Patterns of attrition of the dentition in Macaca were studied, from the morphological and functional points of view, by using 602 skulls consisting of Macaca fuscata and Macaca irus.
The pattern of attrition in each kind of thee teeth appears to depend on not only its shape but also movements of the mandible.
With the advance of age, the remarkable sexual dimorphism concerning the pattern of the dentition is found out in canines and lower first premolars. The development of attrition is very rapid at the lingual surface of lower incisors, and the layer of dentine is exposed over the whole lingual surface in a considerable early stage as compared with other teeth. Such a pattern is thought to be closely related to the very thin layer of enamel on these lingual surface of the incisors.