C Gordon
- Department of Chemistry, University of Otago, Dunedin, New Zealand
| | | | - Erin K Mahoney
- Dental Department, Te Whatu Ora Capital, Coast and Hutt Valley, Wellington, New Zealand
- Department of Paediatrics and Child Health, University of Otago, Wellington, New Zealand
| | - Carolina Loch
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin, New Zealand
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Viglino M, Ezcurra MD, Fordyce RE, Loch C. The better to eat you with: morphological disparity and enamel ultrastructure in odontocetes. Sci Rep 2023; 13:16969. [PMID: 37807006 PMCID: PMC10560669 DOI: 10.1038/s41598-023-44112-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Accepted: 10/03/2023] [Indexed: 10/10/2023] Open
Abstract
Variations in the shape and size of teeth have been associated with changes in enamel ultrastructure across odontocetes. Characterizing these features in extinct taxa can elucidate their functional morphology and feeding strategy, while also shedding light into macroevolutionary patterns during the evolutionary history of cetaceans. This study aimed to (1) describe the enamel and dentine ultrastructure of the Early Miocene odontocetes Notocetus vanbenedeni and Phoberodon arctirostris from Patagonia (Argentina) and (2) quantify tooth and enamel ultrastructure morphological disparity among odontocetes. Enamel was predominantly prismatic, thin in the anterior tooth of N. vanbenedeni and P. arctirostris; whilst thick on the posterior tooth of N. vanbenedeni. Together with skull morphology, data suggests a raptorial feeding strategy for P. arctirostris and a combination suction feeding method for N. vanbenedeni. Statistical analyses supported these inferences, indicating that enamel characters are useful for paleoecological research. Morphological disparity analyses showed that extant odontocetes occupy a larger morphospace and have more disparate morphologies, whilst extinct odontocetes were more similar among each other than with the extant group. There was no clear phylogenetic-based grouping, suggesting that tooth and enamel ultrastructure disparity were mainly driven by ecological pressures. These results highlight enamel ultrastructure as a source for broader-scale paleoecological studies in cetaceans.
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Affiliation(s)
- Mariana Viglino
- Instituto Patagónico de Geología y Paleontología (IPGP), CCT CONICET-CENPAT, U9120ACD, Puerto Madryn, Chubut, Argentina.
| | - Martín D Ezcurra
- Sección Paleontología de Vertebrados, CONICET-Museo Argentino de Ciencias Naturales "Bernardino Rivadavia", C1405DJR, Ciudad Autónoma de Buenos Aires, Argentina
| | - R Ewan Fordyce
- Department of Geology, University of Otago, Dunedin, 9054, New Zealand
| | - Carolina Loch
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin, 9054, New Zealand
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Towle I, Loho T, Salem AS, Berthaume MA, Loch C. Variation in enamel mechanical properties throughout the crown in catarrhine primates. J Hum Evol 2023; 182:103413. [PMID: 37562101 DOI: 10.1016/j.jhevol.2023.103413] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Revised: 07/05/2023] [Accepted: 07/08/2023] [Indexed: 08/12/2023]
Abstract
Enamel mechanical properties vary across molar crowns, but the relationship among mechanical properties, tooth function, and phylogeny are not well understood. Fifteen primate lower molars representing fourteen taxa (catarrhine, n = 13; platyrrhine, n = 1) were sectioned in the lingual-buccal plane through the mesial cusps. Gradients of enamel mechanical properties, specifically hardness and elastic modulus, were quantified using nanoindentation from inner (near the enamel-dentine junction), through middle, to outer enamel (near the outer enamel surface) at five positions (buccal lateral, buccal cuspal, occlusal middle, lingual cuspal, lingual lateral). Cuspal positions had higher mechanical property values than lateral positions. Middle enamel had higher mean hardness and elastic modulus values than inner and outer locations in all five crown positions. Functionally, the thicker-enameled buccal cusps of lower molars did not show evidence of increased resistance to failure; instead, lingual cusps-which show higher rates of fracture-had higher average mechanical property values, with no significant differences observed between sides. Preliminary phylogenetic results suggest there is relatively little phylogenetic signal in gradients of mechanical properties through the enamel or across the crown. There appears to be common mechanical property patterns across molar crowns in Catarrhini and potentially among primates more broadly. These results may allow more precise interpretations of dental biomechanics and processes resulting in mechanical failure of enamel in primates, such as wear and fracture.
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Affiliation(s)
- Ian Towle
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin 9054, New Zealand.
| | - Thomas Loho
- Faculty of Engineering, The University of Auckland, Auckland 1010, New Zealand
| | - Amira Samir Salem
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin 9054, New Zealand
| | - Michael A Berthaume
- Division of Mechanical Engineering and Design, London South Bank University, London SE1 0AA, UK
| | - Carolina Loch
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin 9054, New Zealand
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Towle I, Salem AS, Veneziano A, Loch C. Variation in enamel and dentine mineral concentration and density in primate molars. Arch Oral Biol 2023; 153:105752. [PMID: 37385050 DOI: 10.1016/j.archoralbio.2023.105752] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Revised: 05/24/2023] [Accepted: 06/15/2023] [Indexed: 07/01/2023]
Abstract
OBJECTIVE Variation in enamel and dentine mineral concentration and total effective density can be reliably collected using Micro-CT scans. Both variables are suggested to reflect mechanical properties such as hardness and elastic modulus in dental tissues, meaning Micro-CT methods allow relative composition and mechanical properties to be collected non-destructively. DESIGN 16 lower molars from 16 Catarrhine primates were Micro-CT scanned alongside hydroxyapatite phantoms using standardized settings and methods to calculate mineral concentration and total effective density. Mineral concentration, total effective density and thickness of dentine and enamel were calculated for four cusps, representing each 'corner' of the tooth and four lateral crown positions (i.e., mesial, buccal, lingual and distal). RESULTS The results show mean mineral concentration and total effective density values were higher in areas of thicker enamel, while the opposite was observed for dentine. Buccal positions had significantly higher mineral concentration and total effective density values than lingual areas. Cuspal positions had higher mean values than lateral enamel, for both dentine (mineral concentration cuspal: 1.26 g/cm3; lateral: 1.20 g/cm3) and enamel (mineral concentration cuspal: 2.31 g/cm3; lateral: 2.25 g/cm3). Mesial enamel had significantly lower values than other locations. CONCLUSIONS These common patterns across Catarrhine taxa may be linked to functional adaptations related to optimization of mastication and tooth protection. Variation in mineral concentration and total effective density may also be associated with wear and fracture patterns, and can be used as baseline information to investigate the effect of diet, pathological changes and aging on teeth through time.
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Affiliation(s)
- Ian Towle
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin 9054, New Zealand.
| | - Amira Samir Salem
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin 9054, New Zealand
| | - Alessio Veneziano
- Department of Mechanical Engineering, Universitat Rovira i Virgili, Tarragona, Spain
| | - Carolina Loch
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin 9054, New Zealand
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Coste A, Fordyce RE, Loch C. A new dolphin with tusk-like teeth from the late Oligocene of New Zealand indicates evolution of novel feeding strategies. Proc Biol Sci 2023; 290:20230873. [PMID: 37312551 PMCID: PMC10265015 DOI: 10.1098/rspb.2023.0873] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Accepted: 05/24/2023] [Indexed: 06/15/2023] Open
Abstract
All extant toothed whales (Cetacea, Odontoceti) are aquatic mammals with homodont dentitions. Fossil evidence from the late Oligocene suggests a greater diversity of tooth forms among odontocetes, including heterodont species with a variety of tooth shapes and orientations. A new fossil dolphin from the late Oligocene of New Zealand, Nihohae matakoi gen. et sp. nov., consisting of a near complete skull, earbones, dentition and some postcranial material, represents this diverse dentition. Several preserved teeth are horizontally procumbent, including all incisors and canines. These tusk-like teeth suggest adaptive advantages for horizontally procumbent teeth in basal dolphins. Phylogenetic analysis places Nihohae among the poorly constrained basal waipatiid group, many with similarly procumbent teeth. Features of N. matakoi such as its dorsoventrally flattened and long rostrum, long mandibular symphysis, unfused cervical vertebrae, lack of attritional or occlusal wear on the teeth and thin enamel cover suggest the rostrum and horizontally procumbent teeth were used to injure and stun prey though swift lateral head movements, a feeding mode that did not persist in extant odontocetes.
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Affiliation(s)
- Ambre Coste
- Department of Geology, University of Otago, Dunedin, New Zealand
| | - R. Ewan Fordyce
- Department of Geology, University of Otago, Dunedin, New Zealand
| | - Carolina Loch
- Faculty of Dentistry, University of Otago, Dunedin, New Zealand
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Lopes F, Oliveira LR, Beux Y, Kessler A, Cárdenas-Alayza S, Majluf P, Páez-Rosas D, Chaves J, Crespo E, Brownell RL, Baylis AMM, Sepúlveda M, Franco-Trecu V, Loch C, Robertson BC, Peart CR, Wolf JBW, Bonatto SL. Genomic evidence for homoploid hybrid speciation in a marine mammal apex predator. Sci Adv 2023; 9:eadf6601. [PMID: 37134171 PMCID: PMC10156116 DOI: 10.1126/sciadv.adf6601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Hybridization is widespread and constitutes an important source of genetic variability and evolution. In animals, its role in generating novel and independent lineages (hybrid speciation) has been strongly debated, with only a few cases supported by genomic data. The South American fur seal (SAfs) Arctocephalus australis is a marine apex predator of Pacific and Atlantic waters, with a disjunct set of populations in Peru and Northern Chile [Peruvian fur seal (Pfs)] with controversial taxonomic status. We demonstrate, using complete genome and reduced representation sequencing, that the Pfs is a genetically distinct species with an admixed genome that originated from hybridization between the SAfs and the Galapagos fur seal (Arctocephalus galapagoensis) ~400,000 years ago. Our results strongly support the origin of Pfs by homoploid hybrid speciation over alternative introgression scenarios. This study highlights the role of hybridization in promoting species-level biodiversity in large vertebrates.
