歯科矯正患者群における先天性欠如と歯の喪失

[Congenital absence and loss of teeth in an orthodontic patient group].

抄録

6～15歳の女性655人、男性505人の矯正歯科患者1,160人のパノラマX線写真を選び、先天欠如、永久歯喪失、乳歯早期喪失について調査した。その結果、先天性欠如は100人（8.6％、第三大臼歯を含まない）、185人（16％、第三大臼歯を含む）であった。永久歯の欠損率は上側切歯が22.4％（第3大臼歯を除く）と最も多く、次いで上顎第2小臼歯が17.8％、下顎第2小臼歯が15.1％、下顎側切歯が12.5％であった。また、永久歯の喪失は105人（9.1％）であった。下顎第一大臼歯の喪失が最も多く（52.8％）、次いで上顎第一大臼歯（18.2％）であった。先天性欠如と永久歯喪失のいずれにおいても、女性と男性の間に統計学的有意差は認められなかった（α＝0.01）。乳歯の早期喪失は467人（40.3％）に認められた。第2乳臼歯の喪失が最も多く、次いで第1乳臼歯、乳犬歯の順であった。統計学的有意差（α=0.01）は、男性よりも女性の方が大きかった。

Panoramic radiographs of 1,160 orthodontic patients, 655 females and 505 males, 6-15 years of age were selected for study in congenital absence, loss of permanent teeth and premature loss of deciduous teeth. The result from this investigation showed congenital absence for 100 subjects (8.6%, not including third molars) and 185 subjects (16%, third molars included). The permanent upper lateral incisors are most frequently missing (22.4%, third molars excluded), followed by upper second premolar, 17.8%, lower second premolar, 15.1%, and then lower lateral incisor, 12.5%. The study also showed loss of permanent teeth of 105 subjects (9.1%). The lower first molars are most frequently lost (52.8%), followed by the upper first molar (18.2%). There is no statistical significance (alpha = 0.01) between females and males in both congenital absence and loss of permanent teeth. The premature loss of deciduous teeth was found in 467 subjects (40.3%). The most frequently loss happened to second deciduous molars, followed by first deciduous molars and then deciduous canines. There is more statistical significance (alpha = 0.01) in females than in males.