Automated Identification of Accessory Mental Foramen Using Cone-Beam Computed Tomography and Convolutional Neural Networks.

Background The mental foramen (MF) is the opening through which the mental nerve leaves the mandible and is usually located between the roots of the first and second mandibular premolars. Some anatomical variations, such as accessory mental foramen (AMF), have been reported and must be considered to prevent clinical complications. Various AMF studies have been presented in the literature. However, the MF and AMF remain to be evaluated in detail. This study aimed to assess the AMF via cone beam computed tomography (CBCT) and evaluate its relationship with the MF. Methods Two hundred forty-four CBCT images that met the inclusion criteria were evaluated. The AMF and MF diameter, AMF number, MF–crest distance, MF–mandibular basis distance, AMF–crest distance, and AMF–mandibular basis distance were measured. Results The prevalence of AMF was 9.4%, with a total of 46 (26 on the right and 20 on the left) observed. The diameters of the first and second AMFs were 0.67 ± 0.28 mm and 0.56 ± 0.11 mm on the right and 0.68 ± 0.23 mm and 0.46 ± 0.11 mm on the left, respectively. Regarding the MF, the right and left sides measured 2.06 ± 1.37 mm and 1.91 ± 0.45 mm, respectively. The first and second AMF–crest distances and first and second AMF–mandibular basis distances were 15.18 ± 2.77 mm, 13.5 ± 2.0 mm, 16.63 ± 2.64 mm, and 14.13 ± 4.36 mm (right side) and 13.90 ± 3.01 mm, 12.23 ± 0.9 mm, 13.14 ± 2.4 mm, and 14.40 ± 3.21 mm (left side), respectively. Regarding the diameter of the left MF, the distance between the right and left MF crest and the distance between the MF and mandibular basis were greater in males (p

Anatomy of the accessory mental foramen in a Saudi subpopulation: A multicenter CBCT study

Background: Determining the incidence and anatomic features of accessory mental foramen (AMF) in the Iranian population is of vital importance. This study investigated the prevalence and anatomic characteristics of AMF using cone-beam computed tomography (CBCT) in a selected Iranian population. Methods: A total of 853 CBCT images from 440 women and 413 men were examined in this cross-sectional retrospective study. The images were evaluated by two independent observers using reconstructed 3-dimensional, cross-sectional, and panoramic views. Several parameters were assessed, including the location of AMF relative to mental foramen (MF), size and the point of canal bifurcations, and the distance between the main and accessory canals. Finally, statistical differences in the AMF prevalence in terms of gender and direction and its location were evaluated by the Mann-Whitney U test (P<0.05). Results: The prevalence of AMF was 10.55%, which was more frequently located in the posterior inferior area relative to the main MF, and its nerve was more frequently originated from the anterior loop (P=0.001). There were no statistically significant differences in gender (P=0.26) and direction (P=0.4). The mean distance of AMF was 7.62 mm. The mean height of MF and the AMF vertical height were 13.65 mm and 52.12 mm in those with AMF on one side, respectively, and this difference was statistically significant (P=0.001). The sizes of the MF and AMF were 3.2 mm (large diameter), 2.3 mm (small diameter), and 1.4 mm (large diameter), and 1.1 mm (small diameter), respectively. Conclusions: Based on the findings of the present study, the prevalence of AMF according to hemi-mandibular was 5.80% in the selected Iranian population. Thus, AMF might branch from any section of the inferior alveolar nerve and the mandibular canal.

BackgroundThe mental foramen (MF) is a small foramen located in the anterolateral region of the mandible through which the mental nerve and vessels emerge. The knowledge on the anatomic characteristics and variations of MF is very important in surgical procedures involving that area. The aim of this study was two-fold: firstly, to analyze the anatomic characteristics of MF and the presence of accessory mental foramen (AMF) using CBCT and, secondly, to compare the capability of CBCT and PAN in terms of MF and AMF visualization, as well as influencing factors.Material and MethodsA sample of 344 CBCT scans was analyzed for presence and characteristics (i.e. diameter, area, shape, exit angle) of MF and AMF. Subsequently, corresponding PANs were analyzed to ascertain whether MF and AMF were visible.ResultsOut of the 344 patients, 344 (100%) MFs and 45 (13%) AMFs were observed on CBCT. Regarding gender, MF diameter and area, MF-MIB and MF-MSB distances, and exit angle were all significantly higher in males. Also, statistically significant differences were found in terms of age and dental status. Statistically significant differences in MF long and short diameters and MF area were found with respect to AMF presence (p=.021, p=.008, p=.021). Only 83.87% of the MFs and 45.83% of the AMFs identified on CBCT were also visible on PANs. MF diameter, shape, exit angle, and age had a significant influence on MF visualization on PAN (B=.43, p=.005; B=-.55, p=.020; B=.20, p=.008; B=.61, p=.005).ConclusionsPAN is not an adequate technique to properly identify MF and AMF. Diameter, shape, exit angle, and age are all factors influencing MF visualization on PAN images. For surgery involving the MF anatomical region, a preoperative radiological study with CBCT is of crucial importance to avoid complications.Key words:Mental foramen, accessory mental foramen, mandibular anatomy, cone beam computed tomography, panoramic radiography.

