1
|
Pampush JD, Morse PE, Kay RF. Dental sculpting and compensatory shearing crests demonstrated in a WEAR series of Presbytis rubicunda (Cercopithecoidea, Colobidae) with dental topography analysis. AMERICAN JOURNAL OF BIOLOGICAL ANTHROPOLOGY 2024; 185:e24953. [PMID: 38751320 DOI: 10.1002/ajpa.24953] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Revised: 03/28/2024] [Accepted: 04/29/2024] [Indexed: 08/15/2024]
Abstract
OBJECTIVES Maintaining effective and efficient occlusal morphology presents adaptive challenges for mammals, particularly because mastication produces interactions with foods and other materials that alters the geometry of occlusal surfaces through macrowear and/or catastrophic failure (i.e. "chipping"). Altered occlusal morphologies are often less effective for masticating materials of given diet-but not always-some species exhibit dental sculpting, meaning their dentitions are set up to harness macrowear to hone their occlusal surfaces into more effective morphologies (i.e. secondary morphologies). Here we show that dental sculpting is present in the folivorous Presbytis rubicunda of Borneo. METHODS Thirty-one undamaged lower second molars of P. rubicunda exhibiting various stages of macroscopic wear were micro-CT scanned and processed into digital surfaces. The surfaces were measured for convex Dirichlet normal energy (vDNE, a measure of surface sharpness), and degree of surface wear. Regression analyses compared surface sharpness with several measures of wear to test for the presence and magnitude of dental sculpting. RESULTS Positive correlations between the wear proxies and vDNE reveal that P. rubicunda wear in such a way as to become sharper, and therefore more effective chewing surfaces by exposing enamel-dentine junctions on their occlusal surfaces and then honing these junctions into sharpened edges. Compared to another primate folivore in which increasing surface sharpness with macrowear has been demonstrated (i.e., Alouatta palliata), the worn surfaces are similarly sharp, but the dental sculpting process appears to be different. DISCUSSION The results presented here suggest that not only do some primates exhibit dental sculpting and the attendant secondary morphology, but that there appear to be multiple different morphological configurations that can achieve this result. P. rubicunda has thicker enamel and a more stereotyped wear pattern than A. palliata, although both show positive correlations of occlusal surface sharpness (vDNE) with various wear proxies. These findings shed light on the varied approaches for the maintenance of effective and efficient occlusal surfaces in primates.
Collapse
Affiliation(s)
- James D Pampush
- Department of Health and Human Performance, High Point University, High Point, North Carolina, USA
- Department of Physician Assistant Studies, High Point University, High Point, North Carolina, USA
| | - Paul E Morse
- Department of Cell & Developmental Biology, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
- Florida Museum of Natural History, University of Florida, Gainesville, Florida, USA
| | - Richard F Kay
- Department of Evolutionary Anthropology, Duke University, Durham, North Carolina, USA
- Division of Earth and Climate Sciences, Nicholas School, Duke University, Durham, North Carolina, USA
| |
Collapse
|
2
|
Wall CE, Hanna JB, O'Neill MC, Toler M, Laird MF. Energetic costs of feeding in 12 species of small-bodied primates. Philos Trans R Soc Lond B Biol Sci 2023; 378:20220553. [PMID: 37839441 PMCID: PMC10577031 DOI: 10.1098/rstb.2022.0553] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Accepted: 06/25/2023] [Indexed: 10/17/2023] Open
Abstract
There are no comparative, empirical studies of the energetic costs of feeding in mammals. As a result, we lack physiological data to better understand the selection pressures on the mammalian feeding apparatus and the influence of variables such as food geometric and material properties. This study investigates interspecific scaling of the net energetic costs of feeding in relation to body size, jaw-adductor muscle mass and food properties in a sample of 12 non-human primate species ranging in size from 0.08 to 4.2 kg. Net energetic costs during feeding were measured by indirect calorimetry for a variety of pre-cut and whole raw foods varying in geometric and material properties. Net feeding costs were determined in two ways: by subtracting either the initial metabolic rate prior to feeding or subtracting the postprandial metabolic rate. Interspecific scaling relationships were evaluated using pGLS and OLS regression. Net feeding costs scale negatively relative to both body mass and jaw-adductor mass. Large animals incur relatively lower feeding costs indicating that small and large animals experience and solve mechanical challenges in relation to energetics in different ways. This article is part of the theme issue 'Food processing and nutritional assimilation in animals'.
Collapse
Affiliation(s)
- Christine E. Wall
- Department of Evolutionary Anthropology, Duke University, Durham, NC 27708, USA
- Department of Anatomy, College of Osteopathic Medicine, New York Institute of Technology, New York Institute of Technology, Old Westbury, NY 11568, USA
- Duke Lemur Center, Duke University, Durham, NC 27705, USA
| | - Jandy B. Hanna
- Duke Lemur Center, Duke University, Durham, NC 27705, USA
| | | | - Maxx Toler
- Jerry M. Wallace School of Osteopathic Medicine, Campbell University, Buies Creek, NC 27506, USA
| | - Myra F. Laird
- Department of Basic and Translational Sciences, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| |
Collapse
|
3
|
Laird MF, Iriarte-Diaz J, Byron CD, Granatosky MC, Taylor AB, Ross CF. Gape drives regional variation in temporalis architectural dynamics in tufted capuchins. Philos Trans R Soc Lond B Biol Sci 2023; 378:20220550. [PMID: 37839440 PMCID: PMC10577035 DOI: 10.1098/rstb.2022.0550] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Accepted: 06/10/2023] [Indexed: 10/17/2023] Open
Abstract
Dynamic changes in jaw movements and bite forces depend on muscle architectural and neural factors that have rarely been compared within the same muscle. Here we investigate how regional muscle architecture dynamics-fascicle rotation, shortening, lengthening and architectural gear ratio (AGR)-vary during chewing across a functionally heterogeneous muscle. We evaluate whether timing in architecture dynamics relates to gape, food material properties and/or muscle activation. We also examine whether static estimates of temporalis fibre architecture track variation in dynamic architecture. Fascicle-level architecture dynamics were measured in three regions of the superficial temporalis of three adult tufted capuchins (Sapajus apella) using biplanar videoradiography and the XROMM workflow. Architecture dynamics data were paired with regional fine-wire electromyography data from four adult tufted capuchins. Gape accounted for most architectural change across the temporalis, but architectural dynamics varied between regions. Mechanically challenging foods were associated with lower AGRs in the anterior region. The timing of most dynamic architectural changes did not vary between regions and differed from regional variation in static architecture. Collectively these findings suggest that, when modelling temporalis muscle force production in extant and fossil primates, it is important to account for the effects of gape, regionalization and food material properties. This article is part of the theme issue 'Food processing and nutritional assimilation in animals'.
Collapse
Affiliation(s)
- Myra F. Laird
- Department of Basic and Translational Sciences, University of Pennsylvania, Levy 443, 4010 Locust Street, Philadelphia, PA 19104, USA
| | - Jose Iriarte-Diaz
- Department of Biology, University of the South, Sewanee, TN 37383-1000, USA
| | - Craig D. Byron
- Department of Biology, Mercer University, Macon, GA 312014, USA
| | - Michael C. Granatosky
- Department of Anatomy, New York Institute of Technology, Old Westbury, NY 11545, USA
| | - Andrea B. Taylor
- Department of Foundational Biomedical Sciences, Touro University, Vallejo, CA 94592, USA
| | - Callum F. Ross
- Department of Organismal Biology and Anatomy, University of Chicago, Chicago, IL 60637, USA
| |
Collapse
|
4
|
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] [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.
