RESUMO
INTRODUCTION: The purpose of this study was to assess speech perturbation and adaptation for patients wearing modified C-palatal plates (MCPPs) over time. METHODS: The sample consisted of 40 patients, 20 wearing MCPPs as the experimental group (age: 20.7 ± 5.8 years) and 20 patients wearing a transpalatal arch (TPA) as the control group (age: 21.5 ± 6.4 years). The sounds /t/, /d/, /s/, /n/, /r/, /tÊ/. and /j/ were recorded for each patient at six time points: immediately before (T0) and after (T1) appliance placement; then 1, 2, 3 and 4 weeks after placement (T2-T5). Acoustic analysis of pitch and voice onset time (VOT) was performed by Praat software. Repeated measures analysis of variance (RM-ANOVA) was used to assess changes in the pitch and VOT over time and the difference between the appliances. RESULTS: With the MCPP appliance, /n/, /r/, /tÊ/ and /j/ decreased in VOT starting in the first week while /t/ and /s/ almost returned to pre-treatment levels after 2 weeks. VOT for the /d/ sound did not change between T0 and T3, but it decreased after 3 weeks. There were no significant differences in pitch and VOT between the two groups at any time point. CONCLUSIONS: Wearing an MCPP device caused patients to initially distort the articulation of several sounds, but the distortion dissipated within 1 to 2 weeks. It is recommended that patients and/or their parents be advised during pre-treatment counselling of the possibility of temporary speech changes with MCPP placement.
