Abstract :
Background: The study used CBCT to analyze mandibular symphyseal bone thickness and density in Skeletal Class III subjects with different vertical facial patterns. It found higher cortical bone thickness in Normodivergent and higher bone density in Hypodivergent subjects, emphasizing the importance of careful orthodontic treatment to avoid complications related to reduced bone density and cortical thickness.
Materials and Methods: CBCT images of 30 skeletal Class III subjects were evaluated. Class III subjects were divided by mandibular plane angle: Hyperdivergent (SN–MP > 34o), Normodivergent (SN–MP – 32o), and Hypodivergent (SN–MP < 30o>
Results: The mean cortical bone thickness of the mandibular symphyseal region was highest in Normodivergent subjects (Group I) and lowest in Hyperdivergent subjects (Group III). Group II subjects with a Hypodivergent growth pattern had the highest mean bone density, with the lowest reported in Normodivergent subjects on the labial side and Hyperdivergent subjects on the lingual side. However, differences in bone density among groups were statistically insignificant.
Conclusions: Careful orthodontic treatment in Skeletal Class III malocclusion, especially with Hyper-divergent facial types, is crucial to prevent root issues due to reduced bone density. Bracket adjustments are essential for optimal outcomes by ensuring proper root placement within cancellous bone.
Keyword :
CBCT, Skeletal Class III, Cortical bone thickness, Mandibular symphyseal region, Bone density