Analysis of the Accuracy of Linear Measurements on CBCT in Comparison with the Anatomic Measurements Obtained from Dry Human Skull

Document Type : Original Article


1 Department of Oral and Maxillofacial Radiology, Faculty of Dentistry, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.

2 Postgraduate Student of Oral and Maxillofacial Radiology.

3 Dentist

4 Department of in Instrumentation and Control Engineering, Shiraz University School of Electrical and Computer Engineering, Shiraz, Iran.


Background and Objective: Now a days CBCT, because of its advantages in comparison with CT has many applications in dentistry such as implantation, orthodontics and evaluation of maxillofacial diseases. The aim of this study was to analyze the accuracy of linear measurements on CBCT in comparison with the anatomic measurements obtained from dry human skull.
Subjects and Methods:Sixteen anatomic landmarks on 10 dry human skulls were marked with 1mm gutta-percha round markers. Thirteen linear distances between these landmarks were measured once with a digital caliper on dry human skulls and then on 2D multiplanar CBCT images rendered by NewTomVGi (QR srl -Verona, Italy) system using measurement tools of NNT software. Each distance was measured twice by two observers. Mean of measurements on human dry skulls were considered as real distances and mean of measurements on CBCT images were considered as radiographic distances. Two distances were analyzed by using paired sample t-test. Also Intraclass Correlation Coefficient (ICC) was calculated for repeated measurements on human skulls and CBCT images.
Results: No significant difference was seen between real and radiographic measurements. Mean error measurement for skull measurements and CBCT images was measured -0.36 mm. Mean error measurement percentage was -1.03%. Mean ICC for repeated measurements on skulls was bigger than CBCT.
Conclusion: Linear measurements on CBCT images in craniofacial area are accurate and can be used as a reliable tool in diagnosis and treatment planning.


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