151
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Fracture behavior of inlay and onlay fixed partial dentures – An in-vitro experimental and XFEM modeling study. J Mech Behav Biomed Mater 2016; 59:279-290. [DOI: 10.1016/j.jmbbm.2016.01.035] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2015] [Revised: 01/10/2016] [Accepted: 01/12/2016] [Indexed: 11/21/2022]
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152
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Gresnigt MM, Özcan M, van den Houten ML, Schipper L, Cune MS. Fracture strength, failure type and Weibull characteristics of lithium disilicate and multiphase resin composite endocrowns under axial and lateral forces. Dent Mater 2016; 32:607-14. [DOI: 10.1016/j.dental.2016.01.004] [Citation(s) in RCA: 78] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2015] [Revised: 06/20/2015] [Accepted: 01/15/2016] [Indexed: 11/30/2022]
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153
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Iwasaki M, Yoshihara A, Sato N, Sato M, Taylor GW, Ansai T, Ono T, Miyazaki H. Maximum bite force at age 70 years predicts all-cause mortality during the following 13 years in Japanese men. J Oral Rehabil 2016; 43:565-74. [PMID: 27084614 DOI: 10.1111/joor.12401] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/19/2016] [Indexed: 11/28/2022]
Abstract
There is limited information on the impact of oral function on mortality among older adults. The aim of this prospective cohort study was to examine whether an objective measure of oral function, maximum bite force (MBF), is associated with mortality in older adults during a 13-year follow-up period. Five hundred and fifty-nine community-dwelling Japanese (282 men and 277 women) aged 70 years at baseline were included in the study. Medical and dental examinations and a questionnaire survey were conducted at baseline. Maximum bite force was measured using an electronic recording device (Occlusal Force-Meter GM10). Follow-up investigation to ascertain vital status was conducted 13 years after baseline examinations. Survival rates among MBF tertiles were compared using Cox proportional hazards regression models stratified by sex. There were a total of 111 deaths (82 events for men and 29 for women). Univariable analysis revealed that male participants in the lower MBF tertile had increased risk of all-cause mortality [hazard ratio (HR) = 1·94, 95% confidence interval (CI) = 1·13-3·34] compared with those in the upper MBF tertile. This association remained significant after adjustment for confounders (adjusted HR = 1·84, 95% CI = 1·07-3·19). Conversely, no association between MBF and all-cause mortality was observed in female participants. Maximum bite force was independently associated with all-cause mortality in older Japanese male adults. These data provide additional evidence for the association between oral function and geriatric health.
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Affiliation(s)
- M Iwasaki
- Division of Preventive Dentistry, Department of Oral Health Science, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan.,Division of Community Oral Health Development, Kyushu Dental University, Kitakyushu, Japan
| | - A Yoshihara
- Division of Oral Science for Health Promotion, Department of Oral Health and Welfare, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | - N Sato
- Division of Comprehensive Prosthodontics, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | - M Sato
- Division of Preventive Dentistry, Department of Oral Health Science, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | - G W Taylor
- Department of Preventive and Restorative Dental Sciences, University of California San Francisco, San Francisco, CA, USA
| | - T Ansai
- Division of Community Oral Health Development, Kyushu Dental University, Kitakyushu, Japan
| | - T Ono
- Division of Comprehensive Prosthodontics, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | - H Miyazaki
- Division of Preventive Dentistry, Department of Oral Health Science, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
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154
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Fontana SC, Smith RB, Nazir N, Andrews BT. Biomechanical assessment of fixation methods for segmental mandible reconstruction with fibula in the polyurethane model. Microsurgery 2016; 36:330-3. [PMID: 27059150 DOI: 10.1002/micr.30052] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Revised: 02/15/2016] [Accepted: 03/17/2016] [Indexed: 11/07/2022]
Abstract
BACKGROUND A variety of plating techniques are employed by microsurgeons to provide rigid fixation for vascularized bone constructs of the mandible. The aim of this study was to biomechanically compare three commonly utilized plating techniques for rigid fixation of fibula bone flaps in reconstructing lateral segmental mandibular defects. MATERIALS AND METHODS Polyurethane mandibles with 3-cm segmental defects were reconstructed using polyurethane fibula models. Three fixation techniques were compared (n = 5 models per group): Group 1 used two 2.0-mm miniplates at each osteotomy site, Group 2 used a single 2.3-mm plate, and Group 3 used a single 2.7-mm plate. Biomechanical testing of maximum force and displacement at failure for each plating technique was assessed and statistical comparison performed. RESULTS The average displacement for Group 1 was 14.08 ± 1.42 mm, Group 2 was 5.79 ± 0.89 mm, and Group 3 was 6.03 ± 1.59 mm. Group 1 had significantly greater (P < 0.05) displacement when compared with Group 2 and 3. Analysis of variance demonstrated the three groups varied significantly in mean displacement (0 < 0.01). The average force before failure for Group 1 was 616.4 ± 33.83N, Group 2 was 737.8 ± 72.57N, and Group 3 was 681.0 ± 67.98N. Group 2 withstood significantly greater force than Group 1 (P < 0.05), and withstood greater force than Group 3, although the difference was not significant. Analysis of variance showed the three groups varied significantly in mean force at failure (P < 0.05). CONCLUSION Reconstruction using a single 2.3-mm plate provided the best rigid fixation for lateral segmental defects of the mandible. © 2016 Wiley Periodicals, Inc. Microsurgery 36:330-333, 2016.
