title: Biomechanical analysis of poly-L-lactic acid and titanium plates fixated for mandibular symphyseal fracture with a conservatively treated unilateral condylar fracture using the three-dimensional finite element method.
abstract: The purpose of this study was to investigate stress on poly-L-lactic acid (PLLA) plates with a thickness of 1.4 mm and titanium plates with a thickness of 1.0 and 1.4 mm placed for mandibular symphyseal fractures with or without conservatively treated, unilateral condylar fractures using finite element analysis. The symphyseal fracture region was defined by the following three conditions: the defect, the callus, and the contact condition. Stress on the plates was analyzed by an applying occlusal force of 478.1 N on the first molar of the non-condylar fracture side. In the model of isolated symphyseal fracture, the maximal stresses were below the material strength in all plate types and conditions. In the models with condylar fracture, the maximal stresses on these plates were much higher than those in the models of isolated symphyseal fracture, especially for the defect condition. Although the maximal stresses on all types of plates in the contact condition were below the material strengths, some of those in the defect condition were higher than these strengths. These results suggest that a PLLA plate can theoretically withstand stress under good reductions of symphyseal fractures, even for condylar fractures; however, both the PLLA plate and titanium miniplate may be at risk of fracture under poor reduction.
authors.affiliation: Department of Oral and Maxillofacial Surgery, Nara Medical University, Kashihara City, Nara, Japan.
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Murakami
authors.affiliation: Department of Oral and Maxillofacial Surgery, Nara Medical University, Kashihara City, Nara, Japan.
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Yamamoto
authors.affiliation: Department of Oral and Maxillofacial Surgery, Nara Medical University, Kashihara City, Nara, Japan.
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Sugiura
authors.affiliation: Department of Oral and Maxillofacial Surgery, Nara Medical University, Kashihara City, Nara, Japan.
authors.forename: Masayoshi
authors.initials: M
authors.lastname: Kawakami
authors.affiliation: Department of Oral and Maxillofacial Surgery, Nara Medical University, Kashihara City, Nara, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Horita
authors.affiliation: Department of Oral and Maxillofacial Surgery, Nara Medical University, Kashihara City, Nara, Japan.
authors.forename: Tadaaki
authors.initials: T
authors.lastname: Kirita
mesh_terms: D001696:Biomechanical Phenomena; D001860:Bone Plates; D003799:Dental Stress Analysis; D020342:Finite Element Analysis; D005593:Fracture Fixation, Internal / Q000295:instrumentation*; D006801:Humans; D021621:Imaging, Three-Dimensional; D008335:Mandibular Condyle / Q000293:injuries; D008337:Mandibular Fractures / Q000601:surgery*; D008422:Materials Testing; D011091:Polyesters / Q000737:chemistry*; D013718:Tensile Strength; D014025:Titanium / Q000737:chemistry*; D014057:Tomography, X-Ray Computed
chemical_list: D011091:Polyesters; C033616:poly(lactide); D014025:Titanium
keywords: condyle; finite element method; mandibular fracture; poly-L-lactic acid; symphysis; titanium