Dental Cone-Beam Computed Tomography: Are the Eye Lens and Thyroid at Risk?

Sarah K. Albahiti, Fatima M. Jadu, Fatma Badr, Hanadi Khalifa, Emad Khan, Mawya Khafaji

For citation: Albahiti SK, Jadu F, Badr F, Khalifa H, Khan E, Khafaji M. Dental Cone-Beam Computed Tomography: Are the Eye Lens and Thyroid at Risk? International Journal of Biomedicine. 2024;14(1):77-82. doi:10.21103/Article14(1)_OA11
Originally published March 1, 2024


Background: The purpose of this study was to assess radiation dose to the eye lens (EL) and thyroid gland (TG) from 22 protocols used in maxillofacial imaging with cone-beam computed tomography (CBCT).
Methods and Results: NanoDot optically stimulated luminescence dosimeters were used to assess scattered radiation to the EL and TG using a phantom. The dosimeters were secured at four sites around areas of interest. Mean eye radiation dose was significantly associated with field of view (FOV) size (r=0.830, P<0.001). Meanwhile, the mean thyroid radiation dose was found to be significantly associated only with exposure time (r=0.464, P=0.030). Mandible centralization was observed to be the most significant predictor for a greater effective thyroid dose; mandible FOV centralization had 0.236 odds of a higher thyroid dose than maxilla FOV centralization.
Conclusion: FOV size significantly impacted EL dose. Thyroid exposure was affected by FOV centralization and exposure time. Centering the FOV on the mandible resulted in a greater effective dose due to the proximity of the TG to the primary beam.

