title: Dose reduction in orthodontic lateral cephalography: dosimetric evaluation of a novel cephalographic thyroid protector (CTP) and anatomical cranial collimation (ACC).
abstract: OBJECTIVE
  To test the dose-reducing capabilities of a novel thyroid protection device and a recently introduced cranial collimator to be used in orthodontic lateral cephalography.
  
  
  METHODS
  Cephalographic thyroid protector (CTP) was designed to shield the thyroid while leaving the cervical vertebrae depicted. Using a RANDO(®) head phantom (The Phantom Laboratory, Salem, NY) equipped with dosemeters and a Proline XC (Planmeca, Helsinki, Finland) cephalograph, lateral cephalograms were taken, and the effective dose (ED) was calculated for four protocols: (1) without shielding; (2) with CTP; (3) with CTP and anatomical cranial collimator (ACC); and (4) with a thyroid collar (TC).
  
  
  RESULTS
  The ED for the respective protocols was (1) 8.51; (2) 5.39; (3) 3.50; and (4) 4.97 µSv. The organ dose for the thyroid was reduced from 30.17 to 4.50 µSv in Protocols 2 and 3 and to 3.33 µSv in Protocol 4.
  
  
  CONCLUSIONS
  The use of just the CTP (Protocol 2) resulted in a 36.8% reduction of the ED of a lateral cephalogram. This was comparable to the classical TC (Protocol 4). A 58.8% reduction of the ED was obtained when combining CTP and ACC (Protocol 3). The dose to the radiosensitive thyroid gland was reduced by 85% in Protocols 2 and 3 and by 89% in Protocol 4.
authors.affiliation: Section of Oral and Maxillofacial Radiology, Academic Center for Dentistry Amsterdam ACTA, Amsterdam, Netherlands.
authors.forename: R C
authors.initials: RC
authors.lastname: Hoogeveen
authors.forename: D
authors.initials: D
authors.lastname: Rottke
authors.forename: P F
authors.initials: PF
authors.lastname: van der Stelt
authors.forename: W E R
authors.initials: WE
authors.lastname: Berkhout
mesh_terms: D000465:Algorithms; D001921:Brain / Q000528:radiation effects; D002508:Cephalometry / Q000295:instrumentation / Q000379:methods*; D002574:Cervical Vertebrae / Q000000981:diagnostic imaging; D002610:Cheek / Q000528:radiation effects; D004867:Equipment Design; D004947:Esophagus / Q000528:radiation effects; D006801:Humans; D008334:Mandible / Q000528:radiation effects; D009060:Mouth Floor / Q000528:radiation effects; D009334:Neck Muscles / Q000528:radiation effects; D009915:Orbit / Q000528:radiation effects; D009970:Orthodontics; D010306:Parotid Gland / Q000528:radiation effects; D019047:Phantoms, Imaging; D011829:Radiation Dosage; D011835:Radiation Protection / Q000295:instrumentation*; D011859:Radiography; D012886:Skull / Q000528:radiation effects; D013363:Submandibular Gland / Q000528:radiation effects; D013819:Thermoluminescent Dosimetry / Q000295:instrumentation; D013961:Thyroid Gland / Q000528:radiation effects
keywords: cephalometry; dosimetry; orthodontics; radiation protection; thyroid gland