Study of Mandibular Foramen in Adult Human Mandible Bones: An Osteological Study

Introduction: The mandibular foramen is located on the medial surface of the ramus of mandible through which inferior alveolar nerve and vessels pass and supply the lower jaw. For dentists inferior alveolar nerve block is important to anesthetize the lower jaw for conducting various surgical procedures. Aims: To determine the accurate position of mandibular foramen through which inferior alveolar nerve and vessels were passing and supply the lower jaw and its clinical importance. Methods: This study was conducted on 35 dry mandible bones consisting of 70 mandibular foramens of unknown sex. All the important parameters were studied using vernier caliper. Results: The mean distance of mandibular foramen from mandibular notch was 21.00 mm on right side and 20.29 mm on left side, from posterior border was 12.63 mm on right side and 12.37 mm on left side, from angle of mandible was 20.60 mm on right side and 20.46 mm on left side, from base of the mandible was 23.57 mm on right side and 23.6 mm on left side, from anterior border was 16.74 mm on right side and 16.89 mm on left side. Conclusion: The accurate position of mandibular foramen varies. The knowledge of the average distance of mandibular foramen from various landmarks is useful for dental anesthesia and also helps to avoid complications.

Intra-Oral Ultrasonography of Young Adult Mandibular Foramen: A Reliable Method

Background: The inferior alveolar nerve (IAN) block is the most commonly used mandibular injection method for local anesthesia in restorative and surgical procedures. Ultrasound images can provide more accurate information about the location of the inferior alveolar neurovascular bundle. Objectives: This study aimed to evaluate the ultrasound images of patients to determine the location of the mandibular foramen (MF) relative to the adjacent landmarks. Patients and Methods: In this cross-sectional analytical study, 50 patients were subjected to intra-oral ultrasonography of the right and left sides of the mandible. An Alpinion ultrasound system (Seoul, South Korea) was used for detecting the MF, as well as its distance from different landmarks. Results: In all patients, the MF was found using color Doppler ultrasonography. The probability of detecting MF in conventional ultrasonography was estimated at 36% and 18% for the right and left sides of the mandible without using the Doppler technique, respectively. The mean MF distance from the anterior border of the ramus was 14.6 ± 2.1 and 16.1 ± 2.1 mm on the right and left sides, respectively. Also, the vertical distance of MF from the occlusal plane was 7.5 ± 1.1 mm on the right side and 8.7 ± 1.2 mm on the left side of the mandible. In all studied patients, the MF was above the occlusal plane. Conclusion: The results of this study showed that ultrasonography is not only a suitable option for intra-oral imaging due to its non-ionizing beams, but is also appropriate for localization of the MF and its related landmarks.

Topographical Landmarks for Identification of Inferior Alveolar Nerve and its Surgical Implications - a Cadaveric Study

Background: Inferior alveolar nerve, which arises from the posterior division of the mandibular nerve, contains both sensory and motor fibres. The intraosseous course of the nerve is variable. Mandibular foramen is situated on the medial surface of the mandibular ramus. It is an important anatomical landmark for procedures like sagittal split osteotomies and inferior alveolar nerve block.Methods: The precise location of mandibular foramen was studied by the dissection of formalin fixed cadavers available for undergraduate dissection for a period of two years fron 2014-2016. Results: The mandibular foramen was 21±3.33 mm superior to the gonion at an angle of 980±50 with the base of the mandible. The mandibular foramen was 20.13±3.1 mm inferior to the lowest point of the mandibular notch. Accessory mandibular foramen was observed in 9.37% of the samples dissected.Conclusion: The present study explains the position of mandibular foramen in relation to prominent bony landmarks and the knowledge about the mandibular foramen, helps dental surgeons during inferior alveolar nerve blocks and split osteotomies.Practical implications: Failure rate of the inferior alveolar nerve block has been reported to be approximately 20-25%. A thorough anatomical knowledge of the mandibular ramus is essential for inferior alveolar nerve blocks and sagittal split osteotomies, since they are technically difficult procedures and as they are also associated with a higher incidence of complications.

