Simultaneous Correction of Unilateral Temporomandibular Joint Ankylosis and Mandibular Hypoplasia Using Combined Arthroplasty and Mandibular Distraction

Han, Ki Hwan; Ha, Tae Won; Son, Dae Gu

Abstract

Damage of temporomandibular joints in infancy may result in ankylosis and alteration of the mandibular growth. In case of unilateral ankylosis occurring in early childhood, a mandibular hypoplasia of the affected side usually follows. The patients have limitation of mouth opening, poor oral hygiene, facial and mandibular growth disturbances, and rarely, upper airway obstruction in the form of either night snoring or obstruction sleep apnea. The objective of this study is to show the use of distraction osteogenesis in mandibular hypoplasia associated with ankylosis and to present our technique for the treatment of mandibular hypoplasia with unilateral ankylosis in infancy consisting of simultaneous arthroplasty which treats the ankylosis and mandibular distraction and enables to correct the facial asymmetry in the same procedure. Between November 1999 and May 2000, three girl patients (42, 44, and 48 months old) who had mandibular hypoplasia associated with ankylosis were treated with simulatneous arthroplasty and distraction osteogenesis. Two kinds of arthroplasties, consisting of gap arthroplasty for one patient and interpositional arthroplasty using a temporal fascia turn-over flap for the other two patients, were executed and mandibular distraction in all three patients. Mouth-opening exercises began on the first day following the operation. Mandibular distraction began on the fifth day after the operation at a rate of 1 mm per day (0.5 mm twice a day) and continued to achieve a slight overcorrection of deviated chin. From the first day after the operation, an increase in the mouth opening was achieved. The average duration of distraction was 20 days. Average duration of consolidation was 6 weeks. Oral opening increased from 2 to 20 mm in case of the first patient, from 4 to 28 mm in the second patient, and from 5 to 24 mm in the third patient. The follow-up period was from 5 to 12 months (mean 8 months). At the time of final evaluation, oral opening and a more normal facial contour persist. It is believed that mandibular distraction combined with arthroplasty offers a new therapeutic option for the treatment of mandibular hypoplasia associated ankylosis, with minimal morbidity and complications.