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Affiliation(s)
- Fernando Lopes
- Escola de Ciências da Saúde e da Vida, Pontifícia Universidade Católica do Rio Grande do Sul, PUCRS, Porto Alegre, Brazil
- Laboratório de Ecologia de Mamíferos, Universidade do Vale do Rio dos Sinos, São Leopoldo, Brazil
- Finnish Museum of Natural History, University of Helsinki, Helsinki, Finland
| | - Larissa R Oliveira
- Finnish Museum of Natural History, University of Helsinki, Helsinki, Finland
- Grupo de Estudos de Mamíferos Aquáticos do Rio Grande do Sul (GEMARS), Torres, Brazil
| | - Yago Beux
- Escola de Ciências da Saúde e da Vida, Pontifícia Universidade Católica do Rio Grande do Sul, PUCRS, Porto Alegre, Brazil
| | - Amanda Kessler
- Escola de Ciências da Saúde e da Vida, Pontifícia Universidade Católica do Rio Grande do Sul, PUCRS, Porto Alegre, Brazil
| | - Susana Cárdenas-Alayza
- Centro para la Sostenibilidad Ambiental, Universidad Peruana Cayetano Heredia, Lima, Peru
- Departamento de Ciencias Biológicas y Fisiológicas, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Patricia Majluf
- Centro para la Sostenibilidad Ambiental, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Diego Páez-Rosas
- Colegio de Ciencias Biológicas y Ambientales, COCIBA, Universidad San Francisco de Quito, Quito, Ecuador
- Dirección del Parque Nacional Galápagos, Oficina Técnica San Cristobal, Islas Galápagos, Ecuador
| | - Jaime Chaves
- Colegio de Ciencias Biológicas y Ambientales, COCIBA, Universidad San Francisco de Quito, Quito, Ecuador
- Galapagos Science Center, Puerto Baquerizo Moreno, Ecuador
- Department of Biology, San Francisco State University, 1800 Holloway Ave, San Francisco, CA, USA
| | - Enrique Crespo
- Laboratório de Mamíferos Marinos, CESIMAR - CCT CENPAT, CONICET, Puerto Madryn, Argentina
| | - Robert L Brownell
- Southwest Fisheries Science Center, NOAA Fisheries, La Jolla, CA, USA
| | | | - Maritza Sepúlveda
- Centro de Investigación y Gestión de Recursos Naturales (CIGREN), Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - Valentina Franco-Trecu
- Departamento de Ecología y Evolución, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay
| | - Carolina Loch
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin, New Zealand
| | | | - Claire R Peart
- Division of Evolutionary Biology, LMU Munich, München, Germany
| | - Jochen B W Wolf
- Division of Evolutionary Biology, LMU Munich, München, Germany
| | - Sandro L Bonatto
- Escola de Ciências da Saúde e da Vida, Pontifícia Universidade Católica do Rio Grande do Sul, PUCRS, Porto Alegre, Brazil
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12
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Zhao R, Wang T, Yang R, Adam LA, Zaharic T, Loch C, Tompkins GR, Cooper PR. Enhancing the student learning experience: Co-teaching biochemistry and clinical sciences within the dental curriculum. Biochem Mol Biol Educ 2023; 51:146-154. [PMID: 36478497 DOI: 10.1002/bmb.21701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/01/2022] [Revised: 10/27/2022] [Accepted: 11/15/2022] [Indexed: 06/17/2023]
Abstract
Basic knowledge of biochemistry underpins oral and dental care. Undergraduate dental students do not always engage well with basic science teaching due to not appreciating its clinical relevance. Co-teaching provides one approach to overcome students' disengagement and involves two lecturers, with complementary expertise, presenting the curriculum together. This study investigated student experiences and engagement using co-teaching to integrate biochemistry with clinical sciences in the students' second-year dental curriculum. Two successive second year dental student cohorts were co-taught. Content was delivered by a biochemist and an oral biologist, either online (during the 2020 COVID lockdown) or in-person (2021). Each cohort was surveyed at the end of the teaching module using an online questionnaire containing both interval scale and free-text questions. Responses were received from 39 (42%) and 64 (85%) of students in 2020 and 2021, respectively. Students from both cohorts preferred the co-teaching approach with a mean of 8.74 on a 10-point interval scale. In 2020 and 2021, 77% and 76% of participants, respectively, preferred a combined biochemistry and clinical dentistry delivery, either in-person (37%), via Zoom (19%) or via video recording (14%). Thematic analysis of responses revealed students experienced enhanced engagement when co-taught and they attributed this to integration of the curriculum making the content more relevant and stimulating. Students preferred co-teaching to individual subjects being taught by a single teacher. Co-teaching established the relevance of theoretical biochemistry to clinical dental sciences and enhanced the students' learning experience.
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Affiliation(s)
- Rusin Zhao
- Department of Oral Sciences, Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin, New Zealand
| | - Tao Wang
- Department of Oral Sciences, Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin, New Zealand
| | - Ruijia Yang
- Department of Oral Sciences, Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin, New Zealand
| | - Lee A Adam
- Department of Oral Sciences, Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin, New Zealand
| | - Tony Zaharic
- Centre for Early Learning in Medicine, School of Medicine, Otago Medical School, Dunedin, New Zealand
| | - Carolina Loch
- Department of Oral Sciences, Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin, New Zealand
| | - Geoffrey R Tompkins
- Department of Oral Sciences, Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin, New Zealand
| | - Paul R Cooper
- Department of Oral Sciences, Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin, New Zealand
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Towle I, Constantino PJ, Borths MR, Loch C. Tooth chipping patterns in Archaeolemur provide insight into diet and behavior. Am J Biol Anthropol 2023; 180:401-408. [PMID: 36790760 PMCID: PMC10107942 DOI: 10.1002/ajpa.24674] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Revised: 10/20/2022] [Accepted: 11/13/2022] [Indexed: 12/13/2022]
Abstract
OBJECTIVES Archaeolemur is a recently extinct genus of lemur that is often compared to some Cercopithecidae, especially baboons. This is due in part to their derived dentition, with large anterior teeth and reduced bilophodont molars. Research involving comparative morphology, analysis of coprolites, isotopes, and enamel structure, have suggested Archaeolemur had an omnivorous diet involving mechanically challenging items. Yet, microwear analysis of posterior teeth does not necessarily support this conclusion. MATERIALS AND METHODS In this macroscopic study, dental chipping was recorded on permanent teeth of Archaeolemur from different localities (53 individuals; 447 permanent teeth; including both A. edwardsi and A. majori specimens). This study aimed to compare chipping patterns across the dentition of Archaeolemur with chipping in other primates. RESULTS The results show enamel chipping was prevalent on the anterior teeth of Archaeolemur (38.9% of anterior teeth showed at least one fracture) yet rare in posterior teeth (9%). There was a decrease in chipping frequency across the dentition, moving distally from incisors (50%; 20/40), through caniniform teeth (30%; 15/50), premolars (9.5%; 16/169), and molars (8.5%; 16/188). DISCUSSION The results support previous research suggesting Archaeolemur had a varied omnivorous diet in which the anterior dentition was used for extensive food processing. This likely included mechanically challenging items such as tough/hard large fruits, small vertebrates, and crustaceans. Such a high rate of chipping in the anterior dentition is uncommon in other primates, with exception of hominins.
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Affiliation(s)
- Ian Towle
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin, New Zealand
| | - Paul J Constantino
- Department of Biology, Saint Michael's College, Colchester, Vermont, USA
| | - Matthew R Borths
- Duke Lemur Center Museum of Natural History, Duke University, Durham, North Carolina, USA
| | - Carolina Loch
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin, New Zealand
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Floyd B, Battles HT, White S, Loch C, McFarlane G, Guatelli-Steinberg D, Mahoney P. Longitudinal changes in juvenile and adolescent body mass indices before, during, and after the COVID-19 lockdown in New Zealand. Am J Hum Biol 2023; 35:e23861. [PMID: 36642922 DOI: 10.1002/ajhb.23861] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Accepted: 12/23/2022] [Indexed: 01/17/2023] Open
Abstract
OBJECTIVE This study uses longitudinal data from school children in Dunedin, New Zealand, to evaluate impacts of COVID-19 lockdown measures on changes in body mass (BMI, kg/m2 ). Impacts are assessed using two non-mutually exclusive hypotheses. The "structured days" hypothesis holds that children tend to alter sleep patterns, reduce activity and increase snacking when not in structured environments. The bidirectional hypothesis proposes that over-weight or obese children are predisposed to further gains in unstructured settings. METHODS Juveniles and adolescents (n = 95, 60% female) were recruited from Dunedin schools. Repeated measures analyses assessed variation in intra-individual change in BMI during four periods: P1 (before summer break), P2 (during summer break), P3 (during the COVID-19 lockdown), and P4 (after the lockdown ended). The model also examined if these changes were influenced by participants' sex or body size early in the first period assessed using log-transformed BMI, log-transformed weight, height, or lower leg length. RESULTS Repeated measures analyses of per month gains in BMI (kg/m2 ) during the four periods revealed consistent period (p ≤ .001), period by sex (p ≤ .010), and period by body size (p ≤ .001) interactions across all four body size proxies. Both sexes experienced the greatest gains during the lockdown (P3), but differed in response to their summer break (P2). CONCLUSION Results are mostly consistent with the "structured days" hypothesis, but challenge the bidirectional hypothesis as defined. Further research better characterizing risks of gains in adiposity are needed.
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Affiliation(s)
- Bruce Floyd
- School of Social Sciences, University of Auckland, New Zealand
| | | | - Sophie White
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin, New Zealand
| | - Carolina Loch
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin, New Zealand
| | - Gina McFarlane
- School of Anthropology and Conservation, University of Kent, Canterbury, UK
| | | | - Patrick Mahoney
- School of Anthropology and Conservation, University of Kent, Canterbury, UK
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Sim MY, Tan LF, Adam L, Loch C. No one is born with it: Australasian dental students' perceptions of learning manual dexterity. J Dent Educ 2023; 87:60-69. [PMID: 36066105 DOI: 10.1002/jdd.13101] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Revised: 07/17/2022] [Accepted: 08/11/2022] [Indexed: 01/11/2023]
Abstract
Dentistry requires high manual dexterity, and few studies have investigated the challenges and impact on dental students of attaining manual dexterity skills. This study aimed to investigate dental students' perceptions of manual dexterity, including their awareness of manual dexterity requirements in dentistry, self-perceptions of manual dexterity competency, and whether manual dexterity should be part of admission to dentistry training. A link to a 12-item online Qualtrics survey was sent out to students in either their 2nd or 5th year of the Bachelor of Dental Surgery (BDS) degree at the University of Otago, New Zealand. The anonymous survey collected basic demographic data and included closed and open-ended questions about manual dexterity. Descriptive statistics were calculated for quantitative variables and a general inductive approach was used to analyze free-text responses. Those were later grouped into a theoretical domain framework. The overall response rate was 53%. All participants acknowledged the importance of manual dexterity in dentistry. Most participants thought that manual dexterity can be improved with practice and that including a manual dexterity test in the admission criteria may cause unnecessary stress for students. Striving to achieve manual dexterity impacted participants' performance in the BDS course. However, most participants viewed it as a challenge that can be overcome with practice and improvement, and that current BDS admission requirements are sufficient.
