title: Segment stability in bimaxillary orthognathic surgery after resorbable Poly(L-lactide-co-glycolide) versus titanium osteosyntheses.
abstract: This study compared segment stability after bimaxillary orthognathic surgery, comparing poly(L-lactide-co-glycolide) with titanium osteofixation at 12 months follow up. Fifteen patients were osteofixated with poly(L-lactide-co-glycolide) copolymer, 30 with 2.0-mm titanium miniplates. Preoperative, postoperative, and 1-year follow-up lateral cephalograms were analyzed. Maxillary average advancement in resorbable plate osteosyntheses (+/- standard deviation) was (case numbers/titanium controls) 2.5 (+/- 1.0) mm; n = 7/5.4 (+/- 3.5)mm; n = 21, setback 2.2 (+/- 2.4) mm; n = 7/1.9 (+/- 1.8) mm; n = 8, elongation 6.5 (+/- 3.4) mm; n = 9/3.7 (+/- 5.2) mm; n = 14, intrusion 1.0 (+/- 0.7) mm; n = 5/3.3 (+/- 2.7)mm; n = 13, mandibular average advancement was 5.5 (+/- 3.7) mm; n = 4/6.3 (+/- 8.8) mm; n = 18, setback 11.2 (+/- 7.7) mm; n = 7/7.2 (+/- 3.2) mm; n = 12, mandibular angle enlargement 7.9 (+/- 2.4) degrees ; n = 9/7.9 (+/- 6.6) degrees ; n = 21, reduction 6.9 (+/- 2.6) degrees ; n = 4/6.3 (+/- 6.6) degrees ; n = 9. Changes in landmark position within the study and control groups differed significantly in paired t testing (P =.01); operative movements were comparable in between study and control groups (P = 0.5, two-sided t test), only maxillary advancement was significantly smaller (P = 0.04) within study cases. Absolute instability at advanced A-point was (study group/controls) 1.2 (+/- 0.8)/2.4 (+/- 2) mm; setback 1.8 (+/- 1.9) mm/2.5 (+/- 1.7) mm; elongation at anterior nasal spine (ANS) 2.0 (+/- 1.4) mm/3.1 (+/- 3.6) mm, intrusion 1.1 (+/- 1.1) mm/2.2 (+/- 1.5) mm; advancement instability at B-point was 2.6 (+/- 2.7) mm/5.1 (+/- 8.2) mm, setback 2.7 (+/- 2.6) mm/1.7 (+/- 2) mm; mandibular angle enlargement instability 2.4 (+/- 2.7) degrees /8.2 (+/- 9.6) degrees , angle narrowing 7.0 (+/- 5.4) degrees /4.2 (+/- 5.9) degrees . Absolute postoperative instability was not significantly different in between study and control groups (P = 0.3). Tested resorbable poly(L-lactide-co-glycolide) osteofixation proved to be as reliable in segment fixation as titanium; however, study and control groups were not matched; the study group was small and therefore the results (especially advancement) have to be interpreted as preliminary until larger prospective cohorts become evaluated.
authors.affiliation: Department of Oral, Maxillofacial and Plastic Facial Surgery, University Medical Centre, Frankfurt/Main, Germany. c.landes@lycos.com
authors.forename: Constantin A
authors.initials: CA
authors.lastname: Landes
authors.forename: Alexander
authors.initials: A
authors.lastname: Ballon
authors.forename: Robert
authors.initials: R
authors.lastname: Sader
mesh_terms: D020341:Absorbable Implants; D000293:Adolescent; D000328:Adult; D005260:Female; D005593:Fracture Fixation, Internal / Q000379:methods*; D006801:Humans; D019344:Lactic Acid / Q000737:chemistry*; D008297:Male; D008310:Malocclusion / Q000000981:diagnostic imaging / Q000601:surgery*; D008437:Maxilla / Q000000981:diagnostic imaging / Q000601:surgery*; D008875:Middle Aged; D011100:Polyglycolic Acid / Q000737:chemistry*; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011108:Polymers / Q000737:chemistry*; D011859:Radiography; D014025:Titanium / Q000737:chemistry; D016896:Treatment Outcome
chemical_list: D011108:Polymers; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; D014025:Titanium