Lingual Foramen Research Articles

Topography of the Lingual Foramen Using Micro–Computed Tomography for Improving Safety During Implant Placement of Anterior Mandibular Region

The aim of this study was to determine the location and size of the lingual foramina and the course of their canals using micro-computed tomography. Twenty Korean mandibles were scanned using a micro-computed tomography system and reconstructed three-dimensionally to enable observation of the lingual foramina and their canals. Four mandibles (20%) had a single foramen at the lingual side of the mandibular midline, 8 mandibles (40%) had 2 foramina, and 5 mandibles (25%) had 3 foramina. Three mandibles (15%) had 4 small foramina with short canals. The foramina were classified as either superior lingual foramina or inferior lingual foramina according to their vertical location relative to the mental spine. The diameters of superior lingual foramina and inferior lingual foramina were 0.75 ± 0.36 and 0.73 ± 0.38 mm (mean ± SD), respectively. The distances from the inferior border of the mandible to superior lingual foramina and inferior lingual foramina were 12.58 ± 2.49 and 6.43 ± 3.08 mm, respectively. Ten canals (21%) traveled upward to the labial side, 24 canals (51%) downward, and 13 canals (28%) parallel to it. Ten mandibles (50%) had lateral foramina.With regard to implant surgery of the anterior mandibular region, the most hazardous zones for lingual foramina are 0 to 2 mm from the midline, the upper 3 to 17 mm from the inferior border of the mandible, and the anterior 0 to 7 mm from the lingual side. Careful preoperative planning taking into account the anatomical location of these foramina might help to avoid complications due to damage to the foramina, their canals, and their contents.

Distribution of the lingual foramina in mandibular cortical bone in Koreans

ObjectivesThe interforminal region, between the mandibular foramen, is known as a relatively safe area that is free of anatomic structures, such as inferior alveolar nerve, submandibular fossa, and lingual side of the mandible is occasionally neglected for its low clinical importance. Even in the case of a severely constricted alveolus, perforation of the lingual cortical bone had been intended. However, anterior extension of the inferior alveolar canal, important anatomic structure, such as concavity of lingual bone, lingual foramina, and lingual canal, has recently been reported through various studies, and untypical bleeding by perforation of the lingual plate on implantation has also been reported. Therefore, in this study, we performed radiographic and statistical analysis on distribution and appearance frequencies of the lingual foramina that causes perforation of the mandibular lingual cortical bone to prevent complications, such as untypical bleeding, during surgical procedure.Materials and MethodsWe measured the horizontal length from a midline of the mandible to the lingual foramina, as well as the horizontal length from the alveolar crest to the lingual foramina and from the lingual foramina to the mandibular border by multi-detector computed tomography of 187 patients, who visited Dankook University Dental Hospital for various reasons from January 1, 2008 to August 31, 2012.ResultsFrom a total of 187 human mandibles, 110 (58.8%) mandibles had lingual foramina; 39 (20.9%) had bilateral lingual foramen; 34 (18.2%) had the only left lingual foramen; and 37 (19.8%) had the only right lingual foramen.ConclusionWhen there is consistent bleeding during a surgical procedure, clinicians must consider damages on the branches of the sublingual artery, which penetrate the lingual foramina. Also, when there is a lingual foramina larger than 1 mm in diameter on a pre-implantation computed tomography, clinicians must beware of vessel damage. In order to prevent these complications and progress with a safe surgical procedure, a thorough radiographic examination before the surgery is indispensable. Further, clinicians should retract lingual flap definitely to confirm the shape of the lingual bone and existence of the lingual foramina.

Morphological study of accessory foramina in mandible and its clinical implication

Background: To provide anatomical information on the position and incidence of accessory foramina in mandible as they are important for dental surgeons and anesthetists in achieving complete nerve blocks and for avoiding injury to neurovascular structures passing through them. Materials and Methods: Fifty dried adult human mandibles of Indian origin were scrutinized in a regular manner with a magnifying glass. The accessory foramina and their positions were observed. Results: The accessory lingual foramen may be regarded as a constant finding with incidence of 88%. Frequency of infraspinous was lower than this (i.e., 70%) and that of lateral spinous was 28%. Accessory mandibular foramina were found in 48%, accessory mental in 22%, and retromolar in 18% of the cases. Conclusion: Macroscopic observations revealed the presence of accessory foramina in most of the investigated mandibles. The anatomical variability of incidence and position of accessory foramina should be considered as they may be used to give additional locoregional anesthesia in case of failed mandibular blocks. Knowledge of the commonest positions will be beneficial for oncologists and oromaxillofacial surgeons in planning graft implants.

