Evaluation of treatment outcome in cleft maxillary hypoplasia treated by rigid external distractor: a cephalometric...

The aim of the study was to cephalometrically evaluate hard and soft tissue changes in cases of cleft-induced maxillary hypoplasia treated by distraction osteogenesis using rigid external distractor (RED).

Fifteen cases of cleft-induced maxillary hypoplasia were selected applying the inclusion and exclusion criteria. The cases were operated on under general anesthesia for distraction osteogenesis using RED. Cephalometric evaluation was done at the end of presurgical orthodontics (C1), 1 week after removal of RED (C2), and at the end 12 months postoperatively (C3). The hard tissue parameters considered were Sella Nasion point A angle, Point A-Nasion-point B angle, distance from condylion to point A, anterior nasal spine-menton to Nasion-menton ratio, and upper incisor distance to N vertical. The soft tissue parameters included facial contour angle, nasolabial angle, upper lip to E-line, and lower lip to E-line.

There were 8 males and 7 females with an average age of 13.07 years. The range of maxillary advancement was 8 to 24.5 mm with an average of 14.46 mm. The cephalometric data were compared using paired t test and 1-way analysis-of-variance test. All the hard tissue changes except SNB were statistically highly significant (P > 0.0001). The percentage of relapse was 13.72% at SNA, 13.3% at ANB, 9.83% for maxillary depth, 8.99% for distance of the upper incisor to N perpendicular and 20.73% for facial contour angle, 2.16% for nasolabial angle, 25.69% for distance of UL to E-line, and 25.12% for distance of LL to E-line. Soft tissue relapse except nasolabial angle after 1 year was more as compared with hard tissue.

All the cephalometric parameters except SNB angle showed significant improvement. However, the significant percentage of relapse should be considered in the preoperative planning.