[Clinical study of simultaneous correction of unilateral temporomandibular joint ankylosis and mandibular micrognathia with internal distraction osteogenesis].

OBJECTIVE

To observe the clinical results in correction of unilateral temporomandibular joint(TMJ) ankylosis accompanying with mandibular micrognathia using internal distraction osteogenesis simultaneously.

METHODS

Seven adult patients of unilateral TMJ ankylosis accompanying with mandibular micrognathia (13 sides of mandibular body) were treated simultaneously with internal distraction osteogenesis. Obstructive sleep apnea and hypopnea syndrome(OSAHS) was diagnosed in all patients preoperatively. The treatment includes distraction osteogenesis of mandibular body and transport distraction osteogenesis for TMJ arthroplasty at the same time. Distraction was started on the 6th to 8th day after operation. The distraction rhythm and rate was one mm a day operated in 4 separate times. The patients underwent active mouth opening postoperatively. Distractors were kept in place for 3-5 months after completion of distraction and then removed. Mean distraction distance of the 13 sides of mandibular body was 17.1mm(ranged from 14 to 20 mm) and that of the 7 sides of TMJ was 16.4mm(ranged from 15 to 20mm).

RESULTS

After treatment, micrognathia of the 7 patients was corrected. OSAHS was cured in 6 patients. The mean range of mouth opening was increased from 8.1 mm to 39.9 mm and bone formation in the distraction gaps was observed. The mean following-up period was 34.3 months(ranged from 18 to 51 months). No recurrence of TMJ ankylosis or micrognathia was occurred.

CONCLUSION

Unilateral TMJ ankylosis accompanying with micrognathia and OSAHS can be treated effectively by distraction osteogenesis simultaneously. The operation is simple with low risk. The course of treatment can be simplified and the operation times can be reduced.