Collapse
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
| |
Collapse
|
5
|
Fiorenza L, Harty T, Janocha MM, Kullmer O, Nguyen HN, Bortolini E, Benazzi S. Understanding dietary ecology in great apes from dental macrowear analysis. AMERICAN JOURNAL OF BIOLOGICAL ANTHROPOLOGY 2022. [PMCID: PMC9544277 DOI: 10.1002/ajpa.24533] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Objectives Dietary diversity in primates is reflected in their dental morphology, with differences in size and shape of teeth. The objective of this study is to investigate the relationship between molar morphology and macrowear patterns in Pongo, Gorilla, and Pan to obtain dietary information. Methods We have examined 68 second lower molars using the Occlusal Fingerprint Analysis method including 18 chimpanzees, 28 gorillas, and 22 orangutans. We selected only molars from wildshot specimens characterized by a moderate degree of wear. High‐resolution digital models of teeth were created using a white scanning light system with a resolution of 45 μm. Results The macrowear patterns of Pan were significantly different from those of Gorilla and of Pongo, differences that are mostly due to shearing wear. Gorilla and Pongo macrowear patterns are dominated by phase II areas, followed by lingual phase I facets, while in Pan we observe a significant increase in buccal phase I facets. The latter group also displays the highest macrowear variation across the sample examined in this study. Conclusions The molar macrowear patterns of the great apes analyzed in this study did not confirm our initial hypothesis of finding larger crushing and grinding areas in Pongo and more shearing wear in Gorilla. Pan shows the most variable macrowear, which is probably associated with their more flexible diet. The similarity between Pongo and Gorilla macrowear patterns may be due to a larger intake of mechanically challenging foods that could obfuscate dietary wear signals generated by softer foods.
Collapse
Affiliation(s)
- Luca Fiorenza
- Biomedicine Discovery Institute, Department of Anatomy and Developmental Biology Monash University Melbourne Victoria Australia
| | - Teagan Harty
- Biomedicine Discovery Institute, Department of Anatomy and Developmental Biology Monash University Melbourne Victoria Australia
| | - Marcel M. Janocha
- Division of Palaeoanthropology Senckenberg Research Institute and Natural History Museum Frankfurt Frankfurt am Main Germany
- Department of Palaeobiology and Environment, Institute of Ecology Evolution, and Diversity, Goethe University Frankfurt Germany
| | - Ottmar Kullmer
- Division of Palaeoanthropology Senckenberg Research Institute and Natural History Museum Frankfurt Frankfurt am Main Germany
- Department of Palaeobiology and Environment, Institute of Ecology Evolution, and Diversity, Goethe University Frankfurt Germany
| | - Huynh N. Nguyen
- School of Mechanical Engineering Hanoi University of Science and Technology Hanoi Vietnam
| | - Eugenio Bortolini
- Department of Archaeology and Anthropology, Institución Milá y Fontanals de investigación en Humanidades Consejo Superior de Investigaciones Científicas (IMF – CSIC) Barcelona Spain
- Culture and Socio‐Ecological Dynamics, Department of Humanities Universitat Pompeu Fabra Barcelona Spain
| | - Stefano Benazzi
- Department of Cultural Heritage University of Bologna Ravenna Italy
- Department of Human Evolution Max Planck Institute for Evolutionary Anthropology Leipzig Germany
| |
Collapse
|
6
|
Sign-oriented Dirichlet Normal Energy: Aligning Dental Topography and Dental Function in the R-package molaR. J MAMM EVOL 2022. [DOI: 10.1007/s10914-022-09616-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
7
|
Harty T, Berthaume MA, Bortolini E, Evans AR, Galbany J, Guy F, Kullmer O, Lazzari V, Romero A, Fiorenza L. Dental macrowear reveals ecological diversity of Gorilla spp. Sci Rep 2022; 12:9203. [PMID: 35655071 PMCID: PMC9163330 DOI: 10.1038/s41598-022-12488-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Accepted: 05/10/2022] [Indexed: 11/11/2022] Open
Abstract
Size and shape variation of molar crowns in primates plays an important role in understanding how species adapted to their environment. Gorillas are commonly considered to be folivorous primates because they possess sharp cusped molars which are adapted to process fibrous leafy foods. However, the proportion of fruit in their diet can vary significantly depending on their habitats. While tooth morphology can tell us what a tooth is capable of processing, tooth wear can help us to understand how teeth have been used during mastication. The objective of this study is to explore if differences in diet at the subspecies level can be detected by the analysis of molar macrowear. We analysed a large sample of second lower molars of Grauer’s, mountain and western lowland gorilla by combining the Occlusal Fingerprint Analysis method with other dental measurements. We found that Grauer’s and western lowland gorillas are characterised by a macrowear pattern indicating a larger intake of fruit in their diet, while mountain gorilla’s macrowear is associated with the consumption of more folivorous foods. We also found that the consumption of herbaceous foods is generally associated with an increase in dentine and enamel wear, confirming the results of previous studies.
Collapse
Affiliation(s)
- Teagan Harty
- Biomedicine Discovery Institute, Department of Anatomy and Developmental Biology, Monash University, Melbourne, VIC, Australia
| | - Michael A Berthaume
- Division Mechanical Engineering and Design, London South Bank University, London, UK
| | - Eugenio Bortolini
- Department of Archaeology and Anthropology, Institución Milá y Fontanals de Investigación en Humanidades, Barcelona, Spain.,Culture and Socio-Ecological Dynamics, Department of Humanities, Universitat Pompeu Fabra Ramon Trias Fargas, Barcelona, Spain
| | - Alistair R Evans
- School of Biological Sciences, Monash University, Melbourne, VIC, Australia.,Geosciences, Museums Victoria, Melbourne, VIC, Australia
| | - Jordi Galbany
- Department of Anthropology, Center for the Advanced Study of Human Paleobiology, The George Washington University, Washington, DC, USA.,Department of Clinical Psychology and Psychobiology, University of Barcelona, Barcelona, Spain
| | - Franck Guy
- Laboratory PALEVOPRIM, UMR CNRS 7262, University of Poitiers, Poitiers, France
| | - Ottmar Kullmer
- Department of Paleoanthropology, Senckenberg Research Institute and Natural History Museum Frankfurt, Frankfurt, Germany.,Department of Paleobiology and Environment, Institute of Ecology, Evolution, and Diversity, Goethe University, Frankfurt, Germany
| | - Vincent Lazzari
- Laboratory PALEVOPRIM, UMR CNRS 7262, University of Poitiers, Poitiers, France
| | - Alejandro Romero
- Departamento de Biotecnología, Universidad de Alicante, 03690, Alicante, Spain.,Instituto Universitario de Investigación en Arqueología y Patrimonio Histórico (INAPH), Universidad de Alicante, 03690, Alicante, Spain
| | - Luca Fiorenza
- Biomedicine Discovery Institute, Department of Anatomy and Developmental Biology, Monash University, Melbourne, VIC, Australia.
| |
Collapse
|
8
|
Silvester CM, Kullmer O, Hillson S. A dental revolution: The association between occlusion and chewing behaviour. PLoS One 2021; 16:e0261404. [PMID: 34910787 PMCID: PMC8673603 DOI: 10.1371/journal.pone.0261404] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Accepted: 12/01/2021] [Indexed: 11/19/2022] Open
Abstract
Dentistry is confronted with the functional and aesthetic consequences that result from an increased prevalence of misaligned and discrepant dental occlusal relations in modern industrialised societies. Previous studies have indicated that a reduction in jaw size in response to softer and more heavily processed foods during and following the Industrial Revolution (1,700 CE to present) was an important factor in increased levels of poor dental occlusion. The functional demands placed on the masticatory system play a crucial role in jaw ontogenetic development; however, the way in which chewing behaviours changed in response to the consumption of softer foods during this period remains poorly understood. Here we show that eating more heavily processed food has radically transformed occlusal power stroke kinematics. Results of virtual 3D analysis of the dental macrowear patterns of molars in 104 individuals dating to the Industrial Revolution (1,700-1,900 CE), and 130 of their medieval and early post-medieval antecedents (1,100-1,700 CE) revealed changes in masticatory behaviour that occurred during the early stages of the transition towards eating more heavily processed foods. The industrial-era groups examined chewed with a reduced transverse component of jaw movement. These results show a diminished sequence of occlusal contacts indicating that a dental revolution has taken place in modern times, involving a dramatic shift in the way in which teeth occlude and wear during mastication. Molar macrowear suggests a close connection between progressive changes in chewing since the industrialization of food production and an increase in the prevalence of poor dental occlusion in modern societies.
