Comparison of the accuracy of full head cone beam ct images obtained using A large field of view and stitched images

The aim of the study is to investigate the accuracy of linear measurements in full head images obtained with large FOV and obtained by irradiating limited areas. Cone-beam computerized tomography (CBCT) can provide 3-dimensional (3D) information of the maxillofacial region. Cephalograms have limitations such as superposition, distortion and failure to achieve standardization of head position in repeated shoots. The use of CBCT in orthodontics has begun to gain popularity with the introduction of dentistry. Cone beam computed tomography systems in dental clinics have a limited field ofview (FOV) of approximately 8 to 15 cm, which is too small to obtain an image of the entire craniomaxillofacial area. Increasing the field of view is thought to increase the dose of radiation exposed by the patient while reducing detail and increasing cost in device manufacturing In this study; 8 dry skulls were used. The CBCT scans were obtained byMorita (3D Accuitomo 170-Morita, Kyoto, Japan) and I-CAT (Next Generation; Imaging Sciences International, Hatfield, PA, USA) devices.Frequently used anatomical points in ortodontic evaluations were identified. Then the distances between them were measured on CBCT images. The measurements were made by an observer and three measurements were taken and averaged. The definition of the real distance between the selected points was made using a high precision digital caliper directly on the dryskulls. To assess intraobserver agreement, measurements were repeated by the same observer after 2 weeks. The agreement between the measurements made on the CBCT images and the real measurements was determined using the intraclass correlation coefficient (ICC). In addition, the agreement between the real measurements and the measurements on CBCT images was performed using the mean of difference + - standard deviations and the Bland-Altman limits of agreement. As a result; it was seen that the measurements made by both I-CAT and Morita CBCT devices were very close to the real measurements and high or perfect agreement was revealed between real and CBCT measurements. It was also determined that the results of the Morita CBCT device was slightly better than those of the I-CAT device. In conclusion Although full head images obtained by Morita CBCT device has showed perfect agreement with real measurements, there is lack of information regarding stitching limited scan volüme in the literature.Therefore, it is necessary to evalute the radiation doses of stitching scan volüme images compared to large scan volüme images.