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The purpose of this three-dimensional cone beam computed tomography (CBCT) study was to identify the difference between monocortical fixation (MCF) and bicortical fixation (BCF) in mandibular canal penetration after bilateral sagittal split osteotomy (BSSO) to correct mandibular prognathism, where interosseous fixation was done by BCF or MCF. CBCT was performed 1 week postoperatively and Dolphin 3D software was used to assess direct penetration of the mandibular canal by either type of screw. The primary outcome variable was the presence or absence of mandibular canal penetration and was categorized as a binary coded variable. The BCF and MCF groups were compared by χ2 test, and the odds ratio for canal penetration was estimated. Multiple logistic regression was performed to identify factors related to canal penetration. A total of 118 patients were included. The MCF group had only 6% canal penetrations (3/50 patients) and the BCF group had 58.8% canal penetrations (40/68 patients). The regression model showed that BCF was the only factor causing mandibular canal penetration, with an adjusted odds ratio of 52.5. Awareness of the increased risk of canal penetration with BCF and potential nerve injury might influence case selection.

The mandibular canal bifid and trifid are variations of the mandibular canal. This variation of themandibular canal is essential to recognize in surgical procedures involving mandibles, such as extraction ofimpacted third molars, dental implant treatment, and sagittal split ramus osteotomy. The purpose of this study wasto determine the prevalence of bifid and trifid mandibular canal by panoramic radiograph at RSGM Unsyiah BandaAceh. This research method is descriptive by collecting secondary data in the form of panoramic images frompatients visiting RSGM Unsyiah Banda Aceh for April 2012-March 2017. A total of 2,478 panoramic radiographphotos collected showed the bifid mandibular canal is 1.25%. Based on sex, 21 photos (67.74%) of the bifidmandibular canal cases in women and ten photos (32.26%) in men. Based on the position of the bifid mandibularcanal, 9 images (29.03%) unilateral/ right-sided, 15 photos (48.39%) were unilateral/left side, and seven photos(22.58%) bilateral. KEYWORDS: bifid mandibular canal, panoramic, prevalence, trifid mandibular canal

Background Cone-beam Computed Tomography (CBCT) is widely used for preoperative 3D imaging of lower third molars. Hence, for this imaging indication, the present study aimed to define the minimum field-of-view (FOV) size and its optimum placement, to decrease radiation exposure, and highlight the need of computer-assisted FOV centering technique for dental CBCT devices. To facilitate proper placement of image field, lower second molar was chosen as reference. Methods The retrospective study included 50 CBCT-scans of 46 patients with mean age of 34 years. Based on the lower second molar, a three-dimensional coordinate was formed and the location of mandibular canal (MC) and the dimensions and locations of the lower third molars, and possible associated pathological findings were assessed. Accordingly, the FOV size and position for third-molar imaging were optimized, while ensuring encompassment of all relevant structures. Results The minimum cylindrical volume, covering lower third molars and MC, was 32.1 (diameter) × 31.6 (height) mm, placed in relation to the second molar crown, top 2.2 mm above cusp tips, anterior edge 6.7 mm in the front of the most distal point of the crown, and lingual edge 7.9 mm on the medial side of the lingual wall. Conclusions The optimized FOV for lower third molars was smaller than common standard small FOVs. We recommend using FOV volume 3.5∅ × 3.5 cm for third molars without associated pathology. Accurate FOV protocols are essential for development of new CBCT-devices with computer-assisted and indication-specific FOV placement.

The surgical remedy of problems related to lower jaw 3 molars is related to common surgical risks like contamination, haemorrhage, pain and swelling. Certain unique risks are related with such surgery, specifically inferior alveolar and lingual nerve harm as these are adjacent vital structures. Risk assessment calls for an entire understanding of dental factors that can impact the care of these characteristic structures. Preoperative radiographic assessment warrants to provide data about the tooth itself, its encompassing bone, the neighbouring dentition, and related anatomical structural systems. Parameters that ought to be assessed are level of impaction, root formulations, angulation of the enamel, number of roots, root morphology, related pathology and, most importantly, the relation some of the crown/roots and the mandibular canal. An appropriate imaging method for 3 molars ought to display the complete 3rd molar and the mandibular canal below it. In this mini review, we elaborate on the generally used radiographic assessment methods of mandibular 3rd molars. Keywords: Radiograph, Mandibular, Molar.