Collapse
Affiliation(s)
| | - Ottmar Kullmer
- Department of Paleoanthropology, Senckenberg Research Institute and Natural History Museum Frankfurt, Frankfurt, Germany
- Department of Palaeobiology and Environment, Institute of Ecology, Evolution, and Diversity, Johann Wolfgang Goethe University, Frankfurt, Germany
| | - Simon Hillson
- Institute of Archaeology, University College London, London, United Kingdom
| |
Collapse
|
9
|
Ustriyana P, He R, Srirangapatanam S, Chang J, Arman ST, Sidhu S, Wang B, Kang M, Ho SP. Food hardness can regulate orthodontic tooth movement in mice. J Periodontal Res 2021; 57:269-283. [PMID: 34894155 DOI: 10.1111/jre.12945] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Revised: 09/06/2021] [Accepted: 10/13/2021] [Indexed: 01/28/2023]
Abstract
BACKGROUND AND OBJECTIVES Orthodontic treatment is often accompanied with prescription of softer foods to patients. The question to ask is, is this prescribed load regimen congruent with Wolff's law, and does it provide an adequate mechanical stimulus to maintain the functional health of periodontal complex? This question was answered by studying the effects of mice chewing on soft food (SF) and hard food (HF) while undergoing experimental tooth movement (ETM). METHODS Three-week-old C57BL/6 mice (n = 18) were fed either hard pellet (HF; n = 9) or soft-chow food (SF; n = 9). ETM was performed on mice at 8 weeks of age, and mice were euthanized at 1 min, 2 weeks, and 4 weeks (8, 10, and 12 weeks old, respectively). A logistic regression model was applied to the experimental data to extrapolate the prolonged effects of ETM on the physical features of the dentoalveolar joint (DAJ). RESULTS By 12 weeks, mice that chewed on SF expressed wider periodontal ligament space than those that chewed on HF. Mice that chewed on SF demonstrated increased alveolar socket roughness with larger alveoli and decreased bone volume fraction but with significantly lower bone mineral density and reduced overall tooth movement. CONCLUSIONS These altered physical features when contextualized within the DAJ illustrated that (a) the regions farther away from the "site of insult" also undergo significant adaptation, and (b) these adaptations vary between mesial and distal sides of the periodontal complex and topographically differentiate in the direction of the ETM. These insights underpin the main conclusion, in that there is a need to "regulate chewing loads" as a therapeutic dose following ETM to encourage regeneration of periodontal complex as an effective clinical outcome. The discussed multiscale image analyses also can be used on patient cone beam computed tomography data to identify the effectiveness of orthodontic treatment within the realm of masticatory function.
Collapse
Affiliation(s)
- Putu Ustriyana
- Division of Preclinical Education, Biomaterials & Engineering, Department of Preventive and Restorative Dental Sciences, University of California, San Francisco, California, USA
| | - Rui He
- Hangzhou Normal University, Yuhang District, China
| | - Sudarshan Srirangapatanam
- Division of Preclinical Education, Biomaterials & Engineering, Department of Preventive and Restorative Dental Sciences, University of California, San Francisco, California, USA.,Department of Urology, University of California, San Francisco, California, USA
| | - Jasper Chang
- Division of Preclinical Education, Biomaterials & Engineering, Department of Preventive and Restorative Dental Sciences, University of California, San Francisco, California, USA
| | - Sheeler T Arman
- Division of Preclinical Education, Biomaterials & Engineering, Department of Preventive and Restorative Dental Sciences, University of California, San Francisco, California, USA
| | - Sukhmandeep Sidhu
- Division of Preclinical Education, Biomaterials & Engineering, Department of Preventive and Restorative Dental Sciences, University of California, San Francisco, California, USA
| | - Bo Wang
- Division of Preclinical Education, Biomaterials & Engineering, Department of Preventive and Restorative Dental Sciences, University of California, San Francisco, California, USA
| | - Misun Kang
- Division of Preclinical Education, Biomaterials & Engineering, Department of Preventive and Restorative Dental Sciences, University of California, San Francisco, California, USA
| | - Sunita P Ho
- Division of Preclinical Education, Biomaterials & Engineering, Department of Preventive and Restorative Dental Sciences, University of California, San Francisco, California, USA.,Department of Urology, University of California, San Francisco, California, USA
| |
Collapse
|
10
|
Chipping and wear patterns in extant primate and fossil hominin molars: 'Functional' cusps are associated with extensive wear but low levels of fracture. J Hum Evol 2020; 151:102923. [PMID: 33360110 DOI: 10.1016/j.jhevol.2020.102923] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 11/22/2020] [Accepted: 11/23/2020] [Indexed: 01/01/2023]
|
11
|
The reciprocal jaw-muscle reflexes elicited by anterior- and back-tooth-contacts-a perspective to explain the control of the masticatory muscles. BDJ Open 2020; 6:27. [PMID: 33335091 PMCID: PMC7746706 DOI: 10.1038/s41405-020-00056-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 11/11/2020] [Accepted: 11/16/2020] [Indexed: 11/09/2022] Open
Abstract
AIMS Tooth-contact sensations are considered essential to boost jaw adductor muscles during mastication. However, no previous studies have explained the importance of the inhibitory reflex of human anterior-tooth (ANT)-contacts in mastication. Here I present the "reciprocal reflex-control-hypothesis" of mammalian mastication. SUBJECTS AND SETTING OF THE STUDY I demonstrate the hypothesis with the live kinematics of free jaw-closures as inferred from T-Scan recordings of dental patients. RESULTS The jaw-closures started with negligible force, predominantly with ANT-contacts (the AF-bites). The first ANT-contact inhibited the first kinematic tilt of the mandible, whereas the bites starting from a back-tooth (BAT)-contact (the BF-bites) accelerated the first tilt. The second tilt established a low-force static tripod of the ANT- and bilateral BAT-contacts for a fixed mandible-maxilla relation. Thereafter, semi-static bite force increased rapidly, relatively more in the BAT-area. DISCUSSION AND CONCLUSIONS In the vertical-closure phase of chewing, the primate joint-fulcrum (class 3 lever) conflicts with the food-bolus-fulcrum in the BAT-area (class 1 lever). The resilient class 3 and 1 lever systems are superseded by an almost static mechanically more advantageous class 2 lever with a more rigid fulcrum at the most anterior ANT-contact. For humans, the class 2 levered delivery of force also enables forceful horizontal food grinding to be extended widely to the BAT-area.
