Functional Temporomandibular Joint Reconstruction in Costochondral Grafting of Micrognathia

Rib bone and costochondral complex grafting has been used to treat micrognathia classified as Pruzansky type III. To acquire more physiological joint movement, we reconstructed a temporomandibular joint with the glenoid fossa in addition to the mandibular ramus. The patient underwent a tracheostomy to correct her airway obstruction at 2 months of age. After that, no further surgical treatments were performed on the micrognathia. When she was 6 years of age and during consultation at our department, micrognathia caused by Goldenhar syndrome was confirmed. A head and neck computed tomography scan showed hypoplasia and deficit of the mandible, severe glossoptosis and airway constriction. Initially, a bilateral mandibular body distraction was performed at 6 years of age, and 15 mm of elongation was obtained. Subsequently, reconstruction of the right ramus and right temporomandibular joint fossa was performed at 8 years of age to achieve extubation. Part of her sixth rib and costochondral complex graft was used for the ramus, and costochondral graft was used for the joint fossa. Some new ideas for temporomandibular joint reconstruction were added. Postoperatively, the open mouth range was increased and improvement of the airway space narrowing was observed in a computed tomography scan. The main points of this new method are prevention of ankylosis, skull cortex thinning, and reconstructed ramus’ dislocation. This method may become an effective new treatment for cases of micrognathia with a ramus classified as Pruzansky type III.