Evaluating the Anterior Loop of the Mental Nerve Using Cone Beam CT Scans in the Jordanian Population.

INTRODUCTION: Knowledge of anatomical landmarks is crucial for effective dental treatments, especially in surgical procedures. The mental nerve (MN), a branch of the inferior alveolar nerve, features a critical landmark known as the anterior loop (AL), often overlooked by surgeons. This study aims to assess the occurrence of the MN AL, its type, and its length within a sample of the Jordanian population by utilizing cone beam computed tomography (CBCT) scans. METHODS: This retrospective observational study included the acquisition of CBCT images from a total of randomly selected 268 patients who sought treatment for a range of dental conditions (such as tooth extraction, orthodontic therapy, and dental implants) at hospitals affiliated with the Jordanian Royal Medical Services. Reformatted images were utilized to detect the AL type, length, and the association between the nerve type and mental foramen (MF) position. RESULTS: This study involved 268 patients. The distribution of MF positions and the characteristics of the inferior dental nerve were evaluated, with no significant gender differences observed. The predominant location for the MF in both males and females in both sides was position IV, with 52% of females and 56-59% (left-right sides) of males presenting this trait. The inferior dental nerve types also showed no significant gender variation, with 42-43% (left-right sides) of females having type III and a similar distribution among males. Measurements of the midline-mental foramen and inter-foramen distances revealed slight variations between genders, with significant differences noted in the right AL length for type III nerves, favoring males (p=0.034). A notable correlation was found between the type of inferior dental nerve and the MF position, particularly with type I nerves predominantly associating with position IV mental foramina (p≤0.004). CONCLUSION: CBCT scans are essential in the precise evaluation of the AL, aiding in the prevention of nerve injuries during dental procedures. Our results highlight the diversity of the AL in the Jordanian population and the importance of individualized treatment plans. Future research with larger cohorts is advised to refine these insights, aiming to improve treatment outcomes and patient care.

Injury Risk Estimation in Mandible-Related Surgical Procedures: A CBCT Study Based on Vital Interforaminal Anatomical Structures.

The mandibular interforaminal region has been considered safe for surgical procedures; nevertheless, the risk of injury to neurovascular structures, such as the mental foramen (MF) and its related structures (anterior loop [AL] and lingual foramina [LF]) should not be overlooked. The study aimed to evaluate the relative risk of injury to these structures during surgical procedures in the anterior region of the mandible based on cone-beam computed tomography (CBCT) scans. A retrospective cross-sectional and observational study was performed on 250 CBCTs from adults (18-69 years) with dentate jaws. Linear measurements of the MF, AL, and LF were evaluated to estimate the risk of injury to these structures during chin-related surgical procedures. The most frequent distance between the base of the mandible (BM) and MF was 8 mm (30.2%). In addition, 20.4% of the CTs had 6 mm from the vestibular cortical bone to the LF. The commonly found measurement from LF to the apex of the nearest tooth was 7 mm (24.0%); 64.2% of the CTs showed a 2-mm distance between the most distal point of the dental implant site to the most anterior point of the AL. Safety distances for genioplasty techniques (MF to mandible base > 6 mm, 96.6% [CI 95%, 95.0%-98.2%]) were observed. Considering the 5-mm cut-off point between the lower limit of a hypothetical bone graft and the chin, 65.4% (CI 95%, 58.9%-71.9%) of CTs were within this distance. Regarding the safety margin of 8 mm, 85.6% (CI 95%, 80.8%-90.4%) were up to this value. This study found safety margins for genioplasty and chin bone grafting surgical techniques that adopt a 5-mm cut-off point. Further similar studies assessing other surgical methods and employing larger samples from different geographical origins may contribute to this field of investigation.

Prevalence, length, and patterns of Anterior Loop among the South Indian population: A comparative study between Panoramic Radiography and Cone Beam Computed Tomography.

