[Characteristics of mandible and mandibular dentition according to vertical facial skeletal features of adolescents].

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 (P<0.05). On the other hand, other measurements show that these differences were considered statistically non-significant (P>0.05). 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.