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Affiliation(s)
- May Yee Sim
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin, New Zealand
| | - Li Feng Tan
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin, New Zealand
| | - Lee Adam
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin, New Zealand
| | - Carolina Loch
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin, New Zealand
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16
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Weatherly K, Brunton P, Loch C, McKeage JW, Ruddy BP, Taberner AJ, White DE. Case study of user experience-driven design in a new local anaesthetic dentistry jet injection device. J R Soc N Z 2022. [DOI: 10.1080/03036758.2022.2113809] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/15/2022]
Affiliation(s)
- Kate Weatherly
- AUT BioDesign Lab, Auckland University of Technology, Auckland, New Zealand
| | - Paul Brunton
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin, New Zealand
| | - Carolina Loch
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin, New Zealand
| | - James W. McKeage
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
| | - Bryan P. Ruddy
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
- Department of Engineering Science, University of Auckland, Auckland, New Zealand
| | - Andrew J. Taberner
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
- Department of Engineering Science, University of Auckland, Auckland, New Zealand
| | - David E. White
- AUT BioDesign Lab, Auckland University of Technology, Auckland, New Zealand
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Mahoney P, McFarlane G, Loch C, White S, Floyd B, Dunn EC, Pitfield R, Nava A, Guatelli-Steinberg D. Dental biorhythm is associated with adolescent weight gain. Commun Med 2022; 2:99. [PMID: 36016726 PMCID: PMC9395425 DOI: 10.1038/s43856-022-00164-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Accepted: 07/26/2022] [Indexed: 12/02/2022] Open
Abstract
Background Evidence of a long-period biological rhythm present in mammalian hard tissue relates to species average body mass. Studies have just begun to investigate the role of this biorhythm in human physiology. Methods The biorhythm is calculated from naturally exfoliated primary molars for 61 adolescents. We determine if the timing relates to longitudinal measures of their weight, height, lower leg length and body mass collected over 14 months between September 2019 to October 2020. We use univariate and multivariate statistical analyses to isolate and identify relationships with the biorhythm. Results Participants with a faster biorhythm typically weigh less each month and gain significantly less weight and mass over 14-months, relative to those with a slower biorhythm. The biorhythm relates to sex differences in weight gain. Conclusions We identify a previously unknown factor that associates with the rapid change in body size that accompanies human adolescence. Our findings provide a basis from which to explore novel relationships between the biorhythm and weight-related health risks. The human body undergoes cyclic changes such as the daily cycle of sleeping and waking, and monthly menstruation. This study calculated one cycle that can be tracked through the growth of children’s milk teeth. The timing of the cycle in different children was compared to changes in body size that occurred when these children were in puberty. A link was seen between the children’s cycle and the weight they gained over 14-months. Adolescents with a faster cycle typically weighed less each month and gained less weight over 14 months compared to those with a slower cycle. Mahoney et al. calculate the long-term biorhythm of adolescents from primary molar teeth and examine the relationship with weight, height and mass. Faster biorhythms are associated with a lower weight, and reduced weight and mass gain during adolescence.
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18
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Ratnayake J, Veerasamy A, Ahmed H, Coburn D, Loch C, Gray AR, Lyons KM, Heng NCK, Cannon RD, Leung M, Brunton PA. Clinical and Microbiological Evaluation of a Chlorhexidine-Modified Glass Ionomer Cement (GIC-CHX) Restoration Placed Using the Atraumatic Restorative Treatment (ART) Technique. Materials 2022; 15:ma15145044. [PMID: 35888511 PMCID: PMC9320984 DOI: 10.3390/ma15145044] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Revised: 07/13/2022] [Accepted: 07/15/2022] [Indexed: 12/04/2022]
Abstract
The aims of this study were to investigate the clinical effectiveness and patient acceptability of a modified glass ionomer cement placed using the atraumatic restorative treatment (ART) technique to treat root caries, and to carry out microbiological analysis of the restored sites. Two clinically visible root surface carious lesions per participant were restored using ART. One was restored with commercial glass ionomer cement (GIC) (ChemFil® Superior, DENTSPLY, Konstonz, Germany) which acted as the control. The other carious root lesion was restored with the same GIC modified with 5% chlorhexidine digluconate (GIC-CHX; test). Patient acceptability and restoration survival rate were evaluated at baseline and after 6 months. Plaque and saliva samples around the test and control restorations were collected, and microbiological analysis for selected bacterial and fungal viability were completed at baseline, and after 1, 3, and 6 months. In total, 52 restorations were placed using GIC and GIC-CHX in 26 participants; 1 patient was lost to follow-up. After reviewing the restorations during their baseline appointments, participants indicated that they were satisfied with the appearance of the restorations (n = 25, 96%) and did not feel anxious during the procedure (n = 24, 92%). Forty-eight percent (n = 12) of the GIC-CHX restorations were continuous with the existing anatomic form as opposed to six for the GIC restorations (24%), a difference which was statistically significant (p = 0.036). There was no statistically significant reduction in the mean count of the tested microorganisms in plaque samples for either type of restorations after 1, 3, or 6 months. Restoration of carious root surfaces with GIC-CHX resulted in higher survival rates than the control GIC. ART using GIC-CHX may therefore be a viable approach for use in outreach dental services to restore root surface carious lesions where dental services are not readily available, and for older people and special needs groups.
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Affiliation(s)
- Jithendra Ratnayake
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, P.O. Box 56, Dunedin 9054, New Zealand; (A.V.); (H.A.); (D.C.); (C.L.); (K.M.L.); (N.C.K.H.); (R.D.C.); (M.L.)
- Correspondence: ; Tel.: +64-034797355
| | - Arthi Veerasamy
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, P.O. Box 56, Dunedin 9054, New Zealand; (A.V.); (H.A.); (D.C.); (C.L.); (K.M.L.); (N.C.K.H.); (R.D.C.); (M.L.)
| | - Hassan Ahmed
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, P.O. Box 56, Dunedin 9054, New Zealand; (A.V.); (H.A.); (D.C.); (C.L.); (K.M.L.); (N.C.K.H.); (R.D.C.); (M.L.)
| | - David Coburn
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, P.O. Box 56, Dunedin 9054, New Zealand; (A.V.); (H.A.); (D.C.); (C.L.); (K.M.L.); (N.C.K.H.); (R.D.C.); (M.L.)
| | - Carolina Loch
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, P.O. Box 56, Dunedin 9054, New Zealand; (A.V.); (H.A.); (D.C.); (C.L.); (K.M.L.); (N.C.K.H.); (R.D.C.); (M.L.)
| | - Andrew R. Gray
- Biostatistics Centre, Division of Health Sciences, University of Otago, P.O. Box 56, Dunedin 9054, New Zealand;
| | - Karl M. Lyons
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, P.O. Box 56, Dunedin 9054, New Zealand; (A.V.); (H.A.); (D.C.); (C.L.); (K.M.L.); (N.C.K.H.); (R.D.C.); (M.L.)
| | - Nicholas C. K. Heng
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, P.O. Box 56, Dunedin 9054, New Zealand; (A.V.); (H.A.); (D.C.); (C.L.); (K.M.L.); (N.C.K.H.); (R.D.C.); (M.L.)
| | - Richard D. Cannon
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, P.O. Box 56, Dunedin 9054, New Zealand; (A.V.); (H.A.); (D.C.); (C.L.); (K.M.L.); (N.C.K.H.); (R.D.C.); (M.L.)
| | - Marcus Leung
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, P.O. Box 56, Dunedin 9054, New Zealand; (A.V.); (H.A.); (D.C.); (C.L.); (K.M.L.); (N.C.K.H.); (R.D.C.); (M.L.)
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Brunton PA, McLean M, Vedagiri S, McKeage J, Ruddy B, Weatherly K, White D, Taberner A, Loch C. Jet injection needle-free dental anaesthesia: Initial findings. J Dent 2022; 122:104165. [DOI: 10.1016/j.jdent.2022.104165] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2022] [Revised: 05/10/2022] [Accepted: 05/13/2022] [Indexed: 11/24/2022] Open
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20
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Beckett DM, Broadbent JM, Loch C, Mahoney EK, Drummond BK, Wheeler BJ. Dental Consequences of Vitamin D Deficiency during Pregnancy and Early Infancy-An Observational Study. Int J Environ Res Public Health 2022; 19:ijerph19041932. [PMID: 35206117 PMCID: PMC8872617 DOI: 10.3390/ijerph19041932] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Revised: 02/01/2022] [Accepted: 02/02/2022] [Indexed: 02/01/2023]
Abstract
Vitamin D (25OHD) status during pregnancy is closely correlated with foetal and new-born 25OHD. Calcification for primary teeth begins from the fourth month of intrauterine life and from birth for permanent teeth. Dental consequences of severe 25OHD deficiency are well documented; however, consequences are less documented for milder degrees of 25OHD deficiency. This study examined the dental consequences of vitamin D deficiency/insufficiency during gestation and infancy in a cohort of 81 New Zealand children. Pregnancy and birth data for the children and their mothers and 25OHD status during gestation, birth and at five months were obtained, and dental examinations were conducted. Associations between 25OHD and enamel defects or caries experience were investigated. Of the 81 children, 55% had experienced dental caries and 64% had at least one enamel defect present. Vitamin D insufficiency (25OHD < 50 nmol/L) at all timepoints was not associated with enamel defect prevalence, but during third trimester pregnancy it was associated with an increased caries risk IRR of 3.55 (CI 1.15–10.92) by age 6. In conclusion, maternal 25OHD insufficiency during the third trimester of pregnancy was associated with greater caries experience in primary dentition. No association was found between early life 25OHD and enamel defect prevalence or severity.
