Eruption of incisor teeth in cleft lip and palate.

Longitudinal frontal and lateral cephalometric radiographs were used to study the path of eruption of the permanent central incisors approximating the cleft areas in 15 subjects with unilateral and 7 subjects with bilateral complete clefts of the lip and palate, aged between 3 years 8 months and 9 years. Tracings from the longitudinal transparent templates of the Bolton Standards subjects were used as controls for comparative purposes. The findings indicate that the pattern of eruption of the maxillary central incisor follows the pattern of alveolar development in the cleft subjects. The position of the premaxilla subsequent to cleft repair influences the eruption pattern of the maxillary central incisors approximating the cleft areas. The central incisors erupt down and back, and become more retroclined and retropositioned within the nasomaxillary complex, with increment in age. The crowns of the central incisors approximating the cleft in unilateral cleft lip and palate subjects progressively tipped more towards the cleft with age.