A study on the incidence of retromolar foramen in South Indian adult dried human mandibles and its clinical relevance

Abstract

INTRODUCTIONThe retromolar foramen is an accessory foramen of the mandible situated in the retromolar fossa. The triangular depression between the temporal crest and the anterior border of the ramus of mandible is called the retromolar fossa. Nerves may pass from the substance of temporalis to enter the mandible through the retromolar fossa, where they communicate with branches of the inferior alveolar nerve. Foramina occur in 10% of retromolar fossa and infiltration in this region can abolish sensation which occasionally remains after an inferior alveolar nerve block. 1The retromolar foramen, which is located in the retromolar fossa receives the retromolar canal which normally arises from the mandibular canal behind the third molar.2 This foramen transmits a neurovascular bundle consisting of an artery, vein and nerve that contribute to the nutrition and innervations of the pulp and periodontium of the lower teeth. This area forms an open corridor for the passage of infections arising in ABSTRACT Background: The retromolar foramen is one of the most important non -metrical anatomical variants in the mandible. The present study describes the incidence of retromolar foramen in South Indian adult dried mandibles and its clinical relevance. Methods: One hundred South Indian adult dried mandibles of unknown sex were studied at the Department of Anatomy, MVJ Medical College, Bangalore for the presence of retro molar foramen. Its location, size, shape, distance of the foramen if present from the posterior border of socket for 3 rd molar tooth, anterior border of ramus of the mandible were measured. Results: Retromolar foramen was present in 16 (16%) of the mandibles. Out of the 16 mandibles, it was present bilaterally in 3 (3%) mandibles and unilaterally in 13 (13%) mandibles (In 3 (3%) on the right side and in 10 (10%) on the left side). The mean diameter of the foramen was 1.33mm (range -1.10-1.92 mm). It was oval in shape in 9 (9%) and rounded in shape in 7 (7%) mandibles. The mean distance of retromolar foramen from the posterior border of socket for 3 rd molar tooth and anterior border of ramus were 6.15 mm (2.23-12.10) and 8.02 mm (3.24-13.12) respectively. Conclusions: The knowledge about the incidence of the retromolar foramen is important for dental surgeons during various anaesthetic, implantation and surgical procedures of the mandible, especially during extraction of the lower last molar tooth.

Common Anatomical Variations of Neurovascular Canals and Foramina Relevant to Oral Surgeons: A Review

“…However, it can be located as close as 1 mm from the tooth [29]. It lies 8.02 mm from the anterior aspect of the branch [4,31]. It is closer to the buccal cortex than to the lingual plate [4].…”

The clinical significance of the retromolar canal and foramen in dentistry

“…However, it can be located just 1 mm away from the tooth (Shantharam et al, 2013). It is 8.02 mm from the anterior border of the ramus (Motamedi et al, 2016; Tiwari et al, 2015). Motamedi et al (2016) reported that it is located closer to the buccal cortex than the lingual plate.…”

Morphometric Analysis of Retromolar Triangle in Eastern Indian Population

“…Various Indian studies reported varying incidences of RMF in the different ethnic groups, nuances are still lacking [12][13][14][15][16][17].…”

“…A prominent issue is the nomenclature and categorization of RMF/RMC as reported in various literatures. Some authors considers that RMF/RMC as the bifid or trifid collateral of the main conduit, the mandibular canal, initiating at the mandibular canal and terminating at the retromolar trigone (RMT) [6][7][8][9][10][11][12][13][14][15][16][17][18]. While, Other researchers imply that RMC is as an unique separate entity, emphasizing its clinical relevance [19,20].…”