Anterior Labial Alveolar Bone Thickness after Orthodontic Retraction of Anterior Teeth

Abstract

Introduction: Correction of skeletal Class II malocclusion generally requires extraction of the premolars, followed by the retraction of the anterior teeth to reduce overjet. Morphometric evaluation of alveolar bone can be used to study the limitation of tooth movement to avoid adverse effects. The purpose of this study is to measure the changes in the bone thickness of the maxillary incisors in skeletal Class II malocclusion patients after retraction and determine the relationship between changes in bone thickness and the amount of retractions using lateral cephalometric radiographs. Materials and methods: The design of this study was to determine the cross-sectional changes in bone thickness in linear directions after retraction and the relationship between changes in bone thickness and the amount of retraction. Bone thickness in the linear directions was measured using digital cephalometric radiographs. Results: The measurement results from tracing 43 lateral cephalometric before and after anterior retraction treatment showed that there was a difference in alveolar bone thickness at the 9mm level from the CEJ in a linear direction on the anterior retraction of skeletal Class II malocclusion maxillary incisors (p <0.05), however, there was no difference in alveolar bone thickness at levels 3 and 6 mm from CEJ in the linear direction, and the angular direction (p> 0.05). Changes in alveolar bone thickness did not correlate with the amount of incisor retraction (p> 0.05). Conclusion: The results showed that the change in labial alveolar bone thickness was not significantly correlated to the amount of retraction.