Maxillary Protraction Effects on Anterior Crossbites.

Objective: To test the hypothesis that there is no difference between the effects of maxillary protraction on anterior crossbites in repaired unilateral cleft lip and palate (UCLP) and noncleft prepubertal boys. Materials and Methods: Eighteen operated UCLP boys with anterior crossbite (aged 9.54 ± 1.21 years) were the experimental subjects. Eighteen noncleft boys with similar malocclusion (aged 9.75 ± 1.46 years) were selected as a control group. A Hyrax appliance and reverse headgear were applied. Lateral cephalometric radiographs were taken before and after the treatment. Computerized cephalometric analysis and statistics were carried out. Results: There were no significant differences in anterior movement of point A between the two groups (P > .05). ANB increased by 3.82° and A-Pg (FH) increased by 5.89 mm in the UCLP group. ANB increased by 2.68° and A-Pg (FH) increased by 3.66 mm in the noncleft group. The change of sagittal skeletal intermaxillary relationships was significantly larger in the UCLP group than in the noncleft group (P < .05). The change of lower lip in the UCLP group was less than in the noncleft group (P < .05). Conclusions: The hypothesis is rejected. The changes of sagittal skeletal intermaxillary relationship and mandibular clockwise rotation were larger in the operated UCLP patients than in the noncleft subjects. The amount of the lower lip retrusion was significantly less in the UCLP patients. [ABSTRACT FROM AUTHOR]