Collapse
|
12
|
Knigge RP, Vinyard CJ, McNulty KP. Mandibular symphyseal fusion in fossil primates: Insights from correlated patterns of jaw shape and masticatory function in living primates. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2020; 173:322-336. [PMID: 32167167 DOI: 10.1002/ajpa.24048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 01/27/2020] [Accepted: 02/24/2020] [Indexed: 11/06/2022]
Abstract
OBJECTIVES Variation in primate masticatory form and function has been extensively researched through both morphological and experimental studies. As a result, symphyseal fusion in different primate clades has been linked to either the recruitment of vertically directed balancing-side muscle force, the timing and recruitment of transversely directed forces, or both. This study investigates the relationship between jaw muscle activity patterns and morphology in extant primates to make inferences about masticatory function in extinct primates, with implications for understanding the evolution of symphyseal fusion. MATERIALS AND METHODS Three-dimensional mandibular landmark data were collected for 31 extant primates and nine fossil anthropoids and subfossil lemur species. Published electromyography (EMG) data were available for nine of the extant primate species. Partial least squares analysis and phylogenetic partial least squares analysis were used to identify relationships between EMG and jaw shape data and evaluate variation in jaw morphology. RESULTS Primates with partial and complete symphyseal fusion exhibit shape-function patterns associated with the wishboning motor pattern and loading regime, in contrast to shape-function patterns of primates with unfused jaws. All fossil primates examined (except Apidium) exhibit jaw morphologies suggestive of the wishboning motor pattern demonstrated in living anthropoids and indriids. DISCUSSION Partial fusion in Catopithecus, similar to indriids and some subfossil lemurs, may be sufficient to resist, or transfer, some amounts of transversely directed balancing-side muscle force at the symphysis, representing a transition to greater reliance on transverse jaw movement during mastication. Furthermore, possible functional convergences in physiological patterns during chewing (i.e., Archaeolemur) are identified.
Collapse
Affiliation(s)
- Ryan P Knigge
- Evolutionary Anthropology Lab, Department of Anthropology, University of Minnesota, Minneapolis, Minnesota.,Department of Pathology and Anatomical Sciences, University of Missouri, Columbia, Missouri.,Department of Orthopaedic Surgery, University of Missouri, Columbia, Missouri
| | - Christopher J Vinyard
- Department of Anatomy and Neurobiology, Northeast Ohio Medical University, Rootstown, Ohio
| | - Kieran P McNulty
- Evolutionary Anthropology Lab, Department of Anthropology, University of Minnesota, Minneapolis, Minnesota
| |
Collapse
|
13
|
Hartstone‐Rose A, Hertzig I, Dickinson E. Bite Force and Masticatory Muscle Architecture Adaptations in the Dietarily Diverse Musteloidea (Carnivora). Anat Rec (Hoboken) 2019; 302:2287-2299. [DOI: 10.1002/ar.24233] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Revised: 07/03/2019] [Accepted: 07/03/2019] [Indexed: 01/09/2023]
Affiliation(s)
- Adam Hartstone‐Rose
- Department of Biological Sciences North Carolina State University Raleigh North Carolina
| | - Isabella Hertzig
- Department of Biological Sciences North Carolina State University Raleigh North Carolina
| | - Edwin Dickinson
- Department of Biological Sciences North Carolina State University Raleigh North Carolina
| |
Collapse
|
14
|
The Masticatory Apparatus of Humans (Homo sapiens): Evolution and Comparative Functional Morphology. ACTA ACUST UNITED AC 2019. [DOI: 10.1007/978-3-030-13739-7_21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/03/2023]
|
15
|
Ungar P. Inference of Diets of Early Hominins from Primate Molar Form and Microwear. J Dent Res 2019; 98:398-405. [DOI: 10.1177/0022034518822981] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Paleontologists use fossil teeth to reconstruct the diets of early hominins and other extinct species. Some evidence is adaptive: nature selects for tooth size, shape, and structure best suited to specific food types. Other evidence includes traces left by actual foods eaten, such as microscopic tooth wear. This critical review considers how molars work, how they are used, and how occlusal topography and dental microwear can be used to infer diet and food preferences in the past, particularly for hominins of the Pliocene and early Pleistocene. Understanding that cheek teeth function as guides for chewing and tools for fracturing allows us to characterize aspects of occlusal form that reflect mechanical properties of foods to which a species is adapted. Living primates that often eat leaves, for example, have longer crests and more sloping occlusal surfaces than those that prefer hard foods. Studies of feeding ecology have shown, however, that tooth shape does not always correspond to preferred food items. It often follows mechanically challenging foods whether eaten often or rarely. Other lines of evidence that reflect actual tooth use are required to work out food preferences. Microwear textures, for example, reflect foods eaten by individuals in the past such that hard seeds and bone tend to leave complex, pitted surface textures, whereas tough leaves and meat more often leave anisotropic ones covered in long, parallel scratches. The study of fossil hominin molars shows how these various attributes are combined to infer diet and food preference in the past. A trend in occlusal morphology suggests decreased dietary specialization from Australopithecus to early Homo, and increasing dispersion in microwear complexity values is consistent with this. On the other hand, occlusal morphology may suggest dietary specialization in Paranthropus, although different species of this genus have different microwear texture patterns despite similar craniodental adaptations.
Collapse
Affiliation(s)
- P.S. Ungar
- Department of Anthropology, University of Arkansas, Fayetteville, AR, USA
| |
Collapse
|
16
|
Davis JS, Williams SH. The influence of diet on masticatory motor patterns in musteloid carnivorans: An analysis of jaw adductor activity in ferrets (Mustela putorius furo) and kinkajous (Potos flavus). JOURNAL OF EXPERIMENTAL ZOOLOGY PART 2018; 327:551-561. [PMID: 29441707 DOI: 10.1002/jez.2141] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2017] [Accepted: 12/29/2017] [Indexed: 11/06/2022]
Abstract
Broad similarities in the timing of jaw adductor activity driving jaw movements across distantly related and morphologically disparate species have led to the hypothesis that mammalian masticatory motor patterns are conserved. However, some quantitative analyses also suggest that masticatory motor patterns have evolved in concert with dietary and/or morphological specialization. Here, we assess this relationship in two closely related carnivoran species with divergent diets and morphology: carnivorous ferrets and frugivorous kinkajous. Using electromyography to characterize jaw adductor activity during rhythmic mastication, we test the hypotheses that (1) carnivoran masticatory motor patterns differ from those of non-carnivorans based on previously published data, and (2) differences between ferret and kinkajou motor patterns are associated with dietary and morphological differences. We find that both species exhibit highly synchronous jaw adductor activity that is likely typical of most carnivorans. Kinkajous differ from ferrets, however, in having a balancing-side zygomaticomandibularis that is active later than all other adductors. The significance of these different masticatory motor patterns may relate to morphological differences in the dentition of ferrets and kinkajous. Whereas ferret cheek teeth have vertical occlusal surfaces that limit jaw closing to a primarily dorsally directed movement, kinkajous have relatively flat occlusal surfaces that allow more transverse movement, which may be essential for processing fruits. Our results suggest that some aspects of masticatory motor patterns are highly conserved yet some components are modified in concert with functional and morphological evolution of the masticatory apparatus.
