Three-dimensional hard tissue palatal size and shape in Down syndrome subjects

The aim of the present study was to evaluate palatal morphology in Down syndrome (Ds) subjects, focusing on the effect of dental formula on the hard palate to assist clinicians when planning dental rehabilitation. Palatal landmarks were digitized with a three-dimensional (3D) computerized digitizer on the dental casts of 47 Ds subjects (23 dentate males, 9 edentulous males, and 15 dentate females) aged 20-45 years, 37 dentate reference individuals (20 males and 17 females) aged 30-39 years, and 14 edentulous reference males aged 55-72 years. The co-ordinates of the palatal landmarks were used to construct a mathematical equation of palatal shape, independent of dimensions. Palatal length, slope, width, and maximum palatal height in both the sagittal and frontal planes were measured. In males, palatal length, width, and height were significantly influenced by both the syndrome and edentulism (analysis of variance, P < 0.05). The same measurements were significantly reduced in Ds compared with dentate females (t-test, P< 0.05). In the sagittal plane, Ds did not modify palatal shape; in the frontal plane, Ds individuals showed a higher palate. Overall, palatal shape was influenced by both Ds and edentulousness. Therefore, Ds seems to alter the normal palatal size and shape, although verification on larger samples is required. The findings of the present study may encourage more interdisciplinary dentofacial therapy in the dental and orthodontic care of Ds subjects.