A study of the changes in facial profile after orthodontic treatment. Part 1. Comparison between the improved group and unimproved group.

The purpose of this study was to investigate the harmonious facial profile before and after orthodontic treatment on permanent dentition and to determine the factors which influence lateral facial harmony. Materials were lateral Roentgen cephalograms from 150 subjects (25 males and 25 females each in 3 groups--maxillary protrusion, mandibular protrusion and crowding--) taken before and after treatment. The average age before treatment was 11 years and 6 months and, after treatment, was 14 years and 3 months. The term of active treatment was 2 years and 9 months. Lateral facial evaluation based on the external profile line was performed by a group of 40 persons which included dental students and the general public. In the 5 stage evaluation, each subject could receive from 40 to 200 points. The subjects with more than 121 points were classified in the harmonious group; those with less than 120 points were classified in the disharmonious group. Subjects who had been classified as disharmonious before treatment but became harmonious after treatment constituted the improved group. Subjects classified disharmonious before treatment who remained disharmonious after treatment constituted the unimproved group. The value of the overall harmonious group before treatment was 8.6% and, after treatment, was 36.6%. The increase in the percentage of cases classified as harmonious varied among the different occlusal types: for the mandibular protrusion, the value before treatment was 2% and after treatment was 32%, for crowding it was 18% before and 46% after treatment, and for maxillary protrusion, it was 6% before and 32% after treatment. The ratio of percentage in the harmonious group increased on every malocclusion group after treatment, suggesting the importance of orthodontic treatment for improvement of lateral facial harmony. Before treatment, the morphological conditions in the improved group were more advantageous than those in the unimproved group.

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

UNLABELLED: 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.

Case report of lateral crossbite. Part I. Mixed dentition.

Lateral crossbite on mixed dentition does not always cause facial asymmetry or functionally abnormal movement of the mandible in children. However, it is often observed that facial asymmetry will worsen during growth in the absence of orthodontic treatment. In adult cases, lateral crossbite is one of the etiological factors of temporomandibular joint disorder. This case report presents two cases of lateral crossbite of mixed dentition. The terms of treatment were shorter than those in cases with permanent dentition. Also, methods of treatment were simpler, and the patients developed favorably. The opposite results were obtained in cases of permanent dentition.