Abstract
Crossbite type was determined in 84 patients with cleft lip and/or palate who were first examined between the ages of 6-8 years at the Department of Orthodontics, Tokyo Dental College Suidobashi Hospital.
1. Of the 84 patients, 85.7% showed crossbite at one or more sites. The most common type of crossbite was Type A(28.6%), followed by Type ABP (25.0%), Type AUP (23.8%), Type BP (4.8%) and Type UP (3.6%).
2. The most common type of crossbite by cleft type was Type AUP in unilateral cleft lip and palate (50%), Type ABP in bilateral cleft lip and palate (35.7%), Type A in unilateral cleft lip and alveolus and unilateral cleft lip (54.5% and 66.7%, respectively), and Types A and ABP in cleft palate (30.0% each).
3. Incidence of crossbite at one or more sites was highest in cases of unilateral cleft lip and palate (100%), followed by bilateral cleft lip and palate (92.9%), cleft palate (90.0%), unilateral cleft lip and alveolus (72.7%) and unilateral cleft lip (66.7%).
4. The highest incidence of crossbite was on the affected side in cases with unilateral cleft lip and palate in the anterior teeth, deciduous canines, and deciduous molar regions. The lowest incidence of crossbite was on the healthy side in cases with unilateral cleft lip in the anterior teeth, on the healthy and affected sides in cases of unilateral cleft lip and on the healthy side in unilateral cleft lip and alveolus in deciduous canines and deciduous molars (0%).
5. On the healthy and affected sides in unilateral cleft lip and palate and the affected side in unilateral cleft lip and alveolus, successive decreases in the incidence of crossbite were observed from the anterior teeth towards the molar region. In bilateral cleft lip and palate, however, the deciduous canines were placed higher than the anterior teeth. In cleft palate, the deciduous molars were placed higher than the deciduous canines.
In this study, crossbite type was determined according to the classification of Kitabayashi with modifications together with incidence by affected side and site of cleft. The results clarified the characteristic crossbite type and its incidence for each of the conditions studied.
