Mental foramen and apical foramen: A dangerous anatomical proximity

The study evaluated the spatial position of the mental foramen (MF) using 300 cone-beam computed tomography. The spatial position was analyzed with the horizontal location and relative location (distance between apical foramen and MF). The horizontal location was assessed through three positions (positions 1, 2, and 3). The relative location was determined with the x, y, and x coordinates of the root apex of mandibular premolars and the MF. Student's t-test and chi-square were performed. The most common horizontal location (52%) was position 2, which means between the premolars (p < 0.05). The relative location of the MF to the root apex of the second premolar was closer than the first premolar (p < 0.05). The distance between the root tip of the second premolar and the MF was 5.27 mm, with a minimum value of 1.87 mm. Clinicians should be aware of the possible neural results to the mental nerve of an endodontic infection and the extrusion of irrigation solutions.

Anatomical variant of anteriorly extending mental foramen: A case report

Key Clinical Message

By sharing this case, we aim to enhance the understanding of the mental foramen's intricate morphology, ultimately promoting safer and more successful surgical practices in the field of oral and maxillofacial surgery.

Abstract

In surgical procedures near the mental foramen, preserving this vital structure and its contents is crucial. Surgical treatments, including procedures like implants, orthognathic surgery, and tooth extractions, can potentially lead to injuries of the mental nerve, resulting in sensory disturbances such as numbness or tingling in the lower lip and chin. This case report highlights an uncommon anterior extension of the mental foramen, posing a risk to the patient if unnoticed. Variations in this structure are possible, emphasizing the need for comprehensive three-dimensional radiographic analysis before surgery to ensure patient safety. This report sheds light on the significance of identifying and understanding such variations to enhance the safety and precision of oral and maxillofacial interventions.

Three-dimensional analysis of mandibular and mental canals corroborating with teeth and mental foramen by cone beam computed tomography

BACKGROUND

This study aimed to analyse the 3D patterns of the mandibular and mental canals (MDC and MC) referring to the surrounding prominent surgical landmarks such as teeth and mental foramen by cone beam computed tomography (CBCT).

METHODS

CBCT scans of 354 patients aged 18-67 years with mandibular first premolar to second molar were included and reconstructed 3-dimensionally (3D) by mimics. The parameters of MDC and MC were measured referring to teeth and mental foramen.

RESULTS

From the first premolars to the second molars, the mandibular canals showed a trend of gradually closer to the cementoenamel junction (CEJ) of the adjacent teeth and farther away from the buccal cortical plate. The distance of the MDC with the root apexes (RA) was relatively constant from the first premolar to the first molar, but became much closer to the second molar. About 10.8% of the second molars had MDC-RA distances of shorter than 2 mm, and 1.34% even had the MDC superior to the RA. Moreover, the Type III of MC presented in 66.0% of the subjects and had a relatively longer length. Besides, the existence of Type I MC may be related to the MDC featuring with close distances to the RA and CEJ of the adjacent teeth.

CONCLUSION

Dentists and surgeons should know the patterns of mandibular and mental canals. A better understanding of the MDC and MC and their relationship to local anatomical landmarks may facilitate the planning of surgeries and alert potential nerve injuries in the operative procedures.

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.

Evaluation of Position of Mental Foramen in Dentulous Population by Digital Panoramic Radiography

Need for the Study

The mental branch of the trigeminal nerve, which supplies sensation to the lower lip, originates in the mandibular canal, making it an essential anatomical structure for dentists and oral surgeons to access. It is not well known that there is a spectrum of normal that includes variants in which there may be more than one nerve entry site, which means that if the mental foramen is not protected, normal feeling in the lower lip may be lost permanently. The diagnostic value of global radiographic landmarks like the mandibular trench and the dental foramen in identifying skeletal problems has been investigated.

Materials and Methods

Four hundred patients over 40 who fit the inclusion/exclusion criteria were chosen. Patients were recruited from Vananchal Dental College and Hospital, Garhwa's Out Patient section for Oral Medicine, Diagnosis, and Radiology. The following patients with their consent are subjected for digital orthopantomography (Cephalometric Device for Rotograph EVOD Ref 930790001, SN 14112930, Villa Sistem Medical) and the captured images are then interpreted for the variations in mandibular canal.

Result

The results of our study are as follows: In this study, the mean age of the subjects was 47.27 years, with a range of 40-75 yearsMajority of cases were females (53.75%) and 46.25% were males.The top of the residual ridge, located between the mental foramen and the mandibular canal, is clearly visible to all observers (grade I).Only 1.75% of the people surveyed had a bifid canal, despite the fact that the majority of the people surveyed had a single mandibular canal on both sides (98.25%).Right side mean was 18,682.017, whereas left side mean was 16,331.851; nevertheless, this difference was not statistically significant (P = 0.0860 NS).

Conclusion

The dental foramen was located close to where the mandible and the area housing the next premolar met. These findings may be utilized to improve the safety of peri-apical surgical procedures. Therefore, it is therapeutically relevant to get insight into the structural alterations of the mental foramen and locate its location in preoperative radiological scans.

Topography of the mandibular canal in male human skulls originating from different time periods

BACKGROUND

Dynamic advances in dentistry, especially in implantology has inspired researchers to carry out many studies investigating the topography of the mandibular canal and its ethnic differences. The aim of the study was a comparative analysis of variations in the position and topography of the mandibular canal based on radiographic images of human mandibles originating from modern and medieval skulls.

MATERIALS AND METHODS

Morphometric examination of 126 radiographs of skulls (92 modern and 34 medieval skulls) was included. The age and sex of individuals were determined based on the morphology of the skull, the obliteration of cranial sutures, and the degree of tooth wear. To define the topography of the mandibular canal on X-ray images, we took 8 anthropometric measurements.

RESULTS

We observed significant differences in several parameters. The distance between the base of the mandible and the bottom of the mandibular canal, the distance between the top of the mandibular canal and the crest of the alveolar arch, and the height of the mandibular body. Significant asymmetry was found for two parameters of mandibles from modern skulls: the distance between the top of the mandibular canal and the crest of the alveolar arch at the level of the second molar (p < 0.05), and the distance between the mandibular foramen and the margin of the anterior mandibular ramus (p < 0.007). There were no significant differences between measurements taken on the right and left sides of the medieval skulls.

CONCLUSIONS

Our study revealed differences in the position of the mandibular canal between modern and medieval skulls, confirming the presence of geographical and chronological differences between populations. Knowledge of variability in the position of the mandibular canal between different local populations is fundamental for the correct interpretation of findings from diagnostic radiological studies used in dental practice and in forensic odontology or analysis of archaeological bone materials.

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.

