title: In vitro biomechanical comparison of six different fixation methods following 5-mm sagittal split advancement osteotomies.
abstract: The sagittal split ramus osteotomy (SSRO) is a surgical technique used widely to treat many congenital and acquired mandibular discrepancies. Stabilization of the osteotomy site and the potential for skeletal relapse after the procedure are still major problems. The aim of this study was to compare the mechanical stability of six methods of rigid fixation in SSRO using a biomechanical test model. Sixty polyurethane replicas of human hemimandibles were divided into six groups. In group I, the osteotomies were fixed with two four-hole titanium miniplates; in group II, with one four-hole miniplate; in group III, with one four-hole miniplate+a bicortical screw; in group IV, with a grid miniplate; in group V, with a four-hole locking miniplate; and in group VI, with a six-hole miniplate. A linear load in the premolar region was applied to the hemimandibles. The resistance forces (N) needed to displace the distal segment by 1, 3, and 5mm were recorded and the data transmitted from the load cell to a computer. One-way analysis of variance with Tukey's post hoc test was performed to compare the means between groups. For the three displacement conditions, there was a strong tendency for the 2.0-mm plate+screw and the grid plate to have higher values.
authors.affiliation: Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, Baskent University, Ankara, Turkey. Electronic address: yenero80@yahoo.com.
authors.forename: Y
authors.initials: Y
authors.lastname: Oguz
authors.affiliation: Division of Oral and Maxillofacial Surgery, Dental School of Araraquara, São Paulo State University - UNESP, Araraquara, São Paulo, Brazil.
authors.forename: E R
authors.initials: ER
authors.lastname: Watanabe
authors.affiliation: Department of Prosthodontics, Dental School of Araraquara, São Paulo State University - UNESP, Araraquara, São Paulo, Brazil.
authors.forename: J M
authors.initials: JM
authors.lastname: Reis
authors.affiliation: Section of Oral Radiology, Department of Dentistry, Faculty of Health, Aarhus University, Denmark.
authors.forename: R
authors.initials: R
authors.lastname: Spin-Neto
authors.affiliation: Division of Oral and Maxillofacial Surgery, Dental School of Araraquara, São Paulo State University - UNESP, Araraquara, São Paulo, Brazil.
authors.forename: M A
authors.initials: MA
authors.lastname: Gabrielli
authors.affiliation: Division of Oral and Maxillofacial Surgery, Dental School of Araraquara, São Paulo State University - UNESP, Araraquara, São Paulo, Brazil.
authors.forename: V A
authors.initials: VA
authors.lastname: Pereira-Filho
mesh_terms: D001696:Biomechanical Phenomena; D001860:Bone Plates; D001863:Bone Screws; D006801:Humans; D019248:Jaw Fixation Techniques; D008953:Models, Anatomic; D059229:Osteotomy, Sagittal Split Ramus / Q000379:methods*; D011140:Polyurethanes
chemical_list: D011140:Polyurethanes
keywords: biomechanical test; fixation; polyurethane hemimandibles; sagittal split ramus osteotomy