The purpose of this study was to investigate the angle formed by the Sella-Nasion(SN) plane and Frankort-Horizontal(FH) plane and evaluate the correlation and difference of the FH plane to other horizontal reference planes. Through this study we hope to present a basis for selecting a horizontal reference plane which can be implemented in cephalometric studies and in surgical orthodontic treatment planning. 600 subjects were chosen following a clinical examination and lateral cephlometric X-rays were taken. According to cephalometric analysis the subjects were classified into 3 groups; Skeletal Class I malocclusion or normal occlusion group(male 50, female 50), Skeletal Class II malocclusion group(male 50, female 65) and Skeletal Class III malocclusion group(male 50, female 50). The results were as follows. 1. The angle formed by the SN plane and FH plane showed no difference among the malocclusion groups, but there was a significant sex difference. For males the angle measured was 7.47degrees+/-2.40degrees whereas for females it was 8.93degrees+/-2.72degrees. 2. The angle formed by the SN plane or FH plane and Mandibular plane was higher in females for all malocclusion groups. This angle in the Skeletal Class I malocclusion group was 1 awer than in the other two groups. 3. There was no difference among the sexes or malocclusion groups con ,idering the angle formed by the FH plane and Palatal plane. 4. The gonial angle in the Skeletal Class III malocclusion group was higher than in the Skeletal Class I and Class II malocclusion groups- in both sexes.
Adult* ; Female ; Hope ; Humans ; Male ; Malocclusion ; Sex Characteristics

This study was performed to evaluate soft tissue cephalometric norms for Korean adults which can be implemented in surgical orthodontic treatment planning using selected horizontal reference plane especially for Koreans (Male: SN-7.5degreeC, Female: SN-9.0degreeC) and a simplified analytical method. 70 males and 70 females consisting of freshmen of Yonsei University from 1996 to 1997 and students from the Dental College of Yonsei University were chosen according to clinical examination and cephalometric analysis. The samples had normal profiles, normal anteroposterior skeletal relationship(ANB angle of 0degreeC to 4degreeC and Wits appraisal of -4.0mm to 0mm), and Class I molar and canine relationship. They had no missing or supernumerary teeth and had no experience of orthodontic or prosthetic treatment. After the selection of 15 soft tissue landmarks and the construction of horizontal and vertical reference lines, 25 measurements were taken. These consisted of vertical and horizontal linear measurements and angular measurements. The results were as follows. 1. Mean and standard deviation of the measurements were calculated in males and females. 2. Vertical measurements were comparably bigger in males than females whereas anterior facial height ratio(sN-Sn/Sn-sMe) and lower anterior facial height ratio(Sn-Stms/Stmi-sMe) showed no significant difference between sexes. 3. Most of the horizontal measurements in relation to the vertical reference line(G-perpendicular) showed no significant difference between sexes. 4. Nasofacial angle, columellar angle, nasolabial angle and facial contour angle showed no significant difference between sexes. 5. The upper and lower lip were positioned about -1.0+/-2.0mm and +1.0+/-2.0mm in relation to the Ricketts' esthetic line in both sexes. In this study, soft tissue cephalometric norms of Korean adults for orthognathic surgery were obtained.
Adult ; Female ; Humans ; Lip ; Male ; Molar ; Orthognathic Surgery* ; Tooth, Supernumerary