Outcomes of Palatal Lift Prosthesis on Dysarthric Speech

This study was designed to investigate the effect of palatal lift prosthesis (PLP) on the speech of individuals with different types of dysarthria.

Thirty (19 males and 11 females) native speakers of Jordanian Arabic with dysarthria participated in the study. The age of the participants ranged from 8 to 67 years with an average of 34.1 years. Traumatic brain injury was the most common etiology of dysarthria among 12 participants, stroke among 11, multiple sclerosis among 3, and pseudobulbar palsy among 2; 1 participant had Parkinson disease, and another participant had amyotrophic lateral sclerosis.

Five acoustic and aerodynamic measures were evaluated to determine the speech outcomes including nasalance scores, sequential motion rate, speech rate, vital capacity, and sound pressure level. The acoustic measures were obtained from the participants in PLP-out and PLP-in conditions.

Results showed statistically significant decrease in the nasalance scores of the syllable repetition, vowel prolongation, and sentence repetition tasks in the PLP-in condition below the 28% cutoff score. Furthermore, results revealed statistically significant increase in sequential motion rate, speech rate, vital capacity, and sound pressure level (P = 0.000).

The use of PLP is an effective treatment option of dysarthric speech. Besides nasalance scores, the sequential motion rate, speech rate, vital capacity, and sound pressure level are considered reliable speech measures that may be used to evaluate the effect of PLP on dysarthria.