Trifurcated Mental Foramina: A Cone-Beam Computed Tomography Incidental Finding During the Implant Treatment Planning

The mental foramen is a known skull anatomical structure located bilaterally on the mandible along the buccal cortical plate. It is located approximately between the roots of premolars in the anteroposterior dimension, and its supero-inferior level on the alveolar height varies in every individual. The position of the mental foramen is very crucial when surgical interventions are planned in the area. An accessory mental foramina can be very well detected in the three-dimensional (3D) imaging modality, especially in 3D volume rendering images. It can still be appreciated in two-dimensional (2D) imaging modalities such as a panoramic; however, at times it can be confused with periapical pathology, especially in cases where caries are present in the teeth. Three-dimensional imaging modality plays a critical role in identifying such anatomical variation, and hence, it is important to evaluate any surgical site in three dimensions prior to surgical intervention.

Assessment of anterior loop of mandibular canal and its implication in implant therapy

Context:

Precise identification of anatomic structures is imperative for presurgical planning for implant installation to ensure effectiveness of procedures, especially in the region of mental foramen, and to prevent iatrogenic complications.

Aims:

This study aimed to assess the presence of anterior loop of mandibular canal and its approximation to the alveolar crest using cone-beam computed tomography (CBCT).

Materials and Methods:

CBCT scans of the patients scheduled for implant therapy in the region of mental foramen were retrospectively analyzed for the presence of anterior loop of mandibular canal. Findings were compared based upon gender and side of the mandible. Distance between the most prominent part of anterior loop of mandibular canal and the alveolar crest was measured.

Results:

Anterior loop of the mandibular canal was identified 66.8% of hemimandibles analyzed with the highest prevalence in the fourth decade of life. Males and females exhibited predilection toward the right and left side, respectively. The presence of anterior loop of mandibular canal is associated with reduced distance between the neurovascular bundle and alveolar crest jeopardizing the placement of standard length dental implant.

Conclusion:

The current study emphasizes an increased need for precise identification and preservation of anterior loop of mandibular canal in the third and fourth decades of life, especially in females.

The "sand watch" mandible

The lingual surface of the mandible's body is commonly indicated as presenting the submandibular and sublingual fossae, which are separated by the mylohyoid line. The mylohyoid line attaches to the mylohyoid muscle (MM). Less attention has been paid to the 'mylohyoid boutonnières', which allow the 'sublingual buttons' to pass through the MM in the submandibular space. The cone beam computed tomography (CBCT) files of patients were routinely examined for anatomical studies. Two cases were found with unexpected morphologies of the mandible's body - the mylohyoid lines were incomplete anteriorly, and herniated sublingual tissue determined an additional fossa inferior to that line in the premolar region. That fossa was termed the 'accessory submandibular fossa'. It determined on coronal slices a 'sand watch' contour of the mandible's body. With such a peculiar morphology, the mandible is more prone to fracture. Moreover, when inserting endosseous implants, the procedure should be carefully personalised in such rare cases.

Sexual dimorphism of inferior alveolar canal location: A record- based CBCT Study in Eastern India

BACKGROUND

Sex determination from unidentified skeletal remains a daunting task in forensic odontology. The mandible is the strongest and most durable of bones available for post-mortem profiling and its morphometric characteristics have been investigated. Less explored is the location of the mandibular canal which in a few populations has shown gender dimorphism.

AIM

The present cross-sectional study explores sexual dimorphism in an eastern Indian population of Odisha from an analysis of cone-beam CT system (CBCT) images for the relative position of the mandibular canal and its foramina.

METHOD AND MATERIALS

A total of 120 CBCT images from either gender (1:1 ratio) of adult dentate individuals aged 18-60 years were analysed for the relative position of the mandibular canal. Ten measurements (8- coronal and 2- from axial slices) concerning the mandibular canal; at the level of the mandibular foramen, mandibular first molar and mental foramen were performed. Unpaired Student's t-test was employed to compare variables between the sexes at P < 0.05 level of significance.

RESULTS

The results revealed statistically significant differences (P < 0.05) between the genders in most of the variables (8/10), with higher mean values in males compared to females except in the distance between mandibular foramen and anterior border of the ramus (2.648 ± 0.67 mm in females, 2.527 ± 0.75 mm in males) and in the distance between the canal and lingual cortical plate in the region of the first molar (14.515 ± 1.33 mm in females, 14.288 ± 2.01 mm in males).

CONCLUSION

The relative position of the mandibular canal and its associated foramina show sexual dimorphism in an adult eastern Indian population.

The relative locations of the supraorbital, infraorbital, and mental foramina: A cadaveric study

The purpose of this study is to investigate the applicability of the current surgical guideline stating that the main facial foramina that transmit cutaneous nerves to the face (supraorbital notch/foramen, infraorbital foramen, and mental foramen) are equidistant from the midline in European and Hispanic populations. Previous studies suggest this surgical guideline is not applicable for all ethnicities; however, to our knowledge, no data have been published regarding the accuracy of this guideline pertaining to the Hispanic population. An experimental study was performed on 67 cadavers donated to the Human Anatomy Program at UT Health San Antonio. The supraorbital, infraorbital, and mental foramina were dissected and midline structures including the crista galli, internasal suture, anterior nasal spine, and mandibular symphysis were identified. The distance from each foramen to midline was recorded using a digital caliper. For all cadavers/ethnicities studied, the supraorbital, infraorbital, and mental foramina were 25.32 mm, 29.57 mm, and 25.55 mm to the midline, respectively. Thus, the infraorbital foramen is located significantly more lateral compared to the supraorbital (p < 0.0001) and mental foramina (p < 0.0001). After dividing the sample based on ethnicity, this relationship was also true for the European sample and tended to be true for the Hispanic sample. Significant anatomical variations exist in the current surgical guideline stating that the supraorbital foramen, infraorbital foramen, and mental foramen are equidistant from the midline. Clinicians may need to adjust their methodology during surgical procedures of the face in order to optimize patient care.

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.

Peripheral facial nerve schwannoma at the inferior mandibular margin: a case report

Schwannomas commonly occur in the head and neck region as acoustic neuromas. Facial nerve schwannomas are rare and usually occur in the temporal region. A 57-year-old woman presented with a mass at the right mandibular margin. Magnetic resonance imaging revealed a schwannoma located immediately caudal to the mental foramen. We were initially uncertain whether it arose from the trigeminal nerve or the facial nerve. Excision was performed under general anesthesia. The mass was encapsulated and easily detached from the surrounding tissue. The nerve of origin was identified proximal to the tumor. A facial nerve origin was confirmed as the muscles supplied by the marginal mandibular branch of the facial nerve moved on nerve stimulation. Nerve fibers were not found distal to the tumor, possibly because they had been cut during excision. We believe that this is the first report of a schwannoma arising from the peripheral facial nerve.

