Comparison of anterior mandibular alveolar thickness and height in young adults with different sagittal and vertical skeletal relationships: A CBCT Study

Objective: Alveolar bone surrounding mandibular incisors dictates the range of buccolingual inclination that can be achieved with treatment. The objective of this study was to evaluate the mandibular anterior alveolar thickness and height in individuals with different sagittal and vertical skeletal relationships. Materials and Methods: Cone beam computed tomography scans of 53 individuals (22 males and 31 females; mean age 21.19 ± 3.7 years) were classified into 3 groups according to the sagittal skeletal relationship (class I, class II, and class III) and the vertical growth pattern (hyperdivergent, normodivergent, and hypodivergent). The alveolar thickness and height of both mandibular central incisors were measured. Group comparisons were performed with analysis of variance and post hoc Scheffé tests. Multiple linear regression was applied to evaluate the influence of all variables on the alveolar conditions. Results: Alveolar thickness and height showed no significant differences among the class I, II and III groups (6 and 7 mm regardless of the sagittal group, P > 0.05). The middle and lower alveolar thicknesses were significantly smaller in hyperdivergent (5.76 mm and 6.34 mm) and normodivergent (6.29 mm and 7.40 mm) than hypodivergent individuals (6.63 mm and 8.27 mm respectively). The lingual alveolar height was smaller in hyperdivergent (6.04 mm) than hypodivergent individuals (7.93 mm) (P = 0.029, 95%CI: 0.15–3.63) and the lingual bone height was smaller in hypodivergent (3.24 mm) than hyperdivergent individuals (5.06 mm) (P = 0.029, 95%CI: 0.15–3.48). Multiple linear regression indicated a significant influence of the root length on the alveolar thickness and height. Conclusions: The sagittal skeletal relationship showed no influence on the alveolar thickness or height, even if dental compensation was present. Hyperdivergent individuals showed smaller alveolar thicknesses and heights than hypodivergent individuals.