Characteristics of mandible and mandibular dentition according to vertical facial skeletal features of adolescents / 华西口腔医学杂志

OBJECTIVE@#We aim to examine teenagers with varying vertical facial skeletal types with near-normal occlusion. We further aim to identify and study mandibular morphology and dentition characteristics to establish normal ranges and variations for future clinical reference.@*METHODS@#According to the results of the case studies, 42 adolescents with near-normal occlusion were divided into three groups, namely, low- (7 cases), average- (23 cases) and high-angle (12 cases) groups. We used Invivo 5 software for Digital Imaging and Communications in Medicine (DICOM) data to calculate the cant of occlusal plane, axis corner of L6, ∠L1/MP, ∠L6/MP, Balkwill angle and Bonwill triangle of each group.@*RESULTS@#Markedly, the finding shows that the cant of occlusal plane and axis corner of L6 in the low-angle group were smaller than those of the other two groups. In the average-angle group, ∠L1/MP was larger than that of the high-angle group. Lastly, in the high-angle group, ∠L6/MP was smaller than those of the two other groups. On the one hand, these differences were considered statistically significant (P0.05).@*CONCLUSIONS@#In the low-angle group, the parallelisation of the occlusal plane tends to be more obvious compared with the two other groups. In the coronal section of the low-angle group, the axis of the mandibular first molar is up-right, whereas it is distally tilted in the sagittal section of the high-angle group. Furthermore, a number of differences are noted in the adult groups. Factors, such as aging and development in the craniofacial region, lead to changes in functional occlusion.

Characteristics of mandible and mandibular dentition in patients with near-normal occlusion and different vertical facial skeletal types / 华西口腔医学杂志

Objective The aim of our work is to characterize individual normal occlusions to establish appropriate treatment standards for different vertical facial types. Methods A total of 30 patients with near-normal occlusion were grouped into high-angle group (eight cases), medium-angle group (12 cases), and low-angle group (10 cases) according to vertical facial skeletal type. Invivo5 software was used and digital imaging and communications in medicine data were rebuilt to measure the ∠L1/MP, ∠L6/MP, axis corner of L6, cant of occlusion plane, Balkwill angle, and Bonwill triangle of each group. Results Among the groups, the low-angle group had the smallest ∠L6/MP (P<0.05) and largest cant of occlusion. No significant difference was observed among the three groups with regard to the other parameters (P>0.05). Conclusion Patients with low-angle vertical facial skeletal type requires a modified treatment standard. In this group, the treatment standard must ensure that the cant of occlusion plane is more parallel to the Frankfurt horizontal plane compared with those of the other groups, and the axis of L6 is tilted distally relative to the mandibular plane.