Effect of temporary closure of oronasal fistulae on levator veli palatini muscle activity.
OBJECTIVE
The objective of this study was to clarify electromyographically the effects of closing an oronasal fistula on levator muscle activity and oral air pressure in patients with velopharyngeal incompetence and in those with adequate velopharyngeal function.


METHODS
Five patients with adequate velopharyngeal function and six patients with velopharyngeal incompetence were studied. All subjects had an oronasal fistula at the anterior third portion of the hard palate in spite of primary palatal closure using palatal push-back operation.


METHODS
The smoothed electromyographic activity of the levator veli palatini muscle was measured with the fistula closed with a cotton swab dipped in saline and with the fistula left open.


RESULTS
Under the closed fistula condition, oral air pressure was greater than that observed under the open fistula condition irrespective of velopharyngeal function. Levator veli palatini muscle activity was significantly lower in magnitude under the condition of closure than under the open condition in the patients with adequate velopharyngeal function, whereas in those with velopharyngeal incompetence, it was not significantly changed.


CONCLUSIONS
The results suggest that velopharyngeal function is affected by temporary closure of an oronasal fistula, and that the magnitude of the effect is greater for subjects with adequate velopharyngeal function than for subjects with velopharyngeal incompetence.
Tachimura
T
T
Division for Oral and Facial Disorders, Faculty of Dentistry, Osaka University, Japan.
Hara
H
H
Koh
H
H
Wada
T
T
D000293:Adolescent; D000399:Air Pressure; D000704:Analysis of Variance; D002648:Child; D002972:Cleft Palate / Q000601:surgery; D003679:Deglutition / Q000502:physiology; D004576:Electromyography; D005260:Female; D006801:Humans; D008297:Male; D009055:Mouth / Q000503:physiopathology; D009059:Mouth Diseases / Q000503:physiopathology*; D009668:Nose Diseases / Q000503:physiopathology*; D016155:Oral Fistula / Q000503:physiopathology*; D010156:Palatal Muscles / Q000503:physiopathology*; D010158:Palatal Obturators; D010159:Palate / Q000601:surgery; D010160:Palate, Soft / Q000503:physiopathology; D010614:Pharynx / Q000503:physiopathology; D016156:Respiratory Tract Fistula / Q000503:physiopathology*; D013060:Speech / Q000502:physiology; D013070:Speech Therapy / Q000295:instrumentation; D014681:Velopharyngeal Insufficiency / Q000503:physiopathology