Accessory mental foramen (AMF) is the extra mental foramen (MF) located in the mandible. The recognition of AMF is important to avoid complications during surgical procedures involving MF and cheeks. This study aimed to determine the prevalence, localization, and size of AMF by using cone-beam computed tomography (CBCT). CBCT images of 645 patients over 13-14 years (male 281; female 364) were retrospectively evaluated. The CBCT images were obtained using Promax 3D® (Planmeca, Helsinki, Finland) device with automated exposure parameters varying depending on the cases. Statistical analysis was performed using descriptive statistics, chi-square test and t-test. AMF was detected in 75 (11.6%) patients. There was no significant difference between the presence of AMF and gender (P = 0.57, P > 0.05). Majority of the cases (n = 67, 88.8%) consisted of single AMF, while double AMF was observed in 6 (10%) and triple AMF in 2 (1.2%) patients. The most common location of AMF with respect to MF was posterio-inferior (n = 57, 67.1%), and AMF placed at the root line of first molar tooth in 45 cases (52.9%). AMF can be seen in the mandible one in every ten patients being single in most cases. Considering the high prevalence and present morphological features, AMF should be detected by CBCT before surgical operations, particularly in implant planning for the prevention of possible complications.

This study determined the occurrence and location of the mental foramen (MF) and accessory mental foramen (AMF) in Turkish patients using cone-beam computed-tomography (CBCT) with 3D-imaging software. CBCT scans of 386 sites in 193 (92 male, 101 female) patients were retrospectively analyzed to determine MF and AMF occurrence, sizes, and locations. Digital imaging and communications in medicine (DICOM) data were transferred to surface-rendering software to generate 3D images. Distances between the MF and AMF and from both foramina to the alveolar ridge and to the closest tooth were measured. Differences in AMF incidence by sex, side, and location were evaluated using chi-squared tests, and MF and AMF measurements were evaluated using Mann-Whitney U-tests. AMFs were observed in 6.5% of patients and were most commonly in an anteroinferior location. Mean AMF size did not differ significantly by sex or side [males: horizontal = 1.5 mm (1.0-2.4 mm), vertical = 1.4 mm (0.8-2.4 mm); females: horizontal = 1.5 mm (0.8-3 mm), vertical = 1.3 mm (0.8-2.1 mm); P > 0.05]. Males showed significantly greater mean vertical and horizontal MF dimensions compared with females [males: horizontal = 3.9 mm (1.0-7.0 mm), vertical = 3.6 mm (1.2-7.0 mm); females: horizontal = 3.5 mm (1.3-5.6 mm), vertical = 3.3 mm (0.8-5.8 mm); P < 0.05]. Awareness of the AMF is important to avoid mental nerve damage during surgical intervention and anesthetic applications. CBCT is useful for AMF detection, distributes less ionizing radiation, and allows 3D imaging.

BackgroundThe accessory mental foramen is characterized by small foramina in the surrounding area of the mental foramen with communication with the mandibular canal. The aim of this research was to evaluate epidemiological and radiomorphometric aspects of the accessory mental foramen (AMF) using cone beam computed tomography (CBCT) in Brazilian individuals.Material and MethodsThis was a cross-sectional, quantitative, retrospective descriptive study with 250 CBCT scans of dentate individuals in the anterior mandibular region, aged between 18 and 69 years. Presence/absence, linear measurements (length, height, and width), anatomical distances (to the vestibular, lingual, alveolar bone cortices, base of the mandible, and to the apex of the adjacent tooth) were evaluated concerning the accessory mental foramen.Results Of the 250 scans, the mean age of the patients was 47.44±12.57 years, with 150 female and 100 male individuals. The total prevalence of AMF was 7.2% (n=18) of cases, with 5.2% (n=13) female individuals and 2% (n=5) male individuals. Bilateral presence of AMF was observed in one case (0.4%). Regarding laterality, AMF presence was observed in 10 cases (4.0%) on the right side and 8 (n=3.2%) on the left side. The mean distance from AMF to the mental foramen was 4.67 mm. The mean horizontal diameter was 1.06mm, and the mean vertical diameter was 0.95mm across the entire sample.ConclusionsThe prevalence of the AMF was 7.2% with 95% confidence intervals (95% CI), showing a slight inclination towards female individuals. Key words:Accessory mental foramen, mental foramen, cone beam computed tomography, anatomical variation.

