Maxillary Protraction Therapy in Class III Patients With and Without Cleft Lip and Palate: An Interim Report of a Prospective Comparative Study

Abstract

Objective: To investigate and compare the effects of maxillary protraction therapy on Class III patients with unilateral cleft lip and palate (UCLP) and Class III patients with noncleft. Design: Prospective controlled clinical trial. Patients: Twenty-six Class III patients with UCLP (mean age: 10.32 ± 1.29 years) and 26 Class III patients with noncleft (mean age: 9.82 ± 1.03 years) were included and treated with maxillary protraction therapy. Interventions: Maxillary protraction therapy was performed with an intraoral Hyrax appliance and extraoral facemask. Cone beam computed tomography scans were taken before and after treatment. Pretreatment skeletal and dental characteristics and treatment changes were analyzed and compared. Results: The average treatment duration was 18.44 ± 4.16 months in the UCLP group, which was substantially longer than the 12.46 ± 4.03-month average treatment duration in the noncleft group ( P < .001). No significant difference was found in the maxillary changes (length, advancement of point A, and SNA angle) and improvement of intermaxillary relationship (ANB angle) between the 2 groups. The UCLP group had 1.40° more mandibular clockwise rotation ( P = .034). Regarding dental changes, the UCLP group had more upper incisor proclination ( P = .006) and less lower incisor retroclination ( P = .023). Conclusions: Approximately extended maxillary protraction therapy in patients with UCLP could be as effective as in patients with noncleft. Further study is required to follow patients until completion of growth to elucidate the long-term stability of the treatment.