title: Mechanical and photoelastic analysis of four different fixation methods for mandibular body fractures.
abstract: OBJECTIVE
  The aim of the present study was to compare four methods of fixation in mandibular body fractures.
  
  
  METHODS
  Mechanical and photoelastic tests were performed using polyurethane and photoelastic resin mandibles, respectively. The study groups contained the following: (I), two miniplates of 2.0 mm; (II) one 2.0 mm plate and an Erich arch bar; (III) one 2.4 mm plate and an Erich arch bar, and (IV) one 2.0 mm plate and one 2.4 mm plate. The differences between the mean values were analyzed using Tukey's test, the Mann-Whitney test and the Bonferroni correction.
  
  
  RESULTS
  Group II recorded the lowest resistance, followed by groups I, IV and III. The photoelastic test confirmed the increase of tension in group II.
  
  
  CONCLUSIONS
  The 2.4 mm system board in linear mandibular body fractures provided more resistance and the use of only one 2.0 mm plate in the central area of the mandible created higher tension.
authors.affiliation: Oral and Maxillofacial Surgery Section, Oral Diagnosis Department, Piracicaba Dental School, P.O. Box 52, University of Campinas - UNICAMP, 13414-903, Piracicaba, SP, Brazil.
authors.forename: Danillo Costa
authors.initials: DC
authors.lastname: Rodrigues
authors.affiliation: Oral and Maxillofacial Surgery Section, Oral Diagnosis Department, Piracicaba Dental School, P.O. Box 52, University of Campinas - UNICAMP, 13414-903, Piracicaba, SP, Brazil. Electronic address: saulofalci@hotmail.com.
authors.forename: Saulo Gabriel Moreira
authors.initials: SG
authors.lastname: Falci
authors.affiliation: Oral and Maxillofacial Surgery Section, Oral Diagnosis Department, Piracicaba Dental School, P.O. Box 52, University of Campinas - UNICAMP, 13414-903, Piracicaba, SP, Brazil.
authors.forename: Andrezza
authors.initials: A
authors.lastname: Lauria
authors.affiliation: Oral and Maxillofacial Surgery Section, Oral Diagnosis Department, Piracicaba Dental School, P.O. Box 52, University of Campinas - UNICAMP, 13414-903, Piracicaba, SP, Brazil.
authors.forename: Érica Cristina
authors.initials: ÉC
authors.lastname: Marchiori
authors.affiliation: Oral and Maxillofacial Surgery Section, Oral Diagnosis Department, Piracicaba Dental School, P.O. Box 52, University of Campinas - UNICAMP, 13414-903, Piracicaba, SP, Brazil.
authors.forename: Roger William Fernandes
authors.initials: RW
authors.lastname: Moreira
mesh_terms: D001696:Biomechanical Phenomena; D001860:Bone Plates; D001863:Bone Screws; D004853:Epoxy Resins / Q000737:chemistry; D004867:Equipment Design; D005593:Fracture Fixation, Internal / Q000295:instrumentation / Q000379:methods*; D006801:Humans; D019248:Jaw Fixation Techniques / Q000295:instrumentation; D008337:Mandibular Fractures / Q000503:physiopathology / Q000601:surgery*; D008953:Models, Anatomic; D010796:Phthalic Anhydrides / Q000737:chemistry; D011140:Polyurethanes / Q000737:chemistry; D012117:Resins, Synthetic / Q000737:chemistry; D013314:Stress, Mechanical; D014025:Titanium / Q000737:chemistry
chemical_list: D004853:Epoxy Resins; D010796:Phthalic Anhydrides; D011140:Polyurethanes; D012117:Resins, Synthetic; C005752:araldite; D014025:Titanium
keywords: Bone fracture; Bone plates; Fracture fixation; Mandible