Evaluation of mental foramen and inferior alveolar nerve canal and its relationship to adjacent anatomical landmarks using cone-beam computer tomography

The objective of the research was to evaluate the location, size, variability, and morphologic features of mental foramen (MF) and the inferior alveolar nerve canal (IAN) on cone-beam CT. We evaluated the morphologic findings of mental foramen (MF) and inferior alveolar nerve (IAN) canal of 88 mandibular hemiarches of 65 Caucasian subjects (35 males, 30 females; age range 25-75 years) using cone beam CT. The most common horizontal position of MF was type 3 (53.4%), followed by type 4 (39.8%), type 1 (2.3%), type 2 (2.3%), and type 5 (2.3%). Regarding the vertical position, in 71.6% of cases (63/88) we found type 3 position, followed by type 2 (22.7%) and type 1 (5.7%). MF presented as oval in 51.1% and round in 42%, with double oval and triple foramens having been observed in 5.7% and 1.1% respectively. In 36.9% of cases, we found an anterior loop of the IAN. The mean depth of MF was 6.12±1.65mm; width and height were 3.7±0.83mm and 3.14±0.78mm. Width and height of the IAN distal to MF were 2.27±0.53mm and 2.74±0.51mm, while those of the incisive nerve canal mesial to MF were 1.37±0.44mm and 1.54±0.58mm, respectively. An increase in the width of MF was correlated to oval shape (r=0.45; P < 0.01), and there was a low but significant correlation (r=0.23; P < 0.05) between the round shape of MF and the size of the IAN. MF shape appears to be correlated to MF width and size of the IAN. The individual anatomical variability of this structure is a factor that must be considered when dealing with mandibular surgery.

Tomographic evaluation of the mandibular nerve in the mental region and its surgical implications: a cross-sectional study

The aim of this study was to evaluate the prevalence and length of the anterior loop (AL) of the inferior alveolar nerve, nerve emergence from the mental foramen, and prevalence of sensory disorders after implant placement in the interforaminal region. Four hundred and fifty hemimandibles (225 patients) were evaluated using cone beam computed tomography and panoramic radiographs. Information on the presence of sensory disorders was obtained from the medical records. AL prevalence was 13.6% and mean AL length was 1.25 mm. The false-negative rate for the identification of the AL using panoramic radiography was 58.6%. Straight nerve emergence from the mental foramen was the most prevalent (62.7%), followed by anterior (21.8%) and posterior (15.6%) emergence. The incidence of sensory disorders was 4.4%, and 1.1% were related to the presence of the AL. When implants were placed within the planned distance of the mental foramen or further, 1.2% had sensory problems associated with the presence of the mandibular incisive canal. In cases of distances smaller than planned, 12.9% had sensory alterations. Only five (1.1%) had the AL, with a length between 0 and 4.5 mm. However, in four cases, the planned distance was respected and, even so, there was a sensory disorder. Posterior nerve emergence from the mental foramen was associated with a higher prevalence of AL.

An Alternative Classification Scheme for Accessory Mental Foramen

BACKGROUND

The mental foramen (MF) is an important anatomical landmark on the mandible. MFs may occur singly or with extra foramina (accessory mental foramen (AMF)).

OBJECTIVE

The aim of the present study was to discuss the importance of recognition and classification of AMFs.

METHODS

This study assessed CBCT images of 593 patients (208 male, 385 female) and proposed an AMF classification scheme based on three different characteristics: (1) location of the AMF with respect to the MF; (2) relationship of AMFs with tooth apices; and (3) origin of the AMF. The chi-squared test was used to compare the qualitative data as well as descriptive statistical methods when the study data were evaluated. Significance was assessed at the p &lt; 0.05 level.

RESULTS

A total of 80 AMFs were found in 71 patients. Six cases involved bilateral AMFs, whereas three cases showed double AMFs. The most common AMF location was the region posterior of the MF. Notably, all the AMFs detected in line with the mesial half of the first molar were present in female patients. Based on AMF origins, 44.5%, 48.6%, and 6.7% of the AMFs were categorized as type I, type II, and a new category identified in this study, type III.

CONCLUSION

This study revealed that some foramina locations were not considered in the previous classification. Recognition and identification of these foramina might be critical to prevent possible complications. The proposed classification scheme may facilitate this objective and can be a new focus for future studies.

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.

Anatomical Variation in the Mandibular Foramen in Non-Atrophic and Atrophic Mandibles

Objectives

Previous studies of variation in mandibular foramen characteristics with age have involved comparison in different populations, but few data, between non-atrophic and atrophic mandibles are available. The aim of this original article was to compare the position, shape and area of the mandibular foramen between non-atrophic and atrophic mandibles.

Material and Methods

Morphometric methods were used to study the mandibular foramen variation. Fifty adult dry mandibles from the laboratory of anatomy were selected. Mandibles were considered non-atrophic if the distance between the base and alveolar ridge was homogeneous and greater than 25 mm in the anterior region and 20 mm in the posterior region. Conversely, mandibles were considered atrophic if that distances were lower than those described to a minimum of 11 mm in all areas. All measurements were performed with a digital caliper. For statistical analysis, the admitted level of significance was 5%.

Results

When non-atrophic mandibles were compared to atrophic ones, the mandibular foramen shifted significantly to an anterior position (mean difference [MD]: 4.81 mm; P < 0.0001) and to an inferior position (MD: 3.04 mm; P < 0.0001) and changed from an elliptical shape to round one, with a significant decrease in its area (MD: 3.66 mm²; P < 0.05).

Conclusions

The results indicate that there are significant differences in the position, shape and area of the mandibular foramen between non-atrophic and atrophic mandibles. These data should be considered in anaesthetic techniques and surgical procedures to prevent vascular and nervous lesions.

Age-related radiomorphometric changes on panoramic radiographs

Objectives

We aimed to analyse age‐related anatomical changes in teeth and mandibular structures using panoramic radiographs.

Materials and Methods

We included 471 subjects aged 13–70 years (mean, 35.12 ± 18.72 years). Panoramic radiographs were used to record intraoral condition and radiomorphometric parameters. After grouping the subjects by age decade, descriptive statistics and analysis of variance were performed to assess age‐related patterns.

Results

The number of missing teeth, endodontically treated teeth, full veneer crowns, and implant prosthesis increased with age (all p < .05). The prevalence of periodontitis significantly increased after the 40s and was the highest in the 60s (57.1%). The maxillary canine root was the longest in the 10s and 20s (p < .001). With age, the mandibular canal and mental foramen moved towards the alveolar bone crest, on the opposite side of the mandibular inferior border. The pulp area and pulp‐to‐tooth ratio of maxillary/mandibular first molars were significantly higher in the 10s and 20s than in other age groups (all p < .05).

Conclusions

We provided comprehensive information on age‐related anatomical changes in teeth and mandibular structures based on panoramic radiographs. Various radiographic parameters showed specific changes with increasing age. Assessing these age‐related changes can be useful in determining an individual's age, and may aid in medico‐legal and forensic judgments.

Miniplate Fixation to an Edentulous Mandibular Fracture in Panfacial Trauma

A 70-year-old edentulous male presented with bilateral mandible and left midface fractures following an assault. Imaging confirmed fractures and showed mandible thickness greater than 20 millimeters. The patient was treated by open reduction internal fixation with miniplates via an intra-oral approach and recovered without deficit. While miniplate fixation and an intra-oral approach is typically reserved for the dentulous patient, this case illustrates that in select edentulous patients with sufficient bone thickness and amenable midface fractures this technique may be successfully utilized.

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.

