Correlation between alveolar cleft morphology and the outcome of secondary alveolar bone grafting for unilateral cleft lip and palate

Abstract Background: Secondary alveolar bone grafting (SABG) is an integral part of the treatment for cleft lip and alveolus (CLA) and cleft lip and palate (CLP). SABG stabilizes and restores the continuity of the alveolar bone, supports orthodontic tooth movement afterwards. However, the outcome of SABG was not satisfactory as expected, factors that affecting the outcome were still controversial. The aims of this study were to summarize a new method for the classification of alveolar cleft morphology in patients with unilateral cleft lip and alveolus (UCLA) or unilateral cleft lip and palate (UCLP), to evaluate the correlation between the morphology and secondary alveolar bone grafting (SABG) outcomes, to identify factors that might predict the outcomes. Methods: The characteristics of the cleft morphologies of 120 patients who underwent SABG were observed using the preoperative Cone-Beam Computed Tomography (CBCT) images. 52 patients who had CBCT scans performed at least 6 months after SABG were included for the evaluation of outcomes. Both categorical and continuous evaluation methods were measured. Correlations between cleft morphology and SABG outcomes were assessed using the Pearson correlation coefficient in SPSS 27.0.0. Results: A new method for the classification of cleft morphology was summarized. Categorical evaluation showed 8 failure, 11 poor, 12 moderate, and 21 good results, while the average bone filling rate was 59.24 ± 30.68%. There was a significant correlation between the cleft morphology and categorical/continuous evaluation outcome (p < 0.05). Conclusion: The new method for the classification of alveolar cleft morphology summarized in this study was comprehensive and convenient for clinical application. Both categorical and continuous methods should be used for radiographic assessments in patients undergoing SABG. The chances of a successful procedure are best when the patient has type I or IV morphology, in which the shape is like a funnel in the relatively palatal or occlusal area towards the vertical dimension. A relatively great amount of bone resorption was observed in most patients. Slow orthodontic movement with strict periodontal control is always suggested. Trial registration: Chinese clinical trial registry; registration number: ChiCTR2100054438