title: Effect of mandibular titanium reconstructive plates on radiation dose.
abstract: BACKGROUND
  The effects of the mandibular titanium alloy plates on the radiation-tissue interactions are not clearly defined. Photon beam radiation may be modified after striking a metal plate used to reconstruct the mandible after oncologic surgery. The purpose of this study was to determine, in a human mandible model, the effects of a titanium alloy plate on the radiation dose received at the bone/titanium (plate and screws) interface and bone/soft tissue interface.
  
  
  METHODS
  We used an adult male human head and neck ex vivo model. A medical grade titanium alloy 6-hole plate, 2.4 mm, was fixed in the midline of the mandible. The mandible was then irradiated using 6 MV photon beams. Thermoluminescent dosimeters were used to measure the radiation doses anterior and posterior to the mandible. The experiment was then repeated without the plate and screws.
  
  
  RESULTS
  The difference between the average doses received by the mandible reconstructed with plate/screws and a mandible without plate/screws was +2.1% at the buccal aspect of the mandible and +3.0% at the lingual aspect; respective P values were.741 and .323. Thus, these differences were not statistically significant.
  
  
  CONCLUSIONS
  In this study, we did not observe any significant influence of titanium alloy plate/screws on the radiation doses received by tissues anterior or posterior to the mandible.
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Eye and Ear Institute, University of Pittsburgh School of Medicine, PA 15213, USA.
authors.forename: Francisco V
authors.initials: FV
authors.lastname: de Mello-Filho
authors.forename: Mubina
authors.initials: M
authors.lastname: Auader
authors.forename: Elmer
authors.initials: E
authors.lastname: Cano
authors.forename: Ricardo L
authors.initials: RL
authors.lastname: Carrau
authors.forename: Eugene N
authors.initials: EN
authors.lastname: Myers
authors.forename: Catherine E
authors.initials: CE
authors.lastname: Miles
mesh_terms: D000328:Adult; D001860:Bone Plates; D001863:Bone Screws; D006801:Humans; D008334:Mandible / Q000528:radiation effects* / Q000601:surgery*; D008953:Models, Anatomic; D011829:Radiation Dosage; D019651:Plastic Surgery Procedures / Q000379:methods*; D013819:Thermoluminescent Dosimetry; D014025:Titanium
chemical_list: D014025:Titanium