Neural Network Detection and Segmentation of Mental Foramen in Panoramic Imaging

Objective: To apply the technique of deep learning on a small dataset of panoramic images for the detection and segmentation of the mental foramen (MF). Study design: In this study we used in-house dataset created within the School of Dental Medicine, Tel Aviv University. The dataset contained randomly chosen and anonymized 112 digital panoramic X-ray images and corresponding segmentations of MF. In order to solve the task of segmentation of the MF we used a single fully convolution neural network, that was based on U-net as well as a cascade architecture. 70% of the data were randomly chosen for training, 15% for validation and accuracy was tested on 15%. The model was trained using NVIDIA GeForce GTX 1080 GPU. The SPSS software, version 17.0 (Chicago, IL, USA) was used for the statistical analysis. The study was approved by the ethical committee of Tel Aviv University. Results: The best results of the dice similarity coefficient ( DSC), precision, recall, MF-wise true positive rate (MF_TPR) and MF-wise false positive rate (MF_FPR) in single networks were 49.51%, 71.13%, 68.24%, 87.81% and 14.08%, respectively. The cascade of networks has shown better results than simple networks in recall and MF_TPR, which were 88.83%, 93.75%, respectively, while DSC and precision achieved the lowest values, 31.77% and 23.92%, respectively. Conclusions: Currently, the U-net, one of the most used neural network architectures for biomedical application, was effectively used in this study. Methods based on deep learning are extremely important for automatic detection and segmentation in radiology and require further development.

Clinical and anatomical study of foramen locations in jaw bones and adjacent structures

This study aims to find and locate foramens exactly in maxilla and mandible in case of complications during surgeries.Computer topographic angiography (CTA) images of 120 cases were reviewed. The measurements were performed on coronal, sagittal and axial planes after the 3 dimension volume reconstruction. The distances among foramens, bony landmarks, teeth, and facial artery were all measured with the angles as adjustments.The incisive foramen (IF) was measured 20.55 ± 2.81 mm to margo inferior of incisor, and 45.27 ± 5.27 degree from the axial midline. The greater palatine foramen located 43.17 ± 2.55 mm from the IF, while 21.08 ± 3.75 degree from the midline in axial plane. The lesser palatine foramina located 44.56 ± 5.74 mm from the IF and 20.05 ± 3.59 degree to the midline. The Mandibular foramen (MBF) was 91.15 ± 1.86 mm horizontally to the margo inferior of incisor. The angle that the MBF-margo inferior of incisor line made with the axial midline was 31.25 ± 2.89 degree. The shortest horizontal distance from the mental foramen (MF) to the facial artery in sagittal plane was 21.90 ± 1.86 mm, while it became 13.00 ± 2.05 mm in coronary section. The horizontal distance from the MF to the margo inferior of incisor in sagittal plane was 22.04 ± 3.22 mm. It turned out to be 25.78 ± 5.23 mm between MF and mid-sagittal line in coronary section. The vertical distance was 25.20 ± 3.06 mm from the upper margin of the second premolar to the MF.The foramens were clearly seen through CTA. Moreover, linear and angular measurements were presented, which makes it safer and wiser for surgeons to consider the biometric data before operations.

CBCT Evaluation of the Vital Mandibular Interforaminal Anatomical Structures

BACKGROUND

Oral implants are considered safe in the mandibular anterior region, but complications often occur if vital structures such as inferior alveolar nerve, mandibular incisive canal (MIC), anterior mental loop (AL), or mental foramen (MF) are not properly identified.

AIM

The aim was to evaluate vital anatomical structures in the mandibular interforaminal region and to investigate sexual dimorphism and differences with respect to left and right side regions using cone-beam computed tomography (CBCT).

MATERIALS AND METHODS

Eighty CBCT scans (forty male and forty female) were analyzed for MF position and shape, presence and measurement of AL and MIC (both in mm), emergence patterns of mandibular canal, and symmetry of MF and AL. A pilot study was conducted on five patients to determine interobserver reliability among two oral and maxillofacial radiologists, considered for interpretation of CBCT images. All the scans were taken by CS 9300, CBCT machine adjusted at 80 kVp, 15 mA, voxel size 0.3 × 0.3 × 0.3, and field of view of 10 × 5 (mandible only). The acquired images were reconstructed into multiplanar views (axial, panoramic, and cross-sectional) for evaluation.

RESULTS

The mean age of the study population was 42.64 ± 16.22 years, with males noted with slightly higher age. Position 4 of MF (below the apex of the second premolar) was noted the most on the right side, whereas position 3 (between the first and second premolars) was noted on the left side, with 75% of symmetrical MF position. The oval-shaped MF was most common among both genders and sides. The prevalence of MIC was noted in 93.75% of patients with a mean length of 12.09 ± 5.95 mm. The prevalence of AL was 53.13%, with a mean length of 1.07 ± 1.42 mm. No statistically significant sexual dimorphism (P > 0.05) was found between genders or sides for all the evaluated interforaminal parameters.

CONCLUSION

CBCT evaluation of vital anatomical structures needs to be elicited before planning an interforaminal placement of implants, and no sexual dimorphism was found regarding them.

Topographic and morphometric study of the mental foramina of Abaza goats with its clinical implication for regional anesthesia

In this study, the topographic and morphometric structure of the mental foramen of both female and male Abaza goats, a domestic goat breed found in Turkey, was examined. The mandibles and body weights of 30 adult Abaza goats, both female and male, were used. The goats were obtained during the sale of the Abaza goat herd sacrificial and forbearance. The mandibles were separated from the head and the skin, muscles and ligaments were cleaned and the mandibles were left to dry by standard technique. Various measurements were carried out on the mandible in accordance with relevant studies in the literature. The mental foramina of the goats were round and oval and the mental foramina on one mandible were not necessarily of the same shape. In addition, the number of mental foramina, which differed between goats, was observed to be two in most goats. The distance between the mental foramen and the ventral edge of the mandible was 0.88 ± 0.15 cm. The distance between the first premolar teeth and the mental foramen was found to be 1.59 ± 0.13 cm. The distance between the mental foramen and the lateral inciciv interdental was 1.85 ± 0.39 cm. The distance between the caudal edge of the ramus mandibulae and the mental foramen was calculated as 12.38 ± 1.52 cm.

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.

The temporomandibular joint: pneumatic temporal cells open into the articular and extradural spaces

The pneumatisation of the articular tubercle (PAT) of the temporal squama isa rare condition that modifies the barrier between the temporomandibular joint(TMJ) space and the middle cranial fossa. During a routine examination of thecone-beam computed tomography (CBCT) files of patients who were scannedfor dental medical purposes, we identified a case with multiple rare anatomicvariations. First, the petrous apex was bilaterally pneumatised. Moreover, bilateraland multilocular PAT were observed, while on one side it was further found thatthe pneumatic cells were equally dehiscent towards the extradural space and thesuperior joint space. To the best of our knowledge, such dehiscence has not previouslybeen reported. The two temporomastoid pneumatisations were extendedwith occipital pneumatisations of the lateral masses and occipital condyles, thelatter being an extremely rare evidence. The internal dehiscence of the mandibularcanal in the right ramus of the mandible was also noted. Additionally, doublemental foramen and impacted third molars were found on the left side. Suchmultilocular PAT represents a low-resistance pathway for the bidirectional spreadof fluids through the roof of the TMJ. Further, it could add to a morphologicalpicture of hyperpneumatisation of the posterior cranial fossa floor, which couldsignify the involvement of the last four cranial nerves in the clinical picture of TMJpain.

