Cervical vertebra morphology in different skeletal classes A three-dimensional computed tomography evaluation

Objective: To describe cervical vertebra morphology in subjects with different anteroposterior jaw relationships. Materials and Methods: Cone-beam computed tomography images of 31 female subjects aged 19 to 41 years were evaluated. Subjects constituted two groups according to the ANB angle: group 1, skeletal Class II (ANB angle >5); and group 2, skeletal Class III (ANB angle <1). Nine linear measurements and one angular measurement were used to assess the vertebral morphology. The Mann-Whitney U-test was used for statistical analysis. Results: The mean atlas dorsal arch height was significantly shorter in Class II subjects compared with those in Class III (P<.05). The cervical vertebra morphological analysis by cone-beam computed tomography was of comparable precision to three-dimensional computed tomography evaluations. This study confirmed previous findings that Class II subjects have significantly lower atlas dorsal arch heights. Conclusion: The height of the atlas dorsal arch of cervical vertebrae is affected by the anteroposterior skeletal pattern. (Angle Orthod. 2010;80:719-724.)