Abstract
The present study examines and describes variability and ontogenetic change in the masticatory structures of the orangutan. Mm. temporalis, masseter, pterygoideus lateralis, and pterygoideus medialis as well as m. digastricus are dissected, described, and removed unilaterally for drying from a sample of 10 orangutans. The temporomandibular joint and related structures are also described. Results indicate substantial interindividual variability in muscle morphology as well as possible age-related changes. Age-related changes in m. temporalis include an expansion of attachment area, adjustments in fiber direction, and changes in related bony structures. An increased attachment area is likewise seen in m. masseter in older individuals. Age-related variation is also seen in the position and extent of the origin of m. digastricus as well as in its fiber direction. A comparison of muscle weights indicates that m. pterygoideus lateralis is relatively larger in the neonate, whereas in the older individuals, it is relatively smaller compared to other masticatory muscles. The general morphology of the masticatory structures in the orangutan resembles that of other extant great apes and humans with the exception of m. digastricus. The orangutan differs in possessing only a posterior belly of this muscle.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Anderton, J. C. (1988). Anomalies and atavisms in appendicular myology. In Schwartz, J. H. (ed.)Orang-utan Biology, Oxford University Press, New York, pp. 331–345.
Bluntschli, H. (1929). Die Kaumuskulatur des Orang-utan und ihre bedeutung fur die Formung des Schädels I. Teil: Das morphologische verhalten.Gegenbauers Morph. Jrbk. 63:531–606.
Boyer, E. L. (1939). The cranio-mandibular musculature of the orang-utanSimia satyrus.Am. J. Phys. Anthropol. 24:417–427.
Cachel, S. (1984) Growth and allometry in primate masticatory muscles.Arch. Oral Biol. 29:287–293.
Carlson, D. S. (1983) Growth of the masseter muscle in rhesus monkeys (Macaca mulatta).Am. J. Phys. Anthropol. 60:401–410.
Dechow, P., and Carlson, D. (1990). Occlusal force and craniofacial biomechanics during growth in rhesus monkeys.Am. J. Phys. Anthropol. 83:219–237.
Groves, C. P. (1986).Systematics of the great apes. In Swindler, D. R., and Erwin, J. (eds.).Comparative Primate Biology, Vol. I. Systematics, Evolution, and Anatomy. Alan R. Liss, New York, pp. 187–217.
Herring, S. (1985a). Postnatal development of masticatory muscle function.Fortschritte Zool. 30:213–215.
Herring, S. (1985b). The ontogeny of mammalian mastication.Am. Zool. 25:339–349.
Herring, S., and Lakers, T. C. (1981). Craniofacial development in the absence of muscle contraction.J. Craniofacial Genet. Dev. Biol. 1:341–357.
Houston, W. J. B. (1974). Growth of the muscles of mastication in the rat.Trans. Eur. Orthodont. Soc. 50:85–90.
Hurov, J., Henry-Ward, W., Phillips, L., and German, R. (1988). Growth allometry of craniomandibular muscles, tendons, and bones in the laboratory rat (Rattus norvegicus): Relationships to oromotor maturation and biomechanics of feeding.Am. J. Anal. 183:381–394.
Ingleman-Sundberg, A., Nilsson, L., and Wirsen, C. (1981).A Child Is Born, Dell, New York.
Kiliaridis, S. (1986) Masticatory muscle function and craniofacial morphology, an experimental study in the growing rat fed a soft diet.Swed. Dent. J. Suppl. 36:1–55.
Krogman, W. M. (1931) Studies in growth changes in the skull and face of anthropoids. IV. Growth changes in the skull and face of the orang-utan.Am. J. Anat. 47:343–365.
Maeda, N., Hanai, H. and Kiemegawa, M. (1981). Postnatal development of masticatory organs in rats. III. Effects of mastication in postnatal development of them. masseter superficialis.Anat. Anz. 150:424–427.
McNamara, J. A. (1973). The independent function of the two heads of the lateral pterygoid muscle.Am. J. Anat. 138:197–205.
McNamara, J. A. (1974). An electromyographic study of mastication in the rhesus monkey (Macaca mulatta).Arch. Oral Biol. 19:821–823.
Moore, W. J. (1965). Masticatory function and skull growth.J. Zool. 146:123–131.
