Dento-dental volumetric analysis in sagittal skeletal discrepancies: a retrospective observational study

Abstract

Abstract Background: The aim of this study was to evaluate the correlation between skeletal Class and dental dimensions analyzed through linear, surface area and volumetric measurements. Methods: The sample consisted of 90 patients with an average age of 18 years (44>x>12). In order to investigate any correlation between skeletal Class and tooth size, the following tests were used: Hoeffding test, Cramer's V test, the analysis of variance test (ANOVA) followed by the Tukey’s post hoc hds test and the Logit model. The significance level was set at 0.050. Results: The Hoeffding test showed a weak non-linear association between ANB and tooth values, expressed in millimetres, of element 1.4 (D = 0.0034, p < 0.05) and element 3.2 (D = 0.0042, p < 0.05). The same test also identified a non-linear association, also weak, between ANB and the lower (D = 0.0053, p < 0.05) and anterior (D = 0.0049, p < 0.05) total volumetric values. Cramér's V test indicated a weak association between skeletal Class (I, II, III) and total Bolton index (V = 0.167, p < 0.01). The results of the ANOVA test showed that the total inferior volume and the anterior inferior volume were respectively significantly greater (p = 0.012; p = 0.012) in the skeletal Class III (p = 0.012) than in the other two skeletal Classes. The total upper surface area was significantly greater in patients in skeletal Class III compared to those in Classes II and I (p = 0.029). The anterior superior surface area was significantly, greater in skeletal Class III than in Class II and I (p = 0.028). From the results of Logit analysis, it is possible to state that the third model is able to explain greater variability (21%) in terms of the distribution of results in the variables considered than the first (20%) and the second (14%). Conclusions: Class III skeletal malocclusions are characterized by increased tooth surface and volumetric dimensions compared to Class I and Class II.