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Affiliation(s)
- Stefani C Fontana
- Department of Plastic Surgery, University of Kansas Medical Center, Kansas City, KS
| | - Russell B Smith
- Department of Otolaryngology-Head and Neck Surgery, University of Nebraska Medical Center, Omaha, NE
| | - Niaman Nazir
- Department of Plastic Surgery, University of Kansas Medical Center, Kansas City, KS
| | - Brian T Andrews
- Department of Plastic Surgery, University of Kansas Medical Center, Kansas City, KS
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155
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Al Qassar SSS, Mavragani M, Psarras V, Halazonetis DJ. The anterior component of occlusal force revisited: direct measurement and theoretical considerations. Eur J Orthod 2016; 38:190-6. [PMID: 25888533 PMCID: PMC4914761 DOI: 10.1093/ejo/cjv028] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
BACKGROUND The anterior component of occlusal force (ACF), considered to result from the mesial inclination of teeth relative to the occlusal plane, has been estimated by indirectly measuring contact point tightness (CPT) through interproximal insertion of metal strips. ACF has been observed concurrently with a posterior component, whose theoretical origin is difficult to explain. OBJECTIVES Evaluate ACF by measuring CPT directly, and integrate current data to propose a theoretical basis for ACF. MATERIALS AND METHODS The sample comprised 14 females (age: 22.3±2.8) and 16 males (age: 20.8±2.5). Our device consisted of two force sensors: one for measuring maximum bite force (MBF) (overall thickness: 4mm), and one for measuring CPT directly (0.2mm thick), inserted between the lower first molar and second premolar. ACF was computed as the difference in CPT between the biting (at 75 per cent of MBF) and non-biting conditions. RESULTS Averages of MBF, CPT, and ACF were 666.67 [standard deviation (SD): 36.06], 6.74 (SD: 1.17), and 20.59 (SD: 4.60) N, respectively. ACF, CPT, and MBF were higher in males by approximately 28, 18 and 7 per cent, respectively. A positive correlation was observed between ACF and MBF (R (2): 0.64). CPT was also significantly correlated to MBF (R (2): 0.40). Biomechanical analysis indicates that previously offered explanations do not unriddle the concurrent increase of CPT at anterior and posterior contact points. CONCLUSIONS ACF was related to bite force by a logarithmic model. We speculate that CPT increases during biting through a combination of mesial tipping of teeth and mandibular bending.
