Measurement of Velopharyngeal Movements Induced by Isolated Stimulation of Levator Veli Palatini and Pharyngeal Constrictor Muscles

Abstract

The levator veli palatini (LVP) and superior pharyngeal constrictor muscles (PC) close the velopharynx. However, for the velopharyngeal movements to be understood in detail, each muscle contraction must be analyzed precisely. This study was performed to clarify the velopharyngeal movement which was induced by a single muscle contraction, LVP or PC. Using a nasopharyngeal fiberscope, we analyzed the velopharyngeal movement associated with the contraction of the LVP and PC muscles in mongrel dogs. To elicit the maximal contraction of each muscle, we applied repetitive electrical stimulation to each peripheral nerve efferent to the LVP or PC muscle. Stimulation with a frequency of 77 Hz and 83 Hz induced maximal tension in the LVP and PC muscles, respectively, in isometric contraction. In a second series of experiments, fiberscopic views of the velopharyngeal movements associated with each muscle's maximal contraction were recorded. The degree of closure was calculated at several sections. The LVP muscle pulled the caudal fourth of the soft palate, while the PC projected the posterior wall at the level of the caudal end of the soft palate. The PC muscle also projected the lateral wall of the velopharynx. The effect of LVP contraction on the lateral wall was very small. These results show that the velopharyngeal movement associated with LVP contraction is very different from that with PC contraction.

Keywords

palate velopharyngeal closure levator veli palatini pharyngeal constrictor.

Get full access to this article

View all access options for this article.

References

Bell-Berti F. (1976). An electromyographic study of velopharyngeal function in speech. J Speech Hear Res 19:225-240.

Bell-Berti F. (1980). Velopharyngeal function: A spatial temporal model . In: Speech and language: advances in basic research and practice. Vol. 4. Lass NJ , editor. New York: Academic Press, p. 291.

Calnan JS (1953). Movements of the soft palate. Br J Plast Surg 5:286-296.

Dickson DR (1972). Normal and cleft palate anatomy. Cleft Palate J 9:280-293.

Dickson DR (1975). Anatomy of the normal velopharyngeal

mechanism. Clin Plast Surg 2:235-248.

Dickson DR , Dickson WM (1972). Velopharyngeal anatomy. J Speech Hear Res 15:372-381.

Dickson DR , Maue-Dickson W. (1980). Velopharyngeal structure and function. In: Speech and language: advances in basic research and practice. Vol. 3. Lass NJ , editor. New York: Academic Press.

Fritzell B. (1969). An electromyographic and cineradiographic study . Acta Oto Laryngol 250(Suppl):1-78.

10.

Iglesias A. , Kuehn DP , Morris HL (1980). Simultaneous assessment of pharyngeal wall and velar displacement for selected speech sounds. J Speech Hear Res 23:429-446. Kogo M. , Nishio J. , Matsuya T. , Hamamura Y. , Miyazaki T. (1987). Coordination of the levator veli palatini and intrinsic laryngeal muscles: An evoked electromyographic study in the dog. Cleft Palate J 24:119-125.

11.

Kogo M. , Inoue K. , Matsuya T. , Nishio J. , Hamamura Y. , Yasui Y. , et al. (1991). Mechanical contraction property of the levator veli palatini muscle. Cleft Palate Cranio Fac J 28:221-224. Kogo M. , Kurimoto T. , Koizumi H. , Nishio J. , Matsuya T. (1992). Respiratory activities in relation to palatal muscle contraction. Cleft Palate Cranio Fac J 29:174-178.

12.

Kogo M. , Hamaguchi M. , Matsuya T. (1996). Observation of velopharyngeal closure patterns following isolated stimulation of levator veli palatini and pharyngeal constrictor muscles. Cleft Palate Cranio Fac J 33:273-276. Kuehn DP , Folkins JW , Cutting CB (1982). Relationships between muscle activity and velar position. Cleft Palate J 19:25-35.

13.

Martenson M. , Skoglund CR (1964). Contraction property of intrinsic laryngeal muscles . Acta Physiol Scand 89:482-490. Matsuya T. , Miyazaki T. , Yamaoka M. (1974). Fiberscopic examination of velopharyngeal closure in normal individuals. Cleft Palate J 11:286-291.

14.

Matsuya T. , Yamaoka M. , Miyazaki T. (1979). A fiberscopic

15.

study of velopharyngeal closure in patients with operated cleft palates. Plast Reconstr Surg 63:497-500. McWilliams BJ , Morris H. , Shelton RL (1984). Cleft palate speech. 2nd ed. Philadelphia: B.C. Decker.

16.

Miyazaki T. , Matsuya T. , Yamaoka M. (1975). Fiberscopic methods for assessment of velopharyngeal closure during various activities. Cleft Palate J 12:107-114.

17.

Moll KL ( 1965). A cinefluorographic study of velopharyngeal function in normals during various activities. Cleft Palate J 2:112-122.

18.

Motomura T. (1979). The mode and function of the posterior pharyngeal wall in the velopharyngeal closure-an electromyographic study on normal subjects and cleft palate patients. Osaka Daigaku Shigaku Zasshi 24:95-117. Nishio J. , Matsuya T. , Machida J. , Miyazaki T. (1976a). The motor nerve supply of the velopharyngeal muscles. Cleft Palate J 13:20-30.

19.

Nishio J. , Matsuya T. , Ibuki K. , Miyazaki T. (1976b). Roles of the facial, glossopharyngeal and vagus nerves in velopharyngeal movement. Cleft Palate J 13:201-214. Pigott RW , Bensen JF , White FD (1969). Nasendoscopy in the diagnosis of velopharyngeal incompetence. Plast Reconstr Surg 43:141-147.

20.

Skolnick ML (1970). Videofluoroscopic examination of the velopharyngeal portal during phonation in lateral and base projections-a new technique for studying the mechanics of closure. Cleft Palate J 7:803-816.

21.

Shprintzen RJ , Lencione RM , McCall GN , Skolnick ML (1974). A three dimensional cinefluoroscopic analysis of velopharyngeal closure during speech and non-speech activities in normals . Cleft Palate J 11:412-428.

22.

Shprintzen RJ , McCall GN , Skolnick ML , Lencione RM (1975). Selective movement of the lateral aspects of the pharyngeal walls during velopharyngeal closure for speech, blowing, and whistling in normals. Cleft Palate J 12:51-58.