Journal of Critical Reviews ISSN- 2394-5125 Vol 7, Issue 14, 2020 A REVIEW ON VARIATIONS IN LINGUAL FORAMINA OF THE MANDIBLE MIDLINE 1Jones Jayabalan, 2M.R.Muthusekhar 1Post Graduate Student Department of Oral and Maxillofacial Surgery Saveetha Dental College and Hospitals, Saveetha Institute of Medical and Technical Sciences, Saveetha University, Chennai, India. 2Program Director Department of Oral and Maxillofacial Surgery Saveetha Dental College and Hospitals, Saveetha Institute of Medical and Technical Sciences, Saveetha University, Chennai, India. Corresponding Author: Jones Jayabalan Post Graduate Student Department of Oral and Maxillofacial Surgery Saveetha Dental College and Hospitals, Saveetha Institute of Medical and Technical Sciences, Saveetha University, Chennai-600077Tamil Nadu, India. Email id: [email protected] Received:16.04.2020 Revised: 21.05.2020 Accepted: 20.06.2020 Abstract The sublingual, submental arteries or their anastomosis perforate the lingual cortical plate through the lingual foramen. Both the arteries are branch of facial and lingual arteries respectively which either arises independently from the external carotid artery or arises from a common lingual facial trunk. The anterior mandibular midline at which the lingual foramen is frequently present is subjected to various procedure like dental implants, genioplasty, tori removal, block graft harvesting, screwing with or without plating following trauma or osteotomy. There is a wide range of anatomical variations of lingual foramen among individuals. Cone-beam computed tomography (CBCT) has been shown to be superior to panoramic radiographs in displaying mandibular lingual foramen and its variations. Numerous studies have been carried out to examine the frequency, diameter, and other anatomical features of the lingual foramen and its canals. There is a paucity of the data which compares the different group of the population based on the position and the occurrence of the lingual canal and very few studies compared the gender and population. The main purpose of the review is to examine the anatomical variations of the lingual foramen. Keywords Lingual foramen , Lingual canal , Accessory foramen , Anatomy , Cone beam computed tomography ,Sublingual artery , Submental artery © 2020 by Advance Scientific Research. This is an open-access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/) DOI: http://dx.doi.org/10.31838/jcr.07.14.169 INTRODUCTION lingual canal and very few studies compared the gender and The use of implants and the grafting procedures were population [15]. The main purpose of the review is to examine increasing specifically in the anterior jaw bone results in the the anatomical variations of the lingual foramen. raising reports of postoperative complaints [1]. Many dental anatomy books or reports have failed to report the existence of Clinical Considerations the lingual foramen. Perhaps the lingual foramen is a well- The lingual mandibular foramen is a special anatomical defined through oral radiographs [2]. The awareness of lingual variation on the inferior jaw bone. It consists of both vascular foramen plays a major role in pre-surgical consideration before and nervous anastomosis which is derived from the branches the installation of midline mandible implants. Anterior of the submental and lingual artery and mylohyoid nerve. mandible includes many anatomical structures which include Various studies reported that during implant interventions, mandibular incisive canal (MIC) and lingual foramen[3-5]. The the intraoperative massive bleeding occurs in this area [16-19] lingual foramen is situated in the midline of the mandible and . Bernardi. [20] reviewed the frequency and anatomical features at the equal level, inferior or superior to the mental spines[6]. of the mandibular lingual foramina on the midline of the inferior These anatomical structures in the anterior jaw plays major jaw. The finding highlighted that there exist high frequency of role in optimizing the plans for dental surgeries and also to variation with a quite important diameter, a sign of significant avoid further complications[7]. calibre of the related vessels. If the variation is underestimated in the modern textbooks of oral anatomy, the radiological The structure of the lingual foramen, dimension and the screening is necessary during preoperative planning. Further location of the bony canals have to be considered with greater appropriate risk management is mandatory to minimize injury importance during any anterior dental surgeries such as in the anterior floor of the oral cavity. grafting procedures, implant placement and genioplasty so as to avoid the major complications. Some of the complications In the current scenario, dental