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Turcotte CM, Choi AM, Spear JK, Hernandez-Janer EM, Taboada HG, Stock MK, Villamil CI, Bauman SE, Martinez MI, Brent LJN, Snyder-Mackler N, Montague MJ, Platt ML, Williams SA, Higham JP, Antón SC. Quantifying the relationship between bone and soft tissue measures within the rhesus macaques of Cayo Santiago. AMERICAN JOURNAL OF BIOLOGICAL ANTHROPOLOGY 2024; 184:e24920. [PMID: 38447005 DOI: 10.1002/ajpa.24920] [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: 06/22/2023] [Revised: 12/20/2023] [Accepted: 02/14/2024] [Indexed: 03/08/2024]
Abstract
OBJECTIVES Interpretations of the primate and human fossil record often rely on the estimation of somatic dimensions from bony measures. Both somatic and skeletal variation have been used to assess how primates respond to environmental change. However, it is unclear how well skeletal variation matches and predicts soft tissue. Here, we empirically test the relationship between tissues by comparing somatic and skeletal measures using paired measures of pre- and post-mortem rhesus macaques from Cayo Santiago, Puerto Rico. MATERIALS AND METHODS Somatic measurements were matched with skeletal dimensions from 105 rhesus macaque individuals to investigate paired signals of variation (i.e., coefficients of variation, sexual dimorphism) and bivariate codependence (reduced major axis regression) in measures of: (1) limb length; (2) joint breadth; and (3) limb circumference. Predictive models for the estimation of soft tissue dimensions from skeletons were built from Ordinary Least Squares regressions. RESULTS Somatic and skeletal measurements showed statistically equivalent coefficients of variation and sexual dimorphism as well as high epiphyses-present ordinary least square (OLS) correlations in limb lengths (R2 >0.78, 0.82), joint breadths (R2 >0.74, 0.83) and, to a lesser extent, limb circumference (R2 >0.53, 0.68). CONCLUSION Skeletal measurements are good substitutions for somatic values based on population signals of variation. OLS regressions indicate that skeletal correlates are highly predictive of somatic dimensions. The protocols and regression equations established here provide a basis for reliable reconstruction of somatic dimension from catarrhine fossils and validate our ability to compare or combine results of studies based on population data of either hard or soft tissue proxies.
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Affiliation(s)
- Cassandra M Turcotte
- Department of Anthropology, Center for the Study of Human Origins, New York University, New York, New York, USA
- New York Consortium in Evolutionary Primatology, New York, New York, USA
- Department of Anatomy, New York Institute of Technology, College of Osteopathic Medicine, Old Westbury, New York, USA
| | - Audrey M Choi
- Department of Anthropology, Center for the Study of Human Origins, New York University, New York, New York, USA
- New York Consortium in Evolutionary Primatology, New York, New York, USA
| | - Jeffrey K Spear
- Department of Anthropology, Center for the Study of Human Origins, New York University, New York, New York, USA
- New York Consortium in Evolutionary Primatology, New York, New York, USA
| | - Eva M Hernandez-Janer
- Department of Evolutionary Anthropology, Rutgers University, New Brunswick, New Jersey, USA
| | - Hannah G Taboada
- Department of Anthropology, Center for the Study of Human Origins, New York University, New York, New York, USA
- New York Consortium in Evolutionary Primatology, New York, New York, USA
| | - Michala K Stock
- Department of Sociology and Anthropology, Metropolitan State University of Denver, Denver, Colorado, USA
| | - Catalina I Villamil
- Doctor of Chiropractic Program, School of Health Sciences and Technologies, Universidad Central del Caribe, Bayamón, Puerto Rico, USA
| | - Samuel E Bauman
- Caribbean Primate Research Center, University of Puerto Rico, San Juan, Puerto Rico, USA
| | - Melween I Martinez
- Caribbean Primate Research Center, University of Puerto Rico, San Juan, Puerto Rico, USA
| | | | - Noah Snyder-Mackler
- School of Life Sciences, Arizona State University, Tempe, Arizona, USA
- School for Human Evolution and Social Change, Arizona State University, Tempe, Arizona, USA
- Center for Evolution and Medicine, Arizona State University, Tempe, Arizona, USA
| | - Michael J Montague
- Department of Neuroscience, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Michael L Platt
- Department of Neuroscience, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Scott A Williams
- Department of Anthropology, Center for the Study of Human Origins, New York University, New York, New York, USA
- New York Consortium in Evolutionary Primatology, New York, New York, USA
| | - James P Higham
- Department of Anthropology, Center for the Study of Human Origins, New York University, New York, New York, USA
- New York Consortium in Evolutionary Primatology, New York, New York, USA
| | - Susan C Antón
- Department of Anthropology, Center for the Study of Human Origins, New York University, New York, New York, USA
- New York Consortium in Evolutionary Primatology, New York, New York, USA
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Montuelle SJ, Williams SH. Prolonged use of a soft diet during early growth and development alters feeding behavior and chewing kinematics in a young animal model. J Morphol 2024; 285:e21696. [PMID: 38639429 PMCID: PMC11177321 DOI: 10.1002/jmor.21696] [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: 01/25/2024] [Revised: 04/05/2024] [Accepted: 04/07/2024] [Indexed: 04/20/2024]
Abstract
