- E. Seifert
- C. Runes
- D. Selders
- A. Lamprecht-Dinnesen
- F. Bollmann
Summary of the
It is well known that changes in the oral cavity caused by dentures can affect pronunciation. However, it is unlikely that the voice will be affected at first. In addition to the generation of the fundamental frequency, overtones are also generated by the vocal fold vibrations. Resonances and anti-resonances are formed by the shape of the tube and thus the overtones are amplified to varying degrees. If the dental prosthesis changes the tube, the overtones may be affected, but changes in the basic voice frequency seem unlikely. In this case it is shown that in a subject who has two different dentures, the voice frequency increases by up to 5 semitones when reading a text with the thinner and lighter denture (denture 1). In the singing voice field, the range of the singing voice in the high frequency range is extended by up to 4 semitones. If the lower jaw position is checked with the intraoral supporting pin registration, the lower jaw with prosthesis 1 is slightly shifted forward compared to prosthesis 2. In the sagittal magnetic resonance tomogram, the larynx continues to impress cranially. It is possible that the larynx is moved cranially by the higher-lying tongue of the thinner prosthesis. A higher tension of the laryngeal muscles could lead to an increase in the fundamental frequency and an extension of the vocal range in the high frequency range. The use of a dental prosthesis can therefore have an effect on the voice in individual cases. Although the cause of this observation cannot yet be determined, the phenomenon should be known to the treating dentist, but also to the ENT physician and the phoniatrist, if patients notice a change in the voice after the new or changed restoration with a dental prosthesis.
Received on 14 August 1998 Accepted on 8 February 1999
It is well known that alterations to the oral cavity caused by dental prostheses may affect speech articulation, although influences on the voice are not assumed. In addition to the vocal fundamental frequency, vibrations of the vocal chords generate overtones. Through the shape of the larynx and the upper airway, resonances and antiresonances are formed, and in this way overtones are amplified to a variable extent. Nozzle changes caused by a dental prosthesis in the oral cavity may possibly influence overtones but influences on the vocal fundamental frequency seem unlikely. The influence of dental prostheses on the voice is demonstrated in a patient who owned two different dental prostheses. The fundamental frequency rose by up to five semitones during speech and his vocal range increased by up to four semitones when a thin denture was used instead of a normal denture. When the position of the mandible was checked by intraoral needle point placement, a more rostral position of the mandible was recorded with the thin denture than with the normal denture. Sagittal magnetic resonance tomography imaging also showed that the larynx was in a more cranial position. This change was presumed to be due to an upward movement of the larynx induced by the tongue, which itself was found to be in a more cranial position with the thin denture. In this situation, increased tension of the laryngeal muscles were believed to induce a rise in fundamental frequency, shifting the voice range toward higher frequencies. These findings show that dental prostheses can cause vocal changes in individual cases. The etiology of this occurrence is still not clear. Its consequences, however, should be known to the dentist, ENT surgeon and phoniatrist if patients notice changes in their voice after having altered or replaced their dentures.
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