title: One-year postoperative stability of LeFort I osteotomies with biodegradable fixation: a retrospective analysis of skeletal relapse.
abstract: BACKGROUND
  The purpose of this retrospective analysis was to determine the magnitude of postoperative skeletal relapse of a maxillary LeFort I osteotomy procedure performed with fixation plates and screws composed of a biodegradable copolymer (poly-L lactic and poly-L glycolic acid).
  
  
  METHODS
  Twenty-three consecutively treated subjects, aged 19 to 39, were diagnosed with excess vertical maxillary height or anteroposterior maxillary deficiency and treated with LeFort I impaction or advancement osteotomies. Lateral cephalometric radiographs were measured and compared for the absolute magnitude of skeletal relapse from pretreatment to immediately postoperative to 1 year after surgery.
  
  
  RESULTS
  Correlation analysis determined that a positive relationship existed between the magnitude of the surgical movement and the magnitude of postoperative relapse. The greatest relapse for any subject in any direction was 0.940 mm (anterior nasal spine to nasion-perpendicular). The greatest average relapses were 0.249 mm horizontally (anterior nasal spine to Frankfort horizontal) and 0.141 mm vertically (M-point Frankfort horizontal).
  
  
  CONCLUSIONS
  The most significant contribution of this study to surgical stability literature is reporting the absolute magnitudes of postoperative relapse over a 1-year period of observation. Consistent with previously published reports on postoperative stability, greater magnitudes of relapse were noted for larger surgical movements, yet the absolute values of postoperative relapse with biodegradable copolymers was clinically negligible. Biodegradable copolymers can provide excellent postoperative stability for superior and anterior maxillary surgical repositioning that appears to rival published stability measurements for rigid internal metallic fixation.
authors.affiliation: South County Hospital, Wakefield, RI, USA.
authors.forename: Kevin Daniel
authors.initials: KD
authors.lastname: Kiely
authors.forename: Kyle Stewart
authors.initials: KS
authors.lastname: Wendfeldt
authors.forename: Baxter Edwin
authors.initials: BE
authors.lastname: Johnson
authors.forename: Bruce Steven
authors.initials: BS
authors.lastname: Haskell
authors.forename: Richard C
authors.initials: RC
authors.lastname: Edwards
mesh_terms: D020341:Absorbable Implants; D000328:Adult; D001672:Biocompatible Materials; D001860:Bone Plates; D001863:Bone Screws; D002508:Cephalometry / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D019248:Jaw Fixation Techniques / Q000295:instrumentation*; D019344:Lactic Acid; D008297:Male; D008310:Malocclusion / Q000601:surgery*; D008437:Maxilla / Q000002:abnormalities / Q000601:surgery*; D019340:Osteotomy, Le Fort; D011100:Polyglycolic Acid; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011108:Polymers; D011184:Postoperative Period; D012008:Recurrence; D012189:Retrospective Studies
chemical_list: D001672:Biocompatible Materials; D011108:Polymers; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid