J Korean Assoc Oral Maxillofac Surg.  2010 Apr;36(2):78-86. 10.5125/jkaoms.2010.36.2.78.

Accuracy and reproducibility of landmark of cone beam computed tomography (CT) synthesized cephalograms

• Kwon DK
• Min SK
• Jun IC
• Paeng JY

• KMID: 2189974
• DOI: http://doi.org/10.5125/jkaoms.2010.36.2.78

Abstract

INTRODUCTION
Cone beam computed tomography (CBCT) has various advantages and is used favorably in many fields in dentistry. Especially, CBCT is being used as basic diagnostic tool for 3-dimensional analysis in orthognathic patient. Two-dimensional cephalograms can be synthesized from CBCT digital imaging and communications in medicine (DICOM) data. In this study, conventional cephalograms and CBCT were taken simultaneously, and representative landmarks were located and analyzed in its accuracy and reproducibility.
MATERIALS AND METHODS
Ten patients who had orthognathic surgery in Wonkwang University Daejeon Dental Hospital participated in this study. For each patient, CBCT and conventional cephalogram was taken. By using Ondemand (Cybermad, Korea), 2-dimensional cephalograms was established on CBCT. In addition, 19 landmarks were designated and measured by 3 orthodontists twice a week. After these landmarks were transferred to a coordinate, distance of landmark and axis, standard error, distribution degree were measured, compared and analyzed.
RESULTS
Comparing the CT ceph group and conventional cephalogram group, CT ceph group had shown shorter distance of landmark and axis in S, Hinge axis, Bpt, Ba, Or, Corpus left. Standard error of the mean shows that CT ceph group has better reproducibility in Or, Corpus left, Hinge axis at X axis and Na, U1R, U1T, Bpt, PNS, Ba Corpus left, Hinge axis at Y axis. In both groups, mean error was less than 1.00 mm, no significant difference were found between CT ceph group and conventional cephalogram group in all measurements. Furthermore, comparing two groups, each 17 landmarks out of 19 had its characteristic in distribution degree.
CONCLUSION
No significant difference were found between CBCT composed cephalographic radiograph and conventional cephalograghic radiograph, clinical application may be possible if improved.

Keyword

Cone beam computed tomography (CBCT); Lateral cephalogram; Landmark

MeSH Terms

Axis, Cervical Vertebra
Cone-Beam Computed Tomography
Dentistry
Humans
Orthognathic Surgery

Figure

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  Fig. 1. Digital ceph.

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  Fig. 2. CT ceph.

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  Fig. 3. Landmark.

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  Fig. 4. Notation by X, Y coordinate.

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  Fig. 5. Scattergrams of each landmark in the two groups.

Reference

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