Relationship of buccolingual inclination between the alveolar bone and first molar in different vertical facial types: a CBCT study

Abstract

Abstract Background This study aimed to investigate the differences in the buccolingual inclination and transverse width of maxillary and mandibular first molars among different vertical facial types. Methods In all, 78 samples were divided into three groups based on the GoGn-SN angle: the low-angle group (n = 26, mean age = 24.21 ± 5.11), average-angle group (n = 26, mean age = 22.66 ± 3.72), and high-angle group (n = 26, mean age = 22.23 ± 2.43). Cone beam computed tomography (CBCT) measurements were used to assess the buccolingual inclination of the axis of the maxillary and mandibular first molars, as well as the buccolingual inclination of the basal bone, the dental arch width, and the basal bone width. One-way ANOVA, the LSD test, and Pearson correlation analysis were performed. Results The high-angle group showed significantly greater lingual inclination of the maxillary basal bone than the other two groups. The difference in buccolingual inclination of the axis of the maxillary first molar and the basal bone was significantly greater in the high-angle group than in the low-angle group. Both the maxillary and mandibular dental arch were significantly narrower in the high-angle group than in the other two groups. The mandibular basal bone was also significantly narrower in the high-angle group than in the other two groups. Conclusions The upper basal bone in the high-angle group showed significantly greater lingual inclination than that in the other two groups. Transverse matching of the maxillary and mandibular dental arch and basal bone in the high-angle group may be achieved through lingual inclination of the maxillary basal bone.