Velopharyngeal insufficiency  is a disorder of structure that causes a failure of the velum (soft palate) to close against the posterior pharyngeal wall (back wall of the throat) during speech in order to close off the nose (nasal cavity) during oral speech production. This is important because speech requires sound (from the vocal folds) and airflow (from the lungs) to be directed into the oral cavity (mouth) for the production of all speech sound with the exception of nasal sounds (m, n, and ng). If complete closure does not occur during speech, this can cause hypernasality (a resonance disorder) and/or audible nasal emission during speech (a speech sound disorder). In addition, there may be inadequate airflow to produce most consonants, making them sound weak or omitted.The terms "velopharyngeal insufficiency" "velopharyngeal incompetence, "velopharyngeal inadequacy" and "velopharyngeal dysfunction" have often been used interchangeably, although they do not mean the same thing. "Velopharyngeal dysfunction" now refers to abnormality of the velopharyngeal valve, regardless of cause. Velopharyngeal insufficiency includes any structural defect of the velum or mechanical interference with closure. Causes include a history of 
cleft palate, adenoidectomy, irregular adenoids, cervical spine anomalies, or oral/pharyngeal tumor removal. In contrast, "velopharyngeal incompetence" refers to a neurogenic cause of inadequate velopharyngeal closure. Causes may include stroke, traumatic brain injury, cerebral palsy, or neuromuscular disorders. It is important that the term "velopharyngeal insufficiency" is used if it is an anatomical defect and not a neurological problem. Anatomy
Diagnosis
Speech analysis
Velopharyngeal insufficiency can be diagnosed by a speech pathologist through a perceptual speech assessment.
MRI uses the property of nuclear magnetic resonance to image nuclei of atoms inside the body. MRI is non-radiographic and therefore can be repeated more often in short periods of time. In addition, different studies show that the MRI is better as an imaging tool than videofluoroscopy for visualizing the anatomy of the velopharynx. There are some limitations of the MRI however. Unlike videofluoroscopy and nasopharyngoscopy, MRI does not show the movement of the velopharyngeal structures during speech. In addition, artifacts can be shown on the images when the patient moves while imaging or if the patient has orthodontic appliances. MRI is limited in children who are claustrophobic. Finally, MRI is much more expensive than videofluoroscopy or nasopharyngoscopy. Because of these limits, MRI is currently not widely used for clinical diagnostic purposes. Treatment
Speech pathology
Speech therapy will not correct velopharyngeal insufficiency. The condition results from abnormal structure and requires physical management (surgery, or a prosthetic device if surgery cannot be done). Speech therapy is appropriate to correct the compensatory articulation productions that develop as a result of velopharyngeal insufficiency. Speech therapy is most successful after correction of velopharyngeal insufficiency. Speech pathologists who are associated with a cleft palate/craniofacial team are most qualified for this type of therapy. Operation techniques
In patients with cleft palate, the palate must be repaired through a palatoplasty for normal velopharyngeal function. Despite the palatoplasty, 20-30% of these patients will still have some degree of velopharyngeal insufficiency, which will require surgical (or prosthetic) management for correction. Therefore, a secondary operation is necessary.