Evaluation of incidence of mental nerve loop in Central India population using cone beam computed tomography

Context

Anatomical literature has described the anterior loop being an extension of the mental nerve which is present anterior to the mental foramen while the caudal loop has been described as the distance between the lower border of the mental foramen and the lowest point of the mandibular canal. The knowledge and identification of the anterior and caudal loop of the mental nerve are important in surgical procedures performed around the mental foramen to avoid inadvertent damage to these vital structures resulting in postoperative complications.

Aim

The present study was conducted to determine the incidence and measurement of mental nerve loop in the mandibular arches using cone beam computed tomography (CBCT).

Settings and Design

A total of 200 CBCT images were retrieved and inspected for the presence of the mental nerve loop. The length of the anterior loop was measured by counting the number of consecutive contiguous vertical cross sections displaying two round hypodense images. This number was multiplied by the thickness of the slices. The caudal loop was measured as the distance between the lower border of the mental foramen and the lowest point of mandibular canal.

Statistical Analysis Used

Shapiro-Wilk test and Mann-Whitney U-test were used. P < 0.05 was considered statistically significant.

Results

57.5% (n = 200 scans) presented with the anterior loop of the mental nerve with a mean length of 0.50 mm and 0.37 mm on the right side and left side, respectively. All the samples of CBCT scans taken were having caudal loop extension with a mean length of 3.53 mm.

Conclusion

A considerable number of individuals (57.5%) in the present study presented with the anterior loop of the mental nerve. CBCT was found to be an effective imaging modality for the detection of anterior loop of the mental nerve.

Assessment of the Effect of Dimensions of the Mandibular Ramus and Mental Foramen on Age and Gender Using Digital Panoramic Radiographs: A Retrospective Study

Background

A retrospective study is conducted to evaluate the mental foramen size and ramus height using digital panoramic radiograph to see if these parameters could be used to determine a correlation with age and gender in dentate subjects and to show its relevance in forensic odontology.

Aim

To determine if there is an interrelation between two mandibular parameters (mental foramen, ramus height) in gender and age assessment.

Materials and Methods

Five hundred and forty-five high-quality radiographs of patients aged 20 years and above were selected to see superior and inferior aspects of the mental foramen and the ramus height.

Statistical Analysis

Data obtained were analyzed using the SPSS 20 version software. The mean and standard deviations were calculated for each clinical parameter, and one-way ANOVA statistical test of significance was used to compare superior and inferior aspects of mental foramen and ramus height with age groups and gender for both right and left sides. Statistical significance was set at P < 0.05.

Results

Highly significant relationship was observed, and it was also found that as the age advances, the mental foramen and ramus height increase on both the right and left sides; whereas the mental foramen and ramus height increase among males as compared to females on both the right and left sides.

Conclusion

There were significant changes in the dimensions of mental foramen and ramus height as age advances. The results concluded that ramus height and the mental foramen can be used effectively in the identification of gender using digital panoramic radiography.

Prevalence and measurement of anterior loop of the mandibular canal using CBCT: A cross sectional study

BACKGROUND

Anterior loop of the mental nerve is a very important anatomic landmark in implant placement and anterior mandibular osteotomies.

PURPOSE

Two-dimensional imaging techniques are not competent enough to locate and measure the mental nerve loop in majority of the cases. Any injury to this loop results in pain/paresthesia/numbness in the region supplied by the mental nerve. The aim of this study is to analyze the prevalence and measure the length of the loop using cone beam computerized tomography (CBCT) and calculate the average length and prevalence so that a safe margin can be given while placing the implants or the osteotomy cuts in the premolar region.

MATERIALS AND METHODS

A cross-sectional study was done using CBCT images of 85 patients taken for impaction surgery. The length of the loop was measured in mm using standardized lines drawn along specific anatomic landmarks.

RESULTS

In our study 11.76% of patients had anterior loop in their mental nerve. Mean length of the mental nerve loop was calculated and found to be 2.79 mm.

CONCLUSION

A margin of 4 mm anterior to the mental foramen should be safe to avoid any damage to the mental nerve loop bundle in majority of the cases where the loop is present.

Detection and characterization of the accessory mental foramen using cone-beam computed tomography

OBJECTIVE

This study aimed to investigate the frequency and characteristics of accessory mental foramina (AMFs) and their bony canals in a selected Chinese population using cone-beam computed tomography (CBCT).

MATERIALS AND METHODS

Reconstructed CBCT images of the mandible in 784 Chinese patients (305 males and 479 females) were retrospectively analysed to identify the AMF. The presence, dimension and location of the AMF as well as the origin and course of the associated bony canal were evaluated and classified. Variations in these characteristics were analysed according to gender, side and age.

RESULTS

A total of 66 AMFs were found in 57 (7.3%) of the 784 patients. The frequency of AMFs was significantly influenced by gender and side of the mandible (p < .05). Most AMFs were located apically between apices of the first and second premolars. The high-position AMFs (above the mental foramen) accounted for 54.5% of the total. The mean horizontal and vertical diameters of the AMF were 1.38 ± 0.47 and 1.23 ± 0.37 mm, respectively. Two typical types of the bony canal leading to the AMF were identified according to their bifurcation site from the mandibular canal. Most bony canals originated from the anterior loop of the mental canal (56.1%) and coursed posterosuperiorly (36.3%). The mean length of the bony canals was 5.78 ± 2.31 mm.

CONCLUSIONS

This study presents a considerable frequency of AMFs in a Chinese population. The high-position AMF and the associated bony canal coursing in the oblique upward direction appear frequently. Thus, clinicians should be alert to the presence of the AMF to avoid neurovascular complications especially when dental procedures require periosteum detachment and implant insertion in the mental region.

Morphological and morphometric analysis of accessory mental foramen in dry human mandibles of south indian population

Background

Mental foramen (MF) is an important landmark for administration of local anesthesia in surgical procedures involving the mandible. Additional mental foramina, called accessory mental foramina (AMF) transmitting branches of mental nerve, have been reported. Detection of AMFs in presurgical imaging may reduce postoperative pain in dental surgical procedures. Aim: The aim of the study was to study the incidence and morphometric analysis of accessory MF in the dry human mandibles of South Indian population.

Materials and Methods

Two hundred and sixty dry human mandibles were studied for the presence, location, shape of AMF, and its relation to MF. The horizontal diameter of AMF, and its distance from symphysis menti, the posterior border of mandible and from the base of mandible were measured and statistically analyzed.

