Comparison of the posterior teeth angulations in orthodontic patients with different facial growth patterns

BACKGROUND: Dental relationships can be affected according to the pattern of facial growth. Thus, the aim of this study was to compare the angulations of posterior teeth in patients with different patterns of facial growth. MATERIAL AND METHODS: A total of 412 lateral head radiographs were included. The facial skeletal growth pattern was evaluated with the Björk-Jarabak analysis. For the angular measurements of the posterior teeth, the apex-cusp inclination of the premolars and the long axes of the molars were considered, with respect to the occlusal, palatal and mandibular plane. The intraclass correlation coefficient (ICC) was used to evaluate the intra-examiner concordance. One way ANOVA was used to compare the values between the patterns of facial growth. A significance level was set at 0.05. RESULTS: A high intra-examiner correlation was observed (0.75). Subjects with horizontal and normal growth presented significantly different angulations for the first and second premolars in relation to the palatal plane than the vertical growth (p<0.05). Subjects with horizontal growth pattern showed greater angulation of the teeth with respect to the occlusal plane than the other groups (p<0.05). The angulations of all mandibular teeth related to the mandibular plane were significantly higher for the group with horizontal growth (p<0.05). CONCLUSIONS: The first and second premolars presented greater angulations in subjects with horizontal and normal growth than in those with vertical growth. The angulations of all mandibular teeth were significantly higher in the horizontal growth according to the mandibular plane. Key words:Facial growth pattern, posterior tooth, occlusal plane, palatal plane, mandibular plane.