title: Study by finite element method of the mechanical stress of selected biodegradable osteosynthesis screws in sagittal ramus osteotomy.
abstract: We tested the stability of the bilateral sagittal split osteotomy using four resorbable osteosynthesis screws (the PLLA screw introduced by Harada and Enomoto, the Isosorb screw, the BioSorbFX screw and the Lactosorb screw) which are all currently in clinical use. The distribution of stress in both the bicortically inserted screws and the adjacent bone of a computer-generated mandible was recorded by the three-dimensional finite element method. The stress of the materials under investigation was postulated to have reached threshold values for stability, and maximum chewing forces of 132 N (Harada and Enomoto), 117 N (Isosorb), 115 N (BioSorbFX) and 46.4 N (Lactosorb) were determined. As far as the postoperative chewing forces were concerned, all four screws were sufficiently stable at the osteotomy gap. Finite element modelling seems to be an appropriate method of investigating these clinical issues when the mechanical stress both in implants and in the adjacent bone is taken into account.
authors.affiliation: Department of Oral and Maxillofacial Surgery, Martin Luther University, Halle, Germany. peter.maurer@medizin.uni-halle.de
authors.forename: P
authors.initials: P
authors.lastname: Maurer
authors.forename: S
authors.initials: S
authors.lastname: Holweg
authors.forename: W-D
authors.initials: WD
authors.lastname: Knoll
authors.forename: J
authors.initials: J
authors.lastname: Schubert
mesh_terms: D020341:Absorbable Implants; D001672:Biocompatible Materials; D001732:Bite Force; D001863:Bone Screws; D003198:Computer Simulation; D003799:Dental Stress Analysis / Q000379:methods*; D004548:Elasticity; D020342:Finite Element Analysis; D006801:Humans; D019248:Jaw Fixation Techniques / Q000295:instrumentation*; D019344:Lactic Acid; D008334:Mandible / Q000503:physiopathology / Q000601:surgery*; D008409:Mastication; D008422:Materials Testing; D010027:Osteotomy; D011060:Poloxalene / Q000031:analogs & derivatives; D011091:Polyesters; D011100:Polyglycolic Acid; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011108:Polymers; D013314:Stress, Mechanical
chemical_list: D001672:Biocompatible Materials; D011091:Polyesters; D011108:Polymers; C430808:poly(lactide-pluronic)copolymer; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; C033616:poly(lactide); D011060:Poloxalene