Purpose: To assess the prevalence, length, and patterns of the anterior loop of the inferior alveolar nerve by panoramic radiography and cone beam computed tomography (CBCT). Materials and Methodology: A prospective study was conducted on 300 mental foramen regions by exposing them to panoramic radiography and CBCT scan. Two individual observers evaluated the images to assess the presence of an anterior loop, the mean length of the loop, and the most frequent pattern of the loop in our population. Result Analysis: The prevalence of the anterior loop for male patients and female patients by panoramic radiography was 34% and 32% on the right side and 30% and 36% on left side, respectively. By CBCT, the corresponding values were 69% and 72% on the right and left side, respectively, for male patients, and 73% and 81% on the right and left side, for female patients, respectively. Conclusion: The results from our study strongly emphasize the need for CBCT imaging before planning for procedures in the mental foramen region because the prevalence, length, and pattern of loop significantly varies with respect to age, sex, and population.

Prevalence of Anterior Loop and other Patterns of Mental Nerve in a Sample Population of an Indian City: A Retrospective Study.

Introduction: The final portion of the inferior alveolar nerve (IAN), the mental nerve (MN), is a general somatic afferent nerve that provides sensation to the lip, chin, and gingival tissue. Three patterns of MN have been observed - straight, perpendicular or vertical, and anterior loop (AL) of MN. The interforaminal region of the mandible possesses a MN with a path that creates an AL before entering the mental foramina. The aim of the study is to evaluate the presence of AL of MN using cone-beam computed tomography (CBCT) and to measure the length of the AL of MN, if present, also to evaluate the prevalence of other anatomical patterns of MN - straight and vertical patterns. Materials and Methods: Mandible CBCT of 400 patients with the age of 20 years onward was included in the study. The images obtained were assessed for the different patterns of MN - straight, vertical, and ALs. The statistical analysis was done using the Chi-square test, paired t-test, and sample t-test. Results: Out of 400 CBCT scans comprising 800 hemimandibles, straight pattern was observed in 67.1%, vertical pattern in 26%, and Anterior Loop in 6.9%. The prevalence of AL pattern was 6.9%. AL length was found to be in a range of 2.4-6.6 mm. Discussion: Surgical trauma or injury to the AL of MN is possible during implant surgery in the interforaminal area of the mandible if AL is not assessed preoperatively.

Assessment of the prevalence and length of the anterior and caudal loops of the mental nerve as anatomical variants of exiting the mandible at the mental foramen using cone-beam computed tomography: a systematic review and meta-analysis.

OBJECTIVES: This systematic review aimed to identify the studies that performed cone-beam computed tomography analysis of the prevalence and length of the anterior loop (AL) and caudal loop (CL) of the mental nerve. MATERIALS AND METHODS: An electronic database search was performed across PubMed, EMBASE, Web of Science, Scopus, the Cochrane library, and Google Scholar. Original studies reporting the frequency and length of the AL and CL were selected. Qualitative synthesis and meta-analysis were then conducted to assess the prevalence and length of the AL and CL and their associations with age, gender, sides, and dentition status. RESULTS: A total of 21 studies were included in this review. The pooled prevalence of the AL (95% confidence interval) of the mental nerve at the patient and side level was 51% (31-71%) and 53% (37-69%) while the mean anterior loop length was 2.08 (1.46-2.70) mm. The pooled prevalence of the CL and mean caudal loop length were 100% and 4.73 (3.44-6.01) mm. No significant associations were found between the prevalence and length of the AL and CL and age, gender, sides, and dentition status. CONCLUSIONS: Overall, the pooled prevalence and mean length of AL of the mental nerve varied among different populations while CL seems to be a constant anatomical landmark with a longer CL than AL. CLINICAL RELEVANCE: Surgeons performing inter-foraminal oral surgeries like dental implant placement and genioplasty should be aware of the possible distance of the AL and CL to avoid iatrogenic mental nerve injury.

Radiographic analysis of the anterior mandible and its anatomical variations using cone-beam computed tomography.