Collapse
Affiliation(s)
- Jillian S Davis
- Department of Biological Sciences, Ohio University, Athens, Ohio.,Exercise Science Department, High Point University, High Point, North Carolina
| | - Susan H Williams
- Department of Biomedical Sciences, Ohio University Heritage College of Osteopathic Medicine, Athens, Ohio
| |
Collapse
|
17
|
Perry JMG. Inferring the Diets of Extinct Giant Lemurs from Osteological Correlates of Muscle Dimensions. Anat Rec (Hoboken) 2018; 301:343-362. [DOI: 10.1002/ar.23719] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Revised: 08/01/2017] [Accepted: 08/24/2017] [Indexed: 11/08/2022]
Affiliation(s)
- Jonathan M. G. Perry
- Center for Functional Anatomy and Evolution; The Johns Hopkins University School of Medicine; Baltimore Maryland
| |
Collapse
|
18
|
Expression of MyHC isoforms mRNA transcripts in different regions of the masseter and medial pterygoid muscles in chimpanzees. Arch Oral Biol 2017; 83:63-67. [DOI: 10.1016/j.archoralbio.2017.07.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Revised: 06/27/2017] [Accepted: 07/06/2017] [Indexed: 11/22/2022]
|
19
|
Animal Models for Dysphagia Studies: What Have We Learnt So Far. Dysphagia 2017; 32:73-77. [PMID: 28132098 DOI: 10.1007/s00455-016-9778-7] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Accepted: 12/30/2016] [Indexed: 10/20/2022]
Abstract
Research using animal models has contributed significantly to realizing the goal of understanding dysfunction and improving the care of patients who suffer from dysphagia. But why should other researchers and the clinicians who see patients day in and day out care about this work? Results from studies of animal models have the potential to change and grow how we think about dysphagia research and practice in general, well beyond applying specific results to human studies. Animal research provides two key contributions to our understanding of dysphagia. The first is a more complete characterization of the physiology of both normal and pathological swallow than is possible in human subjects. The second is suggesting of specific, physiological, targets for development and testing of treatment interventions to improve dysphagia outcomes.
Collapse
|
20
|
Edmonds H. Zygomatic Arch Cortical Area and Diet in Haplorhines. Anat Rec (Hoboken) 2016; 299:1789-1800. [DOI: 10.1002/ar.23478] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Revised: 08/18/2016] [Accepted: 08/22/2016] [Indexed: 11/11/2022]
Affiliation(s)
- Hallie Edmonds
- Institute of Human Origins, School of Human Evolution and Social Change, Arizona State University; Arizona
| |
Collapse
|
21
|
Laird MF, Vogel ER, Pontzer H. Chewing efficiency and occlusal functional morphology in modern humans. J Hum Evol 2016; 93:1-11. [PMID: 27086052 DOI: 10.1016/j.jhevol.2015.11.005] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2015] [Revised: 11/18/2015] [Accepted: 11/19/2015] [Indexed: 10/22/2022]
Abstract
The reduction of occlusal dimensions in early Homo is often proposed to be a functional adaptation to diet. With their smaller occlusal surfaces, species of early Homo are suggested to have reduced food-processing abilities, particularly for foods with high material properties (e.g., increased toughness). Here, we employ chewing efficiency as a measure of masticatory performance to test the relationships between masticatory function and food properties. We predicted that humans are more efficient when processing foods of lower toughness and Young's modulus values, and that subjects with larger occlusal surfaces will be less efficient when processing foods with higher toughness and Young's modulus, as the greater area spreads out the overall bite force applied to food particles. Chewing efficiency was measured in 26 adults using high-speed motion capture and surface electromyography. The dentition of each subject was cast and the occlusal surface was quantified using dental topographic analysis. Toughness and displacement-limited index were negatively correlated with chewing efficiency, but Young's modulus was not. Increased occlusal two-dimensional area and surface area were positively correlated with chewing efficiency for all foods. Thus, larger occlusal surface areas were more efficient when processing foods of greater toughness. These results suggest that the reduction in occlusal area in early Homo was associated with a reduction in chewing efficiency, particularly for foods with greater toughness. Further, the larger occlusal surfaces of earlier hominins such as Australopithecus would have likely increased chewing efficiency and increased the probability of fracture when processing tough foods.
Collapse
Affiliation(s)
- Myra F Laird
- Department of Anthropology, New York University, New York, NY, USA; New York Consortium of Evolutionary Primatology, New York, NY, USA.
| | - Erin R Vogel
- Department of Anthropology and the Center for Human Evolutionary Studies, Rutgers University, New Brunswick, NJ, USA
| | - Herman Pontzer
- New York Consortium of Evolutionary Primatology, New York, NY, USA; Department of Anthropology, Hunter College, New York, NY, USA
| |
Collapse
|
22
|
|
23
|
Terhune CE, Cooke SB, Otárola-Castillo E. Form and Function in the Platyrrhine Skull: A Three-Dimensional Analysis of Dental and TMJ Morphology. Anat Rec (Hoboken) 2014; 298:29-47. [DOI: 10.1002/ar.23062] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2014] [Accepted: 10/11/2014] [Indexed: 11/11/2022]
Affiliation(s)
- Claire E. Terhune
- Department of Anthropology; University of Arkansas; Fayetteville Arkansas
| | - Siobhán B. Cooke
- Department of Anthropology; Northeastern Illinois University; Chicago Illinois
- New York Consortium in Evolutionary Primatology Morphometrics Group; New York New York
| | - Erik Otárola-Castillo
- Department of Ecology, Evolution, and Organismal Biology; Iowa State University; Ames Iowa
- Department of Human Evolutionary Biology; Harvard University; Cambridge Massachusetts
| |
Collapse
|
24
|
Schultz JA, Martin T. Function of pretribosphenic and tribosphenic mammalian molars inferred from 3D animation. Naturwissenschaften 2014; 101:771-81. [PMID: 25091547 DOI: 10.1007/s00114-014-1214-y] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2014] [Revised: 07/11/2014] [Accepted: 07/17/2014] [Indexed: 12/01/2022]
Abstract
Appearance of the tribosphenic molar in the Late Jurassic (160 Ma) is a crucial innovation for food processing in mammalian evolution. This molar type is characterized by a protocone, a talonid basin and a two-phased chewing cycle, all of which are apomorphic. In this functional study on the teeth of Late Jurassic Dryolestes leiriensis and the living marsupial Monodelphis domestica, we demonstrate that pretribosphenic and tribosphenic molars show fundamental differences of food reduction strategies, representing a shift in dental function during the transition of tribosphenic mammals. By using the Occlusal Fingerprint Analyser (OFA), we simulated the chewing motions of the pretribosphenic Dryolestes that represents an evolutionary precursor condition to such tribosphenic mammals as Monodelphis. Animation of chewing path and detection of collisional contacts between virtual models of teeth suggests that Dryolestes differs from the classical two-phased chewing movement of tribosphenidans, due to the narrowing of the interdental space in cervical (crown-root transition) direction, the inclination angle of the hypoflexid groove, and the unicuspid talonid. The pretribosphenic chewing cycle is equivalent to phase I of the tribosphenic chewing cycle, but the former lacks phase II of the tribosphenic chewing. The new approach can analyze the chewing cycle of the jaw by using polygonal 3D models of tooth surfaces, in a way that is complementary to the electromyography and strain gauge studies of muscle function of living animals. The technique allows alignment and scaling of isolated fossil teeth and utilizes the wear facet orientation and striation of the teeth to reconstruct the chewing path of extinct mammals.
