The effects of maxillofacial surgery on speech and velopharyngeal function.

Individuals undergoing conventional maxillary advancement surgery or maxillary distraction should have perceptual and instrumental assessment of speech and velopharyngeal function, pre- and postsurgically. They should be counseled on the risk of deterioration in velopharyngeal function, particularly for those who have repaired cleft palate presenting with characteristics of borderline velopharyngeal function. These individuals should also be counseled that there may be a positive change in speech articulation, with normalization of the maxillary-mandibular relationship, especially for the highly sibilant /s/ and /z/ sounds. This article highlights speech errors often seen in individuals who have dentofacial skeletal deformities, and discusses the impact of conventional orthognathic surgery and distraction osteogenesis on speech production. Methods of assessing speech production, including perceptual assessment and instrumentation are also reviewed.