In the oral examination of 22 Japanese monkeys (macaca fuscata) living in semi-wild conditions at Iwatayama, Kyoto Pref., a female adult monkey, ten years of age, which has been suffering from advanced periodontal disease was found. These monkeys were fed on mostly with raw vegetable diets during the last seven years.
This monkey showed severe, almost generalized gingival inflammation, deep pocket formation and remarkable tooth mobility, and its roentgenogram revealed severe alveolar bone resorption in regions of anterior teeth and first molar teeth. Tooth migration and lack of teeth were also observed. Debris and calculus accumulation was found significantly.
As a systemic disorder, tendency of pigment deficiency of hair, skin and eyes was noticed, but it was not serious and may not be related with periodontal disease. Nutritional condition was found to be good. Other monkeys examined had only slight or moderate manifestations of gingivitis and none of them showed bone resorption.
In conclusion, it is generally considered that monkeys fed on raw vegetable diets in field do not suffer from advanced periodontal disease, but in this case, there were many complicated local etiologic factors and these might cause svere periodontal destruction in a semi-wild monkey.