Collapse
Affiliation(s)
- Julia A Schultz
- Steinmann-Institut für Geologie, Mineralogie und Paläontologie, Rheinische Friedrich-Wilhelms-Universität Bonn, Bonn, Germany,
| | | |
Collapse
|
25
|
Terhune CE. How Effective Are Geometric Morphometric Techniques for Assessing Functional Shape Variation? An Example From the Great Ape Temporomandibular Joint. Anat Rec (Hoboken) 2013; 296:1264-82. [DOI: 10.1002/ar.22724] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2013] [Accepted: 04/28/2013] [Indexed: 11/10/2022]
Affiliation(s)
- Claire E. Terhune
- Department of Community and Family Medicine; Duke University Medical Center; Durham North Carolina
| |
Collapse
|
26
|
New Neanderthal remains from Mani peninsula, Southern Greece: The Kalamakia Middle Paleolithic cave site. J Hum Evol 2013; 64:486-99. [DOI: 10.1016/j.jhevol.2013.02.002] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2012] [Revised: 11/02/2012] [Accepted: 02/01/2013] [Indexed: 11/23/2022]
|
27
|
Dental arch restoration using tooth macrowear patterns with application to Rudapithecus hungaricus, from the late Miocene of Rudabánya, Hungary. J Hum Evol 2013; 64:151-60. [DOI: 10.1016/j.jhevol.2012.10.009] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2012] [Revised: 08/30/2012] [Accepted: 10/15/2012] [Indexed: 11/17/2022]
|
28
|
Dietary correlates of temporomandibular joint morphology in the great apes. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2012; 150:260-72. [DOI: 10.1002/ajpa.22204] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2012] [Accepted: 11/09/2012] [Indexed: 11/07/2022]
|
29
|
Wall CE, Briggs MM, Huq E, Hylander WL, Schachat F. Regional variation in IIM myosin heavy chain expression in the temporalis muscle of female and male baboons (Papio anubis). Arch Oral Biol 2012; 58:435-43. [PMID: 23102552 DOI: 10.1016/j.archoralbio.2012.09.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2012] [Revised: 07/30/2012] [Accepted: 09/20/2012] [Indexed: 11/17/2022]
Abstract
OBJECTIVE The purpose of this study was to determine whether high amounts of fast/type II myosin heavy chain (MyHC) in the superficial as compared to the deep temporalis muscle of adult female and male baboons (Papio anubis) correlates with published data on muscle function during chewing. Electromyographic (EMG) data show a regional specialization in activation from low to high amplitude activity during hard/tough object chewing cycles in the baboon superficial temporalis.(48,49) A positive correlation between fast/type II MyHC amount and EMG activity will support the high occlusal force hypothesis. DESIGN Deep anterior temporalis (DAT), superficial anterior temporalis (SAT), and superficial posterior temporalis (SPT) muscle samples were analyzed using SDS-PAGE gel electrophoresis to test the prediction that SAT and SPT will show high amounts of fast/type II MyHC compared to DAT. Serial muscle sections were incubated against NOQ7.5.4D and MY32 antibodies to determine the breadth of slow/type I versus fast/type II expression within each section. RESULTS Type I and type IIM MyHCs comprise nearly 100% of the MyHCs in the temporalis muscle. IIM MyHC was the overwhelmingly predominant fast MyHC, though there was a small amount of type IIA MyHC (≤5%) in DAT in two individuals. SAT and SPT exhibited a fast/type II phenotype and contained large amounts of IIM MyHC whereas DAT exhibited a type I/type II (hybrid) phenotype and contained a significantly greater proportion of MyHC-I. MyHC-I expression in DAT was sexually dimorphic as it was more abundant in females. CONCLUSIONS The link between the distribution of IIM MyHC and high relative EMG amplitudes in SAT and SPT during hard/tough object chewing cycles is evidence of regional specialization in fibre type to generate high occlusal forces during chewing. The high proportion of MyHC-I in DAT of females may be related to a high frequency of individual fibre recruitment in comparison to males.
Collapse
Affiliation(s)
- Christine E Wall
- Department of Evolutionary Anthropology, Duke University, Durham, NC 27708, United States.
| | | | | | | | | |
Collapse
|
30
|
Fitton LC, Shi JF, Fagan MJ, O'Higgins P. Masticatory loadings and cranial deformation in Macaca fascicularis: a finite element analysis sensitivity study. J Anat 2012; 221:55-68. [PMID: 22690885 DOI: 10.1111/j.1469-7580.2012.01516.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Biomechanical analyses are commonly conducted to investigate how craniofacial form relates to function, particularly in relation to dietary adaptations. However, in the absence of corresponding muscle activation patterns, incomplete muscle data recorded experimentally for different individuals during different feeding tasks are frequently substituted. This study uses finite element analysis (FEA) to examine the sensitivity of the mechanical response of a Macaca fascicularis cranium to varying muscle activation patterns predicted via multibody dynamic analysis. Relative to the effects of varying bite location, the consequences of simulated variations in muscle activation patterns and of the inclusion/exclusion of whole muscle groups were investigated. The resulting cranial deformations were compared using two approaches; strain maps and geometric morphometric analyses. The results indicate that, with bite force magnitude controlled, the variations among the mechanical responses of the cranium to bite location far outweigh those observed as a consequence of varying muscle activations. However, zygomatic deformation was an exception, with the activation levels of superficial masseter being most influential in this regard. The anterior portion of temporalis deforms the cranial vault, but the remaining muscles have less profound effects. This study for the first time systematically quantifies the sensitivity of an FEA model of a primate skull to widely varying masticatory muscle activations and finds that, with the exception of the zygomatic arch, reasonable variants of muscle loading for a second molar bite have considerably less effect on cranial deformation and the resulting strain map than does varying molar bite point. The implication is that FEA models of biting crania will generally produce acceptable estimates of deformation under load as long as muscle activations and forces are reasonably approximated. In any one FEA study, the biological significance of the error in applied muscle forces is best judged against the magnitude of the effect that is being investigated.
Collapse
Affiliation(s)
- L C Fitton
- Centre for Anatomical and Human Sciences, Hull York Medical School, University of York, UK.
| | | | | | | |
Collapse
|
31
|
Ramdarshan A, Merceron G, Marivaux L. Spatial and temporal ecological diversity amongst Eocene primates of France: evidence from teeth. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2011; 147:201-16. [PMID: 22101859 DOI: 10.1002/ajpa.21638] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2011] [Accepted: 10/11/2011] [Indexed: 11/06/2022]
Abstract
Diet is of paramount importance in the life of a primate. It is also highly variable, as potential food sources vary in spatial distribution and availability over time. The fossil record, due to its fragmentary nature, offers few possibilities to assess the dietary range of a given primate across its spatial and temporal distribution. Here we focus on three taxa, Leptadapis magnus (Adapidae, Adapiformes), Necrolemur cf. antiquus (Microchoeridae, Omomyiformes), and Pseudoloris parvulus (Microchoeridae, Omomyiformes). These taxa occur at different localities of the Late Eocene in the south of France ranging from MP16 (Robiac, Lavergne; 39 Ma), MP17a (La Bouffie, Euzet, Fons 4; 38 Ma) to MP17b (Perrière; 37 Ma). Diets of fossil taxa are assessed here by dental microwear analysis using a comparative database of 11 species of living strepsirhines. On the whole, leaves were a preferred food for the large-bodied Leptadapis (4-5 kg). However, the diet of this taxon varied from a mix of leaves and fruit at La Bouffie, a closed tropical rain forest environment, to a strictly leaf-eating one in the more open environment of Perrière. Based on body mass (200-350 g) and dental microwear patterns, Necrolemur had a mainly fruit-based diet, perhaps supplemented by insects. However, the comparison of the different localities reveals the dietary range of this small-bodied omomyiform which seems to vary between insects and a much softer diet. Pseudoloris had a diet strictly based on insects. Contrary to Leptadapis or Necrolemur, its diet seems to have been confined to insects whatever the locality considered.
