Variations in anterior tooth morphology and alignment based on alveolar cleft position

Different alveolar cleft positions may influence dental morphology and alignment. The study aimed to summarize the morphology and alignment patterns of maxillary anterior teeth based on the alveolar cleft position and provide a scientific basis for phenotype-specific treatment strategies and prognostic assessments.

The sample consisted of 108 patients with nonsyndromic complete unilateral cleft lip and palate with permanent dentition. In total, 76 patients were in the mesial cleft (MC) group, with the cleft positioned mesial to the lateral incisor, and 32 patients were in the distal cleft (DC) group, with the cleft positioned distal to the lateral incisor. The morphology and alignment of maxillary anterior teeth were measured in cone-beam computed tomography and orthopantomograms. Variables were compared within and between groups.

The occurrence ratio of MC to DC was 2.33:1 in patients with unilateral cleft lip and palate. Cleft-side central incisors in the MC group demonstrated more pronounced retroclination (P = 0.008, q = 0.020) and distal crown inclination (P = 0.011, q = 0.024), along with more severe disruption of eruption (P = 0.004, q = 0.011). Cleft-side lateral incisors exhibited smaller crown width in the MC group (P <0.001, q = 0.004) and smaller root/crown ratio in the DC group (P = 0.004, q = 0.011). The torque and inclination of lateral incisors showed opposing orientations (P <0.001, q = 0.004), leading to a convergence tendency of cleft-adjacent teeth toward the cleft in the 2 groups.

The alveolar cleft position significantly influences the morphology and alignment of anterior teeth. Compared with MCs, DCs are associated with a better prognosis for lateral incisor crown morphology and central incisor alignment.