title: Validity of using fixation screws/wires as alternative landmarks for cephalometric evaluation after LeFort I osteotomy.
abstract: The most widely used method to measure postoperative stability of a surgically repositioned bony segment is based on skeletal landmarks. Unfortunately, orthognathic surgery may alter the skeletal landmarks and bony configurations that are commonly used for cephalometric analysis. Intraosseous wires, plates, and screws are routinely used in orthognathic surgery, and postoperatively they are easier to identify than skeletal landmarks. Cephalometric radiographs from 25 adult patients, who had undergone LeFort I one piece osteotomy, were used to analyze the validity of fixation wires/screws used as landmarks to evaluate postoperative stability of the maxilla. The positional changes of maxillary skeletal landmarks (A point and anterior and posterior nasal spines) and intraosseous fixation wires/screws were measured relative to the cranial base. The fixation screws/wires were also measured relative to the invariant maxillary trabecular patterns and palatal plane from 1 to 6 weeks (T1-T2) and 6 weeks to 1 year postoperatively. The reproducibility of fixation wires/screws was found to be higher than that of skeletal landmarks. The fixation wires/screws remained stable in the maxilla; their postoperative positional changes were not significantly different from those of the skeletal landmarks. When the skeletal landmarks are altered or no longer exist after LeFort I osteotomy, fixation wires/screws could be used as alternative landmarks to measure the maxillary postoperative stability.
authors.affiliation: Craniofacial Center, Chang Gung Memorial Hospital, Taipei, Taiwan.
authors.forename: E J
authors.initials: EJ
authors.lastname: Liou
authors.forename: C S
authors.initials: CS
authors.lastname: Huang
authors.forename: Y R
authors.initials: YR
authors.lastname: Chen
authors.forename: A A
authors.initials: AA
authors.lastname: Figueroa
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D001860:Bone Plates; D001863:Bone Screws; D001864:Bone Wires; D002508:Cephalometry / Q000379:methods*; D005500:Follow-Up Studies; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008437:Maxilla / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery; D009295:Nasal Bone / Q000000981:diagnostic imaging / Q000473:pathology; D019340:Osteotomy, Le Fort / Q000295:instrumentation; D010159:Palate / Q000000981:diagnostic imaging / Q000473:pathology; D011862:Radiography, Panoramic; D015203:Reproducibility of Results; D012658:Sella Turcica / Q000000981:diagnostic imaging / Q000473:pathology; D019291:Skull Base / Q000000981:diagnostic imaging / Q000473:pathology; D014716:Vertical Dimension