OBJECTIVE: The anterior loop, the mandibular incisive canal, and the lingual symphyseal foramen are important structures in the anterior mandible. The purpose of this study was to assess the prevalence of these structures using CBCT. METHOD AND MATERIALS: A total of 170 projections were analyzed in different sectional planes. The study analyzed the prevalence and extension of the anterior loop and the prevalence of both the mandibular incisive canal and the lingual symphyseal foramen by using the GALAXIS software by Sirona. RESULTS: In 98.2 % (n = 167) a lingual symphyseal foramen was detected. An anterior loop was present in 31.2% (n = 53) with statistically significant higher detection rate in younger patients (P = .001). The median length was 1.26 mm (range 0.53-3.70 mm). No statistically significant differences regarding patient side or sex were found in either case. In 72.4% (n = 123) a mandibular incisive canal was detected. There was a statistically significant dependence of the mandibular incisive canal on patient sex (P = .007): female patients had a mandibular incisive canal significantly more often than male patients. Among male patients a significant difference of the mandibular incisive canal regarding the mandibular side (P = .031) was found; it was significantly less frequent on the right than on the left side. CONCLUSION: Anterior loop, mandibular incisive canal, and lingual symphyseal foramen are often present. Furthermore, the anatomical, neurovascular variability in the interforaminal area of the mandible emphasizes the importance of 3D imaging like CBCT in preoperative assessment, and confirms that a general safe zone should not solely be relied upon when performing surgery in this region.

Prevalence, Patterns and Variations of Anterior Loop of Inferior Alveolar Nerve-A CBCT Based Retrospective Study.

The fragment of inferior alveolar nerve (IAN) existing anterior to the mental foramen (MF), before dividing the canal, is known as the "Anterior Loop of the IAN". The presence of anterior loop (AL) is important when placing the implant in inter foraminal area of the mandible or during any other surgical procedure. It is imperative to precisely determine the position and dimensions of these anatomical variations on a cone-beam CT (CBCT) scan. To estimate the prevalence and pattern of anterior loop of IAN and establish any corelation between dimension of the MF with length and angulation of the AL of the IAN. Total 178 CBCT samples were collected fulfilling the inclusion criteria from a private diagnostic centre in Bhubaneswar, Odisha. The greatest diameter of the mental foramen was measured along with anterior loop length and angulation in the panoramic section of the CBCT scan. The angulation formed and the length was corelated with the greatest diameter of the mental foramen and analysed. Our study reveals that the AL was more frequently seen among males, predominantly on the left side of the mandible. The relationship between length of the anterior loop and diameter of the mental foramen demonstrated a mild negative corelation. There was no possible corelation present between angle formed by anterior loop with inferior alveolar canal and diameter of mental foramen. A small positive corelation was established between length of anterior loop and angle formed by the anterior loop with inferior alveolar canal. CBCT scans should be recommended for pre-surgical evaluation of anatomical variations in the mandibular region. Also, a safe margin of 3-4 mm anterior to mental foramen should be maintained while working in the premolar area. Supplementary Information: The online version contains supplementary material available at 10.1007/s12070-021-02691-w.

Mental Foramen and Anterior Loop Anatomic Characteristics: A Systematic Review and Meta-analysis of Cross-sectional Imaging Studies.

INTRODUCTION: The present study aimed to review the epidemiologic, topographic, and morphometric aspects of the mental foramen (MF) and anterior loop (AL) on cone-beam computed tomographic imaging studies. METHODS: An International Prospective Register of Systematic Reviews (PROSPERO)-registered systematic review (CRD42018112991) was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Two reviewers independently performed data extraction from observational studies that evaluated MF and AL on 7 electronic databases. MedCalc (MedCalc Software bv, Ostend, Belgium) software was used to perform a meta-analysis with a 95% confidence level. RESULTS: Of 1545 articles, 66 met the inclusion criteria, totaling 14,233 patients from 5 continents, with a total of 6655 females and 5884 males (some studies did not report sex), with an age range between 8 and 89 years. The most prevalent shapes of MF were oval (48.72%) and circular (44.36%), and the most frequent horizontal positions were between premolars (43.66%) and in line with the long axis of the second premolar (43.12%). CONCLUSIONS: Based on the articles that assessed AL, the mean prevalence was 43.18%, with most studies reporting bilateral localization as the most prevalent.

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.

Anterior loop of the mental nerve in Saudi sample in Riyadh, KSA. A cone beam computerized tomography study.