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Affiliation(s)
- Deanna M. Beckett
- Department of Oral Sciences, Sir John Walsh Research Institute, University of Otago, Dunedin 9016, New Zealand;
- Correspondence: (D.M.B.); (J.M.B.)
| | - Jonathan M. Broadbent
- Department of Oral Sciences, Sir John Walsh Research Institute, University of Otago, Dunedin 9016, New Zealand;
- Correspondence: (D.M.B.); (J.M.B.)
| | - Carolina Loch
- Department of Oral Sciences, Sir John Walsh Research Institute, University of Otago, Dunedin 9016, New Zealand;
| | - Erin K. Mahoney
- Dental Department, Hutt Valley DHB, Lower Hutt 5040, New Zealand;
- Department of Paediatrics and Child Health, University of Otago, Wellington 6242, New Zealand
| | | | - Benjamin J. Wheeler
- Paediatric Endocrinology, Southern District Health Board, Dunedin 9016, New Zealand;
- Department of Women’s and Children’s Health, University of Otago, Dunedin 9016, New Zealand
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Liaw RDY, Ling DCT, Vuli LJ, Loch C, Adam LA. "It's just inappropriate": Harassment of dental students by patients. J Dent Educ 2021; 86:605-614. [PMID: 34951016 DOI: 10.1002/jdd.12854] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Revised: 10/25/2021] [Accepted: 11/23/2021] [Indexed: 11/08/2022]
Abstract
INTRODUCTION Harassment is an issue that occurs in all workplaces and institutions. Due to increased exposure to patients, higher rates of harassment are experienced in health care systems. Health care workers need to form a professional relationship with patients to attend to their health care needs; however, harassment by patients can disrupt this relationship and have detrimental physical, mental, and emotional impacts on the health practitioner. OBJECTIVE The purpose of this study was to examine the prevalence and impact of harassment by patients toward clinical students at a prominent Australasian dental school. METHODS A 14-item survey was distributed to clinical students. The survey collected basic demographic information and contained Likert-scale closed questions on harassment prevalence and experience and a free text question asking for details of a significant harassment experience. Descriptive statistics and analysis of free text data were performed. RESULTS The response rate was 67%. About 20% of respondents reported experiencing at least one incident of harassment. Verbal harassment was most commonly reported, followed by sexual and racial harassment. All incidences of sexual harassment were reported by female students, while racial harassment was most frequently reported by students of Asian ethnicity. Most students indicated they were unsure of how to respond to harassment by patients. CONCLUSION Dental students were exposed to harassment by patients. IMPLICATIONS Appropriate policies and education on responding to harassment, alongside support for the same, could help ensure the safety and wellbeing of students.
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Affiliation(s)
- Royston D Y Liaw
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin, New Zealand
| | - Dobson C T Ling
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin, New Zealand
| | - Lia J Vuli
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin, New Zealand
| | - Carolina Loch
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin, New Zealand
| | - Lee A Adam
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin, New Zealand
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22
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Towle I, Irish JD, Sabbi KH, Loch C. Dental caries in wild primates: Interproximal cavities on anterior teeth. Am J Primatol 2021; 84:e23349. [PMID: 34855230 DOI: 10.1002/ajp.23349] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 10/13/2021] [Accepted: 11/11/2021] [Indexed: 11/10/2022]
Abstract
Dental caries has been reported in a variety of primates, although it is still considered rare in wild populations. In this study, 11 catarrhine primate taxa (n = 339 individuals; 7946 teeth) were studied for the presence of caries. A differential diagnosis of lesions in interproximal regions of anterior teeth was undertaken, since they had been previously described as both carious and non-carious in origin. Each permanent tooth was examined macroscopically, with severity and position of lesions recorded. Two specimens were examined further, using micro-CT scans to assess demineralization. Differential diagnosis confirmed the cariogenic nature of interproximal cavities on anterior teeth (ICATs). Overall results show 3.3% of all teeth (i.e., anterior and posterior teeth combined) were carious (n = 262), with prevalence varying among species from 0% to >7% of teeth affected. Those with the highest prevalence of ICATs include Pan troglodytes verus (9.8% of anterior teeth), Gorilla gorilla gorilla (2.6%), Cercopithecus denti (22.4%), Presbytis femoralis (19.5%), and Cercopithecus mitis (18.3%). ICATs make up 87.9% of carious lesions on anterior teeth. These results likely reflect dietary and food processing differences among species, but also between the sexes (e.g., 9.3% of all female P. troglodytes verus teeth were carious vs. 1.8% in males). Processing cariogenic fruits and seeds with the anterior dentition (e.g., wadging) likely contributes to ICAT formation. Further research is needed in living primate populations to ascertain behavioral/dietary influences on caries occurrence. Given the presence of ICATs in frugivorous primates, their diagnosis in archaeological and paleontological specimens may shed light on diet and food processing behaviors in fossil primates.
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Affiliation(s)
- Ian Towle
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin, New Zealand
| | - Joel D Irish
- Research Centre in Evolutionary Anthropology and Palaeoecology, School of Biological and Environmental Sciences, Liverpool John Moores University, Liverpool, UK.,The Centre for the Exploration of the Deep Human Journey, University of the Witwatersrand, Johannesburg, South Africa
| | - Kris H Sabbi
- Department of Anthropology and Department of Biology, Tufts University, Medford, MA, USA
| | - Carolina Loch
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin, New Zealand
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23
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Masri AABHA, Khang KKY, Shen LLW, Ekambaram M, Loch C. Knowledge of dental enamel defects amongst undergraduate dental students-a cross-sectional survey. Eur J Dent Educ 2021; 25:711-716. [PMID: 33369838 DOI: 10.1111/eje.12650] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Revised: 11/11/2020] [Accepted: 12/15/2020] [Indexed: 06/12/2023]
Abstract
INTRODUCTION/OBJECTIVES Enamel defects are disturbances in the quantity or quality of enamel, due to disruption or damage to the enamel organ during amelogenesis. The correct diagnosis of enamel defects is critical as diverse management options could be required for different conditions. Difficulties in diagnosis can happen, because these defects may have similar clinical presentations. This study evaluated the diagnostic skills in enamel defects of dental students of a prominent Australasian school. METHODS A questionnaire consisting of clinical photographs of the affected teeth/dentition in multiple views and four standardised questions for each case of enamel defect were given to Year 4 and Year 5 students. RESULTS Localised/Chronological Hypoplasia had the lowest percentage of correct diagnosis (20.5%), whilst Enamel White Spot Lesions (EWSLs) had the highest (85%). Localised/Chronological Hypoplasia had the lowest aetiology score (20.5%), and the highest was obtained for EWSLs (85%). In regard to which question to ask to gain insight into the conditions, Enamel Hypomineralisation/MIH had the lowest score for both Year 4 and Year 5 respondents (35.4% and 21.3%). Most respondents agreed more teaching in this topic was needed, with further clinical sessions to observe the enamel defects, workshops/seminars, lectures and student-driven presentations suggested. CONCLUSION Final-year dental students showed variable knowledge in diagnosis, aetiology and clinical management of enamel defects. Further didactic and clinical teaching should be incorporated in the undergraduate curriculum on this topic .
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Affiliation(s)
| | - Kevin Koay Yung Khang
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin, New Zealand
| | - Leon Low Wei Shen
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin, New Zealand
| | - Manikandan Ekambaram
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin, New Zealand
| | - Carolina Loch
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin, New Zealand
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24
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McFarlane G, Loch C, Guatelli-Steinberg D, Bayle P, Le Luyer M, Sabel N, Nava A, Floyd B, Skinner M, White S, Pitfield R, Mahoney P. Enamel daily secretion rates of deciduous molars from a global sample of children. Arch Oral Biol 2021; 132:105290. [PMID: 34695672 DOI: 10.1016/j.archoralbio.2021.105290] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Revised: 10/11/2021] [Accepted: 10/12/2021] [Indexed: 12/01/2022]
Abstract
OBJECTIVE To investigate and describe the variation in enamel daily secretion rates (DSRs) of naturally exfoliated deciduous molars (n = 345) from five modern-day populations (Aotearoa New Zealand, Britain, Canada, France, and Sweden). DESIGN Each tooth was thin sectioned and examined using a high-powered Olympus BX51 microscope and DP25 digital microscope camera. Mean DSRs were recorded for the inner, mid, and outer regions of cuspal and lateral enamel, excluding enamel nearest the enamel-dentin junction and at the outermost crown surface. RESULTS Mean DSRs did not vary significantly between populations, or by sex. Cuspal enamel grew slightly faster than lateral enamel (mean difference 0.16 µm per day; p < 0.001). The trajectory of DSRs remained relatively constant from inner to outer cuspal enamel and increased slightly in lateral enamel (p = 0.003). CONCLUSIONS The DSRs of deciduous molars from modern-day children are remarkably consistent when compared among populations. While growth rates are faster in cuspal than lateral enamel, the trajectory of enamel formation changes only slightly from inner to outer regions. The trajectory of DSRs for deciduous molars differs to that of permanent molar enamel, which typically display a steep increase in matrix deposition from inner to outer enamel.
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Affiliation(s)
- Gina McFarlane
- Human Osteology Lab, School of Anthropology and Conservation, University of Kent, Canterbury, UK.
| | - Carolina Loch
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin, New Zealand
| | | | | | - Mona Le Luyer
- Univ. Bordeaux, CNRS, MC, UMR 5199 PACEA, Pessac, France
| | - Nina Sabel
- Department of Pedodontics, Institute of Odontology, Sahlgrenska Academy, University of Gothenburg, Sweden
| | - Alessia Nava
- Human Osteology Lab, School of Anthropology and Conservation, University of Kent, Canterbury, UK
| | - Bruce Floyd
- School of Social Sciences, University of Auckland, New Zealand
| | - Mark Skinner
- Department of Archaeology, Simon Fraser University, Burnaby, Canada
| | - Sophie White
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin, New Zealand
| | - Rosie Pitfield
- Human Osteology Lab, School of Anthropology and Conservation, University of Kent, Canterbury, UK
| | - Patrick Mahoney
- Human Osteology Lab, School of Anthropology and Conservation, University of Kent, Canterbury, UK
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25
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Jum’ah AA, Elsalem L, Loch C, Schwass D, Brunton PA. Perception of health and educational risks amongst dental students and educators in the era of COVID-19. Eur J Dent Educ 2021; 25:506-515. [PMID: 33188555 PMCID: PMC7753269 DOI: 10.1111/eje.12626] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 10/18/2020] [Accepted: 10/26/2020] [Indexed: 05/07/2023]
Abstract
OBJECTIVE To investigate the perceived educational and health risks associated with the COVID-19 pandemic amongst dental students and educators. METHODS A 17-item electronic survey was sent to 496 undergraduate dental students and 53 clinical faculty members who attended clinical sessions during the outbreak period. The survey explored various aspects related to primary sources and prevention of disease exposure, dental management of suspected cases, impact of COVID-19 on students' clinical performance and effects of suspension of educational activities on academic performance and clinical competence. RESULTS The response rate of the students' was 60.7% (n = 301). The majority of students reported that performing clinical work during the outbreak posed significant health concerns, resulted in a significant stress and negatively affected their clinical performance. The majority of students believed that aerosols generated during dental procedures are the major source for disease exposure and universal protective equipment is not effective for prevention. The decision to suspend teaching activities was supported by 89% of the students. Opinions were divided regarding the impact of the suspension on the academic performance and clinical competence. Educational videos were the most preferred form of distance education. The response rate of faculty members was 60.4% (n = 32). Responses of faculty members were similar to students, though fewer concerns were reported regarding the risk of disease transmission. All respondents agreed that extra-precautionary measures are required to ensure optimum protection against disease exposure. CONCLUSIONS The recent COVID-19 outbreak has adversely affected various elements of dental education. High levels of major health risk perception were noted amongst students and educators. The interruption to academic and clinical activities may lead to an inevitable skill deficit within the new generation of dental graduates. Educators are under significant pressure to accommodate abrupt changes in teaching methods, find solutions to mitigate skill deficit and ensure safe clinical practice once clinical activities are resumed.
