Background: The mental foramen (MnF) is the anatomic landmark where the mental neurovascular bundle exits the mandible. Precisely determining the position of the MnF is necessary before all dentoalveolar therapeutic procedures performed in the mandibular premolar area. Materials and Methods: For the study, we performed two ex vivo direct morphometric determinations on dry human dentate and edentate mandibles, and two in vivo imaging morphometric determinations through cone-beam computed tomography (CBCT) and orthopantomography (OPG) in dentate human patients. The following landmarks were used to locate the MnF: the distance between the MnF and the superior border of the mandible (MnF-SB), the distance between the MnF and the inferior border of the mandible (MnF-IB), and the position of the MnF in relation to the root apices of the posterior teeth. The results obtained from these data were processed statistically using the analysis of variance (ANOVA). Results: By direct morphometry on dentate mandibles, the MnF was situated closer to the IB and by direct morphometry on completely edentulous mandibles, the MnF was located closer to the SB. In both direct morphometry studies, the MnF transverse diameter was larger than the vertical one, with the MnF having an oval shape. ANOVA for both direct morphometry studies showed that the distances MnF-IB and MnF-SB significantly vary statistically with interactions and depending on age (p<0.00001). The vertical diameter of the MnF significantly varies statistically depending on age, interactions and between studies, and its transverse diameter varies statistically significantly with interactions and depending on age (p<0.00001). According to OPG and CBCT imaging studies, the MnF was located closer to the IB, and the transverse diameter of the MnF was larger than the vertical diameter; such results are similar to the direct morphometry study performed on dry dentate human mandibles. Regarding the position of the MnF in relation to the root apices, it was most frequently located inferior to the root apices in 79.45% of cases, in 19.23% of cases it was located at the root apices level and in 1.31% of cases it was located superior (coronal) to the root apices. ANOVA for both imaging morphometry studies showed that the MnF-IB distance varies statistically significantly with the interactions, the study, the sex of the patients and their age, the MnF-SB distance varies statistically significantly with the interactions, the study and the patients' age (p<0.05), and the MnF diameters vary statistically significantly with interactions and patient age (p<0.05). Conclusions:The results of this study can help dental practitioners in improving dentoalveolar surgery procedures in the posterior mandible.

Background : The mandibular foramen (MF) is the anatomic landmark where the interior alveolar nerve enters the mandibular ramus, and the area of choice where anesthesia of this nerve is performed. The position of the MF can vary, and accurately establishing its location and topographic variations is of great importance for the successful anesthesia of the inferior alveolar nerve. Materials and Methods : We carried out two morphometric ex vivo studies concerning the topography of the MF, on dry human mandibles coming from dentate and completely edentulous human subjects of known age and gender and an in vivo morphometric study, through cone-beam computed tomography (CBCT) scans, concerning the topography of the MF in human subjects having Kennedy Class I mandibular edentulism. The morphological characteristics we investigated were: the distance between the MF and the anterior margin of the mandibular ramus (MF–AM distance), the distance between the MF and the posterior margin of the mandibular ramus (MF–PM distance), the distance between the MF and the inferior margin of the mandibular ramus (MF–IM distance), the distance between the MF and the temporal crest of the mandibular ramus (MF–TC distance), the distance between the MF and the superior margin of the mandibular ramus (MF–SM distance), and the vertical and transverse diameters of the MF. The results were statistically processed in Stata/MP13 software package using Student’s t -test and two-way analysis of variance (ANOVA). Results : Through direct morphometry on dentate dry human mandibles, the MF–AM and the MF–SM distances showed statistically significant differences for age, gender and for interactions, while the MF–PM and MF–IM distances showed statistically significant differences for age and for interactions. In the case of the MF–TC distance, the only significant difference observed was for the gender. No statistical significance was found for side, age, gender, and interactions in the cases of MF vertical and transverse diameters. Through direct morphometry on completely edentulous dry human mandibles, the MF–PM and MF–SM distances showed statistically significant differences for age, gender and for interactions, while the MF–AM, MF–IM, and MF–TC distances, as well as the MF vertical and transverse diameters showed statistically significant differences for age and for model (interactions). The results showed that MF is 2 mm closer to the anterior margin of the mandibular ramus after having lost teeth. Through imaging morphometry, the MF–PM distance and the vertical diameter of MF showed statistically significant differences for age, gender and for interactions, while the MF–AM, MF–IM, MF–SM and MF–TC distances, as well as the transverse diameter of MF showed statistically significant differences for age and for interactions. Comparing the results obtained by the three studies, we found no statistically significant diff...

Background: The mental foramen (MnF) is the place where the mental nerve and mental artery exit the body of the mandible, being an important landmark for dentoalveolar surgery. Materials and Methods: For the assessment of MnF topography, we performed a direct morphometric study and two morphometric imaging studies through cone-beam computed tomography (CBCT) scans and orthopantomography (OPG). The following locations of the MnF were investigated: anterior to the first premolar, at the first premolar level, between the two premolars, at the second premolar level, between the second premolar and the 6-year molar, and at the level of the mesial root of the 6-year molar. The data obtained were statistically analyzed by chi-squared test. Results: Through direct morphometry on dentate dry human mandibles, no statistically significant differences were found for the number of MnF located between the two premolars, at the level of the second premolar and between the second premolar and the 6-year molar, depending on age and analyzed side. The number of MnF located between the second premolar and the first molar varies statistically significantly in relation to the subject's gender but does not vary statistically significantly depending on age and side. By means of imaging morphometry through OPG, we found that the number of MnF located at the first premolar level, between the two premolars, at the second premolar level and between the second premolar and the 6-year molar varies statistically significantly in relation to the age of the patients. Using imaging morphometry trough CBCT scans, we found that the number of MnF located between the two premolars, at the second premolar level and between the second premolar and the 6-year molar varies statistically significantly according to the age of the patients. Comparing the results obtained from the three studies, we found that only according to age the number of MnF located between premolars and at the level of the second premolar varies statistically significantly. Conclusions: Wide and accurate knowledge of both the MnF topography and the key anatomical landmarks used in locating it proves to be essential and clinically relevant in dentoalveolar and endodontic surgery, and for improving anesthesia techniques.

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One of the most common anatomical variations of the mandibular canal is the bifid mandibular canal (BMC), more frequently unilateral and rarely bilateral, often located at the level of the posterior mandible; according to literature, this anatomical variation presents several morphological types. The presence of the BMC must be considered prior to anesthesia and surgery performed on the ramus of the mandible (osteotomies) and on the posterior mandible (dentoalveolar surgery procedures). This study presents a clinical case of unilateral BMC on the left side, the buccolingual type, lingual variant, a rare anatomical variation illustrated radiographically in a 27-year-old male adult.