title: Mechanical aspects of a multidirectional, angular stable osteosynthesis system and comparison with four conventional systems.
abstract: BACKGROUND
  Following open reduction, internal fixation of fractures of the mandible is predominantly achieved using plates and screws. Today, a multitude of osteosynthesis systems are available on the market. One therapy modality, primarily developed for orthopaedic surgery, is using angular stable osteosynthesis plate systems. The dominating principle of these is the bond between screw and plate following insertion. This principle of an "internal fixateur" results in a more stable fixation of the fragments associated with less compression of the bone surfaces.
  
  
  METHODS
  A new multidirectional osteosynthesis system (TiFix=Smartlock, Hamburg - Germany) was modified to fit the maxillofacial region and compared with four other well established osteosynthesis systems developed by Mondial, Medicon, Synthes, Leibinger-Stryker, one of these (Unilock by Synthes) being also angular stable. The resistance to deformation in varying directions was investigated following fixation in four different materials.
  
  
  RESULTS
  The TiFix system proved more resistant to deformation even when mounted with fewer screws than the non-angular stable systems.
  
  
  CONCLUSIONS
  This system results in greater stability even when fewer screws are used. For the clinician this means smaller access incisions, less soft tissue trauma, better aesthetic results, decreased duration of operation and a reduction of costs.
authors.affiliation: Department of Oral and Maxillofacial Surgery (Head: Prof. Dr. Dr. R. Schmelzle), University Hospital Hamburg-Eppendorf, Hamburg, Germany. Electronic address: gbara@web.de.
authors.forename: Ali
authors.initials: A
authors.lastname: Gbara
authors.affiliation: Department of Oral and Maxillofacial Surgery (Head: Prof. Dr. Dr. R. Schmelzle), University Hospital Hamburg-Eppendorf, Hamburg, Germany.
authors.forename: Max
authors.initials: M
authors.lastname: Heiland
authors.affiliation: Department of Oral and Maxillofacial Surgery (Head: Prof. Dr. Dr. R. Schmelzle), University Hospital Hamburg-Eppendorf, Hamburg, Germany.
authors.forename: Rainer
authors.initials: R
authors.lastname: Schmelzle
authors.affiliation: Department of Oral and Maxillofacial Surgery (Head: Prof. Dr. Dr. R. Schmelzle), University Hospital Hamburg-Eppendorf, Hamburg, Germany.
authors.forename: Felix
authors.initials: F
authors.lastname: Blake
mesh_terms: D000180:Acrylic Resins; D000818:Animals; D001860:Bone Plates / Q000145:classification; D001863:Bone Screws / Q000145:classification; D004867:Equipment Design; D004868:Equipment Failure; D005593:Fracture Fixation, Internal / Q000295:instrumentation*; D006801:Humans; D008337:Mandibular Fractures / Q000601:surgery; D008953:Models, Anatomic; D018583:Pliability; D011312:Pressure; D012756:Sheep; D013314:Stress, Mechanical; D013499:Surface Properties; D054159:Torsion, Mechanical; D016474:Weight-Bearing
chemical_list: D000180:Acrylic Resins