Mandibular Symphysis Dimensions Across Different Sagittal and Vertical Skeletal Relationships: A Comparative Cephalometric Study

Background: The mandibular symphysis (MS) is a critical anatomical structure influencing facial aesthetics, orthodontic diagnosis, and treatment planning. Variations in MS morphology may reflect underlying sagittal and vertical skeletal discrepancies, thereby affecting orthodontic biomechanics and treatment limits. Objective: To compare mandibular symphysis dimensions among different sagittal and vertical skeletal patterns in non-growing adults, with additional consideration of gender-based differences. Methodology: A comparative cross-sectional study was conducted at the Armed Forces Institute of Dentistry, Rawalpindi. Lateral cephalograms of 230 non-growing adult patients aged 16–40 years with skeletal Class I, II, or III malocclusions were analyzed. Sagittal skeletal relationships were determined using the ANB angle with Wits appraisal as an adjunct, while vertical skeletal patterns were classified using the SN–mandibular plane angle. Mandibular symphysis parameters assessed included dentoalveolar length, skeletal symphysis length, chin length, total symphysis length, vertical symphysis dimension, symphysis convexity, and symphysis concavity. Results: Females comprised 53.04% of the sample and males 46.96%. Significant differences in mandibular symphysis dimensions were observed across vertical skeletal patterns. High vertical patterns demonstrated significantly greater skeletal symphysis length, total symphysis length, and vertical symphysis dimensions (p < 0.001), along with a shorter chin length (p = 0.008) and increased symphysis concavity angle (p = 0.002). Sagittal skeletal patterns showed no significant differences in most symphysis parameters, except for symphysis convexity, which was significantly greater in skeletal Class II subjects (p = 0.02). Gender-specific analysis revealed distinct morphological variations, particularly in high vertical patterns. Conclusion: Mandibular symphysis morphology is significantly influenced by vertical skeletal pattern, whereas sagittal skeletal relationship has a limited effect, except on symphysis convexity. These findings underscore the importance of vertical growth assessment in orthodontic diagnosis and treatment planning. Keywords: Cephalometry, Facial Skeleton, Mandibular Symphysis, Malocclusion, Orthodontics.