Evaluation of Dentoalveolar Symmetries in Angle’s Class I Normal Occlusion, Class II Division 1 and Class II Subdivision Malocclusion

Abstract

Introduction: Dental and alveolar symmetry are essential components of orthodontic diagnosis and treatment planning, significantly impacting both occlusal relationships and facial aesthetics. Symmetry in dental arches is critical for maintaining a functional occlusion and achieving a harmonious facial appearance. Discrepancies in tooth size, developmental disturbances, and external factors such as habits or trauma can lead to dental asymmetries.

Objectives: This study aimed to evaluate and compare inter-arch dental and alveolar symmetry in transverse and anteroposterior planes and analyze mesiodistal tooth widths across Angle's Class I normal occlusion, Class II Division 1, and Class II subdivision malocclusions.

Methods: A total of 140 dental casts, comprising 50 samples each for Class I and Class II Division 1 and 40 for Class II subdivision malocclusion, were analyzed. Subjects aged 18–30 years were selected based on specific inclusion and exclusion criteria. Measurements were performed using vernier calipers to assess 24 transverse, 12 anteroposterior, and 24 mesiodistal parameters. Data were evaluated for symmetry between the right and left sides across the malocclusion groups.

Results: Angle Class I and Class II Division 1 malocclusions displayed symmetry in alveolar lengths and inter-arch measurements. However, statistically significant inter-arch asymmetries were identified in Angle Class II subdivision malocclusion for transverse and anteroposterior parameters. Mesiodistal tooth widths showed no significant asymmetries in the measured distances for teeth 1-6 across all malocclusion classes.

Conclusions: Inter-arch asymmetry was predominantly observed in Angle Class II subdivision malocclusion, whereas Class I and Class II Division 1 malocclusions demonstrated symmetry across the evaluated parameters. These findings emphasize the importance of detailed symmetry assessment in orthodontic diagnosis and treatment planning to achieve functional and aesthetic outcomes.