title: Maxillary fragment stabilization after Le Fort I fracture with 1 screw pair per plate.
abstract: OBJECTIVE
  The aim of the present study was to determine whether plates with only 1 screw pair can be used for Le Fort I fracture management. Good postoperative results motivated the direct application of mandible fixation principles to the fractured midface region without additional experimental research. However, the amount and distribution of the forces in the midface region is different from those on the mandible.
  
  
  METHODS
  Testing was conducted on plastic anatomic models. The validity of the experimental model was tested before the fixation techniques were compared. Standard miniplates and miniscrews were used for fixation of the maxilla. The model surface strain analysis was conducted using the noncontact object grating method, which enabled the surface strain measurement without direct influence on the measured model.
  
  
  RESULTS
  In 2 screw pair fixation, the outer screw pair has little effect on the local strain distribution, but it lowers the contact forces along the crack. One screw pair fixation is stable enough for fixation, but it has a greater strain peak at the crack edges.
  
  
  CONCLUSIONS
  Our results showed that 1 screw pair per plate was enough for stable fixation, and 2 or more screw pairs should only be used when the bone fragment at the fracture site cannot sufficiently transmit forces along the crack.
authors.affiliation: Department of Maxillofacial Surgery, Zagreb School of Dental Medicine, Zagreb, Croatia.
authors.forename: Predrag
authors.initials: P
authors.lastname: Knežević
authors.forename: Lovro
authors.initials: L
authors.lastname: Grgurević
authors.forename: Vedran
authors.initials: V
authors.lastname: Uglešić
authors.forename: Jakša
authors.initials: J
authors.lastname: Grgurević
authors.forename: Nenad
authors.initials: N
authors.lastname: Drvar
authors.forename: Janoš
authors.initials: J
authors.lastname: Kodvanj
mesh_terms: D000539:Alveolar Process / Q000503:physiopathology; D001696:Biomechanical Phenomena; D001860:Bone Plates; D001863:Bone Screws; D005593:Fracture Fixation, Internal / Q000295:instrumentation* / Q000379:methods; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D021621:Imaging, Three-Dimensional / Q000379:methods; D008437:Maxilla / Q000503:physiopathology; D008440:Maxillary Fractures / Q000145:classification / Q000601:surgery*; D008953:Models, Anatomic; D009295:Nasal Bone / Q000503:physiopathology; D010781:Photography / Q000379:methods; D010969:Plastics / Q000737:chemistry; D013314:Stress, Mechanical; D015050:Zygoma / Q000503:physiopathology
chemical_list: D010969:Plastics