A Statistical Investigation on Orthodontic Patients Who Received Appointed Treatment at Kyushu Dental College Hospital during a Five-year Period since 1982

In order to conduct an investigation on patients who had appointed orthodontic treatment at Kyushu Dental College Hospital, we collected the data of patients who came to consult during the 5 years from 1982 to 1986 and sorted them by sex, age at appointment, classification of malocclusion and residing area. The results were as follows : 1) The total number of patients during that period was 2, 329. Of these, 997 (41.7%) received appointed treatment. 2) Of those appointed, 383 (38.4%) were males and 614 (61.6%) were females, Female patients accounted for nearly two thirds of total. 3) By classification of malocclusion, the percentage of each kind was as follows : mandibular protrusion (27.5%), crowding (26.4%), cleft lip, jaw and palate (11.6%), maxillary protrusion (10.6%) and others, The percentage of male to female was as follows : 35.0 to 65.0 in mandibular protrusion, 32.3 to 67.7 in crowding, 58.3 to 41.7 in cleft lip, jaw and palate, 35.8 to 64.2 in maxillary protrusion. 4) By age, patients received appointed treatment at ages of 7 and 8 formed the largest group and about 90% of the total treatment by appointment by the age of 12. 5) Of those receiving appointed treatment, 872 (87.5%) resided in Fukuoka prefecture, including 669 (67.1%) in Kitakyushu city. The remaining 125 (12.5%) were other areas.