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Affiliation(s)
- Ahmad A. Jum’ah
- Faculty of DentistryDepartment of Conservative DentistryJordan University of Science and TechnologyIrbidJordan
| | - Lina Elsalem
- Faculty of MedicineDepartment of PharmacologyJordan University of Science and TechnologyIrbidJordan
| | - Carolina Loch
- Faculty of DentistryUniversity of OtagoDunedinNew Zealand
| | - Donald Schwass
- Faculty of DentistryUniversity of OtagoDunedinNew Zealand
| | - Paul A. Brunton
- Faculty of DentistryUniversity of OtagoDunedinNew Zealand
- Division of Health SciencesUniversity of OtagoDunedinNew Zealand
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26
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Youhanna KMY, Adam L, Monk BC, Loch C. Dentistry students' experiences, engagement and perception of biochemistry within the dental curriculum and beyond. Eur J Dent Educ 2021; 25:318-324. [PMID: 32989891 DOI: 10.1111/eje.12607] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Revised: 08/23/2020] [Accepted: 09/19/2020] [Indexed: 06/11/2023]
Abstract
INTRODUCTION/OBJECTIVES Basic knowledge at the molecular level is necessary to care for the orofacial complex as part of the whole body. Many undergraduate dentistry students struggle to engage with biochemistry during the degree due to difficulty in appreciating the relevance of biochemistry to clinical practice. This study investigated student experiences, perception and engagement with biochemistry as part of the dental curriculum and explored how the teaching of biochemistry might be further developed. METHODS Focus groups were conducted with 21 participants, in groups of four to six students from the 3rd year to 5th year, as well as with recent graduates and post-graduate students from a prominent Australasian dental school. Data were analysed using a general inductive approach. RESULTS Focus group participants viewed the oral biochemistry module as well organised and professionally run. However, participants reported that the large amount of material taught in the module made them feel overwhelmed and demotivated. Biochemistry was regarded by undergraduate participants as relevant to dental practice, but graduate participants thought it was only relevant to those sitting examinations for further training. Biochemistry was perceived as most relevant to dental research and expanding scientific literacy. DISCUSSION/CONCLUSIONS Participants in this study suggested that reducing the amount of material taught, focusing on dentally relevant biochemical concepts and overtly stating the connection of biochemistry to clinical practice could increase engagement and enhance the module within the dental curriculum.
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Affiliation(s)
- Karla Mariah Yumul Youhanna
- Department of Oral Sciences, Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin, New Zealand
| | - Lee Adam
- Department of Oral Sciences, Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin, New Zealand
| | - Brian C Monk
- Department of Oral Sciences, Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin, New Zealand
| | - Carolina Loch
- Department of Oral Sciences, Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin, New Zealand
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27
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Loch C, Jansen van Vuuren L, Duncan WJ, Boyd DH, Foster Page LA. Ultrastructure and properties of primary carious molars treated using the Hall Technique. Int J Paediatr Dent 2021; 31:290-298. [PMID: 32516864 DOI: 10.1111/ipd.12681] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Revised: 04/10/2020] [Accepted: 05/22/2020] [Indexed: 11/29/2022]
Abstract
BACKGROUND The Hall Technique (HT) is a method of restoring decayed primary teeth using stainless steel crowns (SSCs) without tooth preparation, caries removal, or local anaesthetic. AIM To investigate the ultrastructural, biomechanical, and chemical characteristics of teeth managed with the Hall Technique in comparison with conventional SSC (controls). DESIGN Twelve HT-treated primary molars and four controls were analysed. Teeth were dehydrated in ethanol, embedded in methylmethacrylate, mesio-distally sectioned, X-rayed, mounted, and polished. Biomechanical, ultrastructural, and chemical characterisation was performed for carious lesion and sound areas of each specimen. RESULTS Pre-treatment and post-treatment X-rays showed evidence of little to no caries progression over time. In carious lesions, mean hardness and elastic modulus values were lower in HT-treated teeth than in controls. In both controls and HT-treated teeth, carious lesions had the lowest %wt of Ca and P of all tissues sampled. CONCLUSIONS Although the retained carious tissue was biomechanically more compromised in HT-treated teeth, the Ca and P values were higher than reported elsewhere for carious lesions in primary molars, suggesting remineralisation may have occurred in caries in HT-treated teeth. Future investigations will help elucidate the processes involved with carious lesion arrest under SSC.
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Affiliation(s)
- Carolina Loch
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin, New Zealand
| | - Ludwig Jansen van Vuuren
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin, New Zealand
| | - Warwick J Duncan
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin, New Zealand
| | - Dorothy H Boyd
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin, New Zealand
| | - Lyndie A Foster Page
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin, New Zealand
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28
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Abstract
Once considered rare in fossil hominins, caries has recently been reported in several hominin species, requiring a new assessment of this condition during human evolution. Caries prevalence and location on the teeth of South African fossil hominins were observed and compared with published data from other hominin samples. Teeth were viewed macroscopically, with lesion position and severity noted and described. For all South African fossil hominin specimens studied to date, a total of 10 carious teeth (14 lesions), including 4 described for the first time here, have been observed. These carious teeth were found in a minimum of seven individuals, including five Paranthropus robustus, one early Homo, and one Homo naledi. All 14 lesions affected posterior teeth. The results suggest cariogenic biofilms and foods may have been present in the oral environment of a wide variety of hominins. Caries prevalence in studied fossil hominins is similar to those in pre-agricultural human groups, in which 1–5% of teeth are typically affected.
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Affiliation(s)
- Ian Towle
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin, New Zealand
| | - Joel D. Irish
- Research Centre in Evolutionary Anthropology and Palaeoecology, Liverpool John Moores University, Liverpool, United Kingdom
- Evolutionary Studies Institute and Centre for Excellence in PaleoSciences, University of the Witwatersrand, Johannesburg, South Africa
| | | | - Christianne Fernée
- Department of Anthropology and Archaeology, University of Bristol, Bristol, United Kingdom
- Department of Archaeology, University of Southampton, Southampton, United Kingdom
| | - Carolina Loch
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin, New Zealand
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29
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Towle I, Loch C. Tooth chipping prevalence and patterns in extant primates. Am J Phys Anthropol 2021; 175:292-299. [PMID: 33454959 DOI: 10.1002/ajpa.24232] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Revised: 12/27/2020] [Accepted: 01/05/2021] [Indexed: 11/06/2022]
Abstract
OBJECTIVES A tooth chip occurs when a hard object forcefully contacts the surface of the tooth, typically removing enamel from the occlusal edge. In this study, chipping patterns in extant primates were compared, and hard-object-feeding assessed alongside other factors (e.g., grit mastication and dental properties), to elucidate dietary and behavioral inferences in archeological and paleontological samples. MATERIALS AND METHODS Thirteen species of extant primates were studied, including eight species within the Cercopithecidae, two within the Ceboidea, and three within the Hominoidea. Four additional species were also incorporated from the literature for some of the analyses. The severity (Grade 1-3), position (buccal, lingual, mesial, and distal) and number of tooth fractures were recorded for each specimen. RESULTS Species considered hard-object-feeding specialists presented higher rates of chipping, with sakis, mandrills, sooty mangabeys and Raffles' banded langurs having high chipping rates (28.3%, 36.7%, 48.4%, and 34.7% of teeth, respectively). Species that seasonally eat harder foods had intermediate chipping frequencies (e.g., brown woolly monkeys: 18.5%), and those that less commonly consume hard food items had the lowest chipping frequencies (e.g., Kloss gibbon: 7.3%; chimpanzees: 4.4%). DISCUSSION The results suggest hard food mastication influences differences in chipping prevalence among the species studied. Although Homo fossil samples show high rates of chipping comparable to hard-object-feeding extant primates, they display a different pattern of chipping, supporting the hypothesis that these fractures are mostly non-food related (e.g., grit mastication in Homo naledi; non-masticatory tooth use in Neanderthals).
