ارزيابي دقت توموگرافي معمولي در تعيين موقعيت كانال فك پايين

Evaluation of Accuracy of Conventional Tomography in Determination of Mandibular Canal Position

Introduction: In posterior mandibular region, the most important anatomic landmark related to implant place is mandibular canal which precise determination of its distance to alveolar crest as well as its buccolingual position is of great importance. One of the imaging techniques for implant treatment especially in the case of limited number of implants is conventional tomography which provides cross-sectional images as well as lower rate of radiation compared to CT scan. In this article, the accuracy of conventional tomography in determination of mandibular canal position was evaluated. Materials & Methods: This study was a kind of diagnostic test validity 24 sites on 4 dry human mandibles were selected and conventional linear tomography was provided (promax apparetus. On tomograrns, distance of superior border of canal to alveolar crest and distance of mandibular canal to buccal & lingual cortex were measured by a caliper with the accuracy of 0.1 rnrn. Then mandibules were sectioned in certain sites by osteotome and mentioned distances were directly measured on these sections. Obtained measures from tomograrns and mandibular sections were analyzed by student paired r-test. Results: Statistical difference was merely found in distance of canal to buccal cortex. Except for one case, differences in results were in the range of ±I mm. Conclusion: Regarding the acceptable accuracy especially on placement of limited number of teeth, usc of conventional tomography is recommended.