Acoustic analyses of speech changes after maxillectomy and prosthodontic management.

Acoustic speech patterns of five maxillofacial surgery patients were examined before and after prosthodontic reconstruction to determine the effectiveness of a maxillary prosthesis for eliminating (or reducing) nasal resonances. Vowel formant frequencies were measured for /i/ (as in seep) and /u/ (as in in soup). Within-subject, across test-session comparisons were made by using analysis of variance techniques. Prosthodontic restoration significantly reduced the nasal resonances in all patients by either (1) completely eliminating the resonances, (2) reducing the amplitude of the resonances, or (3) changing the frequency of the resonances to more nearby regions of the vowels.