Assessment of Anterior Loop of Inferior Alveolar Nerve and Its Anatomic Variations with Age, Gender, and Dentition Status in Indian Population: A CBCT Study

Background. The posterior region of the mandible is more often related to iatrogenic errors, but the interforaminal region is also not spared for neurovascular complications. This study aimed to use CBCT images to evaluate the prevalence of anterior nerve looping and its variations with age, gender, and dentition status. Methods. This retrospective study was carried out by studying 600 CBCT scans retrieved from archival records of a CBCT center in Lucknow. The scans were inspected by two trained investigators. The length of the anterior loop was measured using the measuring tool of Carestream 3D imaging software. Descriptive and analytical tests were performed. Results. The prevalence of the anterior loop of the inferior alveolar nerve was found to be 56%. The prevalence was found to be more on the right side (29.0%) compared to the left side (27.0%). The most common anterior looping of the inferior alveolar nerve was type 3 followed by type 1. Males were found to have significantly higher loops compared to females. The number of loops was found to decrease significantly with age. The mean length of the loop was found to vary from 1.14 to 1.61 mm. Conclusion. The anterior looping of IAN is very much prevalent in the Lucknow population. The use of the CBCT technique and appropriate preplanning prior to surgery or implant placement should be performed to prevent nerve injury.

Evaluation of the size and location of the mental foramen and anterior loop of the lower alveolar nerve in the Brazilian population using cone beam computed tomography

Objective: The aim of this study was to evaluate the size, shape and location of the mental foramen (MF) and anterior loop (AL) in the Brazilian population through the analysis of cone beam computed tomography (CBCT) and panoramic radiography (PR). Method: We analyzed the location, shape and size of the MF, the distance between the upper wall of the MF and the alveolar crest (AC), the size of the AL and the presence of lingual anastomosis. Results: Fifty PR and CBCT exams were analyzed. In relation to the MF, the most common location was between premolars (56%), the most common shape was the oval shape (83%) and the average size in the PR was 3.63 mm and in the CBCT was3.66 mm. The average distance from the MF to the AC in the PR was 17.29 mm and in the CBCT was 11.48 mm. The average AL size was 3 mm, the smallest being 1 mm and the largest being 5 mm. Static analysis was performed to verify the relationship between the distance from the foramen to the AC with the values ​​that were found in the PR and CBCT, which showed a statistically significant difference (p=<0.001) between them. Lingual anastomosis could be seen in 22% of the analyzed hemimandibles. Conclusion: CBCT is a reliable diagnostic test for planning rehabilitation near the MF. The distance between the implant and the foramen must be analyzed individually.

Bone quality and quantity of the mandibular symphyseal region in autogenous bone grafting using cone-beam computed tomography: a cross-sectional study

Background Bone volume plays a pivotal role in the success of dental implant treatment. Autogenous bone grafts should be harvested from reliable sites in the maxillofacial region. This study sought to assess the quantity and quality of bone in the mandibular symphysis for autogenous bone graft harvesting using cone-beam computed tomography (CBCT). Methods This cross-sectional study evaluated the CBCT scans of 78 adults presenting to three oral and maxillofacial radiology centers. The vertical (VD) and horizontal (HD) alveolar bone dimensions, cortical thickness (CT), and cancellous to cortical bone ratio (C/C) were measured in the interforaminal region of the mandible at the sites of central incisor to first premolar teeth. The interforaminal distance (ID) and the anterior loop length were also measured. Nonparametric statistical tests were used to analyze the data with respect to sex, age, and tooth position. Results The median VD, HD, and CT of the symphysis were 20.21 (3.26), 4.13 (0.37), and 2.25 (0.23) mm, respectively. The median C/C was 1.51 (0.11). The median ID was 52.24 (8.24) mm, and the median anterior loop length was 1.82 (1.06) mm. Significant differences were observed in all parameters among different teeth. Most of the measured parameters were greater in males compared with females. There were significant differences in ID, VD, and CT between different age groups. Conclusions The quantity and quality of the available bone in the mandibular symphysis for bone graft harvesting vary by gender, age, and harvesting site, necessitating careful preoperative evaluation.

Morphometric Analysis of the Mandibular Canal, Anterior Loop, and Mental Foramen: A Cone-Beam Computed Tomography Evaluation

This study investigated the cone-beam computed tomography (CBCT)-based features of the mandibular canal, mental foramen, anterior loop, and accessory mental foramina with respect to age and sex. A total of 306 CBCT mandibular images were included in this retrospective study to measure the mandibular canal location and extension, the mental foramen position, the presence of the anterior loop, and the accessory mental foramina. The measurements were obtained in sagittal, coronal, and axial views. Descriptive statistics are presented. Sex-related differences, correlations, and comparisons were calculated using SPSS at 5% significance level. The mandibular canal was located more coronal and medial in male patients. The majority of cases had the mental foramen located just apical to the mandibular second premolar with a mean height of 2.94 mm and a mean length of 3.28 mm. Age affected the size of the mental foramen. The mental canal in all cases tended to show a coronal direction. Mesial extension of the anterior loop was found in 66.01% of the images while accessory mental foramina were detected in 2.6%. The complexity of the mandibular canal, mental foramen, anterior loop, and accessory mental foramina among Sudanese patients with respect to age and sex was confirmed.

