Transverse differences between cleft lip and palate and non-cleft palate with skeletal Class III malocclusion using buccolingual inclination: a cone-beam computed tomography retrospective study

BACKGROUND: The purpose of this study was to evaluate the differences between buccolingual inclination (BI) of maxillary posterior teeth in patients with cleft lip and palate (CLP) and non-cleft palate with skeletal Class III malocclusion. We propose 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 BI of the maxillary first premolar (BI4), maxillary second premolar (BI5) and first molar (BI6) were measured using cone-beam computed tomography, and the differences between them were compared and analyzed by Student’s t-test. 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. BI6 was similar across all three groups. CONCLUSIONS: The premolars of patients with CLP do not exhibit the same regularity as those with Class III malocclusion; this may be related to surgical scarring of the cleft palate. Greater attention should be paid to the correction of BI in the maxillary expansion of patients with CLP.