Perceptual and acoustic analysis of speech with respect to posterior palatal seal area in complete denture prosthesis wearers

The unique complexity of the oral cavity and adjacent areas presents a continual challenge to prosthodontist. Patients usually maintain acceptable speech if the dentures satisfy the requirement of function and esthetics. However, some patients with dentures encounter difficulty and their speech becomes a major concern. Recording the posterior palatal seal area in complete denture fabrication has always been an attempt by the clinicians. It not only provides a psychological satisfaction in terms of good fit but also provides comfort and better adaption to functions like mastication and speech. The purpose of this study is to compare the perceptual and acoustic characteristics of velar sounds in an edentulous patient, with and without Posterior palatal seal area recorded in the denture of complete denture wearers. Materials and methods: Thirty completely edentulous Malayalam and Kannada speaking subjects aged 45-55 years were included for the study. Conventional complete denture was fabricated for each subject participating in the study. Posterior palatal seal area was recorded in the denture with fluid wax technique in the patient’s mouth and the subjects were evaluated perceptually and acoustically with (fluid wax record simulating P.P.S) and without (scrape off the P.P.S recorded with wax) the record of posterior palatal seal area. Velar Stop consonants in monosyllables /ka/ and /ga/ were used for acoustic analysis for all the subjects and Kannada as well as Malayalam articulation tests appropriate for the language of the subjects were used, for perceptual analysis. All the samples recorded were subjected to acoustic analysis using PRAAT software (version 4.5.06; Paul and David, 2006). The following parameters were extracted: Burst duration, Voice onset time, and Formant frequencies. Results: Acoustic analysis showed a significant relation between the acoustic characteristics of velar sounds and the posterior palatal seal area recorded in the denture. Conclusions and clinical implications: The study implies that Prosthodontist can contribute effectively as a team member, working with Speech Language Pathologist in the appropriate fabrication of the denture, by evaluating the patient’s speech with respect to posterior palatal seal area recorded in the intaglio surface of the denture (post-dam area).