Determination of the position of mental foramen and frequency of anterior loop in Saudi population. A retrospective CBCT study

A Comprehensive Analysis of the Radiographic Characteristics and Bilateral Symmetry of the Mental Foramen

OBJECTIVES

There is currently a scarcity of data on the frequency and bilateral symmetry of the position and other characteristics of the mental foramen (MF) and accessory mental foramina in Yemen. The objective of this study was to analyze the position and other characteristics, as well as the symmetry of the MF, in a sample of the Yemeni population.

MATERIALS AND METHODS

A retrospective analysis was conducted on a sample of 500 digital panoramic radiographs (1000 sides). The study examined various characteristics of the MF, including horizontal and vertical positions, shapes, appearances, and the presence of accessory mental foramina. Additionally, the study explored potential associations between these characteristics and variables such as the subject's gender, sides, and symmetry. Data analysis was performed using SPSS, and statistical significance was evaluated using chi-square tests; the p value was set at 0.05.

RESULTS

The horizontal position of the MF was most frequently observed between the first and second lower premolars (63.2%). The vertical position of the MF was predominantly below the apices of the lower premolars (66.2%). The majority of MFs had a round shape (46.3%). In 72% and 75.6% of cases, there was a continuous and descending relationship between the MF and the mandibular canal, respectively. Accessory mental foramina was present in 3.8% of cases. Gender differences were significant for the shape of the MF and the pattern of the canal on the right side. The symmetry rates for various features included horizontal positions (87.4%), vertical positions (82.6%), and shapes (80.4%).

CONCLUSION

The MF is most commonly situated horizontally between the lower premolars and vertically below the apices of these teeth. The majority of MFs showed a round shape and a continuous and descending relationship with the mandibular canal. In most instances, characteristics of the MF were symmetrical on both sides.

Assessing the Prevalence and Length of the Anterior Loop of Inferior Alveolar Nerve and the Position and Dimension of Mental Foramen Using Cone Beam Computed Tomography

Background To prevent harm to the neurovascular bundle during clinical and surgical operations, it is crucial to understand the position and dimension of the mental foramen, as well as the prevalence and length of the anterior loop (AL). Methods An iCAT Vision (CT Dent, London, UK) was used to take a cone beam computed tomography (CBCT) scan. Measurement of height, length of anterior loop, position and width of mental foramen was examined. Results Assessed prevalence of anterior loop and saw difference among genders, which was found to be more among males than females; anterior loop decreased as age advances. Mean anterior loop length of study subjects in different age group on right side was more than the left side, and the most common location of the mental foramen (61.87% in females and 61.36% in males) is located below the apex of the second premolar. The mean value of the distance from inferior border was 9.72mm in females and 10.78mm in males. Conclusion The current study was done with all of these characteristics in mind to assess the effectiveness of CBCT in determining anterior looping of the inferior alveolar nerve (IAN) and the position and dimension of mental foramen. In more than half of the cases analyzed, an anterior loop was discovered.

Unique anomalous in the main mental foramen opening, mandibular canal pathway, and size and shape of genial tubercles: A case report

This clinical report presents a unique and previously unreported case of anatomical variations in the mandible, specifically involving the main mental foramen (MF), the mandibular canal (MC), and genial tubercles (GTs). The case involves a 21-year-old male seeking dental implant rehabilitation. The patient exhibited an unusual lingual exit path of the main left MF through the lingual cortical bone, with the MC following an anterior lingual direction along a lingual groove before exiting through the labial cortical bone between the apexes of the left canine and first premolar. Additionally, the patient displayed excessive enlargement and rare shape of the GTs. These rare anatomical findings presented challenges in dental implant planning. This case report emphasizes the importance of advanced imaging techniques like cone-beam computed tomography (CBCT) in evaluating mandibular structures for precise treatment planning and highlights the significance of understanding anatomical variations to prevent complications in dental procedures.

Evaluation of Visibility of Mandibular Incisive Canal by Using Cone-Beam Computed Tomography: An Observational Study

Context

Performing surgery on the anterior mandible could harm the mandibular incisive canal (MIC). To prevent it, preoperative radiographic assessment is essential.

