著者

SAKASHITA,Reiko

出版者

日本矯正歯科学会

雑誌

Orthodontic waves : journal of the Japanese Orthodontic Society : 日本矯正歯科学会雑誌

巻号頁・発行日

vol.61, no.6, 2002

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In an effort to promote adequate development of the masticatory system and prevent dental problems, the Oral Health Promotion Project (OHPP) was started in 1984. The study was carried out for 8 years, and then followed up for another 9, in a district with no regular dental service, on Miyako Island, Okinawa, Japan. The study evaluated the Project's effect on occlusion by means of 163 longitudinal data on complete deciduous dentition (II A) at 4 years of age and 112 data on permanent dentition (IVA) at 13-15 years. Each age group was divided into four sections according to their birth year. As a control study, 352 data were collected from a neighbouring district. The presence of normal occlusion significantly increased and that of discrepancy type occlusion decreased among subjects born after 1984. This applied both to deciduous and permanent dentitions. An example would be the discrepancy in permanent dentition fell from 88.9% of children born in 1979-1980 (n=9), to 37.0% in those born in 1984-1985 (n=27) and to 27.8% for children born in 1986-1987 (n=18, p<0.05), while no significant changes were found in the control district. The majority of discrepancies (73.6%) seen at 4 years of age was still evident in the permanent dentition (p<0.001). Based on these results, the authors suggest that incidence of discrepant malocclusion can be reduced, but that it would be crucial to begin intervention soon after birth.