Composition of the blood supply in the sublingual and submandibular spaces and its relationship to the lateral lingual foramen of the mandible

The purpose of this research was to contribute to minimizing arterial disruption during mandibular surgical procedures by clarifying the course of the arteries supplying the sublingual and submental regions. Heads of 75 human cadavers were dissected to identify the arterial supply of the sublingual and submental regions. Computed tomography scans were performed to visualize the lateral lingual foramina of the mandibles. The facial artery was found to contribute to the composition of almost half of the sublingual arteries studied. Furthermore, it was demonstrated that the arterial supply to an incisor tooth is often from the submental artery. Our data provide important information for coping with bleeding or hematoma occurring during surgical procedures in the mandibular region.

A method for mandibular dental arch superimposition using 3D cone beam CT and orthodontic 3D digital model

ObjectiveThe purpose of this study was to develop superimposition method on the lower arch using 3-dimensional (3D) cone beam computed tomography (CBCT) images and orthodontic 3D digital modeling.MethodsIntegrated 3D CBCT images were acquired by substituting the dental portion of 3D CBCT images with precise dental images of an orthodontic 3D digital model. Images were acquired before and after treatment. For the superimposition, 2 superimposition methods were designed. Surface superimposition was based on the basal bone structure of the mandible by surface-to-surface matching (best-fit method). Plane superimposition was based on anatomical structures (mental and lingual foramen). For the evaluation, 10 landmarks including teeth and anatomic structures were assigned, and 30 times of superimpositions and measurements were performed to determine the more reproducible and reliable method.ResultsAll landmarks demonstrated that the surface superimposition method produced relatively more consistent coordinate values. The mean distances of measured landmarks values from the means were statistically significantly lower with the surface superimpositions method.ConclusionsBetween the 2 superimposition methods designed for the evaluation of 3D changes in the lower arch, surface superimposition was the simpler, more reproducible, reliable method.

Characteristics of anatomical landmarks in the mandibular interforaminal region: A cone-beam computed tomography study

Objectives: This study was conducted to assess appearance, visibility, location and course of anatomical landmarks in mandibular interforaminal region using cone-beam computed tomography (CBCT). Study design: A total of 96 CBCT examinations was re-evaluated to exploit anatomical landmarks. The examinations used the Promax 3D CBCT unit. A sole examiner carried out all the measurements. Visibilities of the anatomical landmarks were scored using a four-point rating scale. Results: The mandibular foramen, anterior loop, incisive canal and lingual foramen were observed in 100,84,83,49 % of the images, respectively. The mean size, diameter and width of anterior loop, incisive canal and lingual foramen were obtained 3.54± 1.41, 1.47±0.50 and 0.8 ± 0.09mm, respectively. Conclusion: It is not safe to recommend any definite distance mesially from the mental foramen. The diameter of the canals and foramens should be determined on a case-by-case basis to exploit the appropriate location for each individual. Key words:Anatomical landmarks, cone-beam computed tomography, implant surgery, radiographic evaluation, surgical complications.

Appearance of anatomical structures of mandible on panoramic radiographs in Iranian population

Purpose.Currently panoramic radiography is used for diagnosis of dental and bone lesions, but anatomical structures also can be seen and may be useful in dental managements. This study aimed to investigate the visibility of some important mandibular features relating to neurovascular structures in Iranian population. Materials and methods. Panoramic radiographs were taken by Planmeca machine from 412 patients using standard exposure. The position of patient was in compliance with standard protocol. Then mandibular incisive canal was evaluated and data were analyzed statistically. Results. Mental foramen, anterior loop of mental nerve and incisive canal could be observed in 84.2, 66 and 51.7% of the cases. Respectively, lingual foramen was observed in only 6.1% of the radiographs. Gender doesn't affect on the visibility of these structures. There was a relationship between mandibular foramen and canal with age. Conclusion. Mandibular incisive canal was considered in 51.7% of cases, it was observed that the result obtained was more than those of other researches.

