Abstract
The purpose of the present study was to investigate the distribution of age and cleft types on 3,293 patients with cleft lip and/or palate who visited the Orthodontic Clinic in the Dental Hospital at Tokyo Medical and Dental University during 1971-2005. In addition, the cases of surgical intervention related to orthodontic treatment were surveyed. Results were as follows:
1) The most common age group of the patients registered at the first visit was 6-9, which accounted for 52.7% of all patients. The frequency of adult patients (18 years old and up) has been increasing recently.
2) The most common age group of the patients with whom orthodontic treatment was commenced during 1971-1991 was 9-11, which accounted for 47.1% of all patients. On the other hand, during 1992-2005, patients aged 8-10 accounted for 40.5%. The frequency of adult patients (18 years old and up) has been increasing recently.
3) The distribution by cleft type was 18.1% with cleft lip (unilateral,15.6%; bilateral,2.5%),62.7% with cleft lip and palate (unilateral,46.1%; bilateral,16.6%), and 18.9% with cleft palate.
4) The overall ratio of male to female was 1.2: 1, and that in each cleft type was 1: 1 in cleft lip,1.6: 1 in cleft lip and palate, and 1: 1.8 in cleft palate.
5) Concerning the surgical intervention related to orthodontic treatment, mandibular osteotomy was introduced in 1980, two-jaw surgery in 1984, secondary bone grafting in 1986, and segmental osteotomy in 1994. The RED system was applied to maxillary distraction osteogenesis in 1999, and after that, the Zurich system and dento-alveolar distraction were introduced. The total number of surgical interventions was 796.
