Statement of the problem: Alterations to the oral cavity caused by dental prostheses can affect speech articulation, whereas the influence of dental prostheses on the voice is unknown. For 1 patient, the fundamental frequency rose by up to 5 semitones during speech and his voice range was enlarged by up to 4 semitones when a thin denture was used instead of his normal denture. In this patient, intraoral needlepoint registration revealed a more rostral position of the mandible with the thin denture when compared with the normal denture.
Purpose: This study evaluated the effects of such changes on phonation by varying the dentures of 20 subjects in line with those of the first patient.
Material and methods: The volumes of the test dentures were reduced and the vertical and horizontal dimensions of occlusion were varied. The influences of these changed dentures on speaking fundamental frequency, voice range (in semitones), and lowest and highest frequencies of the voice range were examined with a Homoth phonomat.
Results: A statistically significant influence of the different dentures on the investigated voice parameters was not proven; however, audible changes to the voice parameters for persons were documented.
Conclusions: Variations of thickness and or volume of dentures and of the vertical and horizontal dimension of occlusion may result in unpredictable audible changes to the voice. Patients should be informed about possible effects of modified or new dentures on their voice.