Reasons for extraction of permanent teeth in Japan.

Eight hundred forty-nine Japanese dentists were asked to record the reason for every tooth extraction of permanent teeth during 1 week in each of four seasons. The reasons were assigned to six groups: dental caries, periodontal disease, eruption problems, trauma, orthodontics and other reasons. Thirty-eight to 40% of the dentists returned the forms in each season, relating to a total of 11,175 extracted teeth. Overall, caries was the most frequent reason for tooth extraction (55.4%), followed by periodontal disease (38.0%). The females lost more teeth due to caries than did the males. In the > or = 16 age groups, caries was the main reason for tooth extraction. However, periodontal disease became principal only in the males aged 46-65 yr. Anterior teeth, especially in the mandible, represented the highest percentage of periodontal extractions. A considerable difference in the major reason for maxillary tooth loss was observed between both sexes. Maxillary premolars and molars in the males were extracted for periodontal disease as much as for caries, whereas caries was the predominant reason for loss of all maxillary teeth in the females.