In infants and children with feeding and swallowing issues, modifying solid foods to form a liquid or puree is used to ensure adequate growth and nutrition. However, the behavioral and neurophysiological effects of prolonged use of this intervention during critical periods of postnatal oral skill development have not been systematically examined, although substantial anecdotal evidence suggests that it negatively impacts downstream feeding motor and coordination skills, possibly due to immature sensorimotor development. Using an established animal model for infant and juvenile feeding physiology, we leverage X-ray reconstruction of moving morphology to compare feeding behavior and kinematics between 12-week-old pigs reared on solid chow (control) and an age- and sex-matched cohort raised on the same chow softened to a liquid. When feeding on two novel foods, almond and apple, maintenance on a soft diet decreases gape cycle duration, resulting in a higher chewing frequency. When feeding on almonds, pigs in this group spent less time ingesting foods compared to controls, and chewing cycles were characterized by less jaw rotation about a dorsoventral axis (yaw) necessary for food reduction. There was also a reduced tendency to alternate chewing side with every chew during almond chewing, a behavioral pattern typical of pigs. These more pronounced impacts on behavior and kinematics during feeding on almonds, a tougher and stiffer food than apples, suggest that food properties mediate the behavioral and physiological impacts of early texture modification and that the ability to adapt to different food properties may be underdeveloped. In contrast, the limited effects of food texture modification on apple chewing indicate that such intervention/treatment does not alter feeding behavior of less challenging foods. Observed differences cannot be attributed to morphology because texture modification over the treatment period had limited impact on craniodental growth. Short-term impacts of soft-texture modification during postweaning development on feeding dynamics should be considered as potential negative outcomes of this treatment strategy.
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Affiliation(s)
- Stéphane J. Montuelle
- Department of Biomedical Sciences, Ohio University Heritage College of Osteopathic Medicine, Warrensville Heights, OH 44122
| | - Susan H. Williams
- Department of Biomedical Sciences, Ohio University Heritage College of Osteopathic Medicine, Athens, OH 45701
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Fiber-type phenotype of the jaw-closing muscles in Gorilla gorilla, Pan troglodytes, and Pan paniscus: A test of the Frequent Recruitment Hypothesis. J Hum Evol 2021; 151:102938. [PMID: 33493971 DOI: 10.1016/j.jhevol.2020.102938] [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: 07/06/2020] [Revised: 12/11/2020] [Accepted: 12/12/2020] [Indexed: 11/20/2022]
Abstract
Skeletal muscle fiber types are important determinants of the contractile properties of muscle fibers, such as fatigue resistance and shortening velocity. Yet little is known about how jaw-adductor fiber types correlate with feeding behavior in primates. Compared with chimpanzees and bonobos, gorillas spend a greater percentage of their daily time feeding and shift to herbaceous vegetation when fruits are scarce. We thus used the African apes to test the hypothesis that chewing with unusually high frequency is correlated with the expression in the jaw adductors of a high proportion of type 1 (slow, fatigue-resistant) fibers at the expense of other fiber types (the Frequent Recruitment Hypothesis). We used immunohistochemistry to determine the presence and distribution of the four major myosin heavy chain (MHC) isoforms in the anterior superficial masseter (ASM), superficial anterior temporalis, and deep anterior temporalis of four Gorilla gorilla, two Pan paniscus, and four Pan troglodytes. Serial sections were stained against slow (MHC-1/-α-cardiac) and fast (MHC-2/-M) fibers. Fibers were counted and scored for staining intensity, and fiber cross-sectional areas (CSAs) were measured and used to estimate percentage of CSA of each MHC isoform. Hybrid fibers accounted for nearly 100% of fiber types in the masseter and temporalis of all three species, resulting in three main hybrid phenotypes. As predicted, the gorilla ASM and deep anterior temporalis comprised a greater percentage of CSA of the slower, fatigue-resistant hybrid fiber type, significantly so for the ASM (p = 0.015). Finally, the results suggest that fiber phenotype of the chewing muscles contributes to behavioral flexibility in ways that would go undetected in paleontological studies relying solely on morphology of the bony masticatory apparatus.
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4
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Laird MF, Granatosky MC, Taylor AB, Ross CF. Muscle architecture dynamics modulate performance of the superficial anterior temporalis muscle during chewing in capuchins. Sci Rep 2020; 10:6410. [PMID: 32286442 PMCID: PMC7156371 DOI: 10.1038/s41598-020-63376-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Accepted: 03/30/2020] [Indexed: 11/09/2022] Open
Abstract
Jaw-muscle architecture is a key determinant of jaw movements and bite force. While static length-force and force-velocity relationships are well documented in mammals, architecture dynamics of the chewing muscles and their impact on muscle performance are largely unknown. We provide novel data on how fiber architecture of the superficial anterior temporalis (SAT) varies dynamically during naturalistic feeding in tufted capuchins (Sapajus apella). We collected data on architecture dynamics (changes in muscle shape or the architectural gear ratio) during the gape cycle while subjects fed on foods of different mechanical properties. Architecture of the SAT varied with phases of the gape cycle, but gape distance accounted for the majority of dynamic changes in architecture. In addition, lower gear ratios (low muscle velocity relative to fascicle velocity) were observed when animals chewed on more mechanically resistant foods. At lower gear ratios, fibers rotated less during shortening resulting in smaller pinnation angles, a configuration that favors increased force production. Our results suggest that architectural dynamics may influence jaw-muscle performance by enabling the production of higher bite forces during the occlusal phase of the gape cycle and while processing mechanically challenging foods.