The aim of this study was to evaluate the frequency and location of accessory mental foramen (AMF) in a Turkish population using cone beam computerized tomography (CBCT). CBCT images of 1005 patients were retrospectively reviewed from the archive of the Department of Oral and Maxillofacial Radiology, Faculty of Dentistry, Izmir Katip Celebi University. The prevalence, size, and localization of AMFs were assessed according to gender and age. In addition, the vertical and horizontal dimension of the mental foramen (MF) with and without AMF was measured to investigate the relationship between MF dimensions and the presence and absence of AMF. The average distance between the MF and AMF was also calculated. All measurements were then analyzed statistically. A total of 149 AMFs in 123 (12.23%) patients were identified on the CBCT images of the 1005 patients reviewed. There was no significant correlation between presence of AMF and gender (p = 0.152). The most common localization of an AMF with respect to the MF was posterio-inferior (n = 52; 34.89%). A statistically significant difference was also found between the vertical and horizontal dimensions of the MF with and without AMF (p < 0.05). The results of this study demonstrate the high prevalence of AMF in the studied Turkish population. Considering the high prevalence and the structures passing through it, recognition of AMF and its detection using CBCT is important to prevent complications that may occur during and after surgical procedures.

Detection and characterization of anterior loop, accessory mental foramen, and lateral lingual foramen by using cone beam computed tomography

The accessory mental foramen (AMF) is a type of mandibular variation which transmits extra neurovascular branches, a fact with great importance in dental and surgical procedures. Its range and features do vary between populations, which is why broad based knowledge is required to which out to avoid issues like nerve injury or anesthesia failure. We did this review to look at the anatomical features, that is size and location of AMFs, their global prevalence, and what clinical use they have, and how they play a role in dental practice and forensics. A systematic literature search was conducted using PubMed, Scopus, and Web of Science databases for studies published in the past five years. Keywords included: Accessory mental foramen (AMF), Bucal foramen, Mental foramen, Mandible, Dental surgery. The review was conducted in accordance with the PRISMA guidelines. We did a thorough search of the literature looking at AMF prevalence, morphology and clinical implications across many populations. We looked at studies done on dry mandibles, radiographic reports and at what Cone-Beam Computerized Tomography (CBCT) shows. Also, we put together key studies which we looked at to present prevalence rates, types of variation in anatomy and diagnostic methods. AMF’s range from 1% to 10% worldwide, we see higher rates in South Asian groups at 6 to 8.9% as compared to Iranian at 2 to 3% or Bosnian at 2.7%. AMFs are small, oval and are found near the first molar or second premolar. CBCT does a better job in detecting these as compared to panoramic x rays, also morphological studies give very precise measurements although may not see the smaller AMFs. The presence of AMFs reports anesthetization failure, nerve injury or bleed out during dental procedures and play a role in forensics and anthropology. AMFs are important anatomical variants that require attention in dental and surgical planning. CBCT is the best for accurate detection. By being aware of the AMF’s prevalence and what they look like we see better results in care and less complications. Future research should standardize diagnostic criteria and explore demographic influences to improve clinical and forensic applications

Introduction: Accessory mental foramen (AMF) is defined as any additional opening on the anterior surface of the mandible body that is connected to the mandibular canal. The presence of AMF is an important anatomical parameter when planning the therapy to avoid neurovascular bundle injury and other complications. Cone-beam computed tomography (CBCT) provides an accurate, three-dimensional determining of the position, its dimensions and the relation of AMF to the mental foramen (MF), as well as the distinction from nutritive openings. Material and Methods: The research was carried out at the Department of Dentistry, Faculty of Medical Sciences, University of Kragujevac, as a retrospective study where 148 CBCT images were analyzed. The analysis of the position of AMF, the relation to and the distance from the MF were made on cross-sectional and axial images. Only those openings that have had a clear connection with the mandibular canal were counted as AMF. Results: AMF was present in 12 (8.11%) patients. In most cases, AMF was positioned superior to MF, in 27% of patients. There was no significant statistical difference between sex and the jaw side. The average distance of AMF from MF was 4.52 ± 2.21 mm. In most cases, AMF is round shaped (60%). The average value of the surface area is 1.62 ± 1.14 mm2. Discussion and Conclusion: Timely detection of AMF using CBCT contributes to the diagnosis and planning of appropriate dentures, surgical technique, preventing possible damage to adjacent anatomical structures, or some other therapy.

