Comparative Evaluation of Chin-Throat Morphology in Different Sagittal and Vertical Skeletal Patterns - A Cephalometric Study

Abstract

Aim: To Evaluate and Compare Chin-Throat Morphology in various Sagittal and Vertical Skeletal Patterns.

Material and Method:  Seventy-eight standardized lateral cephalometric radiographs (True Size Lateral Cephalograms with 1:1 Magnification Ratio) were equally divided into Three groups Class I (n=26), Class II (n=26) & Class III (n=26). Further Chin Throat Angle, Mento-cervical Angle and Anterior and Posterior portions of the Mandibular border were measured for sagittal assessment within all three Groups. For Vertical Assessment all 78 standardized lateral cephalometric radiographs were further divided into Hypodivergent, Normodivergent and Hyperdivergent Growth Patterns and total 3 parameters (Chin Throat Angle, Mento-cervical Angle and Anterior and Posterior portions of the Mandibular border) were measured.

Results: Chin Throat Angle showed highest mean value in Class II Malocclusion with Normodivergent Growth Pattern (130.2±2.78) and Lowest mean value in Cass II Malocclusion with Hyperdivergent Growth Pattern (97.43) and this difference (32.77) is clinically significant with p<0.001. Mento-cervical Angle showed highest mean value in Class II Malocclusion with Hypodivergent Growth Pattern (95.14±3.11) and lowest mean value in Class I Malocclusion with Hypodivergent Growth Pattern (72.38±1.9). This difference (22.76) is clinically significant with p<0.001. Posterior portion of the Mandibular border showed highest mean value in the Class I Malocclusion with Hyperdivergent Growth Pattern (60.17±0.98) and Lowest mean value in Class I Malocclusion with Hypodivergent Growth Pattern (46.08 ± 1.04) and this difference (14.09) is clinically significant with p<0.001. Anterior portion of the Mandibular border showed highest mean values in Class I Malocclusion with Hypodivergent Growth Pattern (53.92±1.04) and Lowest mean value in Class I Malocclusion with Hyperdivergent growth pattern (39.83 ± 0.98) and this difference (14.09) is clinically significant with p<0.001.

Conclusion: The Chin Throat Angle, Mento-cervical Angle and Anterior and Posterior portions of the Mandibular border are reliable indicators for Orthodontic Diagnosis and Treatment planning.