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Affiliation(s)
- Myra F Laird
- Department of Integrative Anatomical Sciences, University of Southern California, Los Angeles, CA, USA.
| | | | - Andrea B Taylor
- Basic Science Department, Touro University, Vallejo, CA, USA
| | - Callum F Ross
- Department of Organismal Biology and Anatomy, University of Chicago, Chicago, IL, USA
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Terhune CE, Sylvester AD, Scott JE, Ravosa MJ. Internal architecture of the mandibular condyle of rabbits is related to dietary resistance during growth. J Exp Biol 2020; 223:jeb220988. [PMID: 32127379 DOI: 10.1242/jeb.220988] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2020] [Accepted: 02/25/2020] [Indexed: 12/11/2022]
Abstract
Although there is considerable evidence that bone responds to the loading environment in which it develops, few analyses have examined phenotypic plasticity or bone functional adaptation in the masticatory apparatus. Prior work suggests that masticatory morphology is sensitive to differences in food mechanical properties during development; however, the importance of the timing/duration of loading and variation in naturalistic diets is less clear. Here, we examined microstructural and macrostructural differences in the mandibular condyle in four groups of white rabbits (Oryctolagus cuniculus) raised for a year on diets that varied in mechanical properties and timing of the introduction of mechanically challenging foods, simulating seasonal variation in diet. We employed sliding semilandmarks to locate multiple volumes of interest deep to the mandibular condyle articular surface, and compared bone volume fraction, trabecular thickness and spacing, and condylar size/shape among experimental groups. The results reveal a shared pattern of bony architecture across the articular surface of all treatment groups, while also demonstrating significant among-group differences. Rabbits raised on mechanically challenging diets have significantly increased bone volume fraction relative to controls fed a less challenging diet. The post-weaning timing of the introduction of mechanically challenging foods also influences architectural properties, suggesting that bone plasticity can extend well into adulthood and that bony responses to changes in loading may be rapid. These findings demonstrate that bony architecture of the mandibular condyle in rabbits responds to variation in mechanical loading during an organism's lifetime and has the potential to track dietary variation within and among species.
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Affiliation(s)
- Claire E Terhune
- Department of Anthropology, University of Arkansas, Fayetteville, AR 72701, USA
| | - Adam D Sylvester
- Center for Functional Anatomy and Evolution, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Jeremiah E Scott
- Department of Medical Anatomical Sciences, Western University of Health Sciences, Pomona, CA 91766, USA
| | - Matthew J Ravosa
- Departments of Biological Sciences, Aerospace & Mechanical Engineering, and Anthropology, University of Notre Dame, Notre Dame, IN 46556, USA
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Leonard KC, Boettcher ML, Dickinson E, Malhotra N, Aujard F, Herrel A, Hartstone‐Rose A. The Ontogeny of Masticatory Muscle Architecture in
Microcebus murinus. Anat Rec (Hoboken) 2019; 303:1364-1373. [DOI: 10.1002/ar.24259] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Revised: 07/01/2019] [Accepted: 07/04/2019] [Indexed: 12/22/2022]
Affiliation(s)
- Kaitlyn C. Leonard
- Department of Biological Sciences North Carolina State University Raleigh North Carolina
| | - Marissa L. Boettcher
- Department of Biological Sciences North Carolina State University Raleigh North Carolina
| | - Edwin Dickinson
- Department of Biological Sciences North Carolina State University Raleigh North Carolina
| | - Neha Malhotra
- University of South Carolina School of Medicine Columbia South Carolina
| | | | | | - Adam Hartstone‐Rose
- Department of Biological Sciences North Carolina State University Raleigh North Carolina
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ITO K, ENDO H. The effect of the masticatory muscle physiological cross-sectional area on the structure of the temporomandibular joint in Carnivora. J Vet Med Sci 2019; 81:389-396. [PMID: 30674744 PMCID: PMC6451921 DOI: 10.1292/jvms.18-0611] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
We compared the temporomandibular joint structure between species of the order Carnivora and investigated its variation among family lineages. We also investigated the effect of the
masticatory muscle physiological cross-sectional area (PCSA) on temporomandibular joint structure. The masticatory muscle is composed of multiple muscles, which contract in different
directions and exert pressure on the temporomandibular joint. We investigated the effect of the ratio of each muscle’s PCSA—an indicator of muscle force—and muscle size relative to body size
on temporomandibular joint structure. The temporalis PCSA relative to body size showed the highest correlation with temporomandibular joint structure. When the temporalis PCSA is large
relative to body size, the preglenoid projects caudally, the postglenoid projects rostrally and the pre-postglenoid angle interval is small, indicating that the condyle is locked in the
fossa to reinforce the temporomandibular joint. Most Carnivora use blade-like carnassial teeth when slicing food. However, dislocation occurs when the carnassial teeth are used by the
temporalis muscle. Our results suggest that the temporomandibular joint is reinforced to prevent dislocation caused by the temporalis muscle. In Mustelidae, the temporomandibular joint with
a rostrally projecting postglenoid is suitable for carnassial biting using the temporalis muscle. In Felidae, the force of the masseter onto the carnassial teeth is diverted to the canine by
tightening the temporomandibular joint. In Canidae, the masticatory muscle arrangement is well-balanced, enabling combined action. Hence, reinforcement of the temporomandibular joint by bone
structure is unnecessary.
