PROGNOSIS FOLLOWING THE LAG-SCREW FIXATION FOR THE FRACTURED MANDIBULAR CONDYLE

ABSTRACT

PURPOSE: This is to evaluate the clinical results and radiologic changes of the mandibular condyle fractures following the open reduction and fixation using the Lag-screws introduced by Eckelt and Martin Co. MATERIALS & METHODS: Ten patients who had been treated by the Lag-screw fixation for the unilateral fracture of the mandibular condyle at the high level and followed up for over 6 months(ranged from 24 weeks to 33 weeks). The incisal opening by time elapsed, displacement of the fragments, bone resorption around the Lag-screws, operating time consumed, and untoward complications were evaluated. The data were tested by repeated measure ANOVA and paired t-test. RESULTS: The maximum mouth opening was increased by time as follows ; 20.2+/-2.8mm soon after reduction. 26.3+/-3.9 at the 2nd week, 37.7+/-4.2mm at the 4th week, 44.4+/-4.3mm in PO 2 months(P<0.05). The bone resorption at anterior to lag-screw nut was measured to 1.9+/-1.0mm, while the posterior resorption was 2.6+/-1.9mm on average(P<0.05). Reduction and fixation of the fragments by Lag-screw were done within 80 minutes including the skin closure. The clicking sound of the TMJ(40%), weakness of the marginal branch(60%) were complicated but transient for 4-8weeks. There were no signs of bony displacement, but loosening of screws were observed at the time of removal. CONCLUSION: Open reduction and fixation with condylar Lag-screw(Martin co., Germany) thru the ramus can be a good option to reduce the high level(Kruger's Level III & IV) fracture of the mandibular condyle with anterior or medial displacement. However, this procedure requires 2nd surgery to remove the devices and it may complicate improper reduction for delayed fractures and in case of 's' curved mandibular ramus.