Aim & Objective: This study aims to evaluate the presence of retromolar foramen (RMF) and retromolar canal (RMC) in the mandible using cone beam computed tomography (CBCT) in Chhattishgarh population and to correlate its possible clinical impact. Materials and Methods: 175 CBCT images were collected from which 100 bilateral CBCT images of patients were retrospectively selected from the Department of Oral Medicine and Radiology of the Chhattishgarh Dental College and Research Institute and evaluated bilaterally which were taken for diagnostic purposes from maxillofacial radiology clinic and data were statistically analyzed. This was an observational descriptive study and all the images were processed and analyzed on CS3D imaging software. Statistical analysis used: The data was analyzed using chi square test. Results: The prevalence of RMF and RMC was observed in 8.5%, of which 10 were in females and 7 in males. The RMCs traversed in different directions – horizontal, vertical and angular. Based on the subjective assessment, each of these canals was further subclassified into straight and curved canal. In the present study in 12 of the cases angular curved type was found and in 3 cases, vertical straight was noticed. The bifurcation of the inferior alveolar nerve (IAN) canal was observed in 15% of the scans and remaining 85% had single mandibular canal. The proximity of RMF from buccal and lingual cortical plates was found buccally in 16 cases and in single case was found to be lingually. Conclusion: Position of RMF might change with the presence and absence of third molar. The absence of third molar results in anteriorly located RMF. In majority of cases it was found that RMF was located more buccal than lingual. The parameters considered in the current study will guide the oral and maxillofacial surgeons while giving incisions in 3molar impacted cases, other pathologies and ease to preserve the retromolar foramen. Keywords: Retromolar foramen, Retromolar

Background: Mental foramen is the opening of mandibular canal in the mandibular body, and its place shows contra-versus. As mental foramen is an essential anatomical landmark required for implant surgery, the determination of the exact place for the mental foramen to detect exact amount of local anesthesia solution and to decrease dismissed injuries during the prosthetic surgical treatments. The determination of the situation of mental foramen according to its site in horizontal and vertical direction of mental foramen according to the adjacent premolars and molars on the skull, diagnostic radiographs, and CBCT. Objectives: Assessment of MF related landmarks using computed tomography scan by a new computerized method. Materials and Methods: Twelve patients ranging from 45-60 years old came to the department of prosthodontics, Alexandria University, Alexandria, Egypt. The anatomical structural landmarks such as mandibular canal, mental foramen according to its site relative to the lower border of the mandible of the mandible were evaluated by radiographic CT and scores were assessed. All the measurements done by Image J computed program which was not used in the previous studies. Results: Anatomical landmark structures in the mandible (mandibular canal, mandibular foramen, mental foramen, and incisive canal) were detected and measurements in millimeter were recorded by using CT images. Conclusion: An essential anatomical landmark for the dentist is the place of mental foramen so, the dentists must have attention about this anatomical landmark before any surgical procedure including mental foramen region. Computed tomography (CT) is highly essential measure to avoid any expected complication.

Funding Information: The project was partly supported by Business Finland under project “Digital and Physical Immersion in Radiology and Surgery”. Mandibular canal annotations used in this study were partly provided by Antti Lehtinen, D.D.S. and Mika Mattila, D.D.S., both Specialists of Dentomaxillofacial Radiology. Deep learning approach has been demonstrated to automatically segment the bilateral mandibular canals from CBCT scans, yet systematic studies of its clinical and technical validation are scarce. To validate the mandibular canal localization accuracy of a deep learning system (DLS) we trained it with 982 CBCT scans and evaluated using 150 scans of five scanners from clinical workflow patients of European and Southeast Asian Institutes, annotated by four radiologists. The interobserver variability was compared to the variability between the DLS and the radiologists. In addition, the generalisation of DLS to CBCT scans from