Long-term skeletal stability after maxillary advancement with distraction osteogenesis in nongrowing patients.
OBJECTIVE
We assessed the long-term skeletal stability of the repositioned maxilla, midface in patients who underwent maxillary advancement using distraction osteogenesis (DO).


METHODS
The study included 19 nongrowing patients with maxillary hypoplasia with a Class III relationship, a normally developed mandible, and follow-up after DO exceeding 2 years. Eleven men and 8 women participated, with a mean age at treatment of 20.7 years (range 15.4-33.4 years). Twelve patients had midfacial hypoplasia associated with a cleft lip and palate (CLP), and 7 patients had developed noncleft-related hypoplasia. The surgical treatment included our modified Le Fort I osteotomy in combination with intraoral (5 cases) or extraoral (14 cases) distraction devices. Distraction was started after a latency period of 5 to 7 days and continued until the proper convexity was obtained. After active distraction, a 3- to 4-week period of retention was allowed, followed by rigid internal fixation (IF) with or without distractor removal. Lateral cephalometric films before midfacial distraction (T0), after IF with or without distractor removal (T1), 6 months after T1 (T2), and 2 or more years (mean 2.8 years) after T1 (T3) were analyzed. The maxillary A-point in the Frankfort horizontal reference plane was used to assess the skeletal changes in the maxillary position (x, y) at each time point (T1-T3). In addition, we analyzed the differences in the devices and techniques.


RESULTS
Midfacial DO was successful in all cases, resulting in a mean change obtained at point A of 10.3 mm (8.4 mm horizontally, 4.7 mm inferiorly). Point A underwent a moderate amount of skeletal relapse at T2 [0.4 mm (5%) horizontally and 0.6 mm (13%) superiorly], with a mean of 8% (0.6 mm) horizontally and 19% (1.0 mm) superiorly over the mean 2.8-year (2.0-4.8 years) follow-up. After long-term follow-up, the maxillary advancement with DO was stable in both CLP and non-CLP patients with maxillary hypoplasia. In addition, our original technique using a rigid external device provided the most reliable results in terms of skeletal stability.


CONCLUSIONS
This retrospective study showed that DO of the maxilla gives a very stable midface, offering a promising treatment alternative for patients with maxillary hypoplasia.
Kanno
Takahiro
T
Division of Oral and Maxillofacial Surgery, Kagawa Prefectural Central Hospital, Kagawa, Japan.
Mitsugi
Masaharu
M
Hosoe
Michi
M
Sukegawa
Shintaro
S
Yamauchi
Kensuke
K
Furuki
Yoshihiko
Y
D000293:Adolescent; D000328:Adult; D002508:Cephalometry; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008437:Maxilla / Q000002:abnormalities / Q000254:growth & development / Q000601:surgery*; D009971:Orthodontics, Corrective / Q000379:methods*; D019857:Osteogenesis, Distraction / Q000379:methods*; D019340:Osteotomy, Le Fort / Q000379:methods*; D012008:Recurrence; D012189:Retrospective Studies; D016896:Treatment Outcome