Journal of Oral Medicine and Pain

Korean Academy of Orofacial Pain and Oral Medicine (대한안면통증구강내과학회)
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Development of a Software Program for the Automatic Calculation of the Pulp/Tooth Volume Ratio on the Cone-Beam Computed Tomography

  • Lee, Hoon-Ki (Department of Oral Medicine and Oral Diagnosis, School of Dentistry, Seoul National University) ;
  • Lee, Jeong-Yun (Department of Oral Medicine and Oral Diagnosis, School of Dentistry, Seoul National University)
  • Received : 2016.06.03
  • Accepted : 2016.09.23
  • Published : 2016.09.30
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Abstract

Purpose: The aim of this study was to develop an automated software to extract tooth and pulpal area from sectional cone-beam computed tomography (CBCT) images, which can guarantee more reproducible, objective and time-saving way to measure pulp/tooth volume ratio. Methods: The software program was developed using MATLAB (MathWorks). To determine the optimal threshold for the region of interest (ROI) extraction, user interface to adjust the threshold for extraction algorithm was added. Default threshold was determined after several trials to make the outline of extracted ROI fitting to the tooth and pulpal outlines. To test the effect of starting point location selected initially in the pulpal area on the final result, pulp/tooth volume ratio was calculated 5 times with different 5 starting points. Results: Navigation interface is composed of image loading, zoom-in, zoom-out, and move tool. ROI extraction process can be shown by check in the option box. Default threshold is adjusted for the extracted tooth area to cover whole tooth including dentin, cementum, and enamel. Of course, the result can be corrected, if necessary, by the examiner as well as by changing the threshold of density of hard tissue. Extracted tooth and pulp area are reconstructed three-dimensional (3D) and pulp/tooth volume ratio is calculated by voxel counting on reconstructed model. The difference between the pulp/tooth volume ratio results from the 5 different extraction starting points was not significant. Conclusions: In further studies based on a large-scale sample, the most proper threshold to present the most significant relationship between age and pulp/tooth volume ratio and the tooth correlated with age the most will be explored. If the software can be improved to use whole CBCT data set rather than just sectional images and to detect pulp canal in the original 3D images generated by CBCT software itself, it will be more promising in practical uses.

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References

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