title: Protuberance or fossa on the lateral surface of the mandible in primates.
abstract: In order to clarify the morphological characteristics and function of the protuberance and/or fossa on the lateral surface of the mandible, we examined 778 mandibles of 9 genera, 19 species of non-human primates. Both protuberance and fossa were found in Macaca, Chlorocebus, and Cercocebus at frequencies ranging from 0% to 60%. The protuberance was composed of compact bone and was similar to the mandibular torus in humans. A well-developed protuberance extended from the fourth premolar to third molar region, and was situated at the central part of the mandibular body, or continued on the oblique line. Sometimes the protuberance localized on the mandibular base. A deep and large fossa was found in all individuals of Papio, Theropithecus, and Mandrillus, and the bone width was thin in the center of the fossa. The fossa extended from the third premolar to the second molar region, and the deepest area was the first molar region. In Macaca, Chlorocebus, and Cercocebus, the curvature of the external table of the mandible created a fossa. In Colobus, and Hylobates, the external surface of the mandible looked concave because of the thickened mandibular base. These concavo-convex structures have some biological functions and represent an adaptive change for mastication.
authors: Department of Anatomy, School of Dentistry at Matsudo, Nihon University, 2-870-1 Sakaecho-Nishi, Matsudo, Chiba 271-8587, Japan. Electronic address: kondou.shintarou@nihon-u.ac.jp.
authors: Shintaro
authors: S
authors: Kondo
authors: Department of Oral and Maxillofacial Radiology, School of Dentistry, Aichi-Gakuin University, 2-11 Suemori-Dori, Chikusa-ku, Nagoya 464-8651, Japan.
authors: Munetaka
authors: M
authors: Naitoh
authors: Department of Anatomy, School of Dentistry at Matsudo, Nihon University, 2-870-1 Sakaecho-Nishi, Matsudo, Chiba 271-8587, Japan.
authors: Masanobu
authors: M
authors: Matsuno
authors: Department of Anatomy, School of Dentistry at Matsudo, Nihon University, 2-870-1 Sakaecho-Nishi, Matsudo, Chiba 271-8587, Japan.
authors: Eisaku
authors: E
authors: Kanazawa
authors: Primate Research Institute, Kyoto University, 41-2 Kanrin, Inuyama 484-8506, Japan.
authors: Masanaru
authors: M
authors: Takai
mesh_terms: D000818:Animals; D001641:Bicuspid / Q000033:anatomy & histology; D002428:Cebus; D015186:Hominidae; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008251:Macaca; D008334:Mandible / Q000033:anatomy & histology*; D008964:Molar, Third / Q000033:anatomy & histology; D010215:Papio; D011323:Primates / Q000033:anatomy & histology*; D012727:Sex Characteristics; D013045:Species Specificity; D014057:Tomography, X-Ray Computed; D014096:Tooth, Supernumerary
keywords: Computed tomography; Functional anatomy; Mandibular fossa; Mastication; Protuberance