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Affiliation(s)
- Kai ITO
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
- The University Museum, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku Tokyo 113-0033, Japan
| | - Hideki ENDO
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
- The University Museum, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku Tokyo 113-0033, Japan
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ORSBON COURTNEYP, GIDMARK NICHOLASJ, ROSS CALLUMF. Dynamic Musculoskeletal Functional Morphology: Integrating diceCT and XROMM. Anat Rec (Hoboken) 2018; 301:378-406. [PMID: 29330951 PMCID: PMC5786282 DOI: 10.1002/ar.23714] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Revised: 09/05/2017] [Accepted: 09/11/2017] [Indexed: 12/31/2022]
Abstract
The tradeoff between force and velocity in skeletal muscle is a fundamental constraint on vertebrate musculoskeletal design (form:function relationships). Understanding how and why different lineages address this biomechanical problem is an important goal of vertebrate musculoskeletal functional morphology. Our ability to answer questions about the different solutions to this tradeoff has been significantly improved by recent advances in techniques for quantifying musculoskeletal morphology and movement. Herein, we have three objectives: (1) review the morphological and physiological parameters that affect muscle function and how these parameters interact; (2) discuss the necessity of integrating morphological and physiological lines of evidence to understand muscle function and the new, high resolution imaging technologies that do so; and (3) present a method that integrates high spatiotemporal resolution motion capture (XROMM, including its corollary fluoromicrometry), high resolution soft tissue imaging (diceCT), and electromyography to study musculoskeletal dynamics in vivo. The method is demonstrated using a case study of in vivo primate hyolingual biomechanics during chewing and swallowing. A sensitivity analysis demonstrates that small deviations in reconstructed hyoid muscle attachment site location introduce an average error of 13.2% to in vivo muscle kinematics. The observed hyoid and muscle kinematics suggest that hyoid elevation is produced by multiple muscles and that fascicle rotation and tendon strain decouple fascicle strain from hyoid movement and whole muscle length. Lastly, we highlight current limitations of these techniques, some of which will likely soon be overcome through methodological improvements, and some of which are inherent. Anat Rec, 301:378-406, 2018. © 2018 Wiley Periodicals, Inc.
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Affiliation(s)
- COURTNEY P. ORSBON
- Department of Organismal Biology and Anatomy, The University of Chicago, Chicago, Illinois 60637
| | | | - CALLUM F. ROSS
- Department of Organismal Biology and Anatomy, The University of Chicago, Chicago, Illinois 60637
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Ravosa MJ, Kane RJ. Dietary variation and mechanical properties of articular cartilage in the temporomandibular joint: implications for the role of plasticity in mechanobiology and pathobiology. ZOOLOGY 2017; 124:42-50. [PMID: 29032864 DOI: 10.1016/j.zool.2017.08.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2017] [Revised: 08/18/2017] [Accepted: 08/19/2017] [Indexed: 01/26/2023]
Abstract
Due to their nature as tissue composites, skeletal joints pose an additional challenge in terms of evaluating the functional significance of morphological variation in their bony and cartilaginous components in response to altered loading conditions. Arguably, this complexity requires more direct means of investigating joint plasticity and performance than typically employed to analyze macro- and micro-anatomical phenomena. To address a significant gap in our understanding of the plasticity of the mammalian temporomandibular joint (TMJ), we investigated the histology and mechanical properties of condylar articular cartilage in rabbits subjected to long-term variation in diet-induced masticatory stresses, specifically cyclical loading. Three cohorts of male weanlings were raised for six months on different diets until adulthood. Following euthanasia, the TMJ condyles on one side were dissected away, fixed, decalcified, dehydrated, embedded and sectioned. Safranin O staining was employed to identify variation in proteoglycan content, which in turn was used to predict patterns of articular cartilage stiffness in contralateral condylar specimens for each treatment group. Hematoxylin and eosin staining was used to quantify diet-induced changes in chondrocyte hypertrophy and cellularity. Mechanical tests document significant decreases in articular cartilage stiffness corresponding to patterns of extracellular matrix relative protein abundance in rabbits subjected to greater cyclical loading. This indicates that TMJs routinely subjected to higher masticatory stresses due to a challenging diet eventually develop postnatal decreases in the ability to counter compressive loads during postcanine biting and chewing. These findings provide novel information regarding TMJ performance, with broader implications about the costs and benefits of phenotypic plasticity as well as implications for how such biological processes affect connective tissue mechanobiology and pathobiology.
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Affiliation(s)
- Matthew J Ravosa
- Department of Biological Sciences, Galvin Life Science Center, University of Notre Dame, Notre Dame, IN 46556, USA; Department of Aerospace and Mechanical Engineering, University of Notre Dame, Notre Dame, IN 46556, USA; Department of Anthropology, University of Notre Dame, Notre Dame, IN 46556, USA.
| | - Robert J Kane
- Department of Biological Sciences, Galvin Life Science Center, University of Notre Dame, Notre Dame, IN 46556, USA.