Aims

Aim of our study was to examine the visibility and presence of the MIC along with measurement of the length of MIC by utilizing cone-beam computed tomography (CBCT).

Settings and Design

Images from 50 subjects, ranging in age from 20 to 60 years, who had their mandibles examined by CBCT were taken from the archive.

Methods and Material

Reconstructed images included cross-sectional and panoramic views. The canal's visibility was obtained from the mesial to the mental foramen and finally to the incisal extension. The shortest distance between the mesial and distal portions of the canal was determined to be the length of the MIC.

Statistical Analysis Used

To analyze independent samples, t-tests were employed.

Results

In 40 cases (80%), the visibility of MIC was seen as bilateral, and in 10 cases (20%), as unilateral. The visible length among the population ranged from a minimum of 0.00 to a maximum of 25.25 mm, with an average of 15.37 ± 5.59.

Conclusions

Future research could utilize the differences in prevalence with respect to gender and visibility as a point of reference.

Exploring Undergraduate Students' Perspectives on Endodontic Treatment: A Cross-Sectional Study in Makkah

Background Students at two universities in Saudi Arabia found endodontics or root canal treatment (RCT) difficult due to challenges in the procedures. Until now, there has been no evidence that Umm Al-Qura University students face difficulties when performing RCT. Therefore, this study aims to explore students' perceptions of the critical steps in RCT. Methods A survey was conducted among 146 dental students at Umm Al-Qura University, Makkah, Saudi Arabia to assess their perceptions and challenges during RCT. Demographic information was collected in the first section, while the second section focused on identifying difficulties encountered during endodontic treatment stages. All participants provided signed electronic consent, and the study was approved by the university's institutional review board. Chi-squared tests were used to analyze the results. Results In a survey of 123 students, 94 (76.2%) found the endodontic specialty acceptable compared to other dental specialties (P < 0.001). Eighty-eight (71.5%) found RCT on the molars difficult (P < 0.001). Most students, 104 (84.6%), chose to have more clinical training to improve their clinical endodontic skills, and 77 (62.6%) chose to increase the number of instructors per student in the clinic (P < 0.05). Difficulties in performing RCT on premolars and during root canal obturation were statistically correlated with the academic year of the student (P < 0.05). Conclusion Dental students often struggle when performing RCT on molars. Some difficulties during RCT are correlated with the academic year of the student. Finally, from the students' perspective, improving endodontic skills involves providing better clinical training opportunities and increasing instructor-to-student ratios.

Associations between the 3D position of the mental foramen with sagittal skeletal relationships (classes I, II, and III) and vertical facial growth patterns (normal, long, and short faces) in different ages and sexes: a retrospective cohort study of 360 CBCTs

BACKGROUND

The 3D position of the mental foramen (MF) is of significant clinical value in dental implantology and mandibular surgeries or in local anesthesia. Despite its importance, it is not clearly known how the position of MF can alter in different individuals, since the literature on the associations between the MF position with vertical growth patterns is non-existent and those on links between the MF position and skeletal malocclusions are scarce. Therefore, we aimed to investigate these, for the first time, on cone-beam computed tomographies (CBCTs).

METHODS

Archival CBCTs of 9 sub-groups (i.e., 3 skeletal Classes I, II, and III × 3 vertical growth patterns 'long face, short face, normal face') were collected by evaluating patients' SNA, SNB, ANB, facial angle, lower facial height, and FMA (n = 9 × 40 = 360). Included cases were older than 17 years and without any history of orthodontic/orthognathic treatments (243 women, 117 men, mean age: 22.28 ± 2.80 years). Perpendicular distances between the MF and 3 fixed bony structures (the mandibular symphysis [S/width], the mandibular ramus [R/length], and the mandibular lower cortex [C/height]) were measured on different sectional planes on both hemimandibles. Left- and right-side measurements were combined. Data were analyzed using the 3-way ANCOVA, Bonferroni, one-way ANOVA, Tamhane, Pearson, and t-test (α = 0.05).

