title: A comparison of the stability of single-piece and segmental Le Fort I maxillary advancements.
abstract: This study retrospectively evaluated the stability of Le Fort I maxillary advancements and compared segmental and one-piece maxillary osteotomy procedures. A cephalometric analysis was performed on 26 cases of maxillary advancement. The sample comprised 11 cases of one-piece and 15 cases of segmental maxillary procedures. The tracings were superimposed and digitized by computer software, and the skeletal changes were analyzed before surgery, immediately after surgery, and at a minimum of 1 year of follow-up. Different values were compared by the paired and nonpaired t tests and were correlated by the Pearson correlation test. The significant value was set at a 95% confidence interval. The maxilla was advanced by a mean of 5.0 +/- 1.6 mm (P < 0.001), and the anterior maxilla was repositioned inferiorly by a mean of 1.5 +/- 3.3 mm (P < 0.05). The maxilla relapsed posteriorly by a mean of 0.6 +/- 1.2 mm (P < 0.05) and superiorly at the anterior maxilla by a mean of 0.8 +/- 1.1 mm (P < 0.001). Overjet and overbite did not significantly change (P > 0.05). It was concluded that maxillary advancement using rigid fixation and interpositional bone grafting in both groups was a stable procedure, particularly in the horizontal plane. In the one-piece group, there was a significantly higher relapse in the vertical plane than in the segmental group (P < 0.05), however. Minor skeletal relapse was compensated for by postoperative tooth movement, and segmental procedures are recommended when required to enhance occlusal results.
authors.affiliation: Department of Plastic and Maxillofacial Surgery, University of Melbourne, Melbourne, Australia.
authors.forename: Premjit
authors.initials: P
authors.lastname: Arpornmaeklong
authors.forename: Andrew A
authors.initials: AA
authors.lastname: Heggie
authors.forename: Jocelyn M
authors.initials: JM
authors.lastname: Shand
mesh_terms: D000293:Adolescent; D000328:Adult; D001860:Bone Plates; D016025:Bone Transplantation; D002508:Cephalometry; D016001:Confidence Intervals; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008310:Malocclusion / Q000601:surgery; D016555:Matched-Pair Analysis; D008437:Maxilla / Q000002:abnormalities / Q000473:pathology / Q000601:surgery*; D019340:Osteotomy, Le Fort / Q000145:classification / Q000379:methods*; D010347:Patient Care Planning; D012008:Recurrence; D015203:Reproducibility of Results; D012189:Retrospective Studies; D013223:Statistics as Topic; D014087:Tooth Movement Techniques; D014716:Vertical Dimension