title: Measurement of skin dose from cone-beam computed tomography imaging.
abstract: OBJECTIVE
  To measure surface skin dose from various cone-beam computed tomography (CBCT) scanners using point-dosimeters.
  
  
  METHODS
  A head anthropomorphic phantom was used with nanoDOT optically stimulated luminescence (OSL) dosimeters (Landauer Corp., Glenwood, IL) attached to various anatomic landmarks. The phantom was scanned using multiple exposure protocols for craniofacial evaluations in three different CBCT units and a conventional x-ray imaging system. The dosimeters were calibrated for each of the scan protocols on the different imaging systems. Peak skin dose and surface doses at the eye lens, thyroid, submandibular and parotid gland levels were measured.
  
  
  RESULTS
  The measured skin doses ranged from 0.09 to 4.62 mGy depending on dosimeter positions and imaging systems. The average surface doses to the lens locations were ~4.0 mGy, well below the threshold for cataractogenesis (500 mGy). The results changed accordingly with x-ray tube output (mAs and kV) and also were sensitive to scan field of view (SFOV). As compared to the conventional panoramic and cephalometric imaging system, doses from all three CBCT systems were at least an order of magnitude higher.
  
  
  CONCLUSIONS
  Peak skin dose and surface doses at the eye lens, thyroid, and salivary gland levels measured from the CBCT imaging systems were lower than the thresholds to induce deterministic effects. However, our findings do not justify the routine use of CBCT imaging in orthodontics considering the lifetime-attributable risk to the individual.
authors.affiliation: Department of Orthodontics, The University of Texas Health Science Center at Houston, School of Dentistry, Houston, TX, USA. Sercan.akyalcin@uth.tmc.edu.
authors.forename: Sercan
authors.initials: S
authors.lastname: Akyalcin
authors.forename: Jeryl D
authors.initials: JD
authors.lastname: English
authors.forename: Kenneth M
authors.initials: KM
authors.lastname: Abramovitch
authors.forename: Xiujiang J
authors.initials: XJ
authors.lastname: Rong
mesh_terms: D054893:Cone-Beam Computed Tomography; D006801:Humans; D007908:Lens, Crystalline / Q000528:radiation effects; D062791:Optically Stimulated Luminescence Dosimetry; D009970:Orthodontics; D010306:Parotid Gland / Q000528:radiation effects; D011874:Radiometry; D012867:Skin / Q000528:radiation effects*; D013363:Submandibular Gland / Q000528:radiation effects; D013961:Thyroid Gland / Q000528:radiation effects