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Affiliation(s)
- Ian Towle
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin, 9054, New Zealand
| | - Carolina Loch
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin, 9054, New Zealand
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30
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Mckeage JW, Loch C, Zwirner J, Hammer N, White DE, Ruddy BP, Brunton PA, Taberner AJ. Controllable Jet Injection of Dental Local Anaesthetic. IEEE J Transl Eng Health Med 2021. [DOI: 10.1109/jtehm.2021.3090748] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- James W. Mckeage
- Auckland Bioengineering Institute, The University of Auckland, Auckland, New Zealand
| | - Carolina Loch
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin, New Zealand
| | - Johann Zwirner
- Department of Anatomy, University of Otago, Dunedin, New Zealand
| | - Niels Hammer
- Department of Anatomy, University of Otago, Dunedin, New Zealand
| | - David E. White
- School of Engineering, Computer and Mathematical Sciences, Auckland University of Technology, Auckland, New Zealand
| | - Bryan P. Ruddy
- Auckland Bioengineering Institute, The University of Auckland, Auckland, New Zealand
| | - Paul A. Brunton
- Division of Health Sciences, University of Otago, Dunedin, New Zealand
| | - Andrew J. Taberner
- Auckland Bioengineering Institute, The University of Auckland, Auckland, New Zealand
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31
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Lopes F, Oliveira LR, Kessler A, Beux Y, Crespo E, Cárdenas-Alayza S, Majluf P, Sepúlveda M, Brownell RL, Franco-Trecu V, Páez-Rosas D, Chaves J, Loch C, Robertson BC, Acevedo-Whitehouse K, Elorriaga-Verplancken FR, Kirkman SP, Peart CR, Wolf JBW, Bonatto SL. Phylogenomic Discordance in the Eared Seals is best explained by Incomplete Lineage Sorting following Explosive Radiation in the Southern Hemisphere. Syst Biol 2020; 70:786-802. [PMID: 33367817 DOI: 10.1093/sysbio/syaa099] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Revised: 12/02/2020] [Accepted: 12/08/2020] [Indexed: 12/25/2022] Open
Abstract
The phylogeny and systematics of fur seals and sea lions (Otariidae) have long been studied with diverse data types, including an increasing amount of molecular data. However, only a few phylogenetic relationships have reached acceptance because of strong gene-tree species tree discordance. Divergence times estimates in the group also vary largely between studies. These uncertainties impeded the understanding of the biogeographical history of the group, such as when and how trans-equatorial dispersal and subsequent speciation events occurred. Here, we used high-coverage genome-wide sequencing for 14 of the 15 species of Otariidae to elucidate the phylogeny of the family and its bearing on the taxonomy and biogeographical history. Despite extreme topological discordance among gene trees, we found a fully supported species tree that agrees with the few well-accepted relationships and establishes monophyly of the genus Arctocephalus. Our data support a relatively recent trans-hemispheric dispersal at the base of a southern clade, which rapidly diversified into six major lineages between 3 and 2.5 Ma. Otaria diverged first, followed by Phocarctos and then four major lineages within Arctocephalus. However, we found Zalophus to be nonmonophyletic, with California (Zalophus californianus) and Steller sea lions (Eumetopias jubatus) grouping closer than the Galapagos sea lion (Zalophus wollebaeki) with evidence for introgression between the two genera. Overall, the high degree of genealogical discordance was best explained by incomplete lineage sorting resulting from quasi-simultaneous speciation within the southern clade with introgresssion playing a subordinate role in explaining the incongruence among and within prior phylogenetic studies of the family. [Hybridization; ILS; phylogenomics; Pleistocene; Pliocene; monophyly.].
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Affiliation(s)
- Fernando Lopes
- Escola de Ciências da Saúde e da Vida, Pontifícia Universidade Católica do Rio Grande do Sul, 90619-900 Porto Alegre, RS, Brazil.,Laboratório de Ecologia de Mamíferos, Universidade do Vale do Rio dos Sinos, São Leopoldo, RS, Brazil
| | - Larissa R Oliveira
- Laboratório de Ecologia de Mamíferos, Universidade do Vale do Rio dos Sinos, São Leopoldo, RS, Brazil.,GEMARS, Grupo de Estudos de Mamíferos Aquáticos do Rio Grande do Sul, 95560-000 Torres, RS, Brazil
| | - Amanda Kessler
- Escola de Ciências da Saúde e da Vida, Pontifícia Universidade Católica do Rio Grande do Sul, 90619-900 Porto Alegre, RS, Brazil
| | - Yago Beux
- Escola de Ciências da Saúde e da Vida, Pontifícia Universidade Católica do Rio Grande do Sul, 90619-900 Porto Alegre, RS, Brazil
| | - Enrique Crespo
- Centro Nacional Patagónico - CENPAT, CONICET, Puerto Madryn, Argentina
| | - Susana Cárdenas-Alayza
- Centro para la Sostenibilidad Ambiental, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Patricia Majluf
- Centro para la Sostenibilidad Ambiental, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Maritza Sepúlveda
- Centro de Investigación y Gestión de Recursos Naturales (CIGREN), Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - Robert L Brownell
- Southwest Fisheries Science Center, National Oceanic and Atmospheric Administration, NOAA, La Jolla, USA
| | - Valentina Franco-Trecu
- Departamento de Ecología y Evolución, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay
| | - Diego Páez-Rosas
- Colegio de Ciencias Biológicas y Ambientales, COCIBA, Universidad San Francisco de Quito, Quito, Ecuador
| | - Jaime Chaves
- Colegio de Ciencias Biológicas y Ambientales, COCIBA, Universidad San Francisco de Quito, Quito, Ecuador.,Department of Biology, San Francisco State University, 1800 Holloway Ave, San Francisco, CA, USA
| | - Carolina Loch
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin, New Zealand
| | | | - Karina Acevedo-Whitehouse
- Unit for Basic and Applied Microbiology, School of Natural Sciences, Universidad Autónoma de Querétaro, Querétaro, Mexico
| | | | - Stephen P Kirkman
- Department of Environmental Affairs, Oceans and Coasts, Cape Town, South Africa
| | - Claire R Peart
- Department Biologie II, Division of Evolutionary Biology, Ludwig-Maximilians-Universität München, Münich, Germany
| | - Jochen B W Wolf
- Department Biologie II, Division of Evolutionary Biology, Ludwig-Maximilians-Universität München, Münich, Germany
| | - Sandro L Bonatto
- Escola de Ciências da Saúde e da Vida, Pontifícia Universidade Católica do Rio Grande do Sul, 90619-900 Porto Alegre, RS, Brazil
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32
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McFarlane G, Guatelli-Steinberg D, Loch C, White S, Bayle P, Floyd B, Pitfield R, Mahoney P. An inconstant biorhythm: The changing pace of Retzius periodicity in human permanent teeth. Am J Phys Anthropol 2020; 175:172-186. [PMID: 33368148 DOI: 10.1002/ajpa.24206] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 11/06/2020] [Accepted: 12/06/2020] [Indexed: 12/25/2022]
Abstract
OBJECTIVES Human tooth enamel retains evidence of growth in the form of Retzius lines. The number of daily growth increments between the regularly occurring lines defines their repeat interval, or periodicity. Retzius periodicity is often incorporated into enamel formation times, age-at-death reconstructions, or used to provide a basis from which to explore an underlying biorhythm. Biological anthropologists typically assume that RP remains constant within an individual and does not vary along the tooth-row. Here, we test that assumption. MATERIALS AND METHODS RP was calculated from n = 223 thin sections of human permanent teeth from individuals of British and southern African origin. Forty individuals provided multiple teeth (n = 102 teeth) and a further 121 individuals each provided a single tooth. RESULTS We report first evidence that RP of permanent teeth does not always remain constant within an individual. Of those individuals that provided multiple teeth, 42% (n = 17/40) demonstrated a decrease in RP along the tooth row, with most shifting by two or more days (n = 11). Across the entire sample, mean RP of anterior teeth was significantly higher than molars. Mean premolar RP tended to be intermediate between anterior teeth and molars. DISCUSSION Our data do not support the assumption that RP invariably remains constant within the permanent teeth of an individual. Transferring RP from molars to incisors within an individual can result in a miscalculation of formation time and age-at-death by up to 1 year. Implications for biological anthropologists and the source of the underlying long period biorhythm are discussed.
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Affiliation(s)
- Gina McFarlane
- Human Osteology Lab, School of Anthropology and Conservation, University of Kent, Canterbury, UK
| | - Debbie Guatelli-Steinberg
- Human Osteology Lab, School of Anthropology and Conservation, University of Kent, Canterbury, UK.,Department of Anthropology, The Ohio State University, Columbus, Ohio, USA
| | - Carolina Loch
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, New Zealand
| | - Sophie White
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, New Zealand
| | | | - Bruce Floyd
- School of Social Sciences, University of Auckland, New Zealand
| | - Rosie Pitfield
- Human Osteology Lab, School of Anthropology and Conservation, University of Kent, Canterbury, UK
| | - Patrick Mahoney
- Human Osteology Lab, School of Anthropology and Conservation, University of Kent, Canterbury, UK
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33
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Snoddy AME, Miszkiewicz JJ, Loch C, Tromp M, Buckley HR. An image analysis protocol for the quantification of interglobular dentine in anthropological tooth sections. Am J Phys Anthropol 2020; 174:144-148. [PMID: 32914865 DOI: 10.1002/ajpa.24143] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Revised: 08/19/2020] [Accepted: 08/21/2020] [Indexed: 01/02/2023]
Abstract
The histological identification of interglobular dentine (IGD) in archeological human remains with macroscopic evidence of rickets has opened a promising new avenue for the investigation of metabolic disease in the past. Recent paleopathological studies have shown that histological analysis of archeological human teeth may allow the identification of periods of vitamin D deficiency occurring within very narrow developmental windows, yielding new information on the seasonality or even maternal-fetal transmission of this disease. However, currently available techniques for recording IGD rely on subjective scoring systems or visual estimations, potentially leaving them open to inter and intra-observer error and rendering comparisons of datasets difficult. Here we describe a new imaging protocol that utilizes open access software and may yield more objective and quantitative data on the amount of IGD present within a dentinal region of interest. We demonstrate that grayscale histograms in FIJI®/ImageJ® might be used to provide less subjective estimates of the percentage of a region of interest affected by IGD. Application of this technique may enable more accurate comparison of datasets between researchers.
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Affiliation(s)
| | - Justyna J Miszkiewicz
- School of Archaeology and Anthropology, Australian National University, College of Arts and Sciences, Canberra, Australia
| | - Carolina Loch
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin, New Zealand
| | - Monica Tromp
- Department of Anatomy, University of Otago, Dunedin, New Zealand.,Southern Pacific Archaeological Research, Archaeology Programme, School of Social Sciences, University of Otago, Dunedin, New Zealand
| | - Hallie R Buckley
- Department of Anatomy, University of Otago, Dunedin, New Zealand
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Loch C, Kuan IBJ, Elsalem L, Schwass D, Brunton PA, Jum'ah A. COVID-19 and dental clinical practice: Students and clinical staff perceptions of health risks and educational impact. J Dent Educ 2020; 85:44-52. [PMID: 32914437 DOI: 10.1002/jdd.12402] [Citation(s) in RCA: 54] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Revised: 08/05/2020] [Accepted: 08/20/2020] [Indexed: 12/12/2022]
Abstract
PURPOSE/OBJECTIVES Due to the nature of the profession, dental healthcare workers are exposed to infectious diseases such as coronavirus disease 2019 (COVID-19), and the severity of the pandemic presents challenges to dental education institutions worldwide. This study investigated dental students and clinical staff perceptions of health risks and impacts on clinical competence of working in teaching clinics during the COVID-19 outbreak. METHODS A 39-item survey composed of closed and open questions was sent to students and clinical staff of a prominent Australasian dental school. Questions focused on students and clinical staff perceived impact of COVID-19 on their health, clinical safety and dental education. RESULTS The majority of staff and students perceived their health to be at risk and this increased their stress and impacted clinical performance, particularly for students. The production of aerosols and violation of cross-infection protocols by some students were the main perceived contributors to COVID-19 cross-infection in teaching clinics. Both students and staff considered the closure of teaching clinics would cause extreme impacts on students' clinical competence; however, online case-based discussions and tutorials were suggested as potential alternative teaching methods that could be adopted during that period. CONCLUSION(S) The challenges of the COVID-19 pandemic also bring opportunities for dental education development; mainly in terms of infection prevention and control improvement, preparedness to respond to future contagious diseases, and exploring the benefits of online learning in dentistry.