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Affiliation(s)
| | | | - Vasilis Psarras
- **Department of Stomatognathic Physiology, School of Dentistry, National and Kapodistrian University of Athens, Greece
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156
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Treffel L, Dmitrieva L, Gauquelin-Koch G, Custaud MA, Blanc S, Gharib C, Millet C. Craniomandibular System and Postural Balance after 3-Day Dry Immersion. PLoS One 2016; 11:e0150052. [PMID: 26913867 PMCID: PMC4767814 DOI: 10.1371/journal.pone.0150052] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2015] [Accepted: 02/09/2016] [Indexed: 12/30/2022] Open
Abstract
The objective of the study was to determine the influence of simulated microgravity by exposure to dry immersion on the craniomandibular system. Twelve healthy male volunteers participated in a 3-day dry immersion study. Before and immediately after exposure we measured maximal bite force using piezoresistive sensors. The mechanical properties of the jaw and cervical muscles were evaluated before, during, and after dry immersion using MyotonPRO. Because recent studies reported the effects of jaw motor activity on the postural stability of humans, stabilometric measurements of center of pressure were performed before and after dry immersion in two mandibular positions: rest position without jaw clenching, and intercuspidal position during voluntary teeth clenching. Results revealed no significant changes of maximal bite force after dry immersion. All postural parameters were significantly altered by dry immersion. There were however no significant differences in stabilometric data according to mandibular position. Moreover the masseter tonicity increased immediately after the end of dry immersion period. Dry immersion could be used as a valid model for studying the effects of microgravity on human subjects. However, 3 days appear insufficient in duration to evaluate the effects of weightlessness on maximal bite force. Our research suggests a link between postural disturbance after dry immersion and masseter tonicity.
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Affiliation(s)
- Loïc Treffel
- Université Claude Bernard Lyon 1, Lyon, France
- Université de Strasbourg, Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7178, Strasbourg, France
| | - Liubov Dmitrieva
- Institute of Biomedical Problems, Moscow, Russia
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 6214 - Institut National de la Santé et de la Recherche Médicale 1083, Université d’Angers, Angers, France
| | | | - Marc-Antoine Custaud
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 6214 - Institut National de la Santé et de la Recherche Médicale 1083, Université d’Angers, Angers, France
- Centre de Recherche Clinique, Centre Hospitalo-Universitaire d’Angers, Angers, France
| | - Stéphane Blanc
- Université de Strasbourg, Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7178, Strasbourg, France
| | - Claude Gharib
- Université Claude Bernard Lyon 1, Lyon, France
- Centre International d’Ostéopathie, Saint-Etienne, France
| | - Catherine Millet
- Université Claude Bernard Lyon 1, Lyon, France
- Service d’Odontologie, Hospices Civils de Lyon, Lyon, France
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157
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Araujo DS, Marquezin MCS, Barbosa TDS, Gavião MBD, Castelo PM. Evaluation of masticatory parameters in overweight and obese children. Eur J Orthod 2015; 38:393-7. [DOI: 10.1093/ejo/cjv092] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
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158
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Forces that fracture teeth during extraction with mandibular premolar and maxillary incisor forceps. Br J Oral Maxillofac Surg 2015; 53:982-7. [DOI: 10.1016/j.bjoms.2015.08.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2015] [Accepted: 08/08/2015] [Indexed: 11/15/2022]
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159
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Preis V, Behr M, Hahnel S, Rosentritt M. Influence of cementation on in vitro performance, marginal adaptation and fracture resistance of CAD/CAM-fabricated ZLS molar crowns. Dent Mater 2015; 31:1363-9. [DOI: 10.1016/j.dental.2015.08.154] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2015] [Accepted: 08/17/2015] [Indexed: 10/23/2022]
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160
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Roldán SI, Restrepo LG, Isaza JF, Vélez LG, Buschang PH. Are maximum bite forces of subjects 7 to 17 years of age related to malocclusion? Angle Orthod 2015; 86:456-61. [PMID: 26347948 DOI: 10.2319/051315-323.1] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
OBJECTIVE To determine the effects of occlusion on maximum bite force of growing subjects. MATERIALS AND METHODS Incisor and first molar bite force of children and adolescents was evaluated. Four cohorts were measured annually for 3 years, starting at approximately 7, 9, 12, and 15 years of age, respectively. The initial sample included 182 females and 198 males; there were 130 subjects with normal occlusion, 111 with Class I malocclusion, and 139 with Class II malocclusion. Multilevel analyses were performed to model the growth changes and compare groups. RESULTS Maximum bite force increased significantly (P < .05) over time. Incisal forces peaked at 14.3 and 15.3 years of age for females and males, respectively. Maximum molar bite force peaked at 16 years for both males and females. Subjects with normal occlusion had significantly higher bite force than subjects with malocclusion. Maximum molar bite force exhibited a significant testing effect, with forces increasing 2.6 kg each year that the tests were repeated. CONCLUSIONS Malocclusion has a detrimental effect on bite force. Changes in maximum bite force are also due to age, sex, and repeated testing.
