Buccal cortical bone thickness at miniscrew placement sites in patients with different vertical skeletal patterns

Abstract

Cortical bone thickness plays an important role in the primary stability of miniscrews. The purpose of this study was to evaluate the buccal cortical bone thickness in adolescent subjects with different vertical skeletal patterns using cone-beam computed tomography (CBCT). We examined the CBCT images of 75patients (30males, 45females; mean age 16.5years; range 15.3-17.7years) in the present study. High-, average- and low-angle subgroups were generated according to SN-GoMe angle. On volumetric images, we measured the buccal cortical bone thickness from canine to the second molar teeth at heights of 5, 7 and 9mm from cemento-enamel junction (CEJ). For statistical evaluation, the Wilcoxon signed rank, Kruskal-Wallis and Tukey HSD tests were applied at the p < 0.05 level. Buccal cortical bone was thickest in the low-angle group. We observed statistically significant differences in the maxilla between the high- and low-angle groups at all levels. In the mandible, we noted statistically significant differences between high-angle and low-angle groups in the canine-first premolar regions at heights of 5 and 7mm, and in the second premolar-first molar region at 7mm height from CEJ. Significant differences were also present between the first and second premolars at heights of 7 and 9mm. Average cortical bone thickness ranged from 1.10-1.37mm in the maxilla and 1.20-3.28mm in the mandible for all groups. Buccal cortical bone thickness in adolescents varied in different vertical skeletal patterns and was greater in the mandible than in the maxilla, with the distance increasing from the CEJ to the apex. As the buccal cortical bone is thinner in high-angle patients, patient-specific measures should be taken when performing miniscrew treatment.