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Affiliation(s)
- Carolina Loch
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin, New Zealand
| | - Ian B J Kuan
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin, New Zealand
| | - Lina Elsalem
- Department of Pharmacology, Faculty of Medicine, Jordan University of Science and Technology, Irbid, Jordan
| | - Donald Schwass
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin, New Zealand
| | - Paul A Brunton
- Division of Health Sciences, University of Otago, Dunedin, New Zealand
| | - Ahmad Jum'ah
- Department of Conservative Dentistry, Faculty of Dentistry, Jordan University of Science and Technology, Irbid, Jordan
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Ratnayake J, Guan G, Polonowita A, Li KC, Gray AR, Waddell JN, Loch C, Brunton PA. Can the Measurement of Jaw-Opening Forces Assist in the Diagnosis of Temporomandibular Disorders? J Oral Facial Pain Headache 2020; 34:199-205. [PMID: 32870948 DOI: 10.11607/ofph.2587] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
AIMS To investigate the effectiveness of a novel jaw-opening-force measuring device as a screening tool to aid in the diagnosis of temporomandibular disorders (TMD). METHODS Symptomatic TMD patients (n = 58) and control TMD-free participants (n = 56) were screened by an oral medicine specialist according to the Diagnostic Criteria for TMD (DC/TMD). TMD patients were divided into three subcategories based on TMD symptoms (myofascial pain, disc displacement, and both combined). Jaw-opening forces were measured in both groups with an adjustable head device connected to a 1,000-N-load cell. Seven attempts were recorded at 10-second intervals by a data-capturing system. The geometric mean force values were obtained after discarding the first and last attempts. RESULTS TMD-free participants had greater jaw-opening forces than TMD patients both without and with adjustments for age, sex, height, and weight (both P < .001). The geometric mean ± standard deviation values for TMD patients were 18.5 ± 1.62 N and 47.7 ± 1.53 N for TMD-free participants. Differences in jaw-opening forces among the three TMD subcategories were not statistically significant; however, patients with disc displacement (23.7 ± 1.46 N) had greater jaw forces than patients with myofascial pain (17.0 ± 1.74 N) and both myofascial pain and disc displacement (17.0 ± 1.56 N). CONCLUSION This study demonstrated that differences in jaw-opening forces could be used as a diagnostic tool for TMD. Future studies should explore the potential of this device to measure improvement in jaw-opening forces following TMD treatment.
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Loch C, Vaz Viegas S, Waddell JN, Kemper C, Cook RB, Werth AJ. Structure and properties of baleen in the Southern right (Eubalaena australis) and Pygmy right whales (Caperea marginata). J Mech Behav Biomed Mater 2020; 110:103939. [PMID: 32957233 DOI: 10.1016/j.jmbbm.2020.103939] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Revised: 02/02/2020] [Accepted: 06/15/2020] [Indexed: 12/24/2022]
Abstract
Baleen is a resilient and keratinised filter-feeding structure attached to the maxilla of mysticete whales. It is strong and tough, yet a pliant and resilient material, that withstands extreme pressures in the oral cavity during feeding. We investigated the structure, water content, wettability and mechanical properties of baleen of the Southern right (SRW) and Pygmy right whales (PRW), to understand the effects of hydration on the physical and mechanical properties of baleen. Sixty 25 × 15mm baleen subsamples were prepared from one individual of SRW and PRW. Half were hydrated in circulated natural seawater for 21 days and half were dry. Water content analysis showed that SRW baleen was 21.2% water weight and PRW was 26.1%. Wettability testing indicated that surfaces of both hydrated and dried SRW and PRW baleen were hydrophilic, with hydrated samples of both species having lower contact angle values. For the SRW, the average contact angle of hydrated baleen was 40° ± 13.2 and 73° ± 6 for dried samples. Hydrated PRW baleen had an average contact angle of 44° ± 15.3, which was lower than in dried samples (74° ± 2.9). Three-point bending mechanical tests showed that the average maximum flexural stress of dried SRW (134.1 ± 34.3 MPa) and PRW samples (117.8 ± 22.3 MPa) were significantly higher than those of hydrated SRW (25.7 ± 6.3 MPa) and PRW (19.7 ± 4.8 MPa) baleen. Scanning electron microscope images showed the stratification of the outer cortical layer, with cross-linked keratin fibres observed within and between baleen keratin sheets. Hydrated baleen, as in its natural and functional behaviour, has greater flexibility and strength, attributes necessary for the complex filter feeding mechanism characteristic of whales. Hydration must be considered when addressing the physical and mechanical properties of baleen, especially when using dried museum specimens.
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Affiliation(s)
- Carolina Loch
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin, 9054, New Zealand.
| | - Shaun Vaz Viegas
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin, 9054, New Zealand
| | - J Neil Waddell
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin, 9054, New Zealand
| | - Catherine Kemper
- Biological and Earth Sciences, South Australian Museum, Adelaide, SA, 5000, Australia
| | - Richard B Cook
- National Centre for Advanced Tribology at Southampton (nCATS), University of Southampton, SO17 1BJ, UK
| | - Alexander J Werth
- Department of Biology, Hampden-Sydney College, Hampden-Sydney, VA, 23943, USA
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Loch C, Brunton PA, Rahim ZA, Liew L, Lynch CD, Wilson N, Blum IR, Jum’ah AA. The teaching of removable partial dentures in dental schools in Oceania. J Dent 2020; 95:103309. [DOI: 10.1016/j.jdent.2020.103309] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Revised: 02/23/2020] [Accepted: 02/27/2020] [Indexed: 10/24/2022] Open
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Affiliation(s)
- Jonathan M. Broadbent
- Department of Oral Sciences, Faculty of Dentistry, University of Otago, Dunedin, New Zealand
| | - Carolina Loch
- Department of Oral Sciences, Faculty of Dentistry, University of Otago, Dunedin, New Zealand
| | - Richard D. Cannon
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin, New Zealand
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Veerasamy A, Loch C, Adam L, Brunton PA. Graduate mobility: Where do dentistry graduates choose to practise? Eur J Dent Educ 2019; 23:424-430. [PMID: 31206930 DOI: 10.1111/eje.12448] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Accepted: 06/10/2019] [Indexed: 06/09/2023]
Abstract
BACKGROUND AND OBJECTIVE The international higher education market has grown and developed rapidly. International students generate attractive income for host universities, and gaining an international education benefits students in an increasingly globalised world. However, there is little research regarding where international students intend to work and settle beyond graduation. This study investigated where dentistry students intended to practise after graduation, and whether international students who graduated between 2001 and 2016 are currently practising in their host country (New Zealand) or have migrated overseas. METHODS A cross-sectional survey was used to investigate current students' intended destination of practice after graduation. Additionally, names of international graduates since 2001 were matched against the 2017 register of practitioners to determine if they were currently registered to practise in their host country. A frequency and bivariate analysis was conducted. RESULTS Almost 64% of current international students indicated their intention to stay in their host country after graduation. However, only 22% of graduates since 2001 were currently practising in New Zealand. The number of international graduates who registered to practise in New Zealand increased between 2001 and 2016. CONCLUSION Less than one-quarter of international graduates were currently practising in their host country; however, longitudinal data showed that this is an increasing trend. These findings can be used to inform how we might prepare current and future graduates for both local and globalised labour markets.
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Affiliation(s)
- Arthi Veerasamy
- Faculty of Dentistry, University of Otago, Dunedin, New Zealand
| | - Carolina Loch
- Faculty of Dentistry, University of Otago, Dunedin, New Zealand
| | - Lee Adam
- Faculty of Dentistry, University of Otago, Dunedin, New Zealand
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Werth AJ, Loch C, Fordyce RE. Correction to: Enamel Microstructure in Cetacea: a Case Study in Evolutionary Loss of Complexity. J MAMM EVOL 2019. [DOI: 10.1007/s10914-019-09485-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Affiliation(s)
- Syahirah Abd Aziz
- Department of Oral Sciences, Faculty of Dentistry, University of Otago, Otago, New Zealand
| | - Syazirah Kuan
- Department of Oral Sciences, Faculty of Dentistry, University of Otago, Otago, New Zealand
| | - Emily Jin
- Department of Oral Sciences, Faculty of Dentistry, University of Otago, Otago, New Zealand
| | - Carolina Loch
- Department of Oral Sciences, Faculty of Dentistry, University of Otago, Otago, New Zealand
| | - W. Murray Thomson
- Department of Oral Sciences, Faculty of Dentistry, University of Otago, Otago, New Zealand
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Loch C, Liaw Y, Metussin AP, Lynch CD, Wilson N, Blum IR, Brunton PA. The teaching of posterior composites: A survey of dental schools in Oceania. J Dent 2019; 84:36-43. [DOI: 10.1016/j.jdent.2019.01.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2018] [Revised: 12/19/2018] [Accepted: 01/17/2019] [Indexed: 11/29/2022] Open
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Lee RJ, Ratnayake J, Veerasamy A, Loch C, Cathro P, Brunton PA. Demographics, Practising Arrangements, and Standards: Survey among New Zealand Dentists. Int J Dent 2018; 2018:7675917. [PMID: 30581468 PMCID: PMC6276479 DOI: 10.1155/2018/7675917] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Revised: 10/14/2018] [Accepted: 10/29/2018] [Indexed: 01/26/2023] Open
Abstract
BACKGROUND To determine the demographic profile and practising arrangements of general dentists in New Zealand. METHODS A questionnaire comprising 19 sections with 125 questions was distributed via mail to 351 general dentists in New Zealand who were selected, at random, from the Dental Council of New Zealand's 2016 register. RESULTS Two hundred and four questionnaires were returned, of which 188 were usable giving a response rate of 53.5%. The majority of the respondents (63.5%) were male and practice principals (56.8%). Fifty-nine percent of the practices were located in city or town centres with a wide geographic distribution. Sole practitioners accounted for 24.1% of respondents, with the mean number of dentists per practice being 3.2. The majority of respondents (71.6%) attended five or more continuing professional development courses in the past year. Ninety-one percent of respondents used a computerized management system, and 95.3% used the Internet. The use of nickel-titanium endodontic files (83.9%) and digital imaging (82.2%) was the most frequently cited clinical innovations. Articaine was the most popular local anaesthetic of choice. CONCLUSIONS Dentistry is an ever-changing profession, with evidence that NZ dentists continue to develop, learn, and embrace advancements in technologies to supply high-quality evidence-based treatment.
