Evaluation of the Thickness of Cortical Bone in the Maxillary PosteriorRegion in Subjects with Impacted Maxillary Canine: A Retrospective Study

Abstract

Introduction: Maxillary canine impaction is a frequent orthodontic concern, often resulting in root resorption, loss of arch length, and alveolar bone changes. Accurate evaluation of buccal cortical bone thickness is essential for planning the placement of temporary anchorage devices (TADs), particularly in such cases.

Aim: The study aimed to assess cortical bone thickness in patients with unilateral maxillary canine impaction, focusing on interradicular regions between the first and second premolars and between the second premolar and first molar, on both the impacted and non-impacted sides (ISs).

Material and Methods: Cone-beam computed tomography (CBCT) scans of 31 patients (aged 13–33 years) from Northern India were analyzed. Samples were categorized into Group I (IS) and Group II (non-IS). Cortical bone thickness was measured at 8 mm, 10 mm, 12 mm, and 14 mm from the cementoenamel junction (CEJ) in two interradicular regions: Between interradicular region between the maxillary first premolar and second premolar (IRR PM1 and PM2) and interradicular region between the maxillary second premolar and maxillary first molar (IRR PM2 and M1 ). Statistical analysis was performed using an independent t-test to compare bone thickness between groups.

Results: In both groups, cortical bone thickness increased progressively from CEJ to apex, and from anterior to posterior regions. The IRR PM2–M1 site consistently showed greater thickness than the IRR PM1–PM2 site. Although the non-IS exhibited slightly higher values, inter-group differences were not statistically significant.

Conclusion: Cortical bone thickness increases posteriorly and apically in the maxilla, with minimal variation between impacted and non-ISs. CBCT provides reliable data for identifying optimal TAD placement sites, aiding precise treatment planning in cases involving impacted maxillary canines.

Key words: TADs, Impacted Canine, Cortical bone thickness