RESULTS

Width was the smallest in Class II and greatest in Class III cases (all P values < 0.000001, Bonferroni). It was the shortest in long faces and longest in short faces (all P values ≤ 0.00008). The inferior-superior height was larger in Class III than both Classes I and II (both P values ≤ 0.003); there was no significant difference between Classes I and II in terms of height (P = 0.684). Height was the largest in long faces and smallest in short faces (all P values < 0.000001). The anterior-posterior length was the largest in Class III and smallest in Class II (all P values < 0.000001). Length was larger in short-face people versus normal- or long-face individuals (P ≤ 0.00003); nevertheless, long and normal faces did not differ in terms of length (P = 0.448). Subjects' age was not correlated with their MF positions (P ≥ 0.579, Pearson coefficient). Sex dimorphism existed only for height (P = 0.009, t-test) but not for length or width.

CONCLUSIONS

The MF position may considerably differ in various horizontal or vertical growth patterns and sexes. This should be noted in mandible surgeries.

Mental Foramen Position, Shape, Continuity, and Symmetry Among Malocclusion Patients: A Radiographic Study

INTRODUCTION

Many dental treatments need exact knowledge of the anatomical location of the mental foramen (MF). This retrospective research uses orthopantomograph (OPG) to assess the MF of orthodontic patients in Saudi Arabia and their position, symmetry, shape, and connectivity.

MATERIALS AND METHOD

One hundred and eighty panoramic radiographs of patients having orthodontic treatment were analyzed for the location, form, symmetry, as well as bilateral preservation of the MF. The patients were of varied ages, genders, and degrees of malocclusion and were divided into three classes: Class I (60), Class II (60), and Class III (60). Chi-squared tests and other descriptive statistics were employed to examine the data for statistical significance.

RESULT

When looking at the right side of the mouth, the most frequent location for MF was position 3 (between the apexes of the first and second premolars; 50.6%), whereas on the left side, it was location 4 (near the apical of the second premolar; 47.2%). The most typical form of MF has an irregular shape. MF location on the left side and continuity types differed significantly across malocclusion groups (p<0.05).

CONCLUSION

 OPGs of Saudi orthodontic patients demonstrated a significant variability of position and continuity of the MF across different classes of malocclusion. The third most frequent position was between the first and second premolars, while the shape of MF showed variation across the age of the patients. Hence, this precise comprehension of the anatomical and morphological diversity of the MF is of utmost significance for dental professionals.

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.

Shape and anatomical relationship of the mental foramen to the mandibular premolars in an Indian sub-population: a retrospective CBCT analysis

Objectives

This study assessed the shape and anatomical relationship of the mental foramen (MF) to mandibular posterior teeth in an Indian sub-population.

Materials and Methods

In total, 475 existing cone-beam computed tomography records exhibiting 950 MFs and including the bilateral presence of mandibular premolars and first molars were assessed. Images were evaluated 3-dimensionally to ascertain the position, shape, and anatomical proximity of MFs to mandibular teeth. The position and shape of MFs were measured and calculated. The Pythagorean theorem was used to calculate the distance between the root apex of the mandibular teeth and the MF.

Results

MFs exhibited a predominantly round shape (left: 67% and right: 65%) followed by oval (left: 30% and right: 31%) in both males and females and in different age groups. The root apices of mandibular second premolars (left: 71% and right: 62%) were closest to the MF, followed by distal to the first premolars and mesial to the second premolars. The mean vertical distance between the MF and the nearest tooth apex calculated on sagittal sections was 2.20 mm on the right side and 2.32 mm on the left side; no significant difference was found according to sex or age. The distance between the apices of the teeth and the MF was ≥ 4 mm (left; 4.09 ± 1.27 mm and right; 4.01 ± 1.15 mm).

Conclusions

These findings highlight the need for clinicians to be aware of the location of the MF in treatment planning and while performing non-surgical and surgical endodontic procedures.

Prevalence and extension of the anterior loop of the mental nerve in different populations and CBCT imaging settings: A systematic review and meta-analysis

Purpose

Materials and Methods

Results

Conclusion

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 implant-related anatomical landmarks in the mandibular interforaminal region in an Iranian population using cone-beam computed tomography

Background:

This study was aimed to assess the implant-related anatomical landmarks in the mandibular interforaminal region in an Iranian population using cone-beam computed tomography (CBCT).

