Distributions and trends were examined in 155 malocclusion patients who had been examined and diagnosed at Department of Orthodontics in Youngdong Severance Hospital over a 10 year-period from 1984 to 1993. The results were as follows ;
1. The number of patients per year had nearly quadrupled during the 10 year-period, with females(58.3%) outnumbering males(41.7%).
2. Age distribution had shown 7-12 year-old group being the largest(53.%), but percentages of 7-12 year-old and 13-18 year-old groups had been decreasing while that of above-19 patients had gradually increased.
3. Distributions in the types of malocclusion according to Angle's Classification had shown : 27.8% for Class Ⅰ, 22.6% for Class Ⅱ division 1, 7.9% for Class Ⅱ division 2, and 41.6% for Class Ⅲ. Percentages of Class Ⅰ patients had decreased while percentages of Class Ⅱ and Ⅲ patients had increased.
4. Non-extraction cases (75.4%) had outnumbered extraction cases (24.6%), with a general trend toward fewer extraction cases over the 10 year period.
5. Patients who had orthognathic surgery had been increasing, with Class Ⅰ, Ⅱ and Ⅲ cases comprising 8.8%, 16.9% and 74.3%, respectively. There had been three times as many 2-jaw operations as 1-jaw operations.
6. Nearly 4% of the subjects had facial asymmetries, with Class Ⅲ cases being the most frequent.
7. Patients with TMD symptoms comprised 4.6%, with an increasing trend. The symptoms had occurred more frequently in older patients and in females.
8. Geograpic distributions showed majority (3/4) of patients from the nearby area, namely Gangnam-gu, Seocho-gu and Songpa-gu.