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Böhmer C, Böhmer E. Shape Variation in the Craniomandibular System and Prevalence of Dental Problems in Domestic Rabbits: A Case Study in Evolutionary Veterinary Science. Vet Sci 2017; 4:vetsci4010005. [PMID: 29056664 PMCID: PMC5606619 DOI: 10.3390/vetsci4010005] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2016] [Revised: 01/09/2017] [Accepted: 01/18/2017] [Indexed: 12/20/2022] Open
Abstract
In contrast to wild lagomorphs, pet rabbits exhibit a noticeably high frequency of dental problems. Although dietary habits are considered as a major factor contributing to acquired malocclusions, the exact causes and interrelationships are still under debate. In this regard, an important aspect that has not been considered thoroughly to date is the effect of diet-induced phenotypic plasticity in skull morphology. Therefore, we conducted a geometric morphometric analysis on skull radiological images of wild and pet rabbits in order to quantify intraspecific variation in craniomandibular morphology. The statistical analyses reveal a significant morphological differentiation of the craniomandibular system between both groups. Furthermore, the analysis of covariance shows that the force-generating modules (cranium and mandible) vary independently from the force-receiving module (hypselodont teeth) in pet rabbits, which is in contrast to their wild relatives. Our findings suggest that the phenotypic changes in domestic rabbits impact mastication performance and, consequently, oral health. An adequate close-to-nature nutrition throughout the whole life and especially beginning early parallel to weaning (phase of increased phenotypic plasticity) is necessary to ensure a normal strain on the teeth by promoting physiological lateral gliding movements and avoiding direct axial loads.
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Affiliation(s)
- Christine Böhmer
- UMR 7179 CNRS, Muséum National d'Histoire Naturelle, CP 55, 57 rue Cuvier, 75231 Paris Cedex 05, France.
| | - Estella Böhmer
- Chirurgische und Gynäkologische Kleintierklinik ,Tierärztliche Fakultät, Ludwig-Maximilians-Universität München, Veterinärstr 13, München 80539, Germany.
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11
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Ito K, Endo H. Compartive Study of Physiological Cross-Sectional Area of Masticatory Muscles among Species of Carnivora. MAMMAL STUDY 2016. [DOI: 10.3106/041.041.0403] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Ravosa MJ, Menegaz RA, Scott JE, Daegling DJ, McAbee KR. Limitations of a morphological criterion of adaptive inference in the fossil record. Biol Rev Camb Philos Soc 2015; 91:883-898. [DOI: 10.1111/brv.12199] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2014] [Revised: 05/08/2015] [Accepted: 05/15/2015] [Indexed: 11/29/2022]
Affiliation(s)
- Matthew J. Ravosa
- Department of Biological Sciences Galvin Life Science Center, University of Notre Dame Notre Dame IN 46556 U.S.A
- Department of Aerospace and Mechanical Engineering University of Notre Dame Notre Dame IN 46556 U.S.A
- Department of Anthropology University of Notre Dame Notre Dame IN 46556 U.S.A
| | - Rachel A. Menegaz
- Department of Biomedical and Applied Sciences Indiana University School of Dentistry Indianapolis IN 46202 U.S.A
| | - Jeremiah E. Scott
- Department of Anthropology Southern Illinois University Carbondale IL 62901 U.S.A
| | - David J. Daegling
- Department of Anthropology University of Florida Gainesville FL 32611 U.S.A
| | - Kevin R. McAbee
- Department of Biological Sciences Galvin Life Science Center, University of Notre Dame Notre Dame IN 46556 U.S.A
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Kuijpers MAR, Grefte S, Bronkhorst EM, Carels CEL, Kiliaridis S, Von den Hoff JW. Reduced masticatory function is related to lower satellite cell numbers in masseter muscle. Eur J Orthod 2012; 36:262-7. [DOI: 10.1093/ejo/cjs044] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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14
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Ross CF, Iriarte-Diaz J, Nunn CL. Innovative Approaches to the Relationship Between Diet and Mandibular Morphology in Primates. INT J PRIMATOL 2012. [DOI: 10.1007/s10764-012-9599-y] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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15
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Cvetko E, Karen P, Eržen I. Wearing of complete dentures reduces slow fibre and enhances hybrid fibre fraction in masseter muscle. J Oral Rehabil 2012; 39:608-14. [PMID: 22489880 DOI: 10.1111/j.1365-2842.2012.02294.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Edentulous conditions and use of complete dentures alter the function of jaw muscles, which is presumably reflected in the myosin heavy chain (MyHC) isoform composition. This study is the first dealing with MyHC isoforms expression in edentulous persons with the aim to clarify to which extent the decreased functional load following teeth loss contributes to the changed muscle phenotype during ageing. We analysed MyHC expression in old masseter muscle at decreased and full functional load by comparing age-matched edentulous and dentate subjects. Edentulous subjects had upper and lower complete dentures. Dentate subjects had at least 24 natural teeth in continuous dental arches with two molars present in each quadrant and normal intermaxillary relationship. The adaptive response to the reduced masticatory load was lower numerical and area proportion of MyHC-1 expressing fibres and higher numerical proportion of hybrid fibres in edentulous compared with dentate subjects with no significant difference in the proportion of MyHC-neo-expressing fibres between both groups. We conclude that the observed differences in the proportion of fibre types between denture wearers and dentate subjects cannot be ascribed to degenerative changes intrinsic to the ageing muscle, but to functional differences in muscle activity and to morphological alterations of stomatognathic system accompanying the complete teeth loss.