Methods:

In this retrospective cross-sectional study, 378 CBCT images of the mandible were evaluated for the presence of the incisive canal, anterior loop of the inferior alveolar nerve (IAN), mandibular canal, mental foramen, and incisive canal. The effect of age and gender of patients on the abovementioned variables was also evaluated. Data were analyzed using independent t-test, analysis of variance, and Chi-square test.

Results:

The anterior loop and the incisive canal were present in 36.24% and 97.62% of the cases, respectively. The mean length of the anterior loop and the incisive canal was 2.70 ± 1.20 mm and 12 ± 3.29 mm in the right, and 2.86 ± 1.24 mm and 12.21 ± 3.38 mm in the left side, respectively. The mean diameter of the mental foramen and incisive canal was 4.25 ± 1.08 mm and 1.89 ± 0.46 mm in the right, and 4.21 ± 1.02 mm and 1.94 ± 0.45 mm in the left side, respectively. The descending path was the most common path of the incisive canal. The distance from the incisive canal to the buccal plate and inferior border of the mandible was significantly shorter in females (P < 0.001).

Conclusion:

Considering the high variability and clinical significance of the incisive canal and anterior loop of the IAN, and their high prevalence, it is recommended to assess the presence/absence of these structures in the interforaminal region of the mandible on CBCT scans before surgical procedures in this region.

Structural Features of the Mental Foramen in a Saudi Subpopulation: A Retrospective CBCT Study

Introduction

Accurate and precise knowledge about the position, size, and shape of the mental foramen (MF) are critical in avoiding procedural complications. The MF's anatomical features vary among different ethnic groups, and various radiographic techniques have been used to determine these variations.

Aims

To evaluate the MF's shape, vertical and horizontal positions, and distance from the border of the mandible. To evaluate the differences among genders as they pertain to the right and left sides of the mandible and research the bilateral symmetry regarding the same variables.

Materials and Methods

Cone beam computer tomography (CBCT) scans of 155 Saudi patients (69 males and 86 females) who visited the college of dentistry's clinics were obtained from the college database for this retrospective study. All the scans were analyzed by 3 calibrated examiners. The data collected was analyzed statistically, and results were obtained.

Results

The MF was located under the mandibular second premolar in 56.9% of cases, whereas in 26.9% of cases, it was located between the first and second mandibular premolar. The most prevalent position was below the level of the apices of the mandibular premolar teeth (87.2%). The round shape was most frequent (44.9%) compared to the H-oval (34.7%) and V-oval (20.4%). The V-oval shape was more frequent in males, while the H-oval shape was more frequent in females. The average distance from the center of the MF to the mandibular border was 14.03 ± 1.58 mm, with males exhibiting a greater distance than females. Overall, there were no significant differences between the bilateral symmetry and the right and left sides for all parameters.

Conclusion

The most common position of the MF was under the root apex of the mandibular second premolar, with an average distance of about 14 mm from the border of the mandible. The position and shape of the MF were the same bilaterally in the majority of individuals.

Assessment of the anterior and caudal extent of inferior alveolar nerve canal, location of inferior alveolar canal and mental foramen, and the depth of submandibular fossa using computed tomography

Background:

A well-versed knowledge of the precise location of various anatomical landmarks is necessary to avoid complications during surgery. The study was conducted for the assessment of the anterior and caudal extent of the inferior alveolar nerve canal, location of inferior alveolar canal and mental foramen, and the depth of the submandibular fossa using computed tomography (CT).

Materials and Methods:

One hundred CT scans were randomly selected for this study accounting for 200 hemimandibles. Both axial and coronal images were obtained and evaluated concurrently. Results were subjected to statistical analysis for correct inferences.

Results:

A total of 200 hemimandibles (n = 200) from 100 patients with a mean age was 23.89 ± 1.75 years ranging from 21 to 33 years were evaluated. The mean length of the anterior loop was 0.95 mm for all of the observation combined and measurement range from 0 to 5.1 mm. The total frequency of type I, type II, and type III of mental nerve was found as 71%, 4.5%, and 24.5%, respectively. At the level of the first molar, the mean distance from the center of the inferior alveolar canal to the external surface of the buccal cortex (Q) was 5.44 ± 1.38 mm ranging from 2.4 to 10.4 mm. Furthermore, there was no statistically significant difference in MF-IMB (mental foramen to the inferior border of mandible) between the right and left sides of the mandible. (P = 0.87).

