A comparative study of posterior teeth buccolingual inclination between cleft lip and palate and non-cleft palate with skeletal Class III malocclusion skeleton relationship patients based on CBCT

Abstract

Abstract Background: The purpose of this study was to evaluate the differences between buccolingual inclination of maxillary posterior teeth between cleft lip and palate（CLP）and non-cleft palate with skeletal Class III malocclusion patients. We aimed to examine the reasons for the differences and to explore a method of maxillary expansion which is more suitable for patients with CLP. Methods: For this retrospective study, 40 patients with CLP and 21 patients with skeletal Class III malocclusion were selected. The CLP group was divided into the unilateral cleft lip and palate (UCLP) and bilateral cleft lip and palate (BCLP) groups. The buccolingual inclination of the maxillary first premolar (BI4), maxillary second premolar (BI5) and first molar (BI6) were measured using cone-beam computed tomography (CBCT), and the differences between them were compared and analyzed statistically. Results: There were significant differences between cleft side BI4 and non-cleft side BI4 in the UCLP group, BI5 in the BCLP group, BI4 and BI5 in all CLP groups and the skeletal Class III malocclusion group. There was almost no difference in BI6 between the three groups. Conclusions: The premolars of patients with CLP do not show the same regularity as those with Class III; this may be related to surgical scarring of the cleft palate. Attention should be paid to the correction of buccolingual inclination in the maxillary expansion of patients with CLP.