Final answer:
Velopharyngeal insufficiency or incompetence is caused by factors such as anatomical deficits like cleft palate, irregular adenoids, cranial anomalies, effects of radiation or surgery, nasopharyngeal tumors, and changes post maxillary advancement surgeries.
Step-by-step explanation:
Velopharyngeal insufficiency or incompetence refers to a malfunctioning of the velopharyngeal mechanism, which is critical in separating the nasal and oral cavities during speech and swallowing. The causes of velopharyngeal insufficiency or incompetence include anatomical deficits such as a cleft palate, irregular adenoids that may be oversized or otherwise malformed, cranial anomalies that impact the function of cranial nerves or structure of the palate, sequelae of radiation or surgery that can disrupt the integrity of the velopharyngeal mechanism, nasopharyngeal tumors which may obstruct or displace the velopharyngeal structures, and maxillary advancement surgeries which can alter the spatial relationships in the maxillofacial area. A cleft palate is a developmental defect resulting from the failure of palatine shelves to fuse properly during embryonic growth, leading to a gap that can affect feeding and speech. It requires surgical repair to correct the defect.