A study of the harmonious profile in facial esthetics. Part 1. Descriptive statistics.

Abstract

The purpose of this study was to investigate the relationship between a harmonious profile and normal occlusion, differences between good and poor groups, and the characteristics of a good group from normal occlusion group and after orthodontic treatment groups. The sample included 60 subjects with normal occlusion (normal subjects) and 88 after orthodontic treatment subjects (orthodontic subjects). Evaluators were 20 students and 20 orthodontists from Tokyo Dental College. For the purpose of profile evaluation, normal and orthodontic subjects were classified into 3 groups (good, mediocre, and poor) based in their external profile lines. Lateral Roentgen-cephalograms were used to measure hard and soft tissues. Mean values and Student's t-test were calculated statistically. RESULTS: 1. The frequencies of the good and poor subjects were similar in both normal subjects and orthodontic subjects. When considering the mediocre group, however, the normal subjects were more likely to have a better profile than the other subjects. 2. There were differences in hard tissues between the good group and the poor group in both the normal subjects and the orthodontic subjects, but only slight differences in soft tissues. 3. In the good groups of both normal and orthodontic subjects (all subjects), the edges of the upper and lower central incisors and upper and lower lips retruded, the ratio of upper facial height to total facial height was greater and the chin region was thicker than in the poor group. Additionally, in the good group of normal subjects, the maxilla protruded and the anteroposterior difference between the maxilla and mandible was larger.