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Affiliation(s)
- E Cvetko
- Institute of Anatomy, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia.
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Jasarević E, Ning J, Daniel AN, Menegaz RA, Johnson JJ, Stack MS, Ravosa MJ. Masticatory loading, function, and plasticity: a microanatomical analysis of mammalian circumorbital soft-tissue structures. Anat Rec (Hoboken) 2010; 293:642-50. [PMID: 20235321 DOI: 10.1002/ar.21135] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
In contrast to experimental evidence regarding the postorbital bar, postorbital septum, and browridge, there is exceedingly little evidence regarding the load-bearing nature of soft-tissue structures of the mammalian circumorbital region. This hinders our understanding of pronounced transformations during primate origins, in which euprimates evolved a postorbital bar from an ancestor with the primitive mammalian condition where only soft tissues spanned the lateral orbital margin between frontal bone and zygomatic arch. To address this significant gap, we investigated the postorbital microanatomy of rabbits subjected to long-term variation in diet-induced masticatory stresses. Rabbits exhibit a masticatory complex and feeding behaviors similar to primates, yet retain a more primitive mammalian circumorbital region. Three cohorts were obtained as weanlings and raised on different diets until adult. Following euthanasia, postorbital soft tissues were dissected away, fixed, and decalcified. These soft tissues were divided into inferior, intermediate, and superior units and then dehydrated, embedded, and sectioned. H&E staining was used to characterize overall architecture. Collagen orientation and complexity were evaluated via picrosirius-red staining. Safranin-O identified proteoglycan content with additional immunostaining performed to assess Type-II collagen expression. Surprisingly, the ligament along the lateral orbital wall was composed of elastic fibrocartilage. A more degraded organization of collagen fibers in this postorbital fibrocartilage is correlated with increased masticatory forces due to a more fracture-resistant diet. Furthermore, the lack of marked changes in the extracellular composition of the lateral orbital wall related to tissue viscoelasticity suggests it is unlikely that long-term exposure to elevated masticatory stresses underlies the development of a bony postorbital bar.
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Affiliation(s)
- Eldin Jasarević
- Department of Pathology and Anatomical Sciences, University of Missouri School of Medicine, One Hospital Drive, Columbia, MO 65212, USA
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Ravosa MJ, Ross CF, Williams SH, Costley DB. Allometry of masticatory loading parameters in mammals. Anat Rec (Hoboken) 2010; 293:557-71. [PMID: 20235312 DOI: 10.1002/ar.21133] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Considerable research on the scaling of loading patterns in mammalian locomotor systems has not been accompanied by a similarly comprehensive analysis of the interspecific scaling of loading regimes in the mammalian masticatory complex. To address this deficiency, we analyzed mandibular corpus bone strain in 11 mammalian taxa varying in body size by over 2.5 orders of magnitude, including goats, horses, alpacas, pigs, and seven primate taxa. During alert chewing and biting of hard/tough foods, bone-strain data were collected with rosette gauges placed along the lateral aspect of the mandibular corpus below the molars or premolars. Bone-strain data were used to characterize relevant masticatory loading parameters: peak loading magnitudes, chewing cycle duration, chewing frequency, occlusal duty factor, loading rate, and loading time. Interspecific analyses indicate that much as observed in limb elements, corpus peak-strain magnitudes are similar across mammals of disparate body sizes. Chewing frequency is inversely correlated with body size, much as with locomotor stride frequency. Some of this allometric variation in chewing frequency appears to be due to a negative correlation with loading time, which increases with body size. Similar to the locomotor apparatus, occlusal duty factor, or the duration of the chewing cycle during which the corpus is loaded, does not vary with body size. Peak principal-strain magnitudes are most strongly positively correlated with loading rate and only secondarily with loading, with this complex relationship best described by a multiple regression equation with an interaction term between loading rate and loading time. In addition to informing interpretations of craniomandibular growth, form, function, and allometry, these comparisons provide a skeleton-wide perspective on the patterning of osteogenic stimuli across body sizes.
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Affiliation(s)
- Matthew J Ravosa
- Department of Pathology and Anatomical Sciences, University of Missouri School of Medicine, One Hospital Drive, Columbia, MO 65212, USA.
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Grünheid T, Brugman P, Zentner A, Langenbach GEJ. Changes in rabbit jaw-muscle activity parameters in response to reduced masticatory load. ACTA ACUST UNITED AC 2010; 213:775-81. [PMID: 20154193 DOI: 10.1242/jeb.037762] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Mechanical food properties influence the neuromuscular activity of jaw-closing muscles during mastication. It is, however, unknown how the activity profiles of the jaw muscles are influenced by long-term alterations in masticatory load. In order to elucidate the effect of reduced masticatory load on the daily habitual activity profiles of three functionally different jaw muscles, the electromyograms of the masseter, temporalis and digastric muscles were recorded telemetrically in 16 male rabbits between seven and 20 weeks of age. Starting at eight weeks of age the experimental animals were fed significantly softer pellets than the control animals. Daily muscle activity was quantified by the relative duration of muscle use (duty time), burst number and burst length in relation to multiple activity levels. The daily duty time and burst number of the masseter muscle were significantly lower in the experimental group than in the control group at 5% and 10% of the maximum activity during the two weeks following the change in food hardness. By contrast, altered food hardness did not significantly influence the activity characteristics of the temporalis and digastric muscles. The findings suggest that a reduction in masticatory load decreases the neuromuscular activity of the jaw-closing muscles that are primarily responsible for force generation during mastication. This decrease is most pronounced in the weeks immediately following the change in food hardness and is limited to the activity levels that reflect muscle contractions during chewing. These findings support the conclusion that the masticatory system manifests few diet-specific long-term changes in the activity profiles of jaw muscles.
