Mandibular distraction osteogenesis: effects on articulation and velopharyngeal function.

Mandibular distraction osteogenesis has gained popularity for the treatment of mandibular hypoplasia and asymmetry. With this technique, significant skeletal and soft tissue changes in the lower face can be produced in a relatively short time period without the need for extensive surgery. Despite general acceptance, the long-term sequelae of the procedure have not been well documented. In this report, we describe two patients who experienced changes in their articulation and velopharyngeal function after unilateral mandibular distraction. The first patient underwent 35 mm and the second patient 45 mm of mandibular lengthening. In both cases, articulation skills declined, and there was velopharyngeal inadequacy immediately after distraction. However, in both cases, the velopharyngeal inadequacy was transient; one patient recovered near-normal velopharyngeal function within 1 month after distraction and the second patient recovered function within 8 months. The relations among mandibular distraction, articulation, and velopharyngeal function are discussed.