Collapse
Affiliation(s)
- Anusha Ramdarshan
- Laboratoire de Paléontologie, Institut des Sciences de l'Evolution de Montpellier (ISE-M, UMR-CNRS 5554), c.c. 64, Université Montpellier 2, Place Eugène Bataillon, 95 Montpellier Cedex 05, France.
| | | | | |
Collapse
|
32
|
Dietary correlates of temporomandibular joint morphology in New World primates. J Hum Evol 2011; 61:583-96. [DOI: 10.1016/j.jhevol.2011.08.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2011] [Revised: 08/07/2011] [Accepted: 08/10/2011] [Indexed: 11/18/2022]
|
33
|
Terhune CE, Iriarte-Díaz J, Taylor AB, Ross CF. The Instantaneous Center of Rotation of the Mandible in Nonhuman Primates. Integr Comp Biol 2011; 51:320-32. [PMID: 21622946 DOI: 10.1093/icb/icr031] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Claire E Terhune
- Department of Community and Family Medicine, Duke University School of Medicine, Durham, NC, USA.
| | | | | | | |
Collapse
|
34
|
Benazzi S, Kullmer O, Grosse IR, Weber GW. Using occlusal wear information and finite element analysis to investigate stress distributions in human molars. J Anat 2011; 219:259-72. [PMID: 21615398 DOI: 10.1111/j.1469-7580.2011.01396.x] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Simulations based on finite element analysis (FEA) have attracted increasing interest in dentistry and dental anthropology for evaluating the stress and strain distribution in teeth under occlusal loading conditions. Nonetheless, FEA is usually applied without considering changes in contacts between antagonistic teeth during the occlusal power stroke. In this contribution we show how occlusal information can be used to investigate the stress distribution with 3D FEA in lower first molars (M(1)). The antagonistic crowns M(1) and P(2)-M(1) of two dried modern human skulls were scanned by μCT in maximum intercuspation (centric occlusion) contact. A virtual analysis of the occlusal power stroke between M(1) and P(2)-M(1) was carried out in the Occlusal Fingerprint Analyser (OFA) software, and the occlusal trajectory path was recorded, while contact areas per time-step were visualized and quantified. Stress distribution of the M(1) in selected occlusal stages were analyzed in strand7, considering occlusal information taken from OFA results for individual loading direction and loading area. Our FEA results show that the stress pattern changes considerably during the power stroke, suggesting that wear facets have a crucial influence on the distribution of stress on the whole tooth. Grooves and fissures on the occlusal surface are seen as critical locations, as tensile stresses are concentrated at these features. Properly accounting for the power stroke kinematics of occluding teeth results in quite different results (less tensile stresses in the crown) than usual loading scenarios based on parallel forces to the long axis of the tooth. This leads to the conclusion that functional studies considering kinematics of teeth are important to understand biomechanics and interpret morphological adaptation of teeth.
Collapse
Affiliation(s)
- Stefano Benazzi
- Department of Anthropology, University of Vienna, Vienna, Austria.
| | | | | | | |
Collapse
|
35
|
Thompson CL, Donley EM, Stimpson CD, Horne WI, Vinyard CJ. The influence of experimental manipulations on chewing speed during in vivo laboratory research in tufted capuchins (Cebus apella). AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2011; 145:402-14. [PMID: 21469081 DOI: 10.1002/ajpa.21514] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2010] [Accepted: 01/30/2011] [Indexed: 11/09/2022]
Abstract
Even though in vivo studies of mastication in living primates are often used to test functional and adaptive hypotheses explaining primate masticatory behavior, we currently have little data addressing how experimental procedures performed in the laboratory influence mastication. The obvious logistical issue in assessing how animal manipulation impacts feeding physiology reflects the difficulty in quantifying mechanical parameters without handling the animal. In this study, we measured chewing cycle duration as a mechanical variable that can be collected remotely to: 1) assess how experimental manipulations affect chewing speed in Cebus apella, 2) compare captive chewing cycle durations to that of wild conspecifics, and 3) document sources of variation (beyond experimental manipulation) impacting captive chewing cycle durations. We find that experimental manipulations do increase chewing cycle durations in C. apella by as much as 152 milliseconds (ms) on average. These slower chewing speeds are mainly an effect of anesthesia (and/or restraint), rather than electrode implantation or more invasive surgical procedures. Comparison of captive and wild C. apella suggest there is no novel effect of captivity on chewing speed, although this cannot unequivocally demonstrate that masticatory mechanics are similar in captive and wild individuals. Furthermore, we document significant differences in cycle durations due to inter-individual variation and food type, although duration did not always significantly correlate with mechanical properties of foods. We advocate that the significant reduction in chewing speed be considered as an appropriate qualification when applying the results of laboratory-based feeding studies to adaptive explanations of primate feeding behaviors.
Collapse
Affiliation(s)
- C L Thompson
- Department of Anthropology, Kent State University, OH 44242, USA.
| | | | | | | | | |
Collapse
|
36
|
Fiorenza L, Benazzi S, Tausch J, Kullmer O, Bromage TG, Schrenk F. Molar macrowear reveals Neanderthal eco-geographic dietary variation. PLoS One 2011; 6:e14769. [PMID: 21445243 PMCID: PMC3060801 DOI: 10.1371/journal.pone.0014769] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2010] [Accepted: 02/20/2011] [Indexed: 11/18/2022] Open
Abstract
Neanderthal diets are reported to be based mainly on the consumption of large and medium sized herbivores, while the exploitation of other food types including plants has also been demonstrated. Though some studies conclude that early Homo sapiens were active hunters, the analyses of faunal assemblages, stone tool technologies and stable isotopic studies indicate that they exploited broader dietary resources than Neanderthals. Whereas previous studies assume taxon-specific dietary specializations, we suggest here that the diet of both Neanderthals and early Homo sapiens is determined by ecological conditions. We analyzed molar wear patterns using occlusal fingerprint analysis derived from optical 3D topometry. Molar macrowear accumulates during the lifespan of an individual and thus reflects diet over long periods. Neanderthal and early Homo sapiens maxillary molar macrowear indicates strong eco-geographic dietary variation independent of taxonomic affinities. Based on comparisons with modern hunter-gatherer populations with known diets, Neanderthals as well as early Homo sapiens show high dietary variability in Mediterranean evergreen habitats but a more restricted diet in upper latitude steppe/coniferous forest environments, suggesting a significant consumption of high protein meat resources.
Collapse
Affiliation(s)
- Luca Fiorenza
- Department of Palaeoanthropology and Messel Research, Senckenberg Research Institute, Frankfurt am Main, Germany.
| | | | | | | | | | | |
Collapse
|
37
|
Wang Q, Ashley DW, Dechow PC. Regional, ontogenetic, and sex-related variations in elastic properties of cortical bone in baboon mandibles. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2010; 141:526-49. [PMID: 19927280 DOI: 10.1002/ajpa.21170] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Understanding the mechanical features of cortical bone and their changes with growth and adaptation to function plays an important role in our ability to interpret the morphology and evolution of craniofacial skeletons. We assessed the elastic properties of cortical bone of juvenile and adult baboon mandibles using ultrasonic techniques. Results showed that, overall, cortical bone from baboon mandibles could be modeled as an orthotropic elastic solid. There were significant differences in the directions of maximum stiffness, thickness, density, and elastic stiffness among different functional areas, indicating regional adaptations. After maturity, the cortical bone becomes thicker, denser, and stiffer, but less anisotropic. There were differences in elastic properties of the corpus and ramus between male and female mandibles which are not observed in human mandibles. There were correlations between cortical thicknesses and densities, between bone elastic properties and microstructural configuration, and between the directions of maximum stiffness and bone anatomical axes in some areas. The relationships between bone extrinsic and intrinsic properties bring us insights into the integration of form and function in craniofacial skeletons and suggest that we need to consider both macroscopic form, microstructural variation, and the material properties of bone matrix when studying the functional properties and adaptive nature of the craniofacial skeleton in primates. The differences between baboon and human mandibles is at variance to the pattern of differences in crania, suggesting differences in bone adaption to varying skeletal geometries and loading regimes at both phylogenetic and ontogenetic levels.