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Affiliation(s)
- T Grünheid
- Department of Orthodontics, Academic Centre for Dentistry Amsterdam (ACTA), Research Institute MOVE, University of Amsterdam and VU University Amsterdam, Amsterdam, The Netherlands.
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Menegaz RA, Sublett SV, Figueroa SD, Hoffman TJ, Ravosa MJ, Aldridge K. Evidence for the Influence of Diet on Cranial Form and Robusticity. Anat Rec (Hoboken) 2010; 293:630-41. [DOI: 10.1002/ar.21134] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Jaw-muscle fiber architecture in tufted capuchins favors generating relatively large muscle forces without compromising jaw gape. J Hum Evol 2009; 57:710-20. [PMID: 19875148 DOI: 10.1016/j.jhevol.2009.06.001] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2008] [Revised: 04/12/2009] [Accepted: 06/01/2009] [Indexed: 11/23/2022]
Abstract
Tufted capuchins (sensu lato) are renowned for their dietary flexibility and capacity to exploit hard and tough objects. Cebus apella differs from other capuchins in displaying a suite of craniodental features that have been functionally and adaptively linked to their feeding behavior, particularly the generation and dissipation of relatively large jaw forces. We compared fiber architecture of the masseter and temporalis muscles between C. apella (n=12) and two "untufted" capuchins (C. capucinus, n=3; C. albifrons, n=5). These three species share broadly similar diets, but tufted capuchins occasionally exploit mechanically challenging tissues. We tested the hypothesis that tufted capuchins exhibit architectural properties of their jaw muscles that facilitate relatively large forces including relatively greater physiologic cross-sectional areas (PCSA), more pinnate fibers, and lower ratios of mass to tetanic tension (Mass/P(0)). Results show some evidence supporting these predictions, as C. apella has relatively greater superficial masseter and temporalis PCSAs, significantly so only for the temporalis following Bonferroni adjustment. Capuchins did not differ in pinnation angle or Mass/P(0). As an architectural trade-off between maximizing muscle force and muscle excursion/contraction velocity, we also tested the hypothesis that C. apella exhibits relatively shorter muscle fibers. Contrary to our prediction, there are no significant differences in relative fiber lengths between tufted and untufted capuchins. Therefore, we attribute the relatively greater PCSAs in tufted capuchins primarily to their larger muscle masses. These findings suggest that relatively large jaw-muscle PCSAs can be added to the suite of masticatory features that have been functionally linked to the exploitation of a more resistant diet by C. apella. By enlarging jaw-muscle mass to increase PCSA, rather than reducing fiber lengths and increasing pinnation, tufted capuchins appear to have increased jaw-muscle and bite forces without markedly compromising muscle excursion and contraction velocity. One performance advantage of this morphology is that it promotes relatively large bite forces at wide jaw gapes, which may be useful for processing large food items along the posterior dentition. We further hypothesize that this morphological pattern may have the ecological benefit of facilitating the dietary diversity seen in tufted capuchins. Lastly, the observed feeding on large objects, coupled with a jaw-muscle architecture that facilitates this behavior, raises concerns about utilizing C. apella as an extant behavioral model for hominins that might have specialized on small objects in their diets.
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Organ JM, Teaford MF, Taylor AB. Functional correlates of fiber architecture of the lateral caudal musculature in prehensile and nonprehensile tails of the platyrrhini (primates) and procyonidae (carnivora). Anat Rec (Hoboken) 2009; 292:827-41. [PMID: 19402068 DOI: 10.1002/ar.20886] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Prehensile-tailed platyrrhines (atelines and Cebus) and procyonids (Potos) display bony tail features that have been functionally and adaptively linked to their prehensile behaviors, particularly the need to resist relatively greater bending and torsional stresses associated with supporting their body weight during suspensory postures. We compared fiber architecture of the mm. intertransversarii caudae (ITC), the prime tail lateral flexors/rotators, in 40 individuals distributed across 8 platyrrhine and 2 procyonid genera, divided into one of two groups: prehensile or nonprehensile. We tested the hypothesis that prehensile-tailed taxa exhibit relatively greater physiologic cross-sectional areas (PCSAs) to maintain tail suspensory postures for extended periods. As an architectural trade-off of maximizing force, we also predicted prehensile-tailed taxa would exhibit relatively shorter, more pinnate fibers, and a lower mass to tetanic tension ratio (Mass/P(O)). Prehensile-tailed taxa have relatively higher PCSAs in all tail regions, indicating their capacity to generate relatively greater maximum muscle forces compared to nonprehensile-tailed taxa. Contrary to our predictions, there are no group differences in pinnation angles, fiber lengths or M/P(O) ratios. Therefore, the relatively greater prehensile PCSAs are driven largely by relative increase in muscle mass. These findings suggest that relatively greater ITC PCSAs can be functionally linked to the need for prehensile-tailed taxa to suspend and support their body weight during arboreal behaviors. Moreover, maximizing ITC force production may not come at the expense of muscle excursion/contraction velocity. One advantage of this architectural configuration is it facilitates suspension of the body while simultaneously maximizing tail contact with the substrate.