Results and Conclusions

In our study, AMF were present in 8.85% mandibles (unilateral - 7.6% [4.6% - left, 2.69% - right] and bilateral 1.6%). The most common position was below the second premolar (48.1%). AMF were round in shape (74%) and was often located either superomedial or inferolateral to MF. Their transverse diameter ranged from 0.5 to 1 mm. The AMF were situated at a mean distance of 2.96 mm from MF, 23.47 mm from symphysis menti, 11.24 mm from the lower border of the body of the mandible, and 57.35 mm from the posterior border of ramus of mandible. The knowledge of the presence of AMF and its dimensions would enable the clinicians to do mandibular procedures carefully and avoid injury to the branches of mental nerve that may be passing through it.

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.

Computer-assisted system on mandibular canal detection

BACKGROUND

A dentist always checks a patient by using panoramic radiography (PR) initially. The measurement of the minimal distance (MD) between the alveolar crest and the mandibular canal (MC) superior border is critically important before the dental implant surgery, extraction of 3rd molar teeth or any surgery in the posterior area of minimal distance (MD). However, the image of MC is not always clear to identify.

OBJECTIVE

A software is needed for training dentists as well as a tool of demonstration to patients in clinics precisely and quickly. Moreover, it should be able to calculate the MD between the alveolar crest and the MC superior border before dental implant.

METHODS

A computer-aided software system to semi-automatically detect the MC and mental foramen (MF) in the PR with minimal human interference is proposed.

RESULTS

The result shows that the averaged relative error (RE) is 1.83% with a standard deviation of 2.31%.

CONCLUSION

The results show that the proposed algorithm is able to detect the MC superior and inferior borders. This system has the potential to train young clinicians and to replace the manual work in measuring the MD between the alveolar crest and the MC superior border with a minimal human intervention.

A morphological study of the foramina of the mandible in the Japanese macaque by cone-beam computed tomography

The mandibular canal (MC) contains vessels and nerves in the mandible of the Japanese macaque (JM). The inferior alveolar nerves and vessels of the mandible insert from the mandibular foramen and then run through the MC, the mental foramen and spinal foramen to the outside of the mandible. However, the detailed morphological properties of multiple canals, such as the accessory canal (AC) of the mandible, are unknown in JMs. The purpose of this study was to describe the multiple canals of JMs and to determine the location and analyse the measurements of the JM mandible. In this study, we also showed the course of the lingual foramen in 17 JMs (male: n = 8; female: n = 9) using cone-beam computed tomography (CBCT). In our results, we classified multiple mental foramina and multiple lingual foramina found on the mandibular body at the premolar or molar region. However, there was no significance between the formation of mandibular properties and the lingual foramen. These multiple foramina contain nerves and blood vessels have a few branched canals; these branches run downward and connect with the inferior mandibular nerve and artery. These morphological features may provide useful information about surgical treatment of the alveolus in a human model.

Relationship between the Mental Foramen, Mandibular Canal, and the Surgical Access Line of the Mandibular Posterior Teeth: A Cone-beam Computed Tomographic Analysis

INTRODUCTION

The purpose of this study was to investigate the relationships between the location of the mental foramen (MF) and the mandibular canal (MC) and the surgical access line (SAL) of the mandibular posterior teeth using cone-beam computed tomographic (CBCT) scans.

METHODS

CBCT scans of 204 subjects ranging in age from 18-76 years old were evaluated. The vertical and horizontal distances from the MF to the SAL of the mandibular premolars and first molars and the vertical distance from the MC to the SAL of the second premolars and first molars were measured via CBCT scans.

RESULTS

The average vertical distance between the MF and the SALs showed significant increases sequentially from the first premolars to the distal roots of the first molars, and the shortest average distance of 2.74 mm was obtained for the first premolars. The SALs of the second premolars were the closest to the MF in the horizontal direction with an average distance of 1.5 mm. In 19.9% of the cases, the vertical and horizontal distances between the MF and the SALs of the second premolars were less than 2 mm. In addition, the MF was located superior to the root apices in 6.62% of the cases. The majority of the SALs were located at a vertical distance from the MC that was more than 2 mm. Men and women exhibited significant differences in both the horizontal distance from the MF to the SALs of the first premolars and the vertical distance from the MC to the SALs of the second premolars.

CONCLUSIONS

To improve the success of endodontic microsurgery, adequate knowledge of the anatomic relationships between the location of the MF and MC and the SAL of the mandibular posterior teeth is indispensable to surgeons.

The position of the mental foramen in dentate and edentulous mandibles: clinical and surgical relevance

BACKGROUND

The knowledge of the exact location of the mental foramen (MF) in dentate and edentulous mandibles is clinically important when constructing complete dentures, performing anaesthetic block of the lower-anterior teeth area and intervening in the MF nearby area. In edentulous mandibles, the bone resorption after teeth loss makes the mental nerve (MN) prone to damage due to the extreme location of the MF very close to the alveolar crest (AC). Chronic compression on the MN may result in pain in the area of MN distribution (ipsilateral face and cheek area) and numbness at the lower lip. The purpose of the current study is to evaluate the exact position of the MF, calculating the distances MF-superior border of the AC and MF-inferior border of the mandible (IBM) in dentate and edentulous mandibles.

MATERIALS AND METHODS

One hundred and two (36 edentulous and 66 dentate) adult dry Greek mandibles were studied.

RESULTS

In 9 out of 36 edentulous mandibles (25%), the MF was found nearby the AC, while in 27 edentulous mandibles (75%), the MF was located at an average distance 6.4 mm from the AC and 12.6 mm from the IBM. In 38 out of 66 dentate mandibles (57.6%), the MF was located at an average distance 13.6 mm from the AC and 15.2 mm from the IBM. The dental status significantly affected (p = 0.001) the distances MF-AC and MF-IBM. Side symmetry was observed for both dentate and edentulous mandibles (p = 0.39 and p = 0.45).

CONCLUSIONS

The MF is an important landmark and its location needs to be considered prior to dental implants placement in order to avoid the MN injury and related complications. The position of MF is altered in edentulous mandibles compared with the dentate ones. The MF is a symmetric structure in Greeks.

Gender determination by radiographic analysis of mental foramen in the Maharashtra population of India

Context:

Identification of gender is of primary importance in forensic investigations when only fragment of skull remains. Mandible is a hard bone and exhibits a high degree of sexual dimorphism. Gender differences were observed in the height of mandible, gonial angle, bigonial breadth, bicondylar breadth, and position of mental foramen (MF).

Aims of the Study:

The purpose of this study is to evaluate gender differences in distances from superior border of MF (SMF) and inferior border of MF (IMF) to the lower border of mandible (LBM) and height of mandible in the Maharashtra population.

Materials and Methods:

A total of 400 patients (200 males and 200 females) were considered for the study. The panoramic radiographs of patients were captured using Xtropan 2000 system and Carestream (T-Mat GIRA) films. The distance from SMF and IMF to the LBM and the height of mandible was measured.

Statistical Analysis Used:

Unpaired t-test was applied to calculate the differences between the genders.

