Morphological evaluation of changes in velopharyngeal function following maxillary distraction in patients with repaired cleft palate during mixed dentition

Objective: To describe the morphological changes of nasopharyngeal components after maxillary distraction and clarify whether the morphological characteristics are related to velopharyngeal function (VPF). Design: Perceptual judgments of hypernasality and nasendoscopy were performed before and after treatment. Lateral cephalograms were obtained to describe the morphological changes. Setting: Department of Oral and Maxillofacial Surgery, Miyazaki Medical College, Miyazaki, Japan. Participants: Nine patients with repaired cleft palate in the mixed dentition stage underwent maxillary distraction using a face mask and an intraoral fixed appliance system. Outcome Measures: The severity of hypernasality, velopharyngeal insufficiency, and measurements such as pharyngeal depth, velar length, and the rotation of the palatal plane were evaluated. Results: Increase in pharyngeal depth was not always proportional to the amount of advancement. It depended on the posture of the posterior pharyngeal wall and the rotation of palatal plane. Conclusion: Cephalometric measurements of the nasopharynx before and after surgery confirmed subsequent changes in VPF. These were suggested to be useful in predicting future VPF When performing maxillary distraction in patients with cleft palate in the mixed dentition stage, and when velopharyngeal closure is found to occur by velar contact against the hypertrophied adenoid, patients should be counseled about risks of subsequent deterioration in their speech before surgery.