Comparison of distraction osteogenesis versus costochondral graft in reconstruction of temporomandibular joint condylectomy with disc preservation.

PURPOSE: This study compared transport distraction with costochondral graft in the reconstruction of temporomandibular joint (TMJ) with disc preservation. MATERIALS AND METHODS: Bilateral condylectomies with disc preservation were conducted in 12 adult goats. Transport distraction of the mandibular ramus was performed on 1 side and costochondral graft on the other side. Jaw movements, TMJ healing, and condylar remodeling were assessed by clinical, radiologic, and histologic examinations. RESULTS: Transport distraction and costochondral graft established a new condyle separating from the preserved disc with a joint space. Both techniques showed no significant difference in ankylosis scores up to 24 weeks. Signs of calcification were not noted in the transport distraction or costochondral graft side. No significant change of maximal jaw movements was found at any time point from 2 to 24 weeks. CONCLUSIONS: Distraction osteogenesis is an effective reconstruction method for TMJ reconstruction. No significant difference between these 2 techniques in reconstruction of the TMJ was noted.

Efficacy of functional training of the facial muscles for treatment of incomplete peripheral facial nerve injury.

OBJECTIVE: To investigate the efficacy of functional training of facial mimic muscles for patients with incomplete peripheral facial nerve injury. METHODS: Ninety-two patients with 241 injured branches of incomplete peripheral facial nerve injury were divided into a treatment group and a control group. The treatment group consisted of 58 cases that received functional training of facial mimic muscles. The rest of the cases served as controls. Assessment parameters included the House-Brackmann grading system, a quantitative facial nerve function estimating system and electroneurography. According to the three assessments, the facial nerve injury was divided into four grades: normal, minor, moderate and severe. The treatment group started training facial mimic muscle activity 2 weeks after facial nerve injury. After follow-ups of 1 to 4 years, the outcomes were statistically analysed. RESULTS: In the minor facial nerve injury group, there was no significant difference in the time needed for initial recovery (Ti, the time needed for significant recovery of the facial nerve function after injury) and final recovery (Tf, the time point after which no further improvement of facial nerve function was obtained) between the two groups (P > 0.05). No adverse effect was found in these cases. In the moderate facial nerve injury group, the Ti and Tf of the treatment group were shorter than those of the control group (P < 0.05). One case had synkinesis. In the patients with severe facial nerve injury, the recovery rate of facial nerve function in the treatment group was higher than that of the control group and the sequelae were less. CONCLUSION: Functional training of facial mimic muscles cannot shorten the time of recovery for the patients with minor facial nerve injury but it can speed up the recovery and reduce the undesirable sequelae such as synkinesis and hemifacial spasm for the patients with moderate and severe facial nerve injury.

Transport distraction versus costochondral graft for reconstruction of temporomandibular joint ankylosis: which is better?

OBJECTIVE: This study compared the methods of transport distraction and costochondral graft in reconstruction of temporomandibular joint (TMJ) ankylosis. STUDY DESIGN: Bilateral bony TMJ ankylosis was induced in 12 adult goats. Transport distraction of the mandibular ramus was performed on one side, whereas costochondral graft was performed on the other side. Jaw movements, TMJ healing, condylar remodeling, and recurrence of ankylosis were assessed by clinical, radiological, and histological examinations. RESULTS: Both transport distraction and costochondral graft established a neo-condyle separating from the pseudo-disc with a joint space. The ankylosis scores were higher in the distraction side in the first 12 weeks. Both techniques showed no significant difference in the calcification scores and recurrence of ankylosis in the long term. The maximal jaw movements in 3 directions returned to the pre-ankylosis stage by both methods. CONCLUSIONS: Distraction osteogenesis is an effective reconstruction method for TMJ ankylosis, matching the gold standard of costochondral grafting.

Surgical induction of temporomandibular joint ankylosis: an animal model.

PURPOSE: The aim of this study was to develop an animal model of temporomandibular joint (TMJ) bony ankylosis for future evaluation of surgical reconstructive methods. MATERIALS AND METHODS: An animal model was selected on the basis of 2 sequential experiments. Four goats and 4 minipigs were used in the first experiment, in which 1 goat and 1 minipig served as control animals. Condylectomy with disc preservation was performed on 1 side of 3 animals in each group. On the contralateral TMJ, condylectomy with discectomy was performed, and the arthroplasty gap was filled with the autogenous bone chips. In the second experiment, TMJ ankylosis was induced bilaterally in 3 additional animals of the species that achieved better ankylosis results in the first experiment. All animals were killed postoperatively at 3 months, and the TMJ complexes were examined by plain radiography, computed tomography, and histological evaluation. RESULTS: In the first experiment, only fibrous ankylosis was observed in the bone-grafted side of 2 goats and 3 minipigs, whereas fibro-osseous ankylosis was achieved in the remaining goat. The extent of ankylosis was found to be more severe in the goats than the minipigs. Hence, goats were selected for bilateral surgery in the second experiment, which achieved consistent bony ankylosis of the TMJ in all animals. CONCLUSIONS: Goats provide a better TMJ bony ankylosis model than minipigs. Consistent bony ankylosis can be induced by bilateral condylectomy, disectomy, and bone grafting of the arthroplasty gap.