Comparing the accuracy of Panoramic and spiral tomography to locate in ferior alveolar canal

According to the importance of avoiding injuries to the neurovascular bundles in certain surgical procedures(e.g. placement of implants), an accurate location of the mandibular is necessary. The aim of the present study was to evaluate and compare between the accuracy of the panoramic spiral tomography in location of the mandibular canal.Methods and materials: In this study, by means of the odonto Rama 2000 (Traphy,French), panoramic radiographies were taken and by means of Cranex tome multifunctional unit(orion corporation Sordex, finland), tomographic slices were taken at 3 different location in each posterior mandible segments (distal to the mental foramen). Then the dry mandibles were sectiond at these 3 sites with specialized desiged drill. The fallowing 2 measurments were performed both on the panoramic radiographies (A,B), tomograms (A’,B’) and the bone sections (A’’,B”) at the 3 sites. The research was on 6 dry mandibles (36 sites). We found an average mean difference of 3.9 mm with a standard deviation of 1.57 in panoramic radiography and an average mean differences of 0.21mm with a standard deviation of 0.21 in spiral tomography. The report of data showed that 16.4% of cases are in +_0.5mm and 41.4% of cases are in +_1mm(overstimate and underestimate) in panoramic radiography and 94.6% of cases are in +_0.5mm and 97.3% of cases are in +_1mm in spiral tomography. ICC in panoramic radiography was 0.6932 and in spiral tomography was 0.9982 (P<0.001) and recommendation: Spiral tomography using the Cranex tome multifunctional x-ray unit provides accurate information and sufficient detailes or preoperative planning of implant in the posterior mandible and this method is recommended for surgures, periodontists and prosthodontists.