Conclusion:

Our study demonstrates that analyzing CT scans using the methods described in this study can be a useful tool in avoiding the iatrogenic injuries to inferior alveolar nerve and arteries during various maxillofacial surgical procedures.

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.

Do the location and dimensions of the mental foramen differ among individuals of different facial types and skeletal classes? A CBCT study

STATEMENT OF PROBLEM

Knowledge about the location and dimensions of the mental foramen is important for surgical planning and implant placement in the posterior mandibular region.

PURPOSE

The purpose of this clinical study was to assess the location and dimensions of the mental foramen in individuals of different facial type, skeletal class, and sex by means of cone beam computed tomography (CBCT) images.

MATERIAL AND METHODS

CBCT images of 142 individuals (72 women and 70 men) were classified according to the facial type (dolichocephalic, mesocephalic, or brachycephalic) and skeletal class (I, II, or III). The vertical and horizontal locations of each mental foramen were evaluated on panoramic reconstructions, and the greatest height and width of the mental foramen were determined on multiplanar reconstructions. Also, the distances from the mental foramen to the alveolar crest and to the inferior cortex of the mandible were obtained. The data were compared by using the Kruskal-Wallis test and multiway analysis of variance (α=.05).

RESULTS

The facial type, skeletal class, and sex did not influence the vertical (P=1.00) or the horizontal (P>.15) location of the mental foramen. The most frequent location of the mental foramen was between the first and second premolars and below their apices. The dimensions of the mental foramen were not influenced by the studied factors in men (P>.07); conversely, the mental foramen dimensions were influenced for women (P<.03).

CONCLUSIONS

The most frequent location of the mental foramen was between the first and second premolars and below their apices. An influence of the facial type and skeletal class was observed on the dimensions of the mental foramen in women.

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.

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.

Cone beam CT-based measurement of the accessory mental foramina in the Chinese Han population

Anatomical data of accessory mental foramina (AMFs) were investigated in a Chinese Han population using cone beam CT (CBCT). A retrospective analysis was performed on 527 selected sets of CBCT images. The average frequency and diameter of AMFs, the diameter of the ipsilateral mental foramen (MF), and the center distance and relative position between the AMFs and MF were measured and calculated by three professional dentists. Among the 527 patients, AMFs were identified in 36 cases (frequency 6.83%), of which 68.75% of AMFs were larger than 1 mm. The mean diameters of the AMFs and the ipsilateral MF were 1.32±0.61 mm and 3.26±0.90 mm, respectively. The average distance from the AMFs to the alveolar ridge crest (ARC) was 15.05±3.50 mm, and the average distance to the mandibular plane was 15.87±3.64 mm. The positions of the AMFs relative to the MF varied widely. The AMFs were mostly positioned distal-inferior to the ipsilateral MF and under the mandibular second premolars. Nutrient foramina around the MFs were distinguished from AMFs. The reference plane for measuring AMFs was suggested to be the mandibular plane to increase the repeatability and accuracy of the experiment. Standard planes were proposed to determine the relative position between AMFs and the MFs. Based on our results, we propose that for implant surgeries, the safety region of 2 mm above the MFs should be reevaluated. CBCT examination is recommended before the operation to identify important anatomical structures around the MF region and their variations and set the safety distance on an individual basis.

A CBCT Based Three-Dimensional Assessment of Mandibular Posterior Region for Evaluating the Possibility of Bypassing the Inferior Alveolar Nerve While Placing Dental Implants