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Affiliation(s)
- Robert James Lee
- University of Otago, Faculty of Dentistry, 310 Great King Street, Dunedin 9016, New Zealand
| | - Jithendra Ratnayake
- University of Otago, Faculty of Dentistry, 310 Great King Street, Dunedin 9016, New Zealand
| | - Arthi Veerasamy
- University of Otago, Faculty of Dentistry, 310 Great King Street, Dunedin 9016, New Zealand
| | - Carolina Loch
- University of Otago, Faculty of Dentistry, 310 Great King Street, Dunedin 9016, New Zealand
| | - Peter Cathro
- University of Otago, Faculty of Dentistry, 310 Great King Street, Dunedin 9016, New Zealand
| | - Paul A. Brunton
- University of Otago, Faculty of Dentistry, 310 Great King Street, Dunedin 9016, New Zealand
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Loch C, Townsend G, Dean C. In Memoriam: Julius (Jules) August Kieser (20 December 1950 – 10 June 2014). DAJ 2018. [DOI: 10.26575/daj.v27i1-2.36] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
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Rovaris K, Sousa Melo SL, Queiroz PM, Loch C, Schwass DR, Haiter-Neto F. Beam hardening correction tool improves the diagnosis of incipient caries lesions in Micro-CT images. Dentomaxillofac Radiol 2018; 48:20180123. [PMID: 30084261 DOI: 10.1259/dmfr.20180123] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVE To evaluate the effect of Beam Hardening Correction tool (BHC) on Micro-CT images used in the diagnosis of incipient caries lesions. METHODS Six posterior teeth, with 6 sound proximal surfaces and 6 natural white spot lesions, were scanned using a SkyScan1174 device. Each tooth was imaged 16 times in various acquisition parameters, and reconstructed 3 times applying different levels of BHC (0, 15 and 30%). The 288 datasets were analyzed by three examiners. Gold-standard was obtained by microscopic analyses under polarized light. Area under the ROC curve was obtained for each protocol and the BHC parameter was isolated to individually observe the influence of such parameters of reconstruction. RESULTS Microtomographic images were accurate for the diagnosis of incipient caries lesions even when the BHC tool was not applied. Accuracy was perfect in 50 % of the protocols without BHC. When adding the artefact correction, the number of protocols that reached perfect accuracy increased to 81.25%. No difference was found between the protocols that used 15 or 30% BHC. Statistically significant differences were found only in four comparisons, and on those the images that had BHC were more accurate. Two non-BHC protocols reached accuracy scores of 0.653 and 0.881, and were improved to perfect accuracy with BHC application. CONCLUSION The use of the BHC tool should be encouraged when using Micro-CT to detect incipient caries lesions, especially when low-quality parameters aiming less acquisition and processing time are used.
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Affiliation(s)
- Karla Rovaris
- Department of Oral Diagnosis, Piracicaba Dental School, University of Campinas, Piracicaba, Brazil
| | - Saulo Leonardo Sousa Melo
- Department of Oral Pathology, Radiology and Medicine, College of Dentistry, University of Iowa, Iowa, IA, USA
| | | | - Carolina Loch
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin, New Zealand
| | - Donald R Schwass
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin, New Zealand
| | - Francisco Haiter-Neto
- Department of Oral Diagnosis, Piracicaba Dental School, University of Campinas, Piracicaba, Brazil
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Loch C, Haeger JD, Pfarrer C. IFNτ mediates chemotaxis, motility, metabolism and CK18 downregulation in bovine trophoblast cells in vitro via STAT1 and MAPK42/44 signaling. Placenta 2018; 64:17-26. [DOI: 10.1016/j.placenta.2018.02.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Revised: 02/19/2018] [Accepted: 02/19/2018] [Indexed: 10/18/2022]
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Jett J, Visser IN, Ventre J, Waltz J, Loch C. Corrigendum to "Tooth damage in captive orcas (Orcinus orca)" [Arch. Oral Biol. 84 (2017) 151-160]. Arch Oral Biol 2018; 89:93. [PMID: 29494811 DOI: 10.1016/j.archoralbio.2018.02.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- John Jett
- Biology Department, Stetson University, 421 N. Woodland Blvd., DeLand, FL, 32723, United States.
| | - Ingrid N Visser
- Orca Research Trust, P.O. Box 402043, Tutukaka, Northland, 0153, New Zealand.
| | - Jeffrey Ventre
- Virginia Mason Memorial, Lakeview, 1470 N. 16th Avenue, Yakima, WA, 98902, United States.
| | - Jordan Waltz
- 171 Pier Ave. #234, Santa Monica, CA 90405, United States
| | - Carolina Loch
- Department of Oral Sciences, Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin 9054, New Zealand.
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Brunton PA, Loch C, Waddell JN, Bodansky HJ, Hall R, Gray A. Estimation of jaw-opening forces in adults. Orthod Craniofac Res 2017; 21:57-62. [DOI: 10.1111/ocr.12215] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/25/2017] [Indexed: 11/29/2022]
Affiliation(s)
- P. A. Brunton
- Sir John Walsh Research Institute; Faculty of Dentistry; University of Otago; Dunedin New Zealand
| | - C. Loch
- Sir John Walsh Research Institute; Faculty of Dentistry; University of Otago; Dunedin New Zealand
| | - J. N. Waddell
- Sir John Walsh Research Institute; Faculty of Dentistry; University of Otago; Dunedin New Zealand
| | | | | | - A. Gray
- Department of Preventive and Social Medicine; University of Otago; Dunedin New Zealand
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Duncan WJ, Greer PFC, Lee MH, Loch C, Gay JHA. Wool-derived keratin hydrogel enhances implant osseointegration in cancellous bone. J Biomed Mater Res B Appl Biomater 2017; 106:2447-2454. [PMID: 29226584 DOI: 10.1002/jbm.b.34047] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Revised: 09/26/2017] [Accepted: 10/31/2017] [Indexed: 11/11/2022]
Abstract
AIM This study investigated whether a keratin hydrogel derived from wool enhances ossointegration of dental implants, using a cancellous bone model in sheep. METHOD Ten female sheep received one dental implant per hind leg in the distal femoral condyles. Test implants were coated with 1 mL of keratin hydrogel containing sulphonated keratin and hydroxyapatite; control implants remained uncoated; implants were not functionally loaded axially. Biomechanical stability was tested with resonance frequency analysis (RFA) at placement and euthanasia. Animals were sacrificed after 4 weeks and resin-embedded histomorphometry performed. FINDINGS Bone appeared denser and more mature around the keratin-treated test implants. Average % bone-implant contact was significantly increased for the test (58.1 ± 4.6 [SD]%) compared to control implants (34.4 ± 7.5%) (p = 0.01). RFA values were lower for control (76.5 ± 4.2 ISQ) than test implants (80.4 ± 1.4) after 4 weeks (p = 0.04). CONCLUSION the increase in osseointegration found in this model suggests that keratin hydrogel has the potential to enhance the successful osseointegration of dental implants placed into poor quality bone. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 2447-2454, 2018.
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Affiliation(s)
- Warwick J Duncan
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin, 9054, New Zealand
| | - Philippa F C Greer
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin, 9054, New Zealand
| | - Min-Ho Lee
- School of Dentistry and Institute of Biodegradable Material, Chonbuk National University, Jeonju, South Korea
| | - Carolina Loch
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin, 9054, New Zealand
| | - Jennifer H A Gay
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin, 9054, New Zealand
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Jett J, Visser IN, Ventre J, Waltz J, Loch C. Tooth damage in captive orcas (Orcinus orca). Arch Oral Biol 2017; 84:151-160. [PMID: 28992601 DOI: 10.1016/j.archoralbio.2017.09.031] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2017] [Revised: 09/25/2017] [Accepted: 09/26/2017] [Indexed: 11/25/2022]
Abstract
OBJECTIVES Tooth damage as a result of oral stereotypies is evident in captive orca, yet little research on the topic exists. This study examines the associations between dental pathology, sex, facility, duration of captivity and other factors in captive orca. DESIGN We evaluated mandibular and maxillary teeth from dental images of 29 captive orca owned by a US-based theme park. Each tooth was scored for coronal wear, wear at or below gum line and bore holes. Fractured and missing teeth were also noted. Summary statistics described the distribution and severity of pathologies; inferential statistics examined how pathologies differed between sexes, between wild-captured and captive-born orcas and between captive orca at four facilities. We also evaluated how dental pathology and duration of captivity were related. RESULTS Approximately 24% of whales exhibited "major" to "extreme" mandibular coronal tooth wear, with coronal wear and wear at or below gum line highly correlated. More than 60% of mandibular teeth 2 and 3 exhibited fractures. Bore holes were observed primarily among anterior mandibular teeth, with more than 61% of teeth 2 and 3 bearing evidence of having been drilled. Four of five orca with the highest age-adjusted tooth pathology indices were captive-born. CONCLUSIONS Various dental pathologies were observed across all whales, with pathologies beginning at a young age. Oral stereotypies exhibited by captive orca contributed to the observed dental damage. By making dental and health records of captive whales publicly available, the theme park industry is uniquely positioned to provide further insight into dental pathology and resultant health consequences in captive orca.
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Affiliation(s)
- John Jett
- Biology Department, Stetson University, 421 N. Woodland Blvd., DeLand, FL, 32723, United States.
| | - Ingrid N Visser
- Orca Research Trust, P.O. Box 402043, Tutukaka, Northland, 0153, New Zealand.
| | - Jeffrey Ventre
- Virginia Mason Memorial, Lakeview, 1470 N. 16th Avenue, Yakima, WA, 98902, United States.
| | - Jordan Waltz
- 171 Pier Ave. #234, Santa Monica, CA 90405, United States
| | - Carolina Loch
- Department of Oral Sciences, Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin 9054, New Zealand.
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