BACKGROUND: The portion of inferior alveolar nerve (IAN) existent anterior to the mental foramen, before parting the canal, is referred to as the anterior loop (AL) of the IAN. The presence of AL is important when placing the implant interforaminal area of the mandible. These anatomical discrepancies can be assessed by cone-beam CT (CBCT), for evaluating its position and exact location. The AL is classified into Types I, II and III. In Type I, Y-shaped anatomy; in Type II, anatomy is T-shaped; and in Type III, Y-shaped anatomy is seen, and the incisive branch is thicker as compared to the main branch. AIM: In this study, we aim to analyse the prevalence of different types of AL of the IAN in Saudi sample population. MATERIALS AND METHODS: The present study is a retrospective analysis of 149 (86 female & 63 male) CBCT images of patients records from 2018 June to 2018 September in the department of implant dentistry, KSMC, Riyadh. The age range of the patients who participated in the study was 30-60 years. The mean age of female participants is 42.5 ± 5.8, for the male participants is 48.6 ± 11.4 years respectively. RESULTS: The most frequent type of AL of mental nerve noticed on the right side was of type I (59.1%), followed by type II (27.5%) and type III (13.4%). The most frequent type of AL of mental nerve noticed on the left side was type I (61.7%), followed by type II (26.8%) and type III (11.4%). CONCLUSION: The results of the study encourage the usage of CBCT for planning implant treatment. We also suggest that it is obligatory for professionals to categorise the presence of AL and to measure them appropriately when planning for the procedures in the interforaminal region.

Identification of anterior loop in different populations to avoid nerve injury during surgical procedures-a systematic review and meta-analysis.

Exact recognition of the anterior loop is very important to avert any injury to the neurovascular bundle during surgical procedures. The purpose of this review was to evaluate the prevalence and length of the anterior loop in different populations. A comprehensive search of Medline/Pubmed and Cochrane database was done. The focused question was the presence of anterior loop (including loop length) of the inferior alveolar nerve in mental foramen region in CBCT images of the various subjects. Articles related to the presence of anterior loop (including loop length) were only included. Initial literature search resulted in 3024 papers, after removing duplicate articles, 2821 articles were left. Two thousand seven hundred eighty-four articles were further excluded by the reviewers after screening the abstracts which resulted in 37 studies. Hand searching resulted in 2 additional papers. Seven full-text articles were excluded for not fulfilling the inclusion criteria. Finally, 32 articles were included in the review. Two thousand five hundred three subjects with anterior loop were found, which approximates 38% with 48.4% bilateral, 27.8% right side, and 23.8% left side. The loop distribution in males and females was also found to be different. There was highly significant (P < 0.001; I2 = 98.81%) heterogeneity found in the included studies. Variations were found in the prevalence, length, gender, and side distribution of anterior loop in various populations. This systematic review highly recommends not relying on any average values and the clinician should compulsorily make use of imaging modalities available in each and every case, wherever surgical procedure is to be performed near mental foramen region.

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 / Avaliação auxiliada por CBCT para a localização do forame mentual e o padrão de emergência do nervo mentual em diferentes estados de dentição da população da Arábia Saudita

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 chi-square 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 (AU)

Introdução: Objetivo: A anatomia do forame mentual (FM) é de grande importância durante qualquer procedimento cirúrgico na região inter-foraminal. Por tanto, como objetivo o estudo visa avaliar a localização do FM e o padrão de emergência do NM em três estados de dentição na população da Arábia Saudita. Material e Métodos: Em um estudo prospectivo, analisamos 240 tomografias computadorizadas de feixe cônico (TCFC) para a localização do FM e o padrão de emergência de NM. O estudo compreendeu três grupos, a saber, dentados, parcialmente edêntulos e edêntulos, cada um com oitenta imagens de TCFC. Apresentamos os dados em porcentagens. O teste do Qui-quadrado e o teste de McNemar foram usados para testar associação e análise de pares, respectivamente. Resultados: A localização mais comum do FM foi abaixo do ápice do segundo pré-molar independente do estado da dentição, com 54,2% no lado direito e 60% no lado esquerdo da mandíbula. Dentre as condições da dentição, o lado esquerdo da mandíbula apresentou variação significativa para a localização dos FM, enquanto o sexo e a idade mostraram variação no lado direito. O padrão de emergência (Tipo III) da alça anterior (AL) do NM foi o mais alto em todos os estados de dentição, com 51,7% no lado direito e 53,8% no lado esquerdo. A variação no padrão de emergência de NM em termos de gênero e lado da mandíbula foi estatisticamente significativa. Conclusão: Na população da Arábia Saudita, o ápice do segundo pré-molar e tipo III / AL foi a localização mais prevalente de FM e o padrão de emergência de NM, respectivamente. (AU)

