Assessment of Mandibular Ramus Thickness and Depth for Safe Miniscrew Placement in an Iranian Population: A Cone-Beam Computed Tomography Study

Abstract

Objectives: This study assessed the mandibular ramus for safe miniscrew placement in an Iranian population using cone-beam computed tomography (CBCT).

Materials and Methods: This cross-sectional study was conducted on 212 CBCT scans. The mandibular ramus thickness and depth were measured as the distance between the buccal and lingual surfaces, and the distance between the anterior border of the ramus and the mandibular canal, respectively, at the occlusal plane level and 5mm and 10mm above it. Two-way ANOVA was applied to analyze the effects of gender and presence of third molars on ramus depth and thickness. The right and left sides were compared by paired t-test (alpha=0.05).

Results: As moving from the occlusal plane to 5 and 10mm above it, ramus depth increased while its thickness decreased. In presence of third molars, ramus thickness and depth in males were greater than those in females at both sides. Ramus depth was significantly greater in the right side than the left side at all levels (P<0.001). Presence of third molars (P=0.001, P=0.053) and gender (P<0.001, P=0.052) significantly affected the left-side ramus depth at the occlusal level and 5mm above it. Gender significantly affected the right-side ramus depth at 5 and 10mm levels (P=0.013).

Conclusion: Presence of third molars increased ramus depth and thickness. Ramus depth and thickness were greater in males than females. Miniscrew placement is recommended at 5mm above the occlusal level due to sufficient depth and thickness of the ramus at this region.