The aim of the present study was to clarify the occurrence, diameter, and location of the accessory mental foramen (AMF) using cone-beam computed tomography (CBCT) images from a sample of Turkish children. This retrospective was carried out using a total of 275 CBCT images from child and adolescent patients were randomly selected from existing records in the Department of Oral and Maxillofacial Radiology at the University of Erciyes, Kayseri, Turkey. The mental foramen (MF) and AMF were assessed on axial, sagittal, and coronal CBCT slices. The mean age was 10.51 ± 3.32 years, consisting of 139 males (mean age 10.64 ± 3.42) and 126 females (mean age 10.38 ± 3.18). Twenty-one AMFs were observed in 18 of 275 patients (6.5%, 10 boys and eight girls). There was no significant difference in gender in relation to the prevalence of AMF (p = 0.65). The mean area of the 21 AMFs and the MF on the side with the AMF were 0.7 mm² (SD ± 0.5) and 3.8 mm² (SD ± 2.2), respectively. It is important to stress that detecting the AMN using CBCT with 3D reconstructions may reduce the risk of paralysis, hemorrhage, and postoperative pain in this region. Our study presents the first report assessing the occurrence, diameter, and location of the AMF in the pediatric population using CBCT images. In this respect, not surprisingly, the mean size of the AMF of our population is smaller than other reports in the literature that involve adult populations.

BackgroundThe aim is to assess mental foramen (MF) and anatomical variations using cone beam computed tomography (CBCT) images in a Turkish population.MethodsIn this retrospective study, CBCT images of 301 patients (162 females, 139 males) obtained between November 2021 and February 2022 were evaluated. Patients were analyzed in 4 groups according to age (Group 1: 18–30 years, Group 2: 31–45 years, Group 3: 46–55 years, Group 4: 56 years and older). The position of the MF relative to the teeth, vertical (MFV) and horizontal (MFH) dimensions; the distances of the MF to the mandibular midline (MF-MM), ramus posterior border (MF-MP), lower border (MF-ML) and upper border (MF-MU); the presence of an accessory mental foramen (AMF); and if any, the position of the AMF relative to the MF and the distance of the AMF to the MF (MF-AMF) were recorded separately for the right and left sides. Associations with gender and age were evaluated. The independent samples t test was used to determine the relationship between the measurements and gender and the evaluation of the measurement values according to age groups. The evaluation of the location of MF according to gender and age groups was performed using the Chi-Square Test.ResultsOn the right and left sides, MF was most commonly seen at the apical level of the second premolars (45.4% and 52.1%, respectively). MFV, MFH, MF-MM, MF-MP and MF-ML were significantly higher in males than in females, p < 0.001 on both sides and for each parameter. There was a significant difference between the age groups for MF-MU and MF-ML on the right side, MF-MU on the left side (p < 0.001, p < 0.05, p < 0.001, respectively). A total of 42 AMFs were seen in 39 (13%) of the 301 patients. AMFs were frequently located posteroinferior to the MFs (35.5%). The mean MF-AMF was 7.83 mm.ConclusionsThe findings of this study contribute to the existing literature on the anatomy and variations of MF. The results of this study show that the prevalence of AMF in the Turkish population studied is high at 13%.

Objective: To evaluate the frequency of accessory mental foramen (AMF) and anatomical variants of the mental nerve anterior loop using cone-beam computed tomography (CBCT) in a Peruvian population. Material and methods: This retrospective cross-sectional study evaluated 80 hemi-mandibles from 40 subjects using CBCT. The sample included 38 females and 42 males, with an average age of 25±4.45 years. A 3D multi-planar reconstruction was performed to identify the location and presence of accessory mental foramina, their morphological characteristics (oval or circular), their position with respect to the mental foramen (MF), anterior loop (AL) path and other anatomical landmarks including lengths and angles. Statistical analyses included chi square and t-tests. The significance level was p&lt;0.05. Results: The frequency of AMF was 17% and the average distance AL-MF was 4.76±1.97mm. The measurements of the anterior border of AL and MF to the inferior mandibular border showed significant differences according to the sex (p&lt;0.001 and p=0.009, respectively). Conclusion: The AMF prevalence was approximately 17%. There is no association between the AMF position and its morphology, sex or side evaluated. The distances from the anterior border of the AL and from the inferior border of the MF to the inferior mandibular border were greater in males. These findings should be considered when planning implant or mini-implant placement in this region.

It is critical to determine the location and variation of mental foramen (MF) during the implant treatment. Multiple numbers of MF can be seen in the mandible, and they are called as accessory MF (AMF). Detecting the anatomic variations including AMFs with radiological examinations before surgical applications are important to prevent neurovascular complications. Cone-beam computed tomography (CBCT) is a beneficial method to determine the anatomical structures such as MF and its anatomical variations. The aim of this case report was to present the diagnosis of AMF localized at the left side of the mandible of a 44-year-old woman patient who was applied for implant therapy. Treatment planning and postoperative evaluation were performed with CBCT.