A four-year longitudinal study of palatal plate therapy in children with Down syndrome: effects on oral motor function, articulation and communication preferences.

The orofacial function in 20 children with Down syndrome was evaluated after 4 years of palatal plate therapy in 9 of the children (PPG); the remaining 11 were untreated age-matched controls (CG). All 20 children had received continuous orofacial physical therapy from their speech therapist during the treatment period. A clinical extra- and intraoral examination was performed, including oral motor function, facial expression, the occurrence of malocclusions, and hypertrophic tonsils. A questionnaire requesting data on breathing patterns, drooling, eating problems, and communicative preferences was answered by the parents. An articulation assessment was performed by two speech and language pathologists blinded to the treatment status of the children in order to find out whether the palatal plate had stimulated to improved oral speech behavior. The results for oral motor function showed significant differences between the groups in favor of the PPG for the summary variables for: visible tongue (P < 0.01), visible tongue during non-speech periods (P < 0.05), and lip-rounding during spontaneous speech (P < 0.01). During non-speech time, the PPG had their mouths open significantly less than the CG (P < 0.05). Expressivity of facial expression on a visual analog scale in the PPG scored 75.6 +/- 13.3 compared to 51.8 +/- 25.7 in the CG (P < 0.05). The intraoral examination showed that 6/9 children in the PPG and 7/11 in the CG had enlarged tonsils, resulting in more than 50% inter-tonsillary space reduction. Despite these findings, and no significant differences between the groups with respect to mouth/ nose breathing, nocturnal snoring was significantly less in the PPG than in the CG (P < 0.05), according to the parental questionnaire. After 4 years of palatal plate therapy, orofacial function had improved significantly in the 9 PPG children and specifically in terms of tongue position and lip activity.