Results:

The distance from SMF and IMF to LBM and height of mandible was more in males when compared to females, which was statistically significant.

Conclusion:

The distances from SMF and IMF to the LBM and height of the mandible showed sexual dimorphism in the Maharashtra population of India.

Ultrasonographically locating the mental foramen and its soft tissue relations

OBJECTIVES

This ultrasound-based cross-sectional study aimed to visualize, locate and compare the position of the mental foramen with regard to its relationship to various soft tissue landmarks.

METHODS

100 Black and Caucasian subjects were included. An ultrasound transducer was used to locate the mental foramina. Distances to various landmarks were measured and compared.

RESULTS

All mental foramina were visualized. The mean soft tissue distance of the entire group from the mental foramen on the right and left sides, respectively, were as follows: (a) 3.4 mm [standard deviation (SD) 1.7 mm] and 3.4 mm (SD 1.5 mm) lateral to a vertical line passing through the chelion; (b) 20.1 mm (SD 2.6 mm) and 20.1 mm (SD 2.6 mm) distal to a horizontal line bisecting the chelions; (c) 15.1 mm (SD 2.4 mm) and 15.0 mm (SD 2.4 mm) proximal to the inferior border of the mandible. We found no statistically significant differences between race groups, between gender group and between age categories with regard to the horizontal soft tissue distance from a vertical line passing through the chelion to the mental foramen on the right or left sides. There were statistically significant (but not clinically significant) differences between race groups and between gender groups but not between age groups with regard to the vertical soft tissue distance from a horizontal line bisecting the chelions to the mental foramen as well as from the inferior border of the mandible to the mental foramen on both the right and left sides.

CONCLUSIONS

This study suggests that ultrasound is a feasible imaging modality that can be utilized to locate the mental foramen. Differences in the position of the mental foramen with regard to various soft tissue landmarks are minor and clinically insignificant.

Anterior Loop of the Inferior Alveolar Canal: A Cone-Beam Computerized Tomography Study of 494 Cases

The aim of this study was to use cone-beam computerized tomography (CBCT) images of patients to assess the prevalence of different types, especially anterior loop, of the mental portion of the inferior alveolar canal and to evaluate the anterior loop lengths. CBCT images of 494 patients providing inclusion criteria were examined by 2 oral radiologists. Sagittal, axial, and multiplanar reformatted images were used to detect the type of mental portion of the inferior alveolar canal. The anterior loop length was measured in the respective sections of each CBCT image. Statistical analysis was performed using SPSS v. 15, and t tests were used for statistical analysis. Of the 494 patients, 217 anterior loops were detected in 141 (28.5%) patients. The mean anterior loop lengths for the right side and the left side were 2.19 ± 1 mm and 2.08 ± 0.89 mm, respectively. The difference between males and females in the mean anterior loop length was statistically significant for both sides (Right: P < .05; Left: P < .05). A presurgical CBCT image examination is necessary prior to implant insertion to reveal the presence of anterior loop and to detect actual anterior loop length.

The prevalence of mandibular incisive nerve canal and to evaluate its average location and dimension in Indian population

Aim:

The aim of this study was to find the prevalence of the mandibular incisive canal, evaluate its location and dimensions using cone beam computer tomography (CBCT) in Indian population.

Materials and Methods:

CBCT scan images of 120 subjects were analyzed for the presence of the mandibular incisive canal, its location, size, and its length. The distance between the incisive canal and the buccal and lingual plate of the alveolar bone, and the distance from the canal to the inferior border of the mandible were also measured to position the canal in the mandible.

Results:

About 71.66% of the CBCT scans of Indian subjects examined showed the presence of the Incisive canal, of which 48.33% exhibited canals bilaterally and 23.33% showed unilateral canals. 28.33% of the subjects CBCT scans did not exhibit the presence of incisive nerve canal. The average length of the incisive canal was 10.173 mm. The average diameter of the Incisive canal in the CBCT scans was 2.578 mm. The distance from the Inferior border of the mandible to (a) the origin of the Incisive canal was 9.425 mm and (b) to the apex of the Incisive canal was 9.095 mm. The distance from the buccal cortex of the mandible to (a) the origin of the incisive canal was 1.48 mm and (b) to the apex of the incisive canal was 4.476 mm. The distance from the lingual cortex of the mandible to (a) the origin of the incisive canal was 4.464 mm and (b) to the apex of the incisive canal was 5.561 mm.

Conclusion:

The presence, location, and dimensions of the mandibular incisive canal are an additional required data that needs to be elicited before planning an inter-foraminal placement of implants.

Assessment of the Horizontal and Vertical Position of Mental Foramen in Indian Population in Terms of Age and Sex in Dentate Subjects by Pano-ramic Radiographs: A Retrospective Study with Review of Literature

OBJECTIVE

To familiarize new criteria to access vertical position of mental foramen in panoramic radiographs. Furthermore, to determine and compare the position and symmetry of mental foramen in horizontal as well as in vertical plane in Indian population and to compare the results with those reported for other populations in the literature. Further gender differences in mental foramen position were also accessed to comment on the reliability of panoramic radiographs for sex determination. Methods and Material : Six hundred digital panoramic radiographs were selected and studied regarding the location and symmetry of mental foramen. They were also compared with the other studies in the literature. The method employed is similar to that described by Al Jasser and Nwoku for horizontal position and Fishal et al. for vertical position of mental foramen. Certain modifications were carried out in Fishal's criteria for vertical position assessment. Results : The commonest position of the mental foramen in horizontal plane was in line with the longitudinal axis of the second premolar (61.0%) while in vertical plane it was found to be located inferior to the apex of second premolar (72.2%). Conclusion : Mental foramen exists in different locations and possesses many variations. Hence, Individual, gender, age, race and assessing technique largely influence these variations. It suggests that the clinicians should carefully identify these anatomical landmarks, by analyzing all influencing factors, prior to their diagnostic or the other dental, surgical and implant operation.

Correlation of Radiographic Mental Foramen Position and Occulusion in Three Different Indian Populations

BACKGROUND

The knowledge of the position of the mental foramen (MF) is important for administering local anaesthesia for diagnostic, surgical or operative procedures.

AIMS

To determine the shape, position, symmetry of MF and its continuity with the inferior dental canal (IDC) on a digital panoramic view and to find its correlation with Angle's molar relations in three Indian subpopulations. The study also determines the correlation of inter-foramen distance in both genders of three Indian subpopulations.

SUBJECTS AND METHODS

One hundred and twenty digital panoramic radiographs were evaluated from three Indian subpopulations (Punjab, Rajasthan and Northeast [NE]). The assessment of occlusion was based on Angle's molar relationships. The data obtained were statistically analysed.

RESULTS

The commonest position of the MF in the Rajasthan and NE populations was position 4 bilaterally, while in the Punjab population, it was position 3 on the right and position 4 on the left side. The majority of the MF was round in shape followed by oval. The mean distance between two MF was highest among the Punjab male population and least among the NE female population. The most frequent pattern of MF continuity with IDC was diffuse in Rajasthan population, separated in NE and continuous in Punjab. Correlation between Angle's molar relation with MF position was significant for Classes I and II but not for Class III. Correlation of inter-foramen distance between genders was highly significant in the NE and Punjab populations.