A high rate of nerve injury and related consequences are seen during implant placement in the posterior mandibular arch. An approach has been proposed to avoid nerve injury by dodging the inferior alveolar nerve (IAN) while placing an implant. A prospective study with a total of 240 CBCT (cone beam computed tomography) images of patients with three dentate statuses, namely, edentulous (group I), partially edentulous (group II) and dentate (group III) were included in the study. The nerve path tracing was done on CBCT images with On-demand 3D software. The three dimensions, i.e., the linear distance from the outer buccal cortical plate to the inferior alveolar nerve (BCPN), linear distance from the outer lingual cortical plate to the inferior alveolar nerve (LCPN) and linear distance from the midpoint of the alveolar crest to the inferior alveolar nerve (ACN) were assessed. The data were presented and analyzed between variables using one-way ANOVA and independent t-test in SPSS version 21.LCPN of the right 1st premolar region (p < 0.05) was significantly different among the groups with edentulous subjects recorded with the minimum value (6.50 ± 1.20 mm). Females were found to have significantly (p < 0.05) less available bone (6.03 ± 1.46 mm) on the right side of the mandibular jaw compared to males in edentulous group of patients. On comparing age groups for partially edentulous subjects, LCPN of the right 1st premolar region had significantly (p < 0.05) less available bone (6.03 ± 0.38 mm) in subjects with age ≥54 years. The IAN follows a lingual course in the molar region and later flips to the buccal side in the premolar region. The LCPN dimension in the 1st and 2nd premolar region was found to be more than 6 mm irrespective of age, gender and side of the jaw. Thus, it can be considered as a suitable site for placing implants while bypassing the IAN with CBCT assessment remaining as the mainstay in the pre-surgical phase.

Assessment of prevalence and position of mandibular incisive canal: A cone beam computed tomography study

Objectives

To avoid anatomical and functional damage to mandibular interforaminal region during surgeries, it is necessary to detect the existence of mandibular incisive canal (MIC) and its proximity to adjacent structures. This study was aimed to evaluate the prevalence of MIC and its proximity to adjacent structures among Indian population.

Materials and Methods

The images of 80 subjects with the age range of 20-60 years who had undergone cone beam computed tomography examination of the mandible were retrieved from the archival records. There was equal distribution of males and females.

Results

The prevalence of MIC in the current study sample was found to be 43.89% with a slightly higher prevalence on left side as compared to right side, and higher prevalence among females as compared to males. Among different age groups, there was an increased incidence in the age group of >50 years. The distance of MIC from labial and lingual cortical plates and lower border of mandible were 4.338 ± 1.478 mm, 4.34 ± 1.53 mm and 9.417 ± 1.832 mm respectively.

Conclusions

To conclude, the prevalence of MIC among Indian population was lower as compared to the prevalence among other populations. There were variations in prevalence in terms of age, gender and laterality, which could be used as a reference for further studies conducted on larger sample size. Mapping the incisive nerve canal will enable oral radiologists, to plan safely and negotiate the interforaminal region.

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.

Understanding and addressing waste of food in the Kingdom of Saudi Arabia

INTRODUCTION

Multiple estimates suggest the Kingdom of Saudi Arabia (KSA) may have one of the highest rates of wasted food globally. The KSA has limited arable lands and scarce water and thus relies on extensive imports and food subsidies to meet food demand. Accordingly, waste and loss of food are a significant concern for food security.

MATERIALS AND METHODS

A narrative literature review was performed to identify the available information relevant to characterizing the context, magnitude of food wasted in the KSA, key contributing factors, and existing interventions and recommendations.

RESULTS

Estimates of annual per capita waste of food ranged from 165 kg to 511 kg. Given the country's relatively limited agricultural production, the consumer and retail levels are primary targets for intervention. Key contributors to waste include culture, food valuation, policy and industry factors, and awareness and concern. The country is at an early stage of developing responses. We build upon existing approaches and recommendations, with particular emphasis on the potential role of agricultural extension staff in addressing the issue, and highlight research needs.

CONCLUSIONS

Given the potentially exceptional levels of wasted food in the KSA and the extensive evidence gaps, there is a great need for further research and action. Our review and synthesis presents numerous opportunities to advance innovative waste reduction approaches in the country, with particular relevance for other parts of the Middle East and other areas early in their efforts to address waste of food.

Cone beam computed tomography study on the relation between mental foramen and roots of mandibular teeth, presence of anterior loop and satellite foramina

PURPOSE

To investigate the position of the mental foramen based on its relation with the roots of the mandibular teeth and quantify the prevalence of anterior loop and satellite foramina in the mandible in cone beam computed tomography (CBCT) scans.