Evaluation of Location and Dimensions of Lingual Foramina Using Limited Cone-Beam Computed Tomography

To assess retrospectively the frequency and location of mandibular lingual foramina and their bony canals with limited cone-beam computed tomography. Of 389 consecutively taken cone-beam computed tomograms of the mandible, 191 fulfilled the inclusion criteria of adequate quality, dentate areas within the region of interest, and visualization of the mandibular inferior border. Foramina were located according to tooth areas and were grouped into midline, paramedian, and posterior foramina. Linear measurements included vertical and horizontal diameters of the foramen and its distance to the lower border of the mandible. In addition, the frequency of bony canals originating from lingual foramina was calculated, and the course and anastomoses with other anatomic structures were assessed. In total, 217 lingual foramina were detected in 1,054 sites. The midline of the symphysis had the highest frequency of foramina (96.2%), with the right first premolar area having the second highest frequency (27.5%). The mean diameter of lingual foramina ranged from 0.97 to 1.20 mm (horizontal diameter) and from 0.90 to 1.01 mm (vertical diameter). Sizes differed significantly between midline and posterior foramina. The mean distance from the foramen to the inferior mandibular border varied from 7.07 to 11.54 mm, with extreme outliers in all 3 groups. Overall, 95.4% of lingual foramina presented with a bony canal originating from the lingual surface, and 40.1% of these canals communicated with other anatomic structures, most frequently with the incisive canal. Mandibular lingual foramina and bony canals are frequently present and should be included in presurgical radiographic diagnostics.

Variations in position of lingual foramen of the mandible in reconstructive surgery

Background: The mandible is the largest, strongest and the lowest bone in the face. At birth, the two halves of the mandible are united by a fibrous symphysis menti in the median plane and are replaced by bone after 1 year of postnatal life. Observations and Results: The posterior symphysial surface bears a small elevation often divided into upper and lower parts, the mental spines (genial tubercles). Discussion: Superior to the mental spines, most of the mandible displays a lingual foramen that opens into a canal traversing the bone containing a branch of the lingual artery. The main aim of this present study is to determine the location and variations of the lingual foramen so as to contribute additional information to our existing knowledge during surgical interventions of symphysis menti, especially during genioplasties and implants.

Evaluation of the visibility and the course of the mandibular incisive canal and the lingual foramen using cone‐beam computed tomography

To assess the visibility and the course of the incisive canal and the visibility and the location of the lingual foramen using cone-beam computed tomography (CBCT). In total, 100 CBCT examinations of patients for preoperative planning were used for this study. The examinations were taken using the NewTom 3G CBCT unit, applying a standardized exposure protocol. Image reconstruction from the raw data was performed using the NewTom software. Three experts were asked to assess the visibility of the incisive canal using a four-point rating scale. The position of the incisive canal was recorded in relation to the lower, buccal and lingual border of the mandible using the application provided by the CBCT software. The incisive canal was definitely visible in 83.5% of the scans and the mean endpoint was approximately 15 mm anterior to the mental foramen. The mean distance from the lower border of the mandible was 11.5 mm and its course was closer to the buccal border of the mandible in 87% of the scans. The lingual foramen was definitely visible in 81% of the scans. The high detection rate of the incisive canal and the lingual foramen in the anterior region of the mandible using CBCT indicates the potential high preoperative value of CBCT scan for surgical procedures in the anterior mandible.

Mandibular lingual vascular canals (MLVC): Evaluation on dental CTs of a case series

Purpose The aim of this study was to assess the anatomy of the mandibular lingual foramen (MLF) and its linked canals (mandibular lingual vascular canals – MLVC), describing their frequency, diameter, location, and course. Materials and methods One hundred and fourteen computed tomography (CT) images of the mandible (57 male and 57 female; mean age 44.70 ± 12.53; age range 13–75 years, were evaluated. The CT sections were obtained on axial plane by using a bone reconstruction algorithm and then processed with dedicated software (Dentascan), with a standard protocol. Results 103 patients (90.35%) had at least one lingual vascular canal and 52 (45.61%) had multiple (two or three) canals. The typical locations of MLVC were the midline of the mandible (median lingual canal [MLC]). The mean diameter of the lingual canals in the midline (MLC) was 0.8 mm ± 0. The direction of MLC progresses in an anterior and slightly caudal sense. Conclusions Dental CT examination easily demonstrates the presence, position, direction and size of the lingual foramen and of the lingual vascular canals of the mandible. Radiologists and oral surgeons should be aware of these canals and their importance, in order to prevent bleeding complications during implants placement and other surgical procedures.