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Affiliation(s)
- Jason M Organ
- Department of Surgery, Center for Anatomical Science and Education, Saint Louis University School of Medicine, St. Louis, Missouri 63104, USA.
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Rogers CR, Mooney MP, Smith TD, Weinberg SM, Waller BM, Parr LA, Docherty BA, Bonar CJ, Reinholt LE, Deleyiannis FWB, Siegel MI, Marazita ML, Burrows AM. Comparative microanatomy of the orbicularis oris muscle between chimpanzees and humans: evolutionary divergence of lip function. J Anat 2009; 214:36-44. [PMID: 19166471 PMCID: PMC2631558 DOI: 10.1111/j.1469-7580.2008.01004.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/19/2008] [Indexed: 12/01/2022] Open
Abstract
The orbicularis oris muscle plays a role in the production of primate facial expressions and vocalizations, nutrient intake, and in some non-human primates it is used as a prehensile, manipulative tool. As the chimpanzee (Pan troglodytes) is the closest living relative of humans, a comparison of the orbicularis oris muscle between these species may increase our understanding of the morphological specializations related to the differing functional demands of their lips and the factors responsible for their divergent evolution. To this end, this study compares the microanatomy of the mid-line upper fibers of the orbicularis oris muscle between chimpanzees and humans. A mid-line portion of the orbicularis oris muscle was harvested from the upper lips of three chimpanzee and five human cadavers. The sampled blocks included the area between the lateral borders of the nasal alar cartilages in both species. Each sample was processed for paraffin histology, sectioned and stained with a variety of protocols. Sections were examined for fiber direction and relative thickness of muscle layers. Ratios of cross-sectional connective tissue area vs. cross-sectional muscle tissue area, muscle fiber diameter and relative dermal thickness were calculated for each species. In both species, a clear pars marginalis layer was recognized, contrary to previous reports that only humans possess this layer. In chimpanzees, the relative fiber diameter and relative amount of muscle tissue (i.e. based on ratio of connective tissue area : muscle tissue area) were significantly (P < 0.05) greater than in humans. In contrast, measurements of relative dermal thickness showed that humans have a greater average dermal thickness of the upper lip than chimpanzees. Taken together, these results suggest that both human and chimpanzee orbicularis oris muscle upper fibers meet the specific functional demands associated with their divergent vocal and facial display repertoires, the development of human speech, and the use of the upper lip as a prehensile tool in chimpanzees.
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Affiliation(s)
- Carolyn R Rogers
- Division of Plastic Surgery, Department of Surgery, School of Medicine, University of Wisconsin Hospital and Clinics, USA
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Ravosa MJ, Kunwar R, Stock SR, Stack MS. Pushing the limit: masticatory stress and adaptive plasticity in mammalian craniomandibular joints. ACTA ACUST UNITED AC 2007; 210:628-41. [PMID: 17267649 DOI: 10.1242/jeb.02683] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Excessive, repetitive and altered loading have been implicated in the initiation of a series of soft- and hard-tissue responses or ;functional adaptations' of masticatory and locomotor elements. Such adaptive plasticity in tissue types appears designed to maintain a sufficient safety factor, and thus the integrity of given element or system, for a predominant loading environment(s). Employing a mammalian species for which considerable in vivo data on masticatory behaviors are available, genetically similar domestic white rabbits were raised on diets of different mechanical properties so as to develop an experimental model of joint function in a normal range of physiological loads. These integrative experiments are used to unravel the dynamic inter-relationships among mechanical loading, tissue adaptive plasticity, norms of reaction and performance in two cranial joint systems: the mandibular symphysis and temporomandibular joint (TMJ). Here, we argue that a critical component of current and future research on adaptive plasticity in the skull, and especially cranial joints, should employ a multifaceted characterization of a functional system, one that incorporates data on myriad tissues so as to evaluate the role of altered load versus differential tissue response on the anatomical, cellular and molecular processes that contribute to the strength of such composite structures. Our study also suggests that the short-term duration of earlier analyses of cranial joint tissues may offer a limited notion of the complex process of developmental plasticity, especially as it relates to the effects of long-term variation in mechanical loads, when a joint is increasingly characterized by adaptive and degradative changes in tissue structure and composition. Indeed, it is likely that a component of the adaptive increases in rabbit TMJ and symphyseal proportions and biomineralization represent a compensatory mechanism to cartilage degradation that serves to maintain the overall functional integrity of each joint system. Therefore, while variation in cranial joint anatomy and performance among sister taxa is, in part, an epiphenomenon of interspecific differences in diet-induced masticatory stresses characterizing the individual ontogenies of the members of a species, this behavioral signal may be increasingly mitigated in over-loaded and perhaps older organisms by the interplay between adaptive and degradative tissue responses.
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Affiliation(s)
- Matthew J Ravosa
- Department of Pathology and Anatomical Sciences, University of Missouri School of Medicine, M263 Medical Sciences Building, One Hospital Drive DC055.07, Columbia, MO 65212, USA.
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