One-Year Post-Operative Stability of Lefort I Osteotomies Using Resorbable Fixation: A Retrospective Analysis of Diverse Facial Patterns on Skeletal Relapse

摘要

The purpose of this retrospective study was to determine post-operative skeletal relapse of maxillary LeFort I osteotomies using fixation plates and screws composed of a bioabsorbable copolymer of poly-L lactic and poly-L glycolic acid. The quantity of skeletal relapse from pre-treatment to immediate post-operative to one-year after surgery was measured and compared between two groups of diverse facial patterns, long-faced dolichofacial subjects and short-faced brachyfacial subjects. Twenty-three subjects, 18 dolichofacial and 5 brachyfacial, ages 19-39 were treated with LeFort I osteotomies to correct excess vertical maxillary height. Pre- operative, immediate post-operative, and one-year post-operative lateral cephalometric radiographs were traced and digitized. A template of each pre-operative maxilla allowed a best-fit technique of superimposition to be utilized for measurement of and comp an son with the immediate post-operative and one-year post-operative lateral cephalometric radiographs to horizontal (Frankfort horizontal) and vertical (Nasion perpendicular) reference planes. Linear millimeter measurements were recorded to the following four cephalometric landmarks: Posterior nasal spine (PNS), anterior nasal spine (ANS), A-point, and M- point. M-point is marked by visual inspection at the center point in the widest part of the premaxillary outline.