抄録
This research looks into the tooth extraction data (of 8880 extraction events) gathered from 12 member clinics of the Japan Health Care Dental Association (JHCDA) and made a comparative analysis against that of average dental clinics in Japan. The comparative data is taken from Report on the causes of extraction of permanent teeth (Feb 2005) by 8020 Promotion Foundation originally derived from the questionnaires on one week's extraction records collected from 2001 clinics (9,350 teeth extracted; 7,499 patients). The findings peculiar to the data of 12 JHCDA member clinics include: The ratio of extractions due to tooth fracture was higher at the member clinics than the control and there was a clear trend in the kind of teeth most extracted at the member sites, namely, the second molars and in particular mandibular second molars; There are different trends in the causes of extractions between anterior teeth and molars (multi-rooted); The cause of extractions of mandibular anterior teeth is mostly periodontitis; In the elderly group, extractions due to caries become more common than in the younger age groups.
