Accuracy of panoramic radiographs in determining the distance between mandibular foramen and occlusal plane and anterior border of ramus

Document Type : Original Articles

Abstract

Introduction: Inferior alveolar nerve is responsible for the sensory innervation of the mandible and its teeth. Knowledge about the exact location of mandibular foramen is very important due to its important role in the success of mandibular block injection and possibility of nerve injuries during oral and maxillofacial surgeries. The aim of this study was to evaluate the accuracy of panoramic radiographs in determining the location of mandibular foramen. Materials and Mmethods: In this random cross-sectional study 50 panoramic and lateral cephalometric radiograms were collected from patients, 20‒50 years of age, referring to Afzal Dental Clinic in Esfahan in spring 2012. Measurements were taken by a caliper from the center of the foramen to the occlusal plane and anterior border of ramus. Data was analyzed by t-test and intraclass correlation coefficient (ICC) using SPSS 11.5 (α=0.05).    Results: According to t-test, mean distances from the center of the foramen to the occlusal plane (p value = 0.04) and to the anterior border of ramus (p value < 0.001) on panoramic radiographs were significantly greater than the actual distances measured on lateral cephalograms. In addition, there were similarities between the distances from the mandibular foramen to the occlusal plane (p value < 0.001, r = 0.8315) and the anterior border of ramus (p value < 0.001, r = 0.9126) on panoramic radiographs and the actual distances measured on lateral cephalograms.    Discussion: Under the limitations of the present study, it can be concluded that measurements on panoramic radiographs are similar to those on lateral cephalograms in both anteroposterior and vertical dimensions and on the condition that radiographic principles are observed they can be used to determine the location of mandibular foramen.   Key words: Inferior alveolar nerve, Mandible, Panoramic radiography