SKELETAL STABILITY AND RELAPSE PATTERNS AFTER LE-FORT-I MAXILLARY OSTEOTOMY FIXED WITH MINIPLATES - THE UNILATERAL CLEFT-LIP AND PALATE DEFORMITY

The outcomes of a consecutive series of 35 adults and adolescents judged to be skeletally mature (mean 18 years) who had unilateral cleft lip and palate and had undergone Le Fort I advancement fixed with miniplates were investigated. All patients had received grafts of autogenous iliac bone and were stabilized intraoperatively with four miniplates. The amount and timing- of horizontal and vertical relapse, correlation between advancement and relapse, effect of a pharyngoplasty in place at the time of osteotomy, effect of performing multiple jaw procedures, and maintenance of overjet and overbite were analyzed. Tracings of preoperative and serial postoperative lateral cephalograms (taken immediately and at 6 to 8 weeks and 1 year) were analyzed to calculate horizontal and vertical maxillary change and the amount of overjet and overbite maintained. Clinical follow-up ranged from 1.5 to 4.5 years (mean 1.5 years). No significant difference was seen in horizontal or vertical surgical change or relapse between patients who had maxillary surgery atone (n = 24) and those who had operations on both jaws (n = 11), nor did outcome vary significantly;v for those with a pharyngoplasty in place (n = 13) at the time of their Le Fort I osteotomy (p < 0.05). The mean effective horizontal advancement achieved for the group was 6.9 mm, with 5.3 mm maintained 1 year later (mean relapse of 1.6 mm). The mean effective vertical change of the maxilla was 2.1 mm initially and 1.7 mm 1 year later (mean relapse of 0.4 mm). At the 1-year interval, a positive overjet was maintained in an patients, and a positive overbite was maintained in 30 (86 percent) of 35. Amounts of relapse and advancement or displacement did not correlate significantly (p < 0.05). Our study suggests that although miniplate and screw internal fixation is a useful technique, it does not eliminate the problem of relapse in a large series of unilateral cleft lip and palate patients undergoing Le Fort I osteotomy.