Palatine ridges and tongue position in Turner syndrome subjects

Females with Turner syndrome (TS), X chromosome monosomy, are characterized with palates that are narrow in width, normal in height and which are commonly associated with the presence of lateral palatine ridges. The aim of the present study was to assess the relationship of tongue position, palatal dimensions, and the presence of the lateral palatine ridges in TS subjects. The study also aimed to evaluate the maternal contribution to the palatal dimensions of their TS daughters. The subjects were 71 TS individuals and their female family members (n = 50). Tongue position was evaluated on lateral cephalograms, the palatal height and width measurements and observation of the presence of lateral palatine ridges on dental casts. Differences in tongue position and the palatal index were assessed by an independent sample's t-test, and the relationship between the presence of lateral palatine ridges, tongue position, and palatal dimensions by one-way analysis of variance (ANOVA) and Bonferroni post hoc multiple comparison test. Partial correlation analysis was used to determine the association of palatal dimensions between TS daughters and their mothers. The distance of the tongue from the palate was significantly longer in the TS subjects compared with the controls [10.9 mm (standard deviation, SD, 4.0) versus 7.6 mm (SD 3.4), respectively, P < 0.001] indicating a low tongue position in TS. The TS subjects with prominent lateral palatine ridges had significantly narrower posterior palates compared with the TS subjects without lateral palatine ridges [29.5 mm (SD 3.1) versus 31.5 mm (SD 2.2), respectively, P < 0.05]. There was a trend for an association between mothers and their TS daughters in palatal width measurements at the level of the upper first premolars (r = 0.78, P = 0.07). The tongue position in TS females is low. The presence of prominent lateral palatine ridges is associated with a reduced palatal width.