Dental crown symmetry in unilateral cleft lip and palate patients: A Three-Dimensional analysis on digital dental models

OBJECTIVES: The purpose of this study was to conduct a 3-dimensional assessment of possible dental crown asymmetry in dental crown shape and/or size that was not clinically visible in unilateral cleft lip and palate (UCLP) patients on the maxilla and mandible and make a comparison to the control group without CLP. SETTING AND SAMPLE POPULATION: The maxillary and mandibular digital models of orthodontically treated 35 individuals with non-syndromic UCLP (mean age: 14.6 ± 2.1 years) and 35 class I individuals without CLP (mean age 14.1 ± 1.5 years). MATERIALS AND METHODS: The crowns of the anterior and posterior teeth were segmented and the teeth on the cleft side were mirrored in UCLP patients considering the arbitrary midsagittal plane as reference. The first alignment was landmark-based and it was followed by the best-fit method. After aligning the images, millimetric differences (deviation analysis) between aligned surfaces were analysed. Independent Samples t test and Mann-Whitney U test were used for statistical comparisons. RESULTS: The highest difference between the cleft side and non-cleft side in the UCLP group was observed in the central incisors (1.85 ± 0.79 mm). The mean difference between the groups in the central incisors was 1.20 mm (95% CI: -1.70; -0.69; P < 0.001). The mean of median values was found to be highest in the central incisors in the UCLP group as 0.72 ± 0.27 mm. It was 0.15 ± 0.05 mm in the control group. CONCLUSION: The difference between the cleft and non-cleft side may exceed 1 mm in the maxillary central incisors of unilateral CLP patients.