A comparative evaluation of the relationship of the mental foramen to the mandibular bone using ultrasonography and panoramic radiography

Purpose: The aim of this study is to determine the vertical distance of the mental foramen (MF) from the top of the mandible alveolar crest and the lower edge of the mandible base; By making measurements on panoramic radiography (OPG) and ultrasonography (USG) images, the relationship between the results; to evaluate according to age and gender. Materials and Methods: A total of 120 people participated in this study, 40 people (20 women, 20 men) in each group aged 18-29, 30-39, and over 40. The vertical distance of the MF to the alveolar crest and the lower edge of the mandibular basis was measured on the right and left sides on OPG and USG images. The OPG images of the individuals were transferred to the Microdicom program and calibration was performed. After the MF is marked in the image, the upper border of the MF is drawn to the tangent drawn to the alveolar crest; The distances of the lower border of the MF perpendicular to the tangent drawn to the mandible basis were measured. Additionally, the localization of MF was determined in the OPG. For the USG measurements of the individuals, the probe was placed longitudinally in the MF region. After the image in which MF was most clearly seen was captured, the image was frozen. The distance of the upper edge of the MF to the top of the alveolar crest and the distance of the lower edge of the MF to the lower edge of the basis were measured horizontally with the caliper on the control panel. The measurement results found in OPG and USG were compared and their age and gender relationships were examined. Results: In this study, a total of 240 MF images, right and left, of 120 people were evaluated. Obtained results; In OPG, the average distance of the MF to the alveolar crest was 14.34 (±2.03) mm; The average distance of the MF to the lower edge of the mandible base was found to be 11.04 (±1.60) mm. The average distance of the MF to the alveolar crest on USG was 14.08 (±2.02) mm; The average distance of the MF to the lower edge of the mandible base was found to be 10.79 (±1.72) mm. The localization of the MF was found most frequently in the root of tooth number 5 in OPG; 2nd most frequently between tooth roots numbered 4-5; 3rd most frequently between tooth roots numbered 5-6. A high level of positive correlation was observed between the average distances of the right and left MF to the alveolar crest and the lower edge of the mandible basis, measured by USG, and the average distances of the right and left MF to the alveolar crest and the lower edge of the mandible basis, measured using OPG. According to these results; It was observed that the level of agreement between the measurements made in USG and OPG was very high. Conclusion: MF, is a very important anatomical formation especially in terms of surgical procedures. Because any damage to the nerve bundles arising from MF may result in anesthesia or paresthesia in the lower jaw, lower lip and gums up to the ipsilateral midline in the mandible. Therefore, the location of the MF within the bone is very important for the procedures to be performed in this area. In our study, it was found that the average distances of the MF to the alveolar crest and the lower edge of the mandibular basis in the OPG did not change according to age groups. Only individuals aged 40 and over had a higher average distance to the lower edge of the mandible basis than individuals aged 18-29. There was no significant difference between age groups in the measurement results made on USG. In our study, the average distance of the MF in OPG to the alveolar crest and the lower edge of the mandibular basis; It was found to be higher in men than in women. In our study, the average distance of the MF to the alveolar crest and the average distance to the lower edge of the mandibular basis in USG; was found to be higher in men than women. Only the average distance of the left MF to the alveolar crest did not show a significant difference between men and women. Although the average distances of the MF to the lower edge of the mandible base and the alveolar crest we found in OPG were higher than the measurements in USG, the level of agreement between the measurement results made in USG and OPG was found to be high. Our results show that USG is a reliable method in pregnant patients or when OPG cannot be used. Key Words: Mental Foramen (MF), Lower Edge of Mandible Basis, Alveolar Crest, Ultrasonography (USG), Panoramic Radiography (OPG).