Moore, W. J. (1982). Skull form in hominoids. In Harrison, R. J., and Navaratnam, V. (eds.),Progress in Anatomy, Vol. 2, Cambridge University Press, Cambridge, pp. 49–79.
Moore, W. J., and Lavelle, C. L. B. (1974)Growth of the Facial Skeleton in the Hominoidea, Academic Press, New York.
Morbeck, M. E. and Zihlman, A. L. (1988). Body composition and limb proportions. In Schwartz, J. H. (ed.),Orang-utan Biology, Oxford University Press, New York, pp. 285–297.
Nakato, S. (1981). Relationship between the development and growth of cranial bones and masticatory muscles in postnatal mice.J. Dent. Res. 60:1440–1450.
Oyen, O. J. (1982). Masticatory function and histogenesis of the middle and upper face in chimpanzees (Pan troglodytes). In Dixon, A. D., and Sarnat, B. G. (eds.),Factors and Mechanisms Influencing Bone Growth, Alan R. Liss, New York, pp. 559–568.
Raven, H. C. (1950)The Anatomy of the Gorilla. Columbia University Press, New York.
Rayne, J., and Crawford, G. N. C. (1975). Increase in fibre numbers of the rat pterygoid muscles during postnatal growth.J. Anat. 119:347–357.
Rodman, P. S. (1988). Diversity and consistency in ecology and behavior. In Schwartz, J. H. (ed.),Orang-utan Biology, Oxford University Press, New York, pp. 31–51.
Röhrer-Ertl, O. (1988). Cranial growth. In Schwartz, J. H. (ed.),Orang-utan Biology, Oxford University Press, New York, pp. 201–223.
Schultz, A. H. (1941). Growth and development of the orang-utan.Contrib. Embryol. Carneg. Inst. 29:57–110.
Schumacher, G. H. (1962). Struktur und Funktionswandel der Kaumuskulatur nach der Geburt.Fortsche Kieferorthop. 23:135–166.
Schwartz, J. H. (1988). History, morphology, paleontology, and evolution. In Schwartz, J. H. (ed.),Orang-utan Biology, Oxford University Press, New York, pp. 69–85.
Scott, J. H. (1952). The growth and function of the muscles of mastication in relation to the development of the facial skeleton and of the dentition.Am. J. Orthodont. 40:429–449.
Sirianni, J. E., and Swindler, D. R. (1979). A review of postnatal craniofacial growth in old world monkeys and apes.Yb. Phys. Anthropol. 22:80–104.
Sonntag, C. F. (1924). On the anatomy, physiology, and pathology of the orang-utan.Proc. Zool. Soc. Lond. 24:349–451.
Strzalko, J., and Malinowski, A. (1972). The muscles of mastication and cranial proportions in primates.Folia Morphol. 31:207–213.
Swindler, D. R., and Wood, C. D. (1973).An Atlas of Primate Gross Anatomy, University of Washington Press, Seattle.
Ward, S. C., and Brown, B. (1986). The facial skeleton ofSivapithecus indicus. In Swindler, D. R., and Erwin, J. (eds.),Comparative Primate Biology, Vol. I. Systematics, Evolution, and Anatomy. Alan R. Liss, New York, pp. 413–452.
Weijs, W. A., Brugman, P., and Kolk, E. M. (1987). The growth of the skull and jaw muscles and its functional consequences in the New Zealand rabbit (Oryctolagus cuniculus).J. Morphol. 194:143–161.
Williams, P. L., and Warwick, R. (1980)Gray's Anatomy, W. B. Saunders, Philadelphia.
Winkler, L. (1988). Variation in the suboccipital anatomy. In Schwartz, J. H. (ed.),Orang-utan Biology, Oxford University Press, New York, pp. 225–232.
Woodburne, (1983).Essentials of Human Anatomy, Oxford University Press, New York.
Zey, A. (1940).Funtion des Kauapparates und Schädelgestaltung bei den Wierderkäuern. Ph.D. Dissertation, Universität Frankfurt am Main.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Winkler, L.A. Morphology and variability of masticatory structures in the orangutan. International Journal of Primatology 12, 45–65 (1991). https://doi.org/10.1007/BF02547558
Received:
Revised:
Issue Date:
DOI: https://doi.org/10.1007/BF02547558