Evaluation of the Dimensions of Anterior Loop of Mental Nerve in CBCT: A Radiographic Analysis.

BACKGROUND: Information on the dimensions of the anterior loop of mental nerve is important for dental implant placement. AIMS: The purpose of this study was to determine the total length of anterior loop of mental nerve from the mental foramen. MATERIALS AND METHODS: CBCT data of 150 patients were evaluated. RESULTS: We found that the anterior loop was absent in 56.4% of patients on the left side and 61.7% patients on the right side. 19.5% of the total patients (29 patients) had up to 4 mm length of the loop which was exactly same on both right and left sides. The remaining 16.8% on the left side (25 patients) and 14.1% on the right side (21 patients) had the length of the loop ranging between 4.1 and 8 mm. The rest 7.4% of patients on the left side and 4.7% patients on the right side had more than 8 mm of the loop length. CONCLUSIONS: Based on this study, the dimensions of the anterior loop are variable and hold great significance in dental implant planning in the mandibular premolar region.

Características anatómicas del asa mandibular evaluada por tomografía computarizada de haz cónico / Anatomical characteristics of the mandibular loop evaluated by cone beam computed tomography

Introducción: El nervio dentario inferior es una estructura anatómica de la mandíbula, la cual presenta variaciones como el asa mandibular, ambas estructuras están relacionadas con iatrogenias con tratamientos como cirugías orales, regeneraciones óseas e implantes. El objetivo del presente estudio es evaluar las características del asa mandibular y el agujero mentoniano utilizando tomografía axial computarizada de haz cónico (CBCT) en pacientes del Postgrado de Periodoncia de la Universidad Autónoma de Nuevo León. Material y métodos: Se analizaron un total de 110 CBCT, de los cuales 61 entraron al estudio cumpliendo con los criterios de inclusión, se realizaron cortes transversales utilizando el software On Demand® para identifi car y medir el asa mandibular y localizar la posición del agujero mentoniano de ambos lados separando los grupos por género. Resultados: La prevalencia del asa mandibular fue de 32.8% de 61 CBCT que se analizaron, se observó más comúnmente en hombres y de manera bilateral, y cuando fue unilateral sólo se encontró en el lado derecho, la longitud promedio fue de 6 ± 1 mm. El agujero mentoniano se detectó en mayor porcentaje apical al segundo premolar inferior con un diámetro promedio de 3.5 ± 0.5 mm, alejándose de la raíz del diente adyacente en un promedio de 6 ± 1 mm y del borde de la mandíbula 12.5 mm ± 0.5 mm. Conclusión: Es de suma importancia identifi car las características anatómicas del asa mandibular y localizar la posición del agujero mentoniano durante la planifi cación del tratamiento para evitar complicaciones durante y después del acto quirúrgico (AU)

Introduction: The inferior dental nerve is an anatomical structure of the mandible which presents variations such as the anterior loop, both structures are related to iatrogenies with treatments such as oral surgeries, bone regenerations and implants. The aim of the present study is to evaluate the characteristics of the anterior loop and the mental foramen using cone beam computed tomography (CBCT) in patients of the Graduate Periodontics Program, School of Dentistry, Universidad Autónoma de Nuevo León. Material and methods: 110 CBCT were analyzed of which 61 entered the study fulfi lling the inclusion criteria, cross sections were made using the On Demand® software to identify and measure the anterior loop and locate the position of the mental foramen both sides separating our groups by gender. Results: The prevalence of the anterior loop was 32.8% of 61 CBCT that were analyzed, it was found more commonly in men and bilaterally, and when it was unilateral only found on the right side, the average length was 6 ± 1 mm. The mental hole was found in greater percentage apical to the second lower premolar with an average diameter of 3.5 ± 0.5 mm, moving away from the root of the adjacent tooth by an average of 6 ± 1 mm and from the edge of the mandible 12.5 ± 0.5 mm. Conclusion: It is very important to locate these anatomical structures during treatment planning and avoid complications during and after the surgical act (AU)

