Determination of optimum exposure parameters for dentoalveolar structures of the jaws using the CB MercuRay system with cluster signal-to-noise analysis

  • Warangkana WeerawanichEmail author
  • Mayumi Shimizu
  • Yohei Takeshita
  • Kazutoshi Okamura
  • Shoko Yoshida
  • Gainer R. Jasa
  • Kazunori Yoshiura
Original Article



To determine the optimum cone beam computed tomography exposure parameters for specific diagnostic tasks.


A Teflon phantom attached to a half-mandible in a large container was scanned in dental (D), implant (I), and panoramic (P) modes. An identical phantom in a small container was scanned in D mode. Both were scanned at 60, 80, 100, and 120 kV. We evaluated the image quality of five anatomical structures [dentinoenamel junction (1), lamina dura and periodontal ligament space (2), trabecular pattern (3), cortex–spongy bone junction (4), and pulp chamber and root canal (5)] and analyzed the diagnostic image quality with cluster signal-to-noise analysis. We then evaluated correlations between the two image qualities and calculated the threshold of acceptable diagnostic image quality. Optimum exposure parameters were determined from images with acceptable diagnostic image quality.


For the small container, the optimum exposure parameters were D mode, 80 kV for (1), (3), and (4) and D mode, 100 kV for (5). For the large container, they were D mode, 120 kV for (1), (3), and (5) and D mode, 100 kV for (4). I mode, 120 kV reached the acceptable level for (4). No images reached the acceptable level for (2).


No optimum exposure parameters were identified for the evaluation of the lamina dura and periodontal ligament space. D mode was sufficient for the other structures; however, the tube voltage required for each structure differed. Smaller patients required lower tube voltage. I mode, 120 kV may be used for larger lesions.


Cone-beam computed tomography Imaging phantoms Computer-assisted radiographic image interpretation Anatomic landmarks Visual perception 



This work was supported by JSPS KAKENHI under Grant number 15K11074. We thank our colleagues at the Oral and Maxillofacial Radiology department of Kyushu University for kindly agreeing to act as observers in the study. We thank Libby Cone, MD, MA, from Edanz Group Japan ( for editing a draft of this manuscript.

Compliance with ethical standards

Conflict of interest

Warangkana Weerawanich, Yohei Takeshita, Shoko Yoshida, and Gainer R. Jasa declare that they have no conflict of interest. Mayumi Shimizu, Kazutoshi Okamura, and Kazunori Yoshiura have received Grants from the Japan Society for the Promotion of Science (15K11074).

Human and animal right statement

This article does not contain any studies with human or animal subjects performed by any of the authors.


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Copyright information

© Japanese Society for Oral and Maxillofacial Radiology and Springer Nature Singapore Pte Ltd. 2018

Authors and Affiliations

  1. 1.Department of Oral and Maxillofacial Radiology, Faculty of Dental ScienceKyushu UniversityFukuokaJapan
  2. 2.Department of Oral and Maxillofacial Radiology, Faculty of DentistryMahidol UniversityBangkokThailand
  3. 3.Department of Oral and Maxillofacial RadiologyKyushu University HospitalFukuokaJapan
  4. 4.Department of Oral and Maxillofacial RadiologyOkayama University Graduate School of Medicine, Dentistry and Pharmaceutical SciencesOkayamaJapan
  5. 5.Section of Image Diagnostics, Department of Diagnostics and General CareFukuoka Dental CollegeFukuokaJapan
  6. 6.Oral Radiology Division, Faculty of OdontologyUniversity of the RepublicMontevideoUruguay

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