Adrienn Dobai 1, Zsolt Markella2, Tamás Vízkelety1, Eper Nikoletta 3, József Barabás1
1 Semmelweis University, Department of Oro-Maxillofacial Surgery and Stomatology, Budapest, Hungary
2 Óbuda University, Kandó Kálmán Faculty of Electrical Engineering, Budapest, Hungary
3 Semmelweis University,Faculty of Health Sciences, Budapest, Hungary
The CBCT-based 3D measurement are useful in the planning of surgical and orthodontic treatment, thanks to lack of superimposition, magnification, and distortion. Although the landmark identification on volume tomogram is higher than on the lateral cephalogram the there are no reference values for 3D cephalometry.
This study compared two different technics of CBCT based cephalometry with digital lateral cephalograms to find which method is the most reliable and valid for adaptation of 2D normal values.
Forty dried skull were imaged using lateral cephalograms and Cone Beam CT scans. By CBCT based cephalometry three method were used: 1. X-ray view, 2. Volume rendering surface with multi planar reconstruction (MPR). Two observers detected 12 points using by each method. By measurements using volume rendering and MPR the landmarks were projected to the midplane, which was generated with regression from the following points: I. Nasion, Crista galli, Basion. Measurements of Hasund cephalometry were determined in all ways and we compared the results with correlation and paired t-test.
The intra- and inter-examiner ICCs were the highest (≥0,9) by MPR and volume rendering model based measurement. Although there were significant differences among the LCR technic and the examined CBCT based cephalometry method, the difference in the case of MPR and volume rendering model based measurement were the lowest (≤ 2 mm or 2 degree), and these were not relevant clinically. The results of the methods showed moderate to high correlation coefficients, which were the highest by the MPR method.
The MPR and volume rendering model based cephalometry using projection of the landmark to the midsagittal plane is the most reliable method for the CBCT-based cephalometric analysis. By using this method the 2D normative values are adaptable to the three dimensional analysis allowing us to achieve more accurate planning with the fusion of 2D and CBCT based 3D cephalometry.
Doctoral School:Clinical Medicine
Supervisor: József Barabás