Assistant Professor, Department of Oral and Maxillofacial Radiology, School of Dentistry, Mashhad University of Medical Sciences, Mashhad, Iran
Pedodontist, Department of Community Dentistry, School of Denistry, Mashhad University of Medical Sciences, Mashhad, Iran
Background & Aims: The accuracy of dental implants has increased in recent years. An accurate radiography from the region is needed for precise treatment planning in implants and for determining prognosis of treatment. Because this technique can demonstrate the buccolingual aspect, and due to its lower radiation dose, lower cost, and availability, in comparison with computed tomography, lineartomography could be the most suitable technique in cases with restricted implant sites. In this study we evaluated the accuracy of this technique in determining the quantity of maxillary bone. Methods: This study was a kind of diagnostic test validity. 4 dry human skulls were selected and on each maxilla locations of teeth 7531 1357 were selected and marked with opaque markers (n = 32). On each site, 3 metal bullets, with the diameter of 3 mm, were placed on the alveolar crest to buccal cortex and lingual cortex in different distances from the alveolar crest. Conventional linear tomography was provided by Promax (Planmeca) radiographic unit. Then, the distances from the highest points of the bullets on the alveolar crests to similar points of bullets on the buccal and lingual cortices, and distances from the highest points on the buccal bullets to lingual bullets were measured. These distances were directly measured on maxillary bones in a similar way. The measurements obtained from tomograms and maxillary bones were analyzed by Wilcoxon test. Results: According to Wilcoxon test, measurements on tomograms in buccal height, lingual height, and thickness of the bone were significantly smaller than the gold standard. In 81.3% of measurements distances on tomograms were underestimated; however, in all measurements, differences in results were in the range of 1 mm. Conclusion: Regarding the observed results of linear tomography in determining the quantity of maxillary bone in this study, the gained measurements were smaller than the gold standard. However, considering the mean differences in preoperative treatment planning of implants, especially in placing a limited number of implants, and if it is not possible to use the cone beam computed tomography (CBCT) technique, linear tomography can be used.