Fibrous ankylosis after distraction osteogenesis of a costochondral neomandible in a patient with grade III hemifacial microsomia.

Distraction osteogenesis has recently become a mainstay for treatment of craniofacial syndromes with mandibular hypoplasia. This article presents the difficult case of a patient with a previous costochondral rib graft who underwent mandibular distraction and developed a fibrous pseudoarthrosis at the distraction site. This was attributed in part to an associated temporomandibular joint ankylosis. Resorption of the pseudoarthrosis occurred once the distractor was removed. It appears that distraction osteogenesis of a mandible with an ankylosed temporomandibular joint can result in healing with a fibrous union, presumably because of movement at the distraction site when masticating. This can result in a pseudo "temporomandibular joint" at the distraction site. A temporomandibular joint arthroplasty was performed, followed by repeat distraction. We conclude that if there is an ankylosed temporomandibular joint or a stiff temporomandibular joint that may ankylose during the course of the distraction process, then a temporomandibular joint arthroplasty should be performed before or at the time the distractor is placed.