Collapse
Affiliation(s)
- Qian Wang
- Division of Basic Medical Sciences, Mercer University School of Medicine, Macon, GA 31207, USA.
| | | | | |
Collapse
|
38
|
Crompton AW, Owerkowicz T, Skinner J. Masticatory motor pattern in the koala (Phascolarctos cinereus): a comparison of jaw movements in marsupial and placental herbivores. ACTA ACUST UNITED AC 2010; 313:564-78. [DOI: 10.1002/jez.628] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|
39
|
Vinyard CJ, Taylor AB. A preliminary analysis of the relationship between jaw-muscle architecture and jaw-muscle electromyography during chewing across primates. Anat Rec (Hoboken) 2010; 293:572-82. [PMID: 20235313 DOI: 10.1002/ar.21121] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The architectural arrangement of the fibers within a muscle has a significant impact on how a muscle functions. Recent work on primate jaw-muscle architecture demonstrates significant associations with dietary variation and feeding behaviors. In this study, the relationship between masseter and temporalis muscle architecture and jaw-muscle activity patterns is explored using Belanger's treeshrews and 11 primate species, including two genera of strepsirrhines (Lemur and Otolemur) and five genera of anthropoids (Aotus, Callithrix, Cebus, Macaca, and Papio). Jaw-muscle weights, fiber lengths, and physiologic cross-sectional areas (PCSA) were quantified for this preliminary analysis or collected from the literature and compared to published electromyographic recordings from these muscles. Results indicate that masseter architecture is unrelated to the superficial masseter working-side/balancing-side (W/B) ratio across primate species. Alternatively, relative temporalis architecture is correlated with temporalis W/B ratios across primates. Specifically, relative temporalis PCSA is inversely related to the W/B ratio for the anterior temporalis, indicating that as animals recruit a larger relative percentage of their balancing-side temporalis, they possess the ability to generate relatively larger amounts of force from these muscles. These findings support three broader conclusions. First, masseter muscle architecture may have experienced divergent evolution across different primate clades related to novel functional roles in different groups. Second, the temporalis may be functionally constrained (relative to the masseter) across primates in its functional role of creating vertical occlusal forces during chewing. Finally, the contrasting results for the masseter and temporalis suggest that the fiber architecture of these muscles has evolved as distinct functional units in primates.
Collapse
Affiliation(s)
- Christopher J Vinyard
- Department of Anatomy and Neurobiology, Northeastern Ohio Universities College of Medicine, Rootstown, OH 44272, USA.
| | | |
Collapse
|
40
|
Macho GA, Shimizu D. Kinematic parameters inferred from enamel microstructure: new insights into the diet of Australopithecus anamensis. J Hum Evol 2010; 58:23-32. [DOI: 10.1016/j.jhevol.2009.07.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2009] [Revised: 08/01/2009] [Accepted: 07/30/2009] [Indexed: 11/28/2022]
|
41
|
Dietary adaptations of South African australopiths: inference from enamel prism attitude. J Hum Evol 2009; 57:241-7. [DOI: 10.1016/j.jhevol.2009.05.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2008] [Revised: 01/20/2009] [Accepted: 05/21/2009] [Indexed: 11/20/2022]
|
42
|
Krueger KL, Scott JR, Kay RF, Ungar PS. Technical note: Dental microwear textures of “Phase I” and “Phase II” facets. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2008; 137:485-90. [DOI: 10.1002/ajpa.20928] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
43
|
Vinyard CJ, Wall CE, Williams SH, Hylander WL. Patterns of variation across primates in jaw-muscle electromyography during mastication. Integr Comp Biol 2008; 48:294-311. [PMID: 21669792 DOI: 10.1093/icb/icn071] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Christopher J Vinyard
- *Department of Anatomy and Neurobiology, NEOUCOM, Rootstown, OH, USA; Department of Evolutionary Anthropology, Duke University, Durham, NC, USA; Department of Biomedical Sciences, Ohio University College of Osteopathic Medicine, Athens, OH, USA
| | | | | | | |
Collapse
|
44
|
Crompton AW, Barnet J, Lieberman DE, Owerkowicz T, Skinner J, Baudinette RV. Control of jaw movements in two species of macropodines (Macropus eugenii and Macropus rufus). Comp Biochem Physiol A Mol Integr Physiol 2007; 150:109-23. [PMID: 18065250 DOI: 10.1016/j.cbpa.2007.10.015] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2007] [Revised: 10/25/2007] [Accepted: 10/25/2007] [Indexed: 10/22/2022]
Abstract
The masticatory motor patterns of three tammar wallabies and two red kangaroos were determined by analyzing the pattern of electromyographic (EMG) activity of the jaw adductors and correlating it with lower jaw movements, as recorded by digital video and videoradiography. Transverse jaw movements were limited by the width of the upper incisal arcade. Molars engaged in food breakdown during two distinct occlusal phases characterized by abrupt changes in the direction of working-side hemimandible movement. Separate orthal (Phase I) and transverse (Phase II) trajectories were observed. The working-side lower jaw initially was drawn laterally by the balancing-side medial pterygoid and then orthally by overlapping activity in the balancing- and working-side temporalis and the balancing-side superficial masseter and medial pterygoid. Transverse movement occurred principally via the working-side medial pterygoid and superficial masseter. This pattern contrasted to that of placental herbivores, which are known to break down food when they move the working-side lower jaw transversely along a relatively longer linear path without changing direction during the power stroke. The placental trajectory results from overlapping activity in the working- and balancing-side adductor muscles, suggesting that macropods and placental herbivores have modified the primitive masticatory motor pattern in different ways.
Collapse
Affiliation(s)
- A W Crompton
- Museum of Comparative Zoology, Harvard University, 26 Oxford St, Cambridge, Massachusetts 02138, USA.
| | | | | | | | | | | |
Collapse
|
45
|
Williams SH, Vinyard CJ, Wall CE, Hylander WL. Masticatory motor patterns in ungulates: a quantitative assessment of jaw-muscle coordination in goats, alpacas and horses. ACTA ACUST UNITED AC 2007; 307:226-40. [PMID: 17436331 DOI: 10.1002/jez.362] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
We investigated patterns of jaw-muscle coordination during rhythmic mastication in three species of ungulates displaying the marked transverse jaw movements typical of many large mammalian herbivores. In order to quantify consistent motor patterns during chewing, electromyograms were recorded from the superficial masseter, deep masseter, posterior temporalis and medial pterygoid muscles of goats, alpacas and horses. Timing differences between muscle pairs were evaluated in the context of an evolutionary model of jaw-muscle function. In this model, the closing and food reduction phases of mastication are primarily controlled by two distinct muscle groups, triplet I (balancing-side superficial masseter and medial pterygoid and working-side posterior temporalis) and triplet II (working-side superficial masseter and medial pterygoid and balancing-side posterior temporalis), and the asynchronous activity of the working- and balancing-side deep masseters. The three species differ in the extent to which the jaw muscles are coordinated as triplet I and triplet II. Alpacas, and to a lesser extent, goats, exhibit the triplet pattern whereas horses do not. In contrast, all three species show marked asynchrony of the working-side and balancing-side deep masseters, with jaw closing initiated by the working-side muscle and the balancing-side muscle firing much later during closing. However, goats differ from alpacas and horses in the timing of the balancing-side deep masseter relative to the triplet II muscles. This study highlights interspecific differences in the coordination of jaw muscles to influence transverse jaw movements and the production of bite force in herbivorous ungulates.
Collapse
Affiliation(s)
- Susan H Williams
- Department of Biomedical Sciences, Ohio University College of Osteopathic Medicine, Athens, OH 45701, USA.
| | | | | | | |
Collapse
|