Anatomic assessment of the anterior mandible and relative hemorrhage risk in implant dentistry: a cadaveric study

To evaluate prevalence, size, location and content of foramina and bony canals located on the lingual side of the mandibular midline. The prevalence and the size of midline lingual foramina and canals visible above and/or below genial spines and their distances from the mandibular base were measured in 60 dry mandibles from adult human cadavers. In addition, macro-anatomic dissections were performed on another 20 mandibles injected with red latex to investigate the vascular canal contents associated with these midline lingual foramina and canals. A total of 118 foramina were detected. All mandibles investigated had at least one lingual foramen at the midline above the genial spines, located at a mean height of 12.5+/-2.1 mm (SD) from the inferior border of the mandible. Macro-anatomic dissections showed a clear vascular branch entering the mandibular midline as a single vessel from a sublingual-sublingual anastomosis in 19 out of 20 mandibles studied (95%). Blood vessels in the floor of the mouth may be in close proximity to the lingual cortical plate of the mandibular midline in most cases. This implies that bleeding can occur when the mandibular cortical plate is perforated even minimally. As a consequence, the authors suggest a careful planning of implant positioning at mandibular midline, possibly opting for the use of an even number of implants in the interforaminal region, avoiding the risk of surgical trauma to the lingual cortical plate of the mandibular midline.

Chronologic and geographic variability of neurovascular structures in the human mandible

Objectives To compare the dimensions of mandibular anatomical landmarks of human mandibles of three different chronological periods and seven different geographic regions. Methods Cone beam computed tomography (CBCT) images were acquired from human mandibles of three different chronological periods (Neolithic, Medieval and 19–20th Century). The 19–20th Century consisted of seven human mandibular samples from different geographic locations. Image analysis consisted of comparing anatomic variability and dimensions of the mandibular, lingual and incisive canals, mental foramen and their relationship to specific reference teeth as such to determine geographic region and historic period variabilities. Results There were statistically significant differences between the 19–20th Century group and the Medieval and Neolithic groups. The 19–20th Century group differed significantly in mandibular canal diameter, tooth root length, length of the lateral lingual canal. In addition, the group also differed from the Medieval sample for the lateral lingual foramen diameter and the midline lingual canal length. Furthermore, the prevalence of anatomic variations was significantly different for the geographic samples tested, with double mental foramina significantly more present in the Congolese sample, and significantly more lateral lingual canals noted in Indonesian and Greenland Eskimo samples. Conclusions This study suggests that mandibular neurovascularisation may show some geographic as well as historic variation. Further studies on larger data samples are needed to verify this statement, as such that it can be potentially used in anthropology and forensic dentistry. More research is also needed to address whether the geographic and historic variations are linked, as well to investigate evolutionary trends in these structures.

A distribution of submental artery, especially the relation between lingual foramen and a sublingual artery in the Japanese population

This study evaluates the mandibular lingual foramina (LF) using computed tomographic imaging data from a large Central European cohort, focusing on the most relevant anatomical parameters. We aimed to examine whether there are differences in key parameters between ethnic groups, or based on age and gender. Additionally, we analyze the potential effect of tooth loss on the LF and discuss risk management options before and during surgery.460 CT scans of adults (273 females and 186 males) were examined. The number, the location and the diameter of the median and lateral LF were assessed for each patient. The data was analyzed statistically, whereby a p-value lower than 0.05 was considered as significant.Median and lateral LF were present in 95,9%, and 38,9% of patients, respectively. Male patients had a greater number of LF than females. While the majority of median LF (62%) was located above the mental spine, the majority of lateral LF was located below (84%). The diameter of lateral LF (1,15 mm ± 0,33) was smaller than for median LF (1,22 mm ± 0,35), as well the lateral canals (4,8 mm ± 1,28) were shorter than the median canals (5,32 mm ± 1,74). Lateral LF were equidistant to the symphysis (13,89 ± 3,63 mm) on either side. Critical diameter size >1 mm was found in about 2/3 of our cases. The distance from the foramen to the residual ridge was ∼7 mm less in edentulous patients compared to dentulous patients.The median LF is a near-obligatory structure of the mandible, while the lateral LF is a frequently encountered structure. Age does not seem to affect the frequency of LF. Edentulous patients did not show differences regarding the presence of the LF, but their vertical osseous dimension was diminished by 7 mm and they may, therefore, be at an increased risk of adverse surgical incidents. The main findings of this study relate to the substantial variability in the anatomy and location of the LF and confirm with previous studies. As the LF can be reliably detected using CT/CBCT, the use of three-dimensional-imaging is recommended prior to conducting oral surgery. Careful pre-operative planning and accurate anatomical information may help to avoid surgical complications. To ascertain the potential significance of ethnicity on LF, more data need to be collected using standardized methodologies. A definitive conclusion on the impact of ethnicity on LF thus cannot currently be drawn based on the results of our study and those available from the published medical literature.