CONCLUSION

The commonest MF position was aligned with the 1st premolar and between the 1st and 2nd premolar.

Anthropometrics of mental foramen in dry dentate and edentulous mandibles in Coastal Andhra population of Andhra Pradesh State

AIM

The aim of this study is to determine the morphological features and morphometrics of mental foramen with reference to surrounding anatomical landmarks in Coastal Andhra population of Andhra Pradesh State.

MATERIALS AND METHODS

Two-hundred and nineteen dry dentate and edentulous mandibles are examined in this study. Out of these 127 were dentate and 92 were edentulous. Various morphological and morphometrical parameters were measured by using digital Vernier caliper, metallic wire and metallic scale on both the right and left sides.

RESULTS

In the present study, the distance between most anterior margin of mental foramen and posterior border of ramus of the mandible is [MF-PR], MF-PR is 69.61 ± 6.03 mm on the right side and is 69.17 ± 6. 0 mm on left side in dentate mandible. In edentulous type, MF-PR is 68.39 ±6.4 mm on right side and 68.81 ± 6.55 mm on left side. In the present study, the distance between symphysis menti and most anterior margin of mental foramen [MF-SM] in dentate mandible is 28.24 ± 5.09 mm on right side and is 27.45 ± 3.7 mm on left side. In edentulous mandible (MF-SM) is 28.51 ± 4.5 mm on right side and on left side is 27.99 ± 4.50 mm.

CONCLUSION

Acquiring the knowledge and importance of anatomy of mental foramen is helpful in avoiding neurovascular complications, during regional anesthesia, peri apical surgeries, nerve repositioning and dental implant placement.

Determination of the location of the mental foramen: a critical review

INTRODUCTION

The mental foramen (MF) is an important landmark to consider during surgical endodontic procedures. The purpose of this review article was to discuss the variety of techniques that have been developed to determine the location of the MF, to make recommendations for the current best technique available, and to discuss upcoming technologies.

METHODS

Articles that have addressed the location of the MF were evaluated for information pertinent to include in this review.

RESULTS

Different technologies have been used to help operators determine the clinical location of the MF. Most of the techniques have shortcomings such as magnification, radiation, and cost. Cone-beam computed tomographic imaging is the best current available imaging technology to determine the accurate location of the MF, but it has shortcomings such as radiation, cost, and not being real time, which means the data must be interpreted at a later time than when the information was computed.

CONCLUSIONS

In the future, magnetic resonance imaging and ultrasound technologies seem to provide promising noninvasive imaging techniques.

Factors affecting the success rate of buccal infiltration anaesthesia in the mandibular molar region

AIM

To compare the anaesthetic efficacy of mandibular second premolar infiltration (SP) with that of mandibular first molar infiltration (FM) in inducing pulpal anaesthesia in the mandibular first molar. To further investigate the mechanisms of action that underlie mandibular infiltration, gender-related differences in the anaesthetic efficacy were also assessed.

METHODOLOGY

A total of 29 adult subjects randomly received two sets of SP and FM injections using one cartridge (1.7 mL) of 4% articaine and 1 : 100 000 adrenaline at two separate appointments. The responses of the teeth were assessed using an electronic pulp tester over a 30-min period. A comparison of the anaesthetic success between the SP and FM infiltration routes was analysed using the McNemar's test. Gender-related differences in the anaesthetic success of infiltration routes were assessed using the Fisher's exact test.

RESULTS

For the second premolar and the first and second molar teeth, the success rates of SP were 72.4%, 62.1% and 48.3%, whereas the success rates of FM were 75.9%, 51.7% and 55.1%, respectively. There were no significant differences between the success rates of SP and FM or between the rates obtained for each tooth. Significant gender-related differences were observed for the second premolar (P < 0.01) and the first molar (P < 0.05) using FM. However, a significant difference was observed only for the second premolar using SP (P < 0.05).

CONCLUSIONS

The differences in the injection sites did not affect the anaesthetic success rates for the mandibular second premolar and molar teeth. However, articaine buccal infiltration produced a higher anaesthetic success rate in the second premolar and first molar teeth of Korean female patients.

Configuration of the inferior alveolar canal as detected by cone beam computed tomography

AIMS

The aim of this study is to evaluate the course of the inferior alveolar canal (IAC) including its frequently seen variations in relation to root apices and the cortices of the mandible at fixed pre-determined anatomic reference points using cone beam volumetric computed tomography (CBVCT).

MATERIAL AND METHODS

This retrospective study utilized CBVCT images from 44 patients to obtain quantifiable data to localize the IAC. Measurements to the IAC were made from the buccal and lingual cortical plates (BCP/LCP), inferior border of the mandible and the root apices of the mandibular posterior teeth and canine. Descriptive analysis was used to map out the course of the IAC.

RESULTS

IACs were noted to course superiorly toward the root apices from the second molar to the first premolar and closer to the buccal cortical plate anteriorly. The canal was closest to the LCP at the level of the second molar. In 32.95% of the cases, the canal was seen at the level of the canine.

CONCLUSIONS

This study indicates that caution needs to be exercised during endodontic surgical procedures in the mandible even at the level of the canine. CBVCT seems to provide an optimal, low-dose, 3D imaging modality to help address the complexities in canal configuration.

Position of the mental foramen on panoramic radiographs and its relation to the horizontal course of the mandibular canal: a computed tomographic analysis

AIM

The purposes of this study were (1) to investigate the bucco-lingual course of the mandibular canal in the bony structure and (2) to figure out the relationship between the position of mental foramen on panoramic radiographs and the horizontal course of the mandibular canal.

MATERIALS AND METHODS

A database of panoramic radiography and spiral computed tomography (CT) scans was searched and 100 subjects were selected based on the criteria. Mental foramina were classified into four groups according to its antero-posterior position. Three measurements were made on each slice of coronal CT scans at three different points: (1) apex of second premolar; (2) median point of two root apexes of first molar; and (3) median point of two root apexes of second molar. The bucco-lingual ratios were calculated to access the relative bucco-lingual position of the mandibular canal.

RESULTS

The distribution of subjects according to the type of mental foramen was: (1) type 3, 67%; (2) type 2, 26%; (3) type 4, 5%; and (4) type 1, 2%. The overall horizontal course of the mandibular canal was relatively constant from the second molar to first molar, whereas much significant directional change was found on the remaining course. Between types 2 and 3, no statistically significant differences were found at the level of the second molar and first molar (P = 0.461 and 0.965, respectively). Only below the second premolar, significant differences were found (P = 0.001).

CONCLUSIONS

Based on the findings of our computed tomographic image analysis, the position of mental foramen on panoramic radiographs was affected by its horizontal course of inferior alveolar nerve. The significant horizontal direction change of the course was found after the canal passing below the mandibular first molar regardless of the antero-posterior position of mental foramen.