Approximately 70-80 percent of all cleft palate patients will develop velopharyngeal competence after palate closure and thus the potential for normal speech. The remaining 20-30 percent will require speech therapy and/or an additional surgical procedure called a pharyngeal flap. To correct persistent hypernasal speech, this procedure involves raising a flap of tissue from the posterior pharynx and inserting it into the soft palate. This flap is indicated when the repaired palate is too short or the muscles do not function properly, causing a persistent hypernasal speech. The procedure is performed usually after the age of 4-5 when speech and velopharyngeal competence can be thoroughly assessed and before the child begins school.
Dr. Sargent’s article on Changes in Airflow Dynamics After Pharyngeal Flap in Nonsyndromic Children.