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Affiliation(s)
- Samuel I Roldán
- a Assistant Professor, Department of Orthodontics, CES University, Grupo de Investigación en Bioingeniería GIB, CES-EAFIT, Medellín, Colombia
| | - Luis G Restrepo
- b Instructor, Department of Orthodontics, CES University, Grupo de Investigación en Bioingeniería GIB, CES-EAFIT, Medellín, Colombia
| | - Juan F Isaza
- c Assistant Professor, Department of Product Design Engineering, EAFIT University, Grupo de Investigación en Bioingeniería GIB, CES-EAFIT, Medellín, Colombia
| | | | - Peter H Buschang
- e Regents Professor, Department of Orthodontics, Texas A&M University Baylor College of Dentistry, Dallas, Tex
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161
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Baladhandayutham B, Lawson NC, Burgess JO. Fracture load of ceramic restorations after fatigue loading. J Prosthet Dent 2015; 114:266-71. [PMID: 25985741 DOI: 10.1016/j.prosdent.2015.03.006] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2014] [Revised: 03/04/2015] [Accepted: 03/04/2015] [Indexed: 10/23/2022]
Abstract
STATEMENT OF PROBLEM A clinician must decide what ceramic coping and veneer material to prescribe based on the amount of tooth reduction possible and the desired esthetic outcome of the restoration. PURPOSE The purpose of this in vitro study was to compare the fracture strength of monolithic and bilayered lithium disilicate (IPS e.max) and zirconia (LAVA) crowns at clinically relevant thicknesses after load cycling. MATERIAL AND METHODS Crowns (n=8) were fabricated from 6 groups: 1.2-mm monolithic lithium disilicate, 1.5-mm monolithic lithium disilicate, 1.5-mm bilayered lithium disilicate with hand-layered veneer, 0.6 mm monolithic zirconia, 1.2-mm bilayered zirconia with hand-layered veneer, and 1.2-mm bilayered zirconia with milled veneer (dimension represents thickness at the occlusal pit). Crowns were cemented to identical milled resin dies with resin-modified glass ionomer cement. Cemented crowns were stored at 37°C for 24 hours and load cycled for 200,000 cycles at 25 N at a rate of 40 cycles/minute. The ultimate fracture load for each specimen was measured in a universal testing machine. Data were analyzed with a 1-way ANOVA and Tukey honest significant difference post hoc analysis (α=.05). RESULTS Mean ±SD fracture load values were 1465 ±330 N for monolithic lithium disilicate (1.2-mm thickness) and 2027 ±365 N (1.5-mm thickness) and 1732 ±315 N for bilayered hand-veneered lithium disilicate (1.5-mm thickness). Fracture loads were 1669 ±311 N for monolithic zirconia crowns (0.6mm thickness), 2625 ±300 N for zirconia milled-veneered (1.2-mm thickness), and 2655 ±590N for zirconia hand-veneered crowns (1.2mm thickness). One-way ANOVA showed a statistically significant difference among the groups (P<.01). Veneered zirconia crowns showed the highest fracture strength, 1.2-mm hand veneered zirconia was similar to that of 1.5-mm monolithic zirconia, and all other groups were not statistically different. CONCLUSIONS Crowns of 1.2-mm bilayered zirconia had higher fracture loads than 0.6-mm zirconia or 1.2-mm lithium disilicate monolithic crowns.
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Affiliation(s)
| | - Nathaniel C Lawson
- Assistant Professor, Department of Biomaterials, University of Alabama at Birmingham School of Dentistry, Birmingham, Ala.
