Effect of Prosthodontic Rehabilitation of Maxillary Defects on Hypernasality of Speech.

PURPOSE: To establish a correlation between the effective internal diameter of the maxillary defect, the resonating frequency, and the effectiveness of the definitive obturator in reducing the percentage nasality.

MATERIALS AND METHODS: Twenty-nine patients who underwent maxillectomy confined only to the hard palate (Aramany's class I and class II defect) and were wearing a definitive obturator for at least 3 months were included. The percentage nasality and resonating frequency were calculated with the help of Praat software. The patients were asked to read out a "Rainbow" passage and also to phonate and articulate vowels. Both parameters were assessed with and without the obturator prosthesis.

RESULTS: Following obturator use, a mean change of 1.07 ± 0.83 kHz was observed in the resonating frequency (p < 0.001). The percentage change in resonating frequency was found to be 27.48 ± 4.99% following obturator use (p < 0.001). The effective internal diameter of the maxillary defect was calculated with the help of a Vernier calliper. The correlation between absolute and percentage values of resonating frequency and nasality before and after obturator use was found to be negative.

CONCLUSION: This study found that efficacy of the obturator prosthesis in reducing nasality was greater in smaller defects than in large defects.