title: [Physiology of pharyngeal muscles after surgical restoration of the velopharyngeal sphincter].
abstract: BACKGROUND
  Speech velopharyngeal sphincter restoration is generally performed by pharyngeal flap or sphincter pharyngoplasty.
  
  
  OBJECTIVE
  Evaluate pharyngeal muscle physiology after pharyngeal flap or sphincter pharyngoplasty using simultaneous electromyography and videonasopharyngoscopy.
  
  
  METHODS
  Forty patients were studied. Twenty patients were operated on with an upper base pharyngeal flap. Twenty patients were operated on with sphincter pharyngoplasty. The following muscles were studied: superior constrictor pharyngeus, palatopharyngeus, and levator veli palatini.
  
  
  RESULTS
  None of the patients studied showed electromyographic activity in the lateral flaps of tile pharyngoplasties. None showed electromyographic activity of the upper base pharyngeal flaps. All patients demonstrated strong electromyographic activity on the superior constrictor pharyngeus and the levator veli palatini.
  
  
  CONCLUSIONS
  Lateral pharyngeal flaps in cases of sphincter pharyngoplasties and the central pharyngeal flap in cases of pharyngeal flaps, do not create new sphincters for velopharyngeal closure. The participation of these structures is passive, increasing tissue volume in specific areas, whereas their movements are caused by the contraction of the superior constrictor pharyngeus and the levator veli palatini.
authors: Clínica de Paladar Hendido, Dirección de Investigación, Hospital General Dr. Manuel Gea González, México DF, México. amvsunza@terra.com.mx
authors: Antonio
authors: A
authors: Ysunza
mesh_terms: D000293:Adolescent; D000328:Adult; D002972:Cleft Palate / Q000534:rehabilitation* / Q000601:surgery*; D006801:Humans; D010609:Pharyngeal Muscles / Q000502:physiology*; D020127:Recovery of Function; D013524:Surgical Flaps