Factors related to relapse after Le Fort I maxillary advancement osteotomy in patients with cleft lip and palate.

OBJECTIVE: To identify factors associated with relapse after maxillary advancement in cleft lip and palate patient.
SUBJECTS: Seventy-one cleft lip and palate patients underwent Le Fort I maxillary advancement osteotomy between 1988 and 1998, and 58 patients (42 unilateral cleft and 16 bilateral cleft) with complete data were investigated for relapse by clinical and cephalometric analysis. The clinical follow-up period ranged from 1.5 to 8.5 years (mean 2.5 years).
RESULTS: Horizontal advancement averaged 6.9 mm. There was a significant correlation between surgical movement and postoperative relapse in both the horizontal and vertical planes. In vertical repositioning, 15 patients had maxillary intrusion and 31 had inferior repositioning. There was a significant difference between the intrusion group and the inferior repositioning group. There was a significant correlation between surgical and postoperative rotation regardless of the direction. Other factors were evaluated by the horizontal relapse rate. Type of cleft and the rate of relapse were statistically associated. A relapse was more likely to occur in patients with bilateral cleft. There were no significant associations with the rate of relapse in type of operations or previous alveolar bone grafting. There was no significant correlation between the rate of relapse and the number of missing anterior teeth, postoperative overbite and overjet, and age at operation. Four of 71 patients experienced major relapse, and 3 of them underwent jaw surgery again.
CONCLUSIONS: Based on clinical and cephalometric analysis, two-jaw surgery should be performed in cases of severe maxillary hypoplasia, and overcorrection may be useful in inferior repositioning or surgical rotation. Special attention should be paid to the patient with bilateral cleft, multiple missing teeth, or shallow postoperative overbite.