implants are considered as the involved in these kinds of dental surgeries include pulp canal standard options for the prosthetic rehabilitation for obliteration, intraoperative bleeding, neuropraxia of the edentulous patients. In many cases, the placement of the mandibular incisive nerve, and nerve injury. The short term and implants is a routine and predictable technique [21]. Certain long term disturbances involve alteration or loss of pulp situations leads to hemorrhagic episodes in lingual cortex, this sensitivity in the lower front teeth[8,9]. is perhaps due to dental implants in the anterior mandibular region. Previous studies showed that rupturing of lingual Many studies assume the vascular content, an anastomosis of periosteum leads to hematoma in this region and resulted in the the sublingual branch of the right lingual arteries and left swelling of the floor of the mouth and cause upper airway lingual arteries[10,11]. The size of the artery should be obstruction[22-24]. Hence, pre-operative planning should sufficient enough to aggravate the haemorrhage in the soft include radiological imaging to avoid complications[7]. connective tissues or intraosseously which may be very crucial to control[11]. Numerous studies have been carried out to Oettlé. [25], determined the exact location and the occurrence examine the frequency, diameter, and other anatomical of the midline mandibular canal (MLC) in the different age features of the lingual foramen and its canals[12,14]. There is a groups in both gender and dentition groups. There exists a paucity of the data which compares the different group of the significant difference in dentition pattern among gender shows population based on the position and the occurrence of the Journal of critical reviews 948 A REVIEW ON VARIATIONS IN LINGUAL FORAMINA OF THE MANDIBLE MIDLINE that edentulous females were at higher risk of vessel injury in 40% of the communicated with other anatomic structures, most the MLC in the process of implantation. frequently with the incisive canal. In a retrospective study to improve the safety of the mandibular Liang [7], in a cadaveric study, assessed the anatomic of the surgical procedure, Wang et al. [26] evaluated the occurrence, anterior mandible and its relative hemorrhage risk during location, and the diameter of the mandibular lingual canals implant dentistry. The finding highlighted that all the 118 using CBCT. The study finding emphasized the presence of mandibles detected had at least one lingual foramen above the mandibular lingual canals and lateral lingual canals, among genial spines. The single foramen was most frequently observed which MLC is common, detected using CBCT. Majority of the and the patients with a single lingual foramen will benefit from samples showed at least on lingual perforation (97.0%) and all the inferior location of this foramen, which facilitates deeper the samples showed at least one lingual perforation in the flap surgery and implant placement that reduces the risk of mandible. The further significant difference was observed damage to the canal. Therefore, the cautious preoperative among the gender in both MLC and LLC. planning is required for the implant positioning at mandibular midline, wisely choosing an even number of implants in the In the face mandible is the strongest, lowest and strongest bone interforaminal region, which avoids the risk of surgical in the face. In newborn the two halves of the mandibles are complications. Thus CBCT imaging can be recommended as a joined together by fibrous symphysis in the median plane and it preoperative evaluation before dental implants. has been replaced by the bone after a year. Natekar [27], showed that posterior symphysial surface shows a small The average diameter of the artery was measured at 1.41mm elevation and divided intoupper and lower part in the mental and 0.31 mm with the largest diameter of 1.6mm, this indicates spines. Mandibles having the lingual foramen open into the that the size of the artery entering [13,14] the lingual foramen canal which crosses the bone with the branch of the lingual is sufficient enough to cause hemorrhage in the floor of the artery. The location and the variations in the lingual foramen mouth when the lingual cortex is perforated. The bleeding may help in the pre-operative decision during mandibular surgeries. increase the risk of obstructing the air way[12]. Bilaterally on the lingual surface of the mandible the genial The trauma to the artery in MLC leads to the serious tubercle a group of four bony extensions are situated between haemorrhage, if the artery size increased. Airway obstruction is the superior and inferior borders of the mandible[28]. Although considered as the major complication due