ANATOMICAL STUDY OF MANDIBULAR FORAMEN IN DRY ADULT HUMAN MANDIBLES IN BIHAR STATE REGION

Background: The morphological knowledge of the mandibular foramen is very important during dental procedures involving lower jaw, as structures that pass through this foramen are at risk. Inferior alveolar nerve (IAN) block is the most frequently used nerve block technique in dental practice. Location of mandibular foramen is clinically important in Inferior alveolar nerve (IAN) block, dentoalveolar surgery planning, and various endodontic treatments. Present study aimed to locate the precise location of mandibular foramen in relation to the borders of the mandibular ramus, its distances from different bone landmarks on internal surface of ramus of dry mandible and incidence of occurrence of accessory mandibular foramen in local population. Material And Methods: Present study was a cross-sectional study of 50 (fty) dry adult human mandibles, obtained from the dissection room of the department of Anatomy, NMCH, Patna, Bihar. Location of MF(Mandibular foramen) from various parameters was determined with digital Vernier calipers. The presence of accessory mandibular foramen in and around mandibular foramen on the medial surface of mandibular ramus was by simple visual observation with the help of a magnifying lens and their prevalence rate was noted. All the above parameters were carefully documented and statistically analysed. Statistical analysis was done using SPSS version 23. Student's t test was used as test of signicance to compare the mean values of right and left sides and a P-value less than 0.05 was taken to be statistically signicant. Results: Total 50 dry adult human mandibles were studied. The mean distance of mandibular foramina to anterior border of ramus was 16.97 ± 2.13 (R) mm and 17.04 ± 2.72mm(L), to posterior border was (R): 13.73 ± 2.28 mm and (L): 14.16 ± 2. 05 mm, to mandibular notch was (R): 20.50 ± 2.11 mm and (L): 20.10 ± 2.82 mm and to inferior border was (R): 26.93 ± 3.09 mm and (L): 26.37 ± 4.25 mm. We noted that there was no signicant difference in the values on the right and left sides (p>0.05). All mandibles (100%) have bilateral mandibular foramen. Unilaterally Single Accessory mandibular foramen was present in 11 (22%) mandibles. Unilaterally double accessory mandibular foramen was present in 06 (12%). Bilateral double accessory mandibular foramen was noted in 02(04%) mandibles only. Bilateral single accessory mandibular foramen was noted in 04(08%) mandibles. Conclusion: Present study provides valuable information regarding distances between mandibular foramen and surgically encountered anatomical landmarks, which is very useful to dental surgeons.

Sagittal Split Ramus Osteotomy in the Shortest Buccal Bone Marrow Distances of the Mandible on the Coronal Plane

Purpose. This study investigated the relationship between the shortest buccal bone marrow of the ramus and skeletal patterns. Materials and Methods. Using cone-beam computed tomography data (specifically, the A point-nasion-B point (ANB) angle), we divided patients into three groups as follows: skeletal class I ( 0 ° < ANB < 4 ° ), class II (ANB: ≥4°), and class III (ANB: ≤0°). Sixteen vertical sections in the coronal plane were taken starting from slice 0 (original intact mandibular canal) anteriorly at 2 mm intervals to slice 15 (30 mm). The thickness of the mandible (M) and shortest buccal bone marrow (SBM) were measured. The data of SBM were divided into two groups ( SBM ≥ 1 mm and SBM < 1 mm ). For each skeletal pattern, an SBM value < 1 mm was considered to indicate a high possibility of postoperative nerve paresthesia and bad split. Results. The three skeletal pattern groups also did not significantly differ in their M values for all sections. The mean SBM values of class III (0.91–2.11 mm) at 6–16 mm anterior to the mandibular foramen were significantly smaller than those of class II (1.53–3.17 mm). Comparing the occurrence ratio of SBM < 1 mm , the highest and lowest probabilities in class III (55% and 21.7%, respectively) were significantly larger at 6–20 mm anterior to the mandibular foramen than those in class II (28.3% and 5%, respectively). Conclusion. Class III had a significantly shorter SBM distance and higher SBM occurrence probability than class II at the mandibular ramus region, implying that class III participants are more likely than class II participants to have nerve paresthesia and bad split after sagittal split ramus osteotomy.