Long-term effects of palatal plate therapy on oral motor function in children with Down syndrome evaluated by video registration

Oral motor function was evaluated after 4 years of palatal plate therapy in nine children with Down syndrome (DS); 11 children with DS constituted the control group. During the treatment period all children had orofacial physiotherapy with their speech pathologist. An extraoral examination was performed, as was a video registration of the face. Nine different variables showing positions of the lips, tongue, and facial expression were examined. Children in the palatal plate group (n = 9) had significantly more rounding lips during speech (P < 0.05) than children in the control group (n = 11). The active variables describing normal muscle tension were diagnosed to constitute 81.0% +/- 11.0% of the registered video time in the palatal plate group, compared with 68.2% +/- 22.5% in the control group. Statistically significant differences were found between the groups in the summary variables describing an inactive open mouth and inactive tongue protrusion (P< 0.01). The results indicate that palatal plate therapy has a long-term effect on oral motor function.