Comparative Evaluation Of Different Anatomical Sites In Buccal Shelf Region For Mini Screw Insertion In Skeletal Class II And Class III Patients-A CBCT Study

Background: To evaluate different anatomical sites in buccal shelf region at different levels (4mm, 6mm, 8mm, 10mm) from cemento-enamel junction for mini screw insertion in skeletal class II and class III patients using cone beam computed tomography (CBCT). Materials and Methods: The sample consists of cone beam computed tomography images of 48 subjects (24 skeletal class II and 24 skeletal class III) were evaluated. Mandibular buccal shelf area was evaluated at the regions (i) mesial to lower first molar (ML6) (ii) between the mesiodistal roots of the first molar (iii) distal to lower first molar (DL6) (iv) mesial to lower second molar (ML7) (v) between mesiodistal roots of the second molar (vi) distal to lower second molar (DL7) and cortical bone thickness was determined at 4, 6, 8, 10 mm level from cemento-enamel junction Results: Mandibular buccal shelf bone thickness increases from mesial surface of first molar to distal surface of second molar and from cemento-enamel junction to 8 mm level. Comparative evaluation between class II and class III shows significant differences (p<0.05) at the level of 8mm distal to second molar in the mandibular buccal shelf region. Conclusion: Skeletal class III subjects have more cortical bone thickness than class II subjects at the level of 8mm distal to second molar in the buccal shelf region.