Date of Award
Department of Orthodontics
First Committee Member
Introduction: The purpose of this study is to compare dental and skeletal differences between Class I and Class II sides and their contributions to the degree of asymmetric molar relationship in Class II subdivision malocclusions using CBCT.
Methods: One hundred and eight patients presenting with Angle Class II subdivision malocclusions (mean age =21.05 years) were assessed with 3-dimensional cone-beam computed tomography scans. Paired t-tests were used to compare linear skeletal, angular and dental measurement differences between Class I and Class II sides. Correlations of linear skeletal, angular and dental measurement differences between Class I and Class II sides were made against the Asymmetric Molar Relationship measurement. Differences between Class I and Class II sides were correlated to the degree of skeletal asymmetry, as defined by defined as menton deviation from mid-sagittal plane.
Results: Maxillary first molar position was more mesially positioned on the Class II side and the mandibular first molar position was more distally positioned on the Class II side. No significant skeletal differences were found between Class I and Class II sides. Asymmetric Molar Relationship was correlated with a more mesially positioned maxillary first molar position and distally positioned mandibular first molar position on the Class II side. There were no significant skeletal differences that were correlated significantly with the Asymmetric Molar Relationship.
Conclusion: In a sample of one hundred and eight patients exhibiting Class II subdivision malocclusion with and without skeletal asymmetry, the Class I and Class II sides display differences that are mainly dentoalveolar in nature. The degree of molar relationship asymmetry was correlated with a more a mesially positioned maxillary molar and a more distally positioned mandibular molar on the Class II side. There were no significant skeletal differences between Class I and Class II sides and no significant skeletal contributions to molar asymmetry.
Lo, Ivan; Suh, Heeyeon; Park, Joorok; and Oh, Heesoo, "COMPARISON OF SKELETAL AND DENTAL DIFFERENCES BETWEEN CLASS I AND CLASS II SIDES AND THEIR RELATIONSHIP WITH ASYMMETRIC MOLAR RELATIONSHIPS IN CLASS II SUBDIVISION MALOCCLUSIONS – A CBCT STUDY" (2020). Orthodontics and Endodontics Theses. 10.