Uniformity of palatal volume and surface area in various malocclusions

To assess palatal volume, surface area and linear dimensions across sagittal and vertical components of malocclusion.

Pre-treatment cephalographs and dental casts of 178 non-growing patients (88 males, 90 females, age 25.81 ± 8.23 years) were used for classification in sagittal malocclusion groups: Class I (n = 48), Class II division 1 (n = 42), Class II division 2 (n = 40) and Class III (n = 48); and in vertical divergence groups based on the MP/SN angle: hypodivergent (n = 35), normodivergent (n = 95) and hyperdivergent (n = 48). Dental casts were scanned and palatal measurements recorded: palatal width, depth and interdental distances; palatal surface area (PSA, mm² ) and volume (PV, mm³ ). A 3-way ANOVA was used to compare palatal dimensions across groups. Pearson product-moment correlations were employed to assess associations among variables.

PSA and PV (in both sex groups) were not statistically significantly different across sagittal malocclusions and vertical patterns. Significant differences were depicted more among the vertical divergence groups than sagittal groups. Correlations between PSA and PV and palatal dimensions were low to moderate. Predictability of PSA and PV ranged between 15 and 18%.

The finding of similar palatal volume and surface area, on average, across malocclusions possibly underscores the limitations of environmental influences within the inherited orofacial phenotype. The vertical facial pattern seems to be more interactive with palatal dimensions than sagittal relations. Studies of palatal changes following orthodontic and orthognathic treatments are warranted.