Evaluation of Mental Foramen with Cone Beam Computed Tomography: A Systematic Review of Literature

Purpose. The aim of this systematic review is to assess whether the anatomy of mental foramen is precisely evaluable with cone beam computed tomography (CBCT) before implantation in humans. Methods. A systematic review was carried out to evaluate the anatomy of mental foramen (size, position, symmetry, anterior loop, and accessory mental foramen or multiple mental foramina). According to Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines, an electronic search of three databases (Medline, Web of Science, and Cochrane Library) was undertaken until June 2020 and was supplemented by manual searching. Two reviewers will independently perform the processes of study inclusion, data extraction, and quality assessment. Systematic reviews, studies about children, and case reports were excluded. Only studies using CBCT to do preoperative evaluation were selected. Results. From 728 potentially eligible articles, 72 were included in the qualitative analysis and quantitative synthesis. This systematic review provided an assessment of the anatomy of the mental foramen. The mental foramen was located mostly between the two premolars (between 50.4% and 61.95%) or apically to the second premolar (from 50.3% to 57.9%). The mean diameter of the mental foramen was bigger in males than in females; the difference between them could reach 0.62 mm. The anterior loop seemed to be longer in males (between 0.87 ± 1.81 and 7.25 ± 2.02 mm) than in females (between 0.81 ± 1.18 and 6.52 ± 1.63 mm) and with the presence of teeth (from 0.91 ± 1.18 to 2.55 ± 1.28 for dentate people and from 0.25 ± 0.61 to 2.40 ± 0.88 mm for edentate population). The anterior loop and the accessory mental foramina were detected more frequently with CBCT than panoramic X-ray: only between 0.0 and 48.6% AMFs detected with CBCT were also seen with panoramic images. Clinical Significance. The mental foramen (MF) is an important landmark for local anesthesia and surgical and implantology procedures. Its location, morphology, and anatomical variations need to be considered to avoid mental nerve injury. The aim of this review is to evaluate the mental foramen using CBCT through a systematic literature review to improve knowledge of this complex area for the clinician.

A CBCT aided assessment for the location of mental foramen and the emergence pattern of mental nerve in different dentition status of the Saudi Arabian population

Objective: The anatomy of mental foramen (MF) is a noteworthy landmark during any surgical procedures in the inter-foraminal region. Thus, the study aims at evaluating the location of MF and the emergence pattern of MN in three status of dentition in Saudi Arabian population. Material and Methods: In a prospective study, we have analyzed 240 cone beam computed tomography (CBCT) for the location of MF and the emergence pattern of MN. The study comprising three groups, namely dentulous, partially edentulous and edentulous, each having eighty CBCT scans. We presented the data in percentages. The chisquare and McNemar’s test were used for testing association and pair-wise analysis, respectively. Results: The most common location of MF was below the apex of the second premolar irrespective of dentition status, with 54.2% in right and 60% in the left side of the jaw. Among the dentition status, left side of the mandible has shown significant variation for the location of MF, whereas gender and age showed variation in the right side. Anterior loop (AL) (Type-III) the emergence pattern of MN was the highest in all dentition status, with 51.7% in right and 53.8% on the left side. The variation in the emergence pattern of MN in terms of gender and side of the jaw was statistically significant. Conclusion: In the Saudi Arabian population, the apex of second premolar and type III/AL was the most prevalent location of MF and the emergence pattern of MN, respectively. KEYWORDS Anterior loop; Cone beam CT; Mandible; Mental foramen; Mental nerve.

CBCT INVESTIGATION OF THE INTRABONY CANAL COMMUNICATIONS BETWEEN THE VESTIBULAR AND LINGUAL PLATES IN THE ANTERIOR MANDIBLE

Purpose: To assess the presence of the vestibulo - lingual intrabony canal communications (VLC) in the anterior mandible using cone beam computed tomography (CBCT). Materials and methods: Study material included 200 CBCT scans taken for preoperative planning of implant placement. The images were examined carefully by three observers concerning the presence of VLC. Interobserver agreement in identification of the canal communications was excellent (mean kappa value – 0.82). Results: Vestibulo - lingual communications were found in 27 % of cases. The communications appeared as a crossing of the lateral lingual canal with the mandibular incisive canal (type 1), as a connection between midline lingual canal (or canals) and a vestibular nutrient canal (type 2) or as a lateral lingual canal connected with the anterior loop of the mandibular canal (type 3). The main type of VLC is those between a lateral lingual canal and mandibular incisive canal – 85.2% from all of the VLCs. Conclusions: A considerable part (27%) of Bulgarian citizens has vestibulo - lingual communications in the anterior mandible. The type 1 communication prevails, and it is more frequently located on the right side. The knowledge about vestibulo - lingual communications could contribute a better understanding of bone tumor invasion but further studies are necessary.