| | - John O Burgess
- Professor, Division of Biomaterials, University of Alabama at Birmingham School of Dentistry, Birmingham, Ala
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162
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Kataoka K, Ekuni D, Mizutani S, Tomofuji T, Azuma T, Yamane M, Kawabata Y, Iwasaki Y, Morita M. Association Between Self-Reported Bruxism and Malocclusion in University Students: A Cross-Sectional Study. J Epidemiol 2015; 25:423-30. [PMID: 25865057 PMCID: PMC4444496 DOI: 10.2188/jea.je20140180] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2014] [Accepted: 01/07/2015] [Indexed: 12/21/2022] Open
Abstract
OBJECTIVES Bruxism can result in temporomandibular disorders, oral pain, and tooth wear. However, it is unclear whether bruxism affects malocclusion. The aim of this study was to examine the association between self-reported bruxism and malocclusion in university students. METHODS Students (n = 1503; 896 men and 607 women) aged 18 and 19 years were examined. Malocclusion was defined using a modified version of the Index of Orthodontic Treatment Need. The presence of buccal mucosa ridging, tooth wear, dental impression on the tongue, palatal/mandibular torus, and the number of teeth present were recorded, as well as body mass index (BMI). Additional information regarding gender, awareness of bruxism, orthodontic treatment, and oral habits was collected via questionnaire. RESULTS The proportion of students with malocclusion was 32% (n = 481). The awareness of clenching in males with malocclusion was significantly higher than in those with normal occlusion (chi square test, P < 0.01). According to logistic regression analysis, the probability of malocclusion was significantly associated with awareness of clenching (odds ratio [OR] 2.19; 95% confidence interval [CI], 1.22-3.93) and underweight (BMI <18.5 kg/m(2)) (OR 1.89; 95% CI, 1.31-2.71) in males but not in females. In subgroup analyses, the probability of crowding was also significantly associated with awareness of clenching and underweight (P < 0.01) in males. CONCLUSIONS Awareness of clenching and underweight were related to malocclusion (crowding) in university male students.
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163
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Lillo R, Parra C, Fuentes R, Borie E, Engelke W, Beltrán V. Compressive resistance of abutments with different diameters and transmucosal heights in Morse-taper implants. Braz Dent J 2015; 26:156-9. [PMID: 25831107 DOI: 10.1590/0103-6440201300221] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2014] [Accepted: 01/09/2015] [Indexed: 11/22/2022] Open
Abstract
The aim of this study was to evaluate the compressive resistance under oblique loads of abutments with two different diameters and transmucosal heights used for cement-retained implant-supported prostheses in Morse-taper implants. Forty Morse-taper implants were divided into four groups with different abutment sizes for cement-retained prostheses in order to perform the compressive test. The groups were divided by abutment diameter and transmucosal height as follows: Group 1: 4.5 x 2.5 mm; Group 2: 4.5 x 3.5 mm; Group 3: 3.3 x 2.5 mm; and Group 4: 3.3 x 3.5 mm. An oblique compressive loading test was performed on each sample located in a platform at 30° using a universal testing machine with a load cell of 1,000 kgf and 0.5 mm/min speed until achieving the deformation of abutment's neck. The compressive resistance and its mechanical behavior were recorded for each group and the data were analyzed using ANOVA, the Shapiro-Wilk and Scheffé tests. In addition, the detailed damage of all samples was recorded with a conventional camera linked to the endoscopic equipment. Significant differences were observed among the groups, except between Groups 2 and 3 (p>0.005). All the abutments showed permanent deformations in the upper region and at the transmucosal portion, but the threads of the screws were intact. Fractures were only identified in Groups 3 and 4. Stronger mechanical behavior and compressive resistance was observed in the abutments with 4.5 mm diameter and 2.5 mm transmucosal height.
