Three-Dimensional Assessment of Mandibular Morphology Across Vertical Facial Growth Patterns Using Cone-Beam Computed Tomography: A Cross-Sectional Study.

Introduction: Mandibular morphology exhibits significant variation across vertical facial growth patterns. A clear understanding of these variations is essential for precise orthodontic diagnosis, treatment planning, and the prediction of growth trends. This study aimed to compare the mandibular morphological characteristics among individuals with normodivergent, hypodivergent, and hyperdivergent growth patterns using cone-beam computed tomography (CBCT), focusing on parameters such as condylar dimensions, ramus morphology, symphysis measurements, and mandibular notch features.

Materials And Methods: A cross-sectional observational study was conducted at the Department of Orthodontics and Dentofacial Orthopaedics. Based on Jarabak's ratio, the 27 subjects (aged 18-36 years) were categorized into three groups (normodivergent, hypodivergent, and hyperdivergent). CBCT scans were acquired using standard protocols and were analyzed. Mandibular parameters, including condylar width, length, height, shape, coronoid process, mandibular notch morphology, ramus height and width, and symphysis height and thickness were measured. All the statistical analyses were performed. One-way analysis of variance (ANOVA) and Tukey's post-hoc test were used to assess intergroup differences, and Spearman's correlation was used to analyze the relationship between the mandibular notch type and other measurements. Statistical significance was set at p < 0.05.

Results: Type 4 condylar shape and Type 1 coronoid process were the most prevalent but showed no significant association with growth pattern. Significant differences were observed in ramus width (p = 0.017) and symphysis thickness (p = 0.036), particularly between the hypodivergent and hyperdivergent groups. The hyperdivergent group exhibited taller condyles, narrower rami, and increased symphysis height, while the hypodivergent group showed thicker symphyses and broader rami. Correlation analysis revealed weak and inconsistent relationships between the mandibular notch type and mandibular measurements, with the strongest correlation noted between the notch type and symphysis height (r = -0.52).

Conclusion: Mandibular morphology demonstrated measurable variation across vertical facial growth patterns. While some dimensions, such as ramus width and symphysis thickness, differed significantly, mandibular notch morphology appeared largely independent of other anatomical features.