Quantitative Morphometric Analysis of Anatomical Landmarks Involved in Bilateral Sagittal Split Osteotomy in Different Skeletal Malocclusions Using Cone-Beam Computed Tomography.

BACKGROUND: To assess and compare the anatomical landmarks involved in bilateral sagittal split osteotomy (BSSO) in different skeletal malocclusions quantitatively using cone-beam computed tomography (CBCT). METHODS: This retrospective study evaluated 63 CBCT scans of the three malocclusion classes (n = 21). Twenty-one quantitative variables were measured and compared between different malocclusion classes. One-way ANOVA, Welch test, Kruskal Wallis test and the Mann-Whitney test with Bonferroni adjustment were used for data analysis. The level of significance was set at ≤0.05. RESULTS: The patients had a mean age of 26.35 years (range 18-58 years). The width of the lateral cortex in the posterior third (T1-P) of ramus in the left side, and the mean value in the right and left sides were significantly different between different classes of malocclusion (P = 0.049) such that class II patients had significantly thinner lateral cortex. No other significant differences were noted between different malocclusion classes in other variables. CONCLUSION: The quantitative morphological assessment of the mandible in BSSO of different malocclusion classes did not reveal significant differences. There is no superiority in the dimensions of discussed landmarks involved in BSSO among different malocclusion classes. So the risk or the safety of this kind of surgery is similar for these classes. Thus, diagnostic preoperative workup by CBCT is imperative for selection of a surgical approach with minimal postoperative complications.