Abstract
The frequency and the position of congenitally missing teeth (excluding third molars) were examined in 3, 435 students in Hokkaido. X-ray photographs were taken of suspected cases with occlusal film. Among the subjects, 296 cases (8.6 percent) had congenitally missing teeth. Cases with one tooth missing were most frequent, followed by cases with two missing. In the present samples, the premolars were most frequently missing followed by the incisors. Among 172 cases with missing premolars, 81 cases were in the mandible, 64 cases in the maxilla and 27 cases in both jaws, whereas of the cases with missing incisors, 86 were in the mandible, 36 in the maxilla and 3 cases in both jaws.