cone-beam computed tomography • radiation dose • thyroid gland • eye lens
  1. Farris K, Spelic D. Nationwide evaluation of X-Ray trends: highlights of the 2014-15 next dental survey. Proceedings of 47th National Conference on Radiation Control May 18 - 21, 2015, St. Louis, Missouri.  Control Program Directors (CRCPD) Publication, CRCPD Publication E-15-4.
  2. Jaju PP, Jaju SP. Clinical utility of dental cone-beam computed tomography: current perspectives. Clin Cosmet Investig Dent. 2014 Apr 2;6:29-43. doi: 10.2147/CCIDE.S41621. PMID: 24729729; PMCID: PMC3979889.
  3. International Atomic Energy Agency (IAEA). Safety Report Series No 108: Radiation protection in dental radiology; 2022.
  4. Ogbole GI. Radiation dose in paediatric computed tomography: risks and benefits. Ann Ib Postgrad Med. 2010 Dec;8(2):118-26. doi: 10.4314/aipm.v8i2.71823. PMID: 25161479; PMCID: PMC4111023.
  5. Ludlow JB, Timothy R, Walker C, Hunter R, Benavides E, Samuelson DB, Scheske MJ. Effective dose of dental CBCT-a meta analysis of published data and additional data for nine CBCT units. Dentomaxillofac Radiol. 2015;44(1):20140197. doi: 10.1259/dmfr.20140197. Erratum in: Dentomaxillofac Radiol. 2015;44(7):20159003. PMID: 25224586; PMCID: PMC4277438.
  6. Shao YH, Tsai K, Kim S, Wu YJ, Demissie K. Exposure to Tomographic Scans and Cancer Risks. JNCI Cancer Spectr. 2019 Nov 14;4(1):pkz072. doi: 10.1093/jncics/pkz072. PMID: 32337490; PMCID: PMC7050152.
  7. Fisher DR, Fahey FH. Appropriate Use of Effective Dose in Radiation Protection and Risk Assessment. Health Phys. 2017 Aug;113(2):102-109. doi: 10.1097/HP.0000000000000674. PMID: 28658055; PMCID: PMC5878049.
  8. FDA U.S. Food & Drug Administration. Dental Cone-beam Computed Tomography. Content current as of: 09/28/2020. Available from:
  9. Araki K, Patil S, Endo A, Okano T. Dose indices in dental cone beam CT and correlation with dose-area product. Dentomaxillofac Radiol. 2013;42(5):20120362. doi: 10.1259/dmfr.20120362. Epub 2013 Mar 21. PMID: 23520392; PMCID: PMC3635780.
  10. Seibert JA, Morin RL. The standardized exposure index for digital radiography: an opportunity for optimization of radiation dose to the pediatric population. Pediatr Radiol. 2011 May;41(5):573-81. doi: 10.1007/s00247-010-1954-6. Epub 2011 Apr 14. PMID: 21491197; PMCID: PMC3076558.
  11. Jacobs R, Salmon B, Codari M, Hassan B, Bornstein MM. Cone beam computed tomography in implant dentistry: recommendations for clinical use. BMC Oral Health. 2018 May 15;18(1):88. doi: 10.1186/s12903-018-0523-5. PMID: 29764458; PMCID: PMC5952365.
  12. Kim IH, Singer SR, Mupparapu M. Review of cone beam computed tomography guidelines in North America. Quintessence Int. 2019 Jan 25;50(2):136-145. doi: 10.3290/j.qi.a41332. Epub 2018 Nov 8. PMID: 30411089.
  13. Ghanbarnezhad Farshi R, Mesbahi A, Johari M, Kara Ü, Gharehaghaji N. Dosimetry of Critical Organs in Maxillofacial Imaging with Cone-beam Computed Tomography. J Biomed Phys Eng. 2019 Feb 1;9(1):51-60. PMID: 30881934; PMCID: PMC6409370.
  14. Authors on behalf of ICRP; Stewart FA, Akleyev AV, Hauer-Jensen M, Hendry JH, Kleiman NJ, Macvittie TJ, Aleman BM, Edgar AB, Mabuchi K, Muirhead CR, Shore RE, Wallace WH. ICRP publication 118: ICRP statement on tissue reactions and early and late effects of radiation in normal tissues and organs--threshold doses for tissue reactions in a radiation protection context. Ann ICRP. 2012 Feb;41(1-2):1-322. doi: 10.1016/j.icrp.2012.02.001. PMID: 22925378.
  15. Li T, Li X, Yang Y, Zhang Y, Heron DE, Huq MS. Simultaneous reduction of radiation dose and scatter for CBCT by using collimators. Med Phys. 2013 Dec;40(12):121913. doi: 10.1118/1.4831970. PMID: 24320524.
  16. Vázquez-Bañuelos J, Campillo-Rivera GE, García-Duran Á, Rivera ER, Arteaga MV, Baltazar Raigosa A, Vega-Carrillo HR. Doses in eye lens, thyroid, and gonads, due to scattered radiation, during a CT radiodiagnosis study. Appl Radiat Isot. 2019 May;147:31-34. doi: 10.1016/j.apradiso.2019.02.012. Epub 2019 Feb 15. PMID: 30798202.
  17. Chetlen AL, Brown KL, King SH, Kasales CJ, Schetter SE, Mack JA, Zhu J. JOURNAL CLUB: Scatter Radiation Dose From Digital Screening Mammography Measured in a Representative Patient Population. AJR Am J Roentgenol. 2016 Feb;206(2):359-64; quiz 365. doi: 10.2214/AJR.15.14921. PMID: 26797364.
  18. Alwasiah R, Jawhari A, Orri RA, Khafaji M, Al Bahiti S. MEASUREMENT OF RADIATION DOSE TO THE EYE LENS IN NON-ENHANCED CT SCANS OF THE BRAIN. Radiat Prot Dosimetry. 2021 Aug 14;195(1):56-60. doi: 10.1093/rpd/ncab118. PMID: 34337658.