Cone-Beam Computed Tomography Analysis of the Prevalence, Length, and Passage of the Anterior Loop of the Mandibular Canal.

When placing implants in the anterior mandible, it is important to avoid damaging the mandibular nerve and its terminal extensions. The objective of this study was to determine the prevalence, length, and passage of the anterior loop of the mandibular canal, as well as the quantity of alveolar bone that is coronal to the canal, to help with implant placement in the anterior mandible. Cone-beam computerized tomography (CBCT) scans of 124 patients with 248 hemi-sections were evaluated. Anterior loop prevalence was determined using reconstructed panoramic and cross-sectional views; length was measured as the distance between the most mesial aspect of the mental foramen to the most mesial aspect of the anterior loop on cross-sectional views. The bucco-lingual position of the anterior loop inside the mandible and the apico-coronal dimensions of the alveolar bone above it were measured on cross-sectional views to determine the passage of the anterior loop and the bone available coronally, respectively. The effects of sex, age, side, and dentate status on the prevalence and length of the anterior loop were analyzed statistically. Prevalence of the anterior loop at the patient and hemi-section levels was 25% and 24%, respectively, and its median length was 1.63 mm (range, 0.52-3.92 mm). The anterior loop was apical to the mental foramen and mostly located within the buccal or middle one-third of the alveolar ridge, with an average height of coronal alveolar bone of 17.12 mm. Sex, age, side, and dentate status did not affect anterior loop prevalence and length. In conclusion, because of great variation, a case-by-case CBCT evaluation of the anterior loop is necessary before placing implants in the anterior mandible.

Location of the Mandibular Incisive Canal Related to the Placement of Dental Implants: A Case Report.

Cone-beam computerized tomography (CBCT) can show an uncommon mandibular incisive canal that cannot be detected by panoramic radiography, which is used preoperatively to form the initial plan of the size and length of an implant fixture for surgical placement in the mandibular interforaminal area. Determination of the position and anatomical configuration of the mandibular incisive canal is challenging. The purpose of this case report is to discuss anatomical variations in the mandibular incisive canal and the mental canal by reviewing previous studies. Furthermore, we propose that the anterior loop length of the mental canal near the mental foramen, as well as the diameter of the mandibular incisive canal, should be verified by CBCT prior to performing implant surgery in the anterior mandibular area to prevent possible nerve damage.

Assessment of the Anterior Loop of the Mandibular Canal Using Cone-Beam Computed Tomography in Eastern India: A Record-Based Study.

OBJECTIVE: The aim of this study was to assess the presence and course of the anterior loop (AL) in an Odisha sample population using cone-beam computed tomography (CBCT) and to accurately identify and analyze the length, height, and diameter of AL in male and females. MATERIALS AND METHODS: CBCT images from 1000 patients obtained for various clinical indications were randomly selected and evaluated to determine the presence, length, height, and diameter of the AL. The various parameters were then compared based on gender, age, and the side of the mandible. The data were analyzed using the Chi-square test, independent t-test, multiple post hoc procedure, and one-way ANOVA test. RESULTS: An AL was identified in 9.7% of the cases, and its mean length ranged from 1.8 to 4.8 mm. The loop had a greater mean length and was significantly more prevalent in males. The diameter ranged from 1 to 4 mm and height ranged from 7.8 to 15.1 mm. The AL was most commonly found in the middle-aged patients (39-48 years) which attributed to around 27.83%. CONCLUSION: In this study, a lower prevalence of the AL of the mandibular canal was found. Being an anatomical variation, an exact evaluation of the AL must be established using the imaging techniques prior to any surgical procedure.

