Roentgenocephalometric study on the teeth and skull
For the purposes of augmentation of the aid for case analysis and diagnosis of malocclusion, a roentgenocephalometric study was made from 84 Korean adolescences.
The subjects consist of 42 males and 42 females aged from 17 to 20 years with normal occlusion and acceptable facial appearance. The author measured 18 angles and 14 linear distances as suggested by Jarabak.
The following results were obtained.
1) Each linear measurement of the males' skull was greater than that of the females.
2) The posterior to anterior facial height was 69.2% in the males and 67.1% in the females.
3) In the relationship of upper lip to esthetic line, the lip of females was more behind than that of males.
4) Saddle angle was 124.7°, articular angle was 148.7°, gonial angle was 119.4°and upper and lower gonial angles were 45.1(N-Go-a) and 74.2(N-Go-Me).
5) The ratio of mandibular body to anterior cranial base was about 1:1.1.
6) The angulations of SNA°, SNB° and SNPo° were as follows; SNA°, 80.3°, SNB°, 79.8°, SNPo°, 81.1°.
7) The angle of the sella-nasion plane to the mandibular plane(SNGoMe°) was 32.0° and that of the occlusal plane to the mandibular plane was 18.2°.
8) The angle of the maxilary central incisor to the sella-nasion plane(1-SN°) was 105.6°. That of the mandidular central incisor to the mandidular plane(1-GoMe°) was 94.0°, and the interincisal angle(1 to 1°) was 127.6°.
9) The linear distance from incisal edge of upper central incisor to facial plane was 8.0㎜ and that of lower central incisor was 4.6㎜.
10) In the relationship of the lower lip to the esthetic line, the lower lip was 0.2㎜ front of the esthetic line.