METHODS

The sample consisted of 400 CBCT scans of males (n=190) and females (n=210) from Moscow, Russia. Using the system proposed by Tebo and Telford (1950), the position of the mental foramen was classified into: I) mesial to the mandibular first premolar; II) at the apex of the mandibular first premolar; III) between the roots of the mandibular first and second premolars; IV) at the apex of the mandibular second premolar; V) between the roots of the mandibular second premolar and first molar; and VI) at the apex of the roots of the mandibular first molar. Additionally, the images were assessed to investigate the prevalence of the anterior loop of the mandibular canal and the presence of satellite foramina.

RESULTS

Mental foramen position class III was the most prevalent (61%) followed by class IV (27%), II (8%), I, V and VI (together <4%). Statistically significant differences were not detected between males and females (P<0.05). In Russian males and females, the anterior loop of the mandibular canal was found in 15.78% and 3%, respectively; while satellite foramina were found in 31.58% and 19.62%, respectively.

CONCLUSION

The spatial position of the mental foramen and the morphological alterations of the mandibular canal and adjacent foramina must be known prior to surgical interventions in the mandible.

Analysis of mandibular premolar root position in relation to adjacent cortical plates and mental foramen using cone beam computed tomography in the Saudi population

OBJECTIVES

To evaluate the horizontal and vertical location of the mental foramen (MF), as well as the relationship of lower premolars to buccal and lingual cortical plates using cone beam computed tomography (CBCT). Methods: Retrospective cross-sectional study conducted using CBCT scans that were obtained between early 2014 and late 2016 from King Saud University Dental hospital database in Riyadh, Kingdom of Saudi Arabia; 94 patients (53 males and 41 females) were included. Three examiners independently performed one-sided measurements for each patient. Data analyzed statistically and a p less than 0.05 was considered significant. Results: The mean distances from the outer boundary of the buccal cortex to the first and second premolars (R1) were 1.55 mm and 1.98 mm. The mean distances from the outer boundary of the lingual cortical plate to the first and second premolars (R2) were 4.06 mm and 4.73 mm. The respective mean total bone thicknesses, including the roots of the first and second premolars (R3), were 9.32 mm and 10.08 mm. The mean distance between the MF and the mandibular second premolar apex was 3.13 mm. Conclusion: Mandibular premolars are in close proximity to MF especially mandibular second premolar. Presurgical assessment is essential when surgical treatment is planned at this area.

Mandibular Canal Course and the Position of the Mental Foramen by Panoramic X-Ray in Chilean Individuals

The object of this study was to analyse the morphology and morphometry of the mandibular canal (MC) course and the mental foramen (MF) position in relation to the inferior teeth by panoramic X-ray (PAN). Vertical linear measurements were taken of each hemimandible to obtain the length of the distances analysed. We studied the MF position in relation to inferior premolar roots and the relation between the MC and mandibular teeth roots (MCR). The MF was usually located between the apices of the first and second premolars in younger individuals and immediately below the apex of the inferior second premolar in older individuals. The MC evinced proximity to the third molar, and this relation was not affected by sex or age group. The distances analysed in this study presented a marked difference between gender, with larger values in males than in females. The variations which may occur between individuals and different populations make it essential for dentists and surgeons to plan carefully before procedures involving this region.

Assessment of the Mental Foramen Location in a Sample of Fully Dentate Lebanese Adults Using Cone-beam Computed Tomography Technology

OBJECTIVE

The literature reports that the location of mental foramen shows differences among races. The aim of this study was to assess the mental foramen position in a sample of Lebanese population using cone-beam computed tomography (CBCT) technology.

MATERIALS AND METHODS

In this study, we investigated CBCT images of 50 fully dentate Lebanese adults (23 males and 27 females). We assessed the horizontal position of the mental foramen in relation with the mandibular premolars in both right and left sides and the vertical position by measuring the distance from the upper border of the foramen to the inferior border of the body of the mandible. The data obtained were statistically analyzed using Chi-square test, and two-sided t-test. Statistical significance was set at p < 0.05.

RESULTS

In our sample, the mental foramen was mostly found in line with the second mandibular premolar in both sides and the mean distance from the superior border of the foramen to the inferior border of the body of the mandible was 13.0120 ± 0.98487 mm on the right and 13.0728 ± 0.96029 mm on the left.

CONCLUSION

Within the limits of this study, we concluded that in our sample of Lebanese population, there was substantial variability in the mental foramen location.