Cone-beam CT assessment of implant-related anatomy landmarks of the anterior mandible in a Chinese population.

PURPOSE: To investigate the prevalence, location, and morphology of the mandibular lingual foramen (MLF), mandibular incisive canal (MIC), and anterior loop of the inferior alveolar canal (ALC) in a Chinese population using cone-beam CT (CBCT). MATERIALS AND METHODS: From 2014 to 2016, CBCT images from patients with various scanning purposes were obtained from the database of the Affiliated Stomatology Hospital of Kunming Medical University, China. Imaging analyses of the MLF, MIC, and ALC were performed via the NNT viewer software. The prevalence, location, length, classification of MLF, and its distances to the alveolar crest and the lower border of mandible were investigated, and the prevalence and length of MIC and the prevalence of ALC were also studied. RESULTS: This study examined 1008 subjects, 521 (51.7%) males, and 487 (48.3%) females. 916 (90.9%) subjects showed the medial lingual foramina (LF), a single medial LF with the supraspinous-type predominating. Lateral LF were observed in 547 (54.3%) subjects mostly located in the premolar areas. 876 (86.9%) subjects had the MIC on the left side, whereas 877 (87.0%) had the MIC on the right side. The ALC was present in 147 (14.6%) subjects. CONCLUSIONS: This study showed a high prevalence of LF and MIC in the Southwest Chinese population. Therefore, caution should be taken during the implant treatment at the anterior mandible region.

Momentousness of the Mental Loop: A Comparative Study.

BACKGROUND AND PURPOSE: To assess the anterior (aAL) and caudal (cAL) extensions of Anterior loop (AL) of Inferior alveolar nerve (IAN) using Digital Panoramic (DP) and Cone Beam Computed Tomography (CBCT) for its presence and dimensions in various age groups, genders, right and left sides of the mandible and between dentulous and edentulous patients. METHODS: A 1-year retrospective comparative study between DP and CBCT to assess the extensions of AL of IAN was conducted on individuals referred to a private imaging center located in Bengaluru, South India. 360 mandibular sites were examined using DP and CBCT to assess the presence and dimensions of AL. RESULTS: Results showed higher frequency of AL in CBCT compared to DP. Also there was a decreasing frequency of AL with increasing age and an insignificant difference in frequency between males and females. Bilateral looping was most common, aAL was more frequent on the left side and cAL on the right of the mandible. Statistically higher frequency in dentate group compared to edentulous. A decreasing mean value with increasing age and higher mean values in CBCT than DP. No significant difference in mean values among males and females or between the dentulous and edentulous groups. Higher mean values in CBCT compared to DP on the left side of the mandible compared to the right. CONCLUSION: Choosing mental foramen as reference for termination of IAN could result in injury to AL; low sensitivity and specificity of DP compared to CBCT in assessing frequency and extent of AL underlines its inadequacy, while CBCT can be performed with comparable resolution, to accurately analyze AL.

Radiographic Evaluation of Anterior Loop of Inferior Alveolar Nerve: A Cone-Beam Computer Tomography Study.

BACKGROUND: A well awareness of the variation of inferior alveolar canal is mandatory to avoid iatrogenic complication. This study was conducted among 90 patients to determine variation in inferior alveolar nerve (IAN) loop through cone-beam computed tomography (CBCT) images. MATERIALS AND METHODS: CBCT images of 90 patients were involved in this study. All images were studied by the expert radiologist to see Type I, Type II, and Type III pattern of IAN canal (IANC). Results were subjected to statistical analysis for correct inferences. RESULTS: Forty males and 50 females were included in the study. The difference was statistically nonsignificant (P = 0.5). Type I pattern was seen in 26 patients, Type II in 19, and Type III in 45 patients. The difference was statistically significant (P < 0.05). The most prevalent pattern was Type III (males - 15 and females - 30), followed by Type I (males - 14 and females - 12) and Type II (males - 11 and females - 8). There was statistical significance difference between males and females in Type II (P < 0.05). CONCLUSION: The anterior loop of IAC is quite common and IANC may show variation in structure. The most common pattern recorded was Type III. CBCT is very useful in the detection of IANC.