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Affiliation(s)
- Ricardo Lillo
- Faculty of Dentistry, Universidad Mayor, Santiago, Chile
| | - Carlos Parra
- Faculty of Dentistry, Universidad Mayor, Santiago, Chile
| | - Ramón Fuentes
- Dental School, CIMOFIR Research Centre, Universidad de La Frontera, Temuco, Chile
| | - Eduardo Borie
- Dental School, CIMOFIR Research Centre, Universidad de La Frontera, Temuco, Chile
| | - Wilfried Engelke
- Department of Oral and Maxillofacial Surgery, University of Göttingen, Germany, Germany
| | - Víctor Beltrán
- Dental School, CIMOFIR Research Centre, Universidad de La Frontera, Temuco, Chile
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164
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The impact of luting agents and stiffness of implant-abutments on marginal adaptation, chipping, and fracture resistance of zirconia crowns. J Mech Behav Biomed Mater 2014; 39:279-91. [PMID: 25168974 DOI: 10.1016/j.jmbbm.2014.07.021] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2014] [Accepted: 07/21/2014] [Indexed: 11/20/2022]
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165
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Takaki P, Vieira M, Bommarito S. Maximum bite force analysis in different age groups. Int Arch Otorhinolaryngol 2014; 18:272-6. [PMID: 25992105 PMCID: PMC4297017 DOI: 10.1055/s-0034-1374647] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2013] [Accepted: 03/07/2014] [Indexed: 11/02/2022] Open
Abstract
Introduction Maximum bite force (MBF) is the maximum force performed by the subject on the fragmentation of food, directly related with the mastication and determined by many factors. Objective Analyze the MBF of subjects according to age groups. Methods One hundred individuals from the city of São Paulo were equally divided according to age groups and gender. Each individual submitted to a myotherapy evaluation composed of anthropometric measurements of height and weight to obtain body mass index (BMI), using a tape and a digital scale (Magna, G-life, São Paulo), and a dental condition and maximum bite force evaluation, using a digital dynamometer model DDK/M (Kratos, São Paulo, Brazil), on Newton scale. The dental and bite force evaluations were monitored by a professional from the area. Analysis of variance was used with MBF as a dependent variable, age group and gender as random factors, and BMI as a control variable. Results Till the end of adolescence, it was possible to observe a decrease in MBF in both sexes, with the male force greater than the female force. In young adults, the female force became greater the males, then decreased in adulthood. There was no correlation between MBF and BMI. Conclusion There are MBF variations that characterizes the human development stages, according to age groups.
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Affiliation(s)
- Patricia Takaki
- Speech Therapy Department, Universidade Federal de São Paulo, São Paulo, São Paulo, Brazil
| | - Marilena Vieira
- Speech Therapy Department, Universidade Federal de São Paulo, São Paulo, São Paulo, Brazil
| | - Silvana Bommarito
- Speech Therapy Department, Universidade Federal de São Paulo, São Paulo, São Paulo, Brazil
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166
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Stanford ND, Ip TB, Durham J. Adult orthodontic patients' views regarding dentofacial normality: A qualitative study. Am J Orthod Dentofacial Orthop 2014; 145:287-95. [DOI: 10.1016/j.ajodo.2013.11.016] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2013] [Revised: 11/01/2013] [Accepted: 11/01/2013] [Indexed: 10/25/2022]
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167
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Seydler B, Rues S, Müller D, Schmitter M. In vitro fracture load of monolithic lithium disilicate ceramic molar crowns with different wall thicknesses. Clin Oral Investig 2013; 18:1165-1171. [DOI: 10.1007/s00784-013-1062-8] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2012] [Accepted: 07/17/2013] [Indexed: 11/28/2022]
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168
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Preis V, Dowerk T, Behr M, Kolbeck C, Rosentritt M. Influence of cusp inclination and curvature on the in vitro failure and fracture resistance of veneered zirconia crowns. Clin Oral Investig 2013; 18:891-900. [DOI: 10.1007/s00784-013-1029-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2013] [Accepted: 06/27/2013] [Indexed: 11/28/2022]
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169
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Preis V, Letsch C, Handel G, Behr M, Schneider-Feyrer S, Rosentritt M. Influence of substructure design, veneer application technique, and firing regime on the in vitro performance of molar zirconia crowns. Dent Mater 2013; 29:e113-21. [PMID: 23726361 DOI: 10.1016/j.dental.2013.04.011] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2012] [Revised: 04/23/2013] [Accepted: 04/25/2013] [Indexed: 11/25/2022]
Abstract
OBJECTIVES The aim of this in vitro study was to evaluate the influence of substructure design, veneer application technique, and firing regime on the failure and fracture resistance of molar zirconia crowns. METHODS Six groups (n=8/group) of zirconia crowns were fabricated in simple core (SC) or anatomically reduced (AR) design, veneered with different feldspathic or glass ceramic materials, and defined according to the application technique and firing regime (LT: layering technique; LT_L: LT with long-term cooling; PT: press technique; DV: digital veneering technique). The following groups were investigated: SCLT, ARLT, SCLT_L, SCPT, ARPT, ARDV. Crowns were adhesively bonded to polymethylmethacrylate abutment teeth and subjected to thermal cycling (TC: 2×3000×5°/55°) and mechanical loading (ML: 1.2×10(6); 50N; 1.6Hz) in a chewing simulator with metal-ceramic molar crowns as antagonists. Failures were monitored and fracture resistance determined after aging. Data were statistically analyzed (one-way analysis of variance, ANOVA; post hoc Bonferroni, α=0.05). Crowns were subjected to scanning electron microscopy for fractographic failure analysis. RESULTS Failures (chipping, cracks) during TCML were observed in groups SCLT (2×), ARDV (2×) and SCLT_L (1×). Defect sizes varied between 3.5mm (SCLT: crack) and 30.0mm(2) (SCLT_L: chipping). Mean (SD) fracture forces ranged between 1529.0 (405.2)N for SCPT and 2372.3 (351.8)N for ARDV. SIGNIFICANCE The failure frequency of veneered zirconia crowns could be reduced by using anatomically reduced substructures, the press veneering technique, and an adapted cooling protocol. Fracture resistance increased with use of anatomically reduced substructures and the digital veneering technique.
