Host: Primate Society of Japan
Name : The Congress Primate Society of Japan
Number : 35
Location : [in Japanese]
Date : July 12, 2019 - July 14, 2019
Chimpanzee has the same number of permanent teeth as humans. The permanent teeth of humans are worn or decayed mainly by caries and aging, but the tendency for loss of permanent teeth in chimpanzees is unclear. The objective of this study was to investigate the change in permanent teeth of adult chimpanzees. The records of dental checkup for 110 chimpanzees obtained from 1980 to 2018 in Kumamoto Sanctuary were analyzed. The slopes of regression lines of age to total number of teeth for males were smaller than those for females, which indicated that males lost their teeth more rapidly than females. When the percentages of worn teeth to total teeth were compared between upper and lower teeth, the percentage of worn canines was higher for upper teeth than lower teeth only in males and the percentages of worn incisors were higher for upper teeth than lower teeth in both sexes. Canines and premolars of males were worn at a higher rate than those of females, which might be due to high incidence of fighting among males. Incisors were worn with aging in both sexes. Humans generally lose molars, but chimpanzees in the present study rarely lost molars. In conclusions, aging characteristics of permanent teeth in chimpanzees differ from those of humans, and the patterns of changes in permanent teeth of chimpanzees are different between sexes due to social behaviors such as fighting in males.
