Characteristics Of Craniofacial Structure And The Correlation Analysis Between Occlusal Plane And Mandible,Denture In High-angle Skeletal Class â…¡ Malocclusion

ObjectiveTo study the characteristics of craniofacial structure and the relationship between occlusal planes and mandile as well as denture by examining skeletal and dental morphologies in adult high-angle skeletal Class â…¡ malocclusion for providing references for diagnosis and clinical treatment plane.Methods48subjects with normal occlusion individuals and103subjects with high-angle skeletal Class â…¡ malocclusion were selected and measured with V-ceph7.0. Several symbols and measurements that represented skeletal, dental and occlusal frames were selected. Independent samples t-est was employed for comparison of females and males as well as control group and malocclusion group. The correlation of mandible and occlusal planes was evaluated by Pearson correlation, as well as between the occlusal planes and the denture patterns.Results1. Comparison of males and females:The values of the cephalograms showed significantly difference in the mandible measurements, inclination of denture measurements and vertical height of the upper incisor between males and females (P<0.05)2. Comparison of cranial base and maxillary, mandibular: In malocclusion group, the cranial base angle and posterior cranial base length had no significant difference with normal group, as well as the sagittal maxillary position, maxillary length, the inclination of palatal plane and upper anterior facial height (P>0.05). The length of mandibular and ramus, the sagittal mandibular position and posterior face height were significantly smaller than that of control group (P<0.05). The inclination of ramus, mandibular angle, Y axial angle and lower anterior face height were significantly larger than that of control group (P<0.05)3. Comparison of denture and occlusal plane:In malocclusion group, the labial inclination of the upper incisor did not show significant difference (P>0.05). The distal inclination of the upper second premolar, first and second molars were significantly larger than that of control group (P<0.05). The mesial inclination of lower dentals relative to Frankfurt plane were significantly larger than that of control group (P<0.05). Relative to Mandibular plane, lower molars had a distal incline tendency (P<0.05). The vertical height of incisor and second premolar were significantly larger than that of control group (P<0.05). The anterior occlusion plane, posterior occlusion plane and occlusion plane difference in malocclusion group were found to be significantly larger than that of control group (P<0.05)4. Correlation coefficient between occlusal plane and mandible as well as denture:In malocclusion group, it became apparently that anterior and posterior occlusal planes were significantly correlated to the mandibular plane, Y axial angle, mandibular length, ramus inclination and the sagittal mandibular position (P<0.05) Posterior occlusal plane showed strong correlation with the vertical height of upper second premolar and second molar (P<0.05). Anterior occlusal plane showed strong correlation with the vertical height of upper second premolar and upper incisor (P<0.05). Anterior and posterior occlusal planes were significantly correlated to the distal inclination of the upper second premolar, first and second molars (P<0.05)Conclusion1. Female were more hyperdivergence than male in high-angle skeletal Class II malocclusion. Dentation of different sex had characteristics differently.2. The abnormal in high-angle skeletal Class II malocclusion is mandible. Upper and lower dentation had different characteristics for dentoalveolar compensation.3. Anterior and posterior occlusion planes were Steep. The steep cant of anterior and posterior occlusal planes showed a strong correlation with a small, retruded mandible with backward rotation, as well as the vertical height of upper denture and the distal inclination of upper molars in high-angle skeletal Class â…¡ malocclusion.