Evaluation of mandibular buccal shelf area in skeletal class I and class III patients for miniscrew applications with cone beam computed tomography

Aim: The purpose of this study is to evaluate mandibular buccal shelf area for miniscrew applications in normodivergent skeletal Class I and Class III patients. Material and Method: CBCT of a total 40 individuals including; 20 individuals (10 male, 10 female) with skeletal Class I and 20 individuals (10 male, 10 female) with skeletal Class III were examined in our study. Measurements performed on right mandibular first molar's distal root (6D) and right mandibular second molar's distal root (7D) level on coronal sections that obtained from axial images. Miniscrew insertion angle measured on coronal sections and in the direction of this angle we measured cortical bone thickness, total bone thickness and closest distance to the root. Results: Statistically no significant changes were found in angle, cortical bone thickness, total bone thickness and closest distance to the root between Class I and Class III groups in both areas. In Class I group, the cortical bone thickness in the 6D area (4.81±1.24 mm) was found to be statistically significantly higher than in the 7D area (3.95±0.81 mm). In Class III group, cortical bone thickness in the 6D area (4.43±1.17 mm) was found to be statistically significantly higher than in the 7D area (3.75±0.81 mm). Conclusion: : In Class I and Class III individuals, sufficient cortical bone thickness and total bone thickness were observed in both areas for miniscrew placement. A significant decrease in cortical bone thickness was observed in both Class I and Class III group when going towards posteriorly. On the areas that we examined, we think that the miniscrews can be inserted safely with the insertion angle that determined via our method. However, clinician could consider taking CBCT images because the anatomical variations can differ individually. Key Words: Cone beam computed tomography, mandibular buccal shelf, miniscrew