European Radiology

, Volume 29, Issue 12, pp 7009–7018 | Cite as

The growing concern of radiation dose in paediatric dental and maxillofacial CBCT: an easy guide for daily practice

  • Andreas StratisEmail author
  • Guozhi Zhang
  • Reinhilde Jacobs
  • Ria Bogaerts
  • Hilde Bosmans
Head and Neck



To provide an indication-based and scanner-specific radiation dose and risk guide for paediatric patients undergoing dental and maxillofacial cone beam computed tomography (CBCT) examinations.


Five commercially available scanners were simulated in EGSnrc Monte Carlo (MC) code. Dedicated, in-house built, head and neck voxel models, each consisting of 22 segmented organs, were used in the study. Organ doses and life attributable risk (LAR) for cancer incidence were assessed for males and females, aged 5 to 14 years old, for every clinically available protocol: central upper and lower incisors, upper and lower premolars, upper and lower jaws, cleft palate, temporal bone, sinus, dentomaxillofacial complex, and face and skull imaging. Dose results were normalised to the x-ray tube load (mAs) and logarithmic curves were fit to organ dose and risk versus age data.


Females demonstrated higher LAR values in all cases. A well-established dose decreasing pattern with increasing age-at-exposure was observed. Central upper incisor protocols were those with the lowest risk, contrary to skull protocols which provided the highest LAR values. Salivary glands and oral mucosa were the highest irradiated organs in all cases, followed by extrathoracic tissue (ET) in protocols where the entire nasal cavity was inside the primary field. The dose to thyroid was considerably high for younger patients.


This work provides an extensive dose assessment guide for 5 dental CBCTs, enabling detailed dose assessment for every paediatric patient.

Key Points

• Radiation dose concerns due to the growing use of paediatric dental and maxillofacial CBCT underline the need for justification that should in part be based on radiation exposure in radiology.

• Patient-specific dose calculations based on Monte Carlo simulations and head-neck paediatric voxel models overcome the limitations of conventional thermoluminescent dosimeter (TLD) dosimetry and provide proper guidance for justification of CBCT exposures.

• Monte Carlo simulations with head-neck models reveal an organ dose and radiation risk decreasing pattern with increasing age at exposure, and with decreasing size of the scanning volume of interest (field of view).


Cone beam computed tomography Radiation dosage Child Head X-rays 









Cone beam computed tomography


Central lower incisors


Central upper incisors


Coefficient of variance


Effective dose


Extrathoracic tissue


Field of view


Life attributable risk


Lower jaw


Milli ampere second product


Monte Carlo


Multi-detector computed tomography


Lower premolar


Upper premolar


Red bone marrow


Source to axis of rotation distance


Source to detector distance




Tube current modulation


Thermoluminescent dosimeter


Upper and lower jaw



This work was supported by the European 415 Atomic Energy Community’s Seventh Framework Programme FP7/ 416 2007–2011 under grant agreement No. 604984 (OPERRA: Open 417 Project for the European Radiation Research Area) and by the research fund of KU Leuven (OT/13/109).


This work was supported by the European 415 Atomic Energy Community’s Seventh Framework Programme FP7/ 416 2007–2011 under grant agreement No. 604984 (OPERRA: Open 417 Project for the European Radiation Research Area) and by the research fund of KU Leuven (OT/13/109).

Compliance with ethical standards


The scientific guarantor is Prof. Dr. Ir. Hilde Bosmans (

Conflict of interest

The authors of this manuscript declare no relationships with any companies whose products or services may be related to the subject matter of the article.

Statistics and biometry

No complex statistical methods were necessary for this paper.

Informed consent

Written informed consent was not required for this study; this study was based on blind CT image datasets, not on patients themselves.

Ethical approval

YES: Commissie Medische Ethiek van de Universitaire Ziekenhuizen KU Leuven, B322201525196.


• Retrospective

• Experimental

• Multicentre study

Supplementary material

330_2019_6287_MOESM1_ESM.docx (2.5 mb)
ESM 1 (DOCX 2547 kb)


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Copyright information

© European Society of Radiology 2019

Authors and Affiliations

  1. 1.Katholieke Universiteit Leuven, Department of Imaging and Pathology, OMFS-IMPATH Research GroupLeuvenBelgium
  2. 2.University Hospitals of Leuven, Department of RadiologyLeuvenBelgium

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