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Affiliation(s)
- Verena Preis
- Department of Prosthetic Dentistry, University Medical Center Regensburg, 93042 Regensburg, Germany.
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170
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He T, Stavropoulos D, Hagberg C, Hakeberg M, Mohlin B. Effects of masticatory muscle training on maximum bite force and muscular endurance. Acta Odontol Scand 2013; 71:863-9. [PMID: 23157209 DOI: 10.3109/00016357.2012.734411] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
OBJECTIVE This study evaluates the effects of chewing training on strength and endurance of the masticatory muscles. MATERIALS AND METHODS Of the 49 healthy young adults included in the study, nine served as controls for a baseline measurement of bite force. The 40 participants who actively trained their masticatory muscles were randomly divided into a 'continuous training group' (CTG) and an 'intermittent training group' (ITG). The participants performed oral motor training by clenching silicon tubes (Chewy Tubes(™)) according to a designed protocol. The muscular strength was studied in terms of maximum bite force. Muscular endurance was evaluated by measuring the duration for which the participants held 50% of their maximum bite force value. RESULTS Both the maximum bite force and the muscular endurance capacity increased after intensive training for both groups. After 2 months, the ITG stopped training for 1 month. At this point, a significant difference was identified both in the mean bite force values and the mean muscular endurance duration: the ITG exhibited lower values. For both groups, the highest values were attained after 3 months of training. The maximum bite force values and the muscular endurance duration were observed to follow similar patterns. The effects attained decreased rapidly in both groups when the training stopped. CONCLUSIONS For both the continuous and intermittent training groups, 4 months of chewing exercises strengthened masticatory muscles, but such effects diminished gradually for both groups when the exercises stopped.
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Affiliation(s)
- Tailun He
- Department of Orthodontics, Institute of Odontology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
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Preis V, Behr M, Hahnel S, Handel G, Rosentritt M. In vitro failure and fracture resistance of veneered and full-contour zirconia restorations. J Dent 2012; 40:921-8. [DOI: 10.1016/j.jdent.2012.07.010] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2012] [Revised: 07/13/2012] [Accepted: 07/16/2012] [Indexed: 11/26/2022] Open
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172
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Iinuma T, Arai Y, Fukumoto M, Takayama M, Abe Y, Asakura K, Nishiwaki Y, Takebayashi T, Iwase T, Komiyama K, Gionhaku N, Hirose N. Maximum Occlusal Force and Physical Performance in the Oldest Old: The Tokyo Oldest Old Survey on Total Health. J Am Geriatr Soc 2011; 60:68-76. [DOI: 10.1111/j.1532-5415.2011.03780.x] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
| | - Yasumichi Arai
- Department of Internal Medicine; Division of Geriatric Medicine
| | | | | | - Yukiko Abe
- Department of Internal Medicine; Division of Geriatric Medicine
| | - Keiko Asakura
- Department of Preventive Medicine and Public Health; Keio University School of Medicine; Tokyo; Japan
| | - Yuji Nishiwaki
- Department of Preventive Medicine and Public Health; Keio University School of Medicine; Tokyo; Japan
| | - Toru Takebayashi
- Department of Preventive Medicine and Public Health; Keio University School of Medicine; Tokyo; Japan
| | - Takashi Iwase
- Department of Pathology; Nihon University School of Dentistry; Tokyo; Japan
| | - Kazuo Komiyama
- Department of Pathology; Nihon University School of Dentistry; Tokyo; Japan
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