[The study on the orthodontic patients who visited department of orthodontics, Seoul National University Hospital].

From 1965 to 1974, the total number of the orthodontic patients who visited Seoul National University Hospital was only about 1000. But in the last several years the number has been increasing so rapidly that we have about 1000 new orthodontic patients every year. This made it necessary to undertake an epidemiologic study on them so that we can accommodate their orthodontic needs adequately. Accordingly, the present study was done in an attempt to provide reliable quantitative information regarding the characteristics of malocclusion-Angle's classification etc.--of patients who visited Department of Orthodontics, Seoul National University Hospital from 1985 to 1989. The total number was 3305. This study sought to determine the annual trend in total number during 5 years, frequency in each age and sex group and distribution according to Angle's classification. It was found that: 1. Total number of orthodontic patients has been increasing and the number of female patients was 1.55 times as high as that of male. 2. Percentage of Class III malocclusion has been increasing, but that of Class I decreasing. Each percentage of Class I, Class II div. 1, Class II div. 2 and Class III was 35.92%, 13.40%, 1.54%, and 49.14%. 3. Percentages of 8 to 12-year-old group and 12 to 18-year-old group showed decreasing trends, but that of adult patients showed increasing trend.