Dehiscence and buccal bone thickness after rapid maxillary expansion in young patients with unilateral cleft lip and palate

Introduction: The present study aimed to evaluate the consequences of rapid maxillary expansion in the buccal bone thickness and dehiscence of subjects with unilateral cleft lip and palate. Methods: This prospective cohort study consisted of 30 participants, 20 males and 10 females, between 8 and 15 years old. Participants were allocated into 3 groups, according to the type of maxillary constriction, and were treated with different types of expanders: G1, hyrax; G2, fan-type; G3, inverted mini-hyrax. Cone-beam computed tomography scans were performed immediately before treatment and after 90 days of retention. Linear measurements were obtained by the same calibrated and blinded examiner. Results: An average of 0.8 mm decrease in buccal bone thickness (P\0.001) and a 0.5 mm increase in dehiscence (P\0.001) were observed. There was no significant difference between the cleft and noncleft side for all variables (P.0.05), as there was no significant difference between groups (P.0.05). Conclusion: The findings in this study allow the conclusion that the orthopedic forces of rapid maxillary expansion lead to a decrease in the posterior buccal bone volume in unilateral cleft lip and palate patients. (Am J Orthod Dentofacial Orthop 2022;162:16-23)