Metric analysis of the hard palate in children with Down syndrome: a comparative study.

The hard palate is viewed as playing an important role in the passive articulation of speech. Its probable role in the defective articulation of speech in individuals with Down syndrome has been examined in the present study. In individuals with Down syndrome, the hard palate is highly arched, constricted, and narrow and stair type with malformed misaligned teeth and a large and fissured tongue. As a result good palato-lingual contact is not achieved, with resulting defective articulation. Using orthodontic and prosthodontic principles could modify this situation, i.e. the anatomy of the hard palate. The altered palatal contour may give better placing to the tongue, leading to improved palato-lingual contact and articulation. The dimensional parameters measured were: average linear width (AVL), average curvilinear width (AVCL), average height (AVH) at different planes; average antero-posterior length (AAP), average volume (V), palatal arch length (PAL), and palatal index (PI). The findings were compared with those of controls of the same age and sex. The AVL, AVCL, AAP, PAL, V and PI values of patients with Down syndrome were found to be less than the corresponding values of controls and the average height values of patients with Down syndrome were greater than the corresponding values of controls. Statistical significance was observed in all measurements between the controls and the patients with Down syndrome, especially in those concerning the height and the volume of the oral cavity. Observations from this study have suggested that prostheses might be designed to modify the palatal anatomy and produce better articulation in people with Down syndrome.