Canine impaction in patients with unilateral cleft lip and palate (UCLP) after secondary alveolar bone grafting: a retrospective study

AIM: To retrospectively evaluate clinical and radiographic differences between impacted and spontaneously erupted canines in unilateral cleft lip and palate (UCLP) patients after secondary alveolar bone grafting. SUBJECTS AND METHOD: Eighty seven non-syndromic UCLP patients divided into two groups according to canine eruption. Group A included 39 patients with unilateral impacted canines on the cleft side (A1) and spontaneously erupted canines on the non-cleft side (A2). Group B included 48 patients with spontaneously erupted canines on both the cleft (B1) and non-cleft sides. Groups A1 with A2 were compared with a split-mouth design and group A1 with B1. Clinical records, study models, panoramic and cephalometric radiographs and cone beam computed tomograms were used to evaluate the following parameters: presence of a crossbite, history of interceptive treatment, occlusion and skeletal relationship, development, position and angular measurements of the canine, resorption and condition of the lateral incisor. A generalized linear mixed model for binomial responses with a logit-link was used for statistical analysis. RESULTS: Cleft-associated impacted canines could be distinguished from spontaneously erupted canines by a less developed root, frequently by a higher position in the maxilla and a higher sector score (P < 0.05). Angular measurements (canine to midline and canine to lateral incisor) were significantly larger for impacted canines than for spontaneously erupted canines (P < 0.001). CONCLUSIONS: Based on these measurements, the eruption of the maxillary canine in the bone grafted region requires careful follow-up in UCLP patients. These measurements are a valuable tool to support the diagnosis of impacted canines.