Anatomical characteristics of the mandibular lingual foramina observed on limited cone‐beam CT images

The study aimed to investigate the regional frequency and anatomical properties of mandibular lingual foramina. The regional frequency of the lingual foramina was investigated using limited cone-beam computed tomographic images of mandibles obtained from 190 examinations of 181 patients. The mesio-distal position of the lingual foramina was classified into 17 areas of the midline area and each tooth area. The vertical position was assessed from the positional relationship between the lingual foramina and mandibular canals. Additionally, anastomoses of the lingual canals from the lingual foramina to mandibular canals were observed on the images. One hundred and fifty-four lingual foramina were observed. The highest regional frequency was recognized in the midline area followed by second premolar and canine area. Plural lingual foramina were observed only in the midline areas. No lingual foramina were observed in the superior area of the mandibular canals. Thirty-one lingual foramina showed anastomoses between the lingual canals and mandibular canals. Information on the high regional frequency of lingual foramina in the second premolar area would be clinically significant to avoid life-threatening incidents because of the possible presence of an artery. It is therefore important to confirm the location of lingual foramina.

Assessment of the blood supply to the lingual surface of the mandible for reduction of bleeding during implant surgery

The aim of this study was to assess the frequency of the foramina and their canals on the lingual surface of the mandible using computed tomography (CT), which was carried out for dental implant planning. First, the visibility of the lingual canals of the CT image was verified by dissecting five cadavers. CT images of 200 patients, who had decided on implant treatment, were used in this study. The visibility of the foramina and their canals on the lingual surface of the mandible were assessed. The foramina were divided into two groups by the positions of the mandible, the medial lingual foramen and the lateral lingual foramen. At least one foramen was found in all patients. In the medial group, a higher level of mental spine was seen in 190 patients, the same level of mental spine was observed in 99 patients and a lower level of mental spine was observed in 114 patients. The lateral lingual foramina were found in 160/200 patients and 88/200 patients presented bilaterally. CT can predict the position and the size of the foramina and their canals on the lingual surface of the mandible. All the patients had more than one foramen in the middle of the lingual surface of the mandible on the CT image. The frequency of the lingual foramina in the medial region was 100% and that in the lateral region was 80%. It would also be useful to emphasize the significant variation in the precise location of these lingual foramina, and that these can only be visualized presurgically with volumetric imaging modalities, such as CT or Cone beam 3D systems.

Lingual Foramina in the Canine/Premolar Region of the Mandible: CBCT Observations

Objectives. The present study investigated the variations of “lingual” foramina (LF) and their bony canals in the canine/premolar region of the mandible, using cone-beam computerized tomography (CBCT) images.

Classification of the lingual foramina and their bony canals in the median region of the mandible: cone beam computed tomography observations of dry Japanese mandibles

Objectives We investigated the lingual foramina and their bony canals in the median region of the mandible using cone beam computed tomography (CBCT).

Hemorrhage in the Floor of the Mouth After Second-Stage Surgery: Case Report

Placement of dental implants in the interforaminal region of the mandible is generally considered a routine, simple, and safe procedure. However, severe bleeding and hematoma in the floor of the mouth have been reported as a rare but potentially fatal complication related to the placement of an implant in this region. The following report describes a case of life-threatening hemorrhage in the floor of the mouth after second-stage surgery to place the healing abutment. The implants were forced to match with the prosthesis in a severely atrophic upper jaw, resulting in a perforation of the lingual cortex and mucosa of the floor of the mouth. Clinicians who place implants should be knowledgeable in the treatment of such a serious complication.

Lingual foramina on the mandibular midline revisited: A macroanatomical study

The purpose of the present study was to determine the incidence, size, location, course, and content of the foramina and bony canals located on the lingual side of the mandibular midline. Fifty dry human mandibles were morphometrically analyzed by measuring the distances of these midline foramina from the mandibular base and the dimensions of these foramina and their bony canals. In addition, macro- and microanatomical dissection was performed on 12 intact cadaver mandibles. The macroanatomic midline foramina were classified into superior and inferior genial spinal foramina according to their vertical location with respect to the genial spines. This study showed that out of 50 dry mandibles, 49 (98%) had at least one midline lingual foramen; only one lacked a true midline foramen. Evaluation of the microanatomical dissections indicated a clear neurovascular bundle in both superior and inferior genial spinal foramina and canals. For the superior canal, the content was found to derive from the lingual artery and the lingual nerve. For the inferior canal, however, the arterial origin was submental and/or sublingual, while the innervation derived from a branch of the mylohyoid nerve. In conclusion, different kinds of lingual foramina have been identified according to their location. The superior and inferior genial spinal foramina have different neurovascular contents, determined by their anatomical location above or below the genial spines.