Establishment of National Diagnostic Reference Levels and Effective Dose Estimation for Cone-Beam Computed Tomography Examina-tions in Jordan: A Multicenter Retrospective Study

cone-beam computed tomography; diagnostic reference levels; dose-area product; effective dose; radiation protection; dose optimization

Mohammad Ayasrah,1*
Radiologic Sciences Department, Department of
Allied Medical Sciences, Faculty of Applied
Medical Sciences, Jordan University of Science
and Technology, Irbid, Jordan;

Nour Mahmoud Alahmad, MSc.1
Radiologic Sciences Department, Department of
Allied Medical Sciences, Faculty of Applied
Medical Sciences, Jordan University of Science
and Technology, Irbid, Jordan;

Yasmeen Khalid Abdalla, Dentist2
College of Dentistry, Jordan University of
Science and Technology, Irbid, Jordon.
*Correspondence: [email protected]

Received:10-06-2026
Revised:15-07-2026
Accepted:21-07-2026

European Journal of Prosthodontics and Restorative Dentistry (2026) 347S), 212–219

Establishment of National Diagnostic Reference Levels and Effective Dose Estimation for Cone-Beam Computed Tomography Examinations in Jordan: A Multicenter Retrospective Study

Background/Objectives: Cone-beam computed tomography (CBCT) is widely used in dental and maxillofacial imaging; however, radiation dose optimisation remains essential because radiosensitive organs such as the salivary glands, thyroid, extrathoracic airway, and eye lens may be partially irradiated during CBCT. Diagnostic reference levels (DRLs) provide practical benchmarks for dose optimisation at local and national levels. Methods: A multicenter retrospective study was conducted on 1098 adult CBCT examinations performed between February 2025 and August 2025. Dose-area product (DAP; mGy·cm²) and exposure parameters were extracted from DICOM headers. The national DRL was defined as the 75th percentile of the DAP distribution. Effective dose and selected organ equivalent doses were estimated using field-of-view (FOV)-specific published conversion coefficients. Results: The mean patient age was 39.2 ± 15.9 years, and 55.1% were female (n = 605). The overall DAP was 946.2 ± 513.3 mGy·cm² (median 690.0 mGy·cm²), and the national DRL was 1153.0 mGy·cm². The estimated effective dose was 75.0 ± 44.0 µSv (median 57.0 µSv; DRL 97.0 µSv). Median equivalent doses were 1933 µSv for the salivary glands, 229 µSv for the thyroid, 1409 µSv for the extrathoracic airway, and 1412 µSv for the eye lens. Conclusions: Jordan’s first national DRLs for CBCT examinations were established, together with DAP-based effective-dose and organ-dose estimates. These benchmarks support protocol harmonisation, continuous audit, and targeted optimisation across Jordanian CBCT services.

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