  19. Pauwels R, Zhang G, Theodorakou C, Walker A, Bosmans H, Jacobs R, Bogaerts R, Horner K; SEDENTEXCT Project Consortium. Effective radiation dose and eye lens dose in dental cone beam CT: effect of field of view and angle of rotation. Br J Radiol. 2014 Oct;87(1042):20130654. doi: 10.1259/bjr.20130654. PMID: 25189417; PMCID: PMC4170857.
  20. Goren AD, Prins RD, Dauer LT, Quinn B, Al-Najjar A, Faber RD, Patchell G, Branets I, Colosi DC. Effect of leaded glasses and thyroid shielding on cone beam CT radiation dose in an adult female phantom. Dentomaxillofac Radiol. 2013;42(6):20120260. doi: 10.1259/dmfr.20120260. Epub 2013 Feb 14. PMID: 23412460; PMCID: PMC3667524.
  21. Qu X, Li G, Zhang Z, Ma X. Thyroid shields for radiation dose reduction during cone beam computed tomography scanning for different oral and maxillofacial regions. Eur J Radiol. 2012 Mar;81(3):e376-80. doi: 10.1016/j.ejrad.2011.11.048. Epub 2011 Dec 29. PMID: 22209523.
  22. Yusof FH, Ung NM, Wong JH, Jong WL, Ath V, Phua VC, Heng SP, Ng KH. On the Use of Optically Stimulated Luminescent Dosimeter for Surface Dose Measurement during Radiotherapy. PLoS One. 2015 Jun 8;10(6):e0128544. doi: 10.1371/journal.pone.0128544. PMID: 26052690; PMCID: PMC4459977.
  23. Scarboro SB, Cody D, Alvarez P, Followill D, Court L, Stingo FC, Zhang D, McNitt-Gray M, Kry SF. Characterization of the nanoDot OSLD dosimeter in CT. Med Phys. 2015 Apr;42(4):1797-807. doi: 10.1118/1.4914398. PMID: 25832070; PMCID: PMC4368592.
  24. Jadu FM, Alzahrani AA, Almutairi MA, Al-Amoudi SO, Jan AM, Khafaji MA. The effect of varying cone beam computed tomography image resolution and field-of-view centralization on effective radiation dose. Saudi Med J. 2018 May;39(5):470-475. doi: 10.15537/smj.2018.5.21658. PMID: 29738006; PMCID: PMC6118184.
  25. SEDENTEXCT consortium, Horner, K., Lindh, C., Birch, S. and Christell, H. Cone Beam CT for Dental and Maxillofacial Radiology: Evidence Based Guidelines, Radiation Protection Publication 172 (2012).
  26. Pauwels R, Beinsberger J, Collaert B, Theodorakou C, Rogers J, Walker A, Cockmartin L, Bosmans H, Jacobs R, Bogaerts R, Horner K; SEDENTEXCT Project Consortium. Effective dose range for dental cone beam computed tomography scanners. Eur J Radiol. 2012 Feb;81(2):267-71. doi: 10.1016/j.ejrad.2010.11.028. Epub 2010 Dec 31. PMID: 21196094.
  27. Davies J, Johnson B, Drage N. Effective doses from cone beam CT investigation of the jaws. Dentomaxillofac Radiol. 2012 Jan;41(1):30-6. doi: 10.1259/dmfr/30177908. PMID: 22184626; PMCID: PMC3520268.
  28. Schilling R, Geibel MA. Assessment of the effective doses from two dental cone beam CT devices. Dentomaxillofac Radiol. 2013;42(5):20120273. doi: 10.1259/dmfr.20120273. Epub 2013 Feb 18. PMID: 23420855; PMCID: PMC3635778.
  29. Morant JJ, Salvadó M, Hernández-Girón I, Casanovas R, Ortega R, Calzado A. Dosimetry of a cone beam CT device for oral and maxillofacial radiology using Monte Carlo techniques and ICRP adult reference computational phantoms. Dentomaxillofac Radiol. 2013;42(3):92555893. doi: 10.1259/dmfr/92555893. Epub 2012 Aug 29. PMID: 22933532; PMCID: PMC3667542.
  30. Rehani MM, Vano E, Ciraj-Bjelac O, Kleiman NJ. Radiation and cataract. Radiat Prot Dosimetry. 2011 Sep;147(1-2):300-4. doi: 10.1093/rpd/ncr299. Epub 2011 Jul 14. PMID: 21764807.
  31. Yuan MK, Tsai DC, Chang SC, Yuan MC, Chang SJ, Chen HW, Leu HB. The risk of cataract associated with repeated head and neck CT studies: a nationwide population-based study. AJR Am J Roentgenol. 2013 Sep;201(3):626-30. doi: 10.2214/AJR.12.9652. PMID: 23971456.
  32. Pauwels R, Horner K, Vassileva J, Rehani MM. Thyroid shielding in cone beam computed tomography: recommendations towards appropriate use. Dentomaxillofac Radiol. 2019 Oct;48(7):20190014. doi: 10.1259/dmfr.20190014. Epub 2019 Jul 9. PMID: 31237774; PMCID: PMC6775792.
  33. Hidalgo A, Davies J, Horner K, Theodorakou C. Effectiveness of thyroid gland shielding in dental CBCT using a paediatric anthropomorphic phantom. Dentomaxillofac Radiol. 2015;44(3):20140285. doi: 10.1259/dmfr.20140285. Epub 2014 Nov 20. PMID: 25411710; PMCID: PMC4614166.
  34. Grüning M, Koivisto J, Mah J, Bumann A. Impact of thyroid gland shielding on radiation doses in dental cone beam computed tomography with small and medium fields of view. Oral Surg Oral Med Oral Pathol Oral Radiol. 2022 Aug;134(2):245-253. doi: 10.1016/j.oooo.2022.03.002. Epub 2022 Mar 12. PMID: 35534405.
  35. ICRP; Rehani MM, Gupta R, Bartling S, Sharp GC, Pauwels R, Berris T, Boone JM. Radiological Protection in Cone Beam Computed Tomography (CBCT). ICRP Publication 129. Ann ICRP. 2015 Jul;44(1):9-127. doi: 10.1177/0146645315575485. PMID: 26116562.

Download Article
Received January 9, 2024.
Accepted February 26, 2024.
©2024 International Medical Research and Development Corporation.