2009 年 43 巻 2 号 p. 157-161
We investigated the vertical relation between the skeletal and alveolar components of the Japanese face using a simple assessment of vertical proportions of the face. We analyzed 114 lateral cephalometric radiographs of subjects judged to have attractive profiles. Subjects were selected who had upper and lower lips within the soft tissue E-line. They were divided into five groups based on FMA. The principal measurement items used in this analysis were the N-Me line, the S-Go line, the distance of Me perpendicular to the palatal plane, the distance from Ar to Go, and the FMA. We used the ratio of S-Go to N-Me to assess the skeletal component and the ratio of Ar-Go to the distance of Me perpendicular to the palatal plane to assess the alveolar component. We also investigated how FMA correlates with these two components.
We found that the ratio of the distance of Ar-Go to the distance of Me perpendicular to the palatal plane was correlated with FMA and with the ratio of S-Go to N-Me in all groups. The most acceptable ratio of the alveolar component occurred for an FMA between 25 and 32 degrees.
For an FMA between 25 and 32 degrees, 72% was the best ratio of for the alveolar component in order to present was best good balance in the profile. These findings suggest that we can use both FMA and the ratio of the distance of Ar-Go to the distance of Me perpendicular to palatal plane when determining individualized treatment targets.
