３地域におけるチベット系住民の口腔状態の比較 ＩＩＩ 永久歯う蝕り患状態について

Abstract

a comparative study was made in Karakoram (Goma village, 1974), northwest Nepal (Simikot village, 1983) and Yunnan province (Sinong village, 1989). Japanese data (1987) was used for comparison.1) In Goma and Simikot, the number of cases of permanent tooth caries was extremely small. On the other hand, it was very great in Sinong and Japan.2) The patterns of DFT can be divided into two groups: one group includes Sinong and Japan, the other Goma and Simikot.3) The DFT rate according to the location of teeth. The patterns can be divided into two groups, Sinong and Japan, Goma and Simikot.4) Caries surfaces: in Simikot, there was not a great difference between the number of cases of occlusal, proximal or distal and labiolingual surface caries. In Sinong, both upper and lower jaws had a great number of cases of occlusal surface caries, but the difference between the surfaces decreased according to age.5) The transition of caries grade: in the three Tibetan areas, the ratio of C4 to all carious teeth was quite similar.6) Missing teeth: in Goma, where the number of caries cases was extremely small, the number of missing teeth was the greatest after 35 years of age, probably because of severe attrition.7) Caries ratio of three molar teeth:Second and third molars: caries increase patterns were similar in the three Tibetan areas and in Japan.First molar: in Sinong, caries increased rapidly after eruption, Goma and Japan followed Sinong and in Simikot, caries increased very slowly.