We investigated the oral health condition in 221 subjects; 120 men and 101 women of the age 10 to 69 years old, at a hill village, named Kotyang, which located about 50 km east of Kathmandu from August 5 through August 25, 1987. The condition of the oral cavity in each subject was assessed by RD-test which is a simple method of semi-quantitative analysis for bacterial number in the oral cavity. 108 CFU/ml or more of bacterial number were detected in 55.8% of men and in 66.0% of women examined. The estimated numbers of the bacteria in their oral cavities were much more than those of Japanese. The color photographs of the oral cavity of each subject examined were taken and the periodontal status was assessed by means of PMA-index ; P. M and A represent papillary gingiva, marginal gingival and attached gingiva, respectively. The prevalence of periodontal diseases tended to be high as compared with that of Japanese, especially at their age of 50s and 60s. The hardness and fluorine contents in drinking water at several places in the village were 9-5lppm and 0.13-0.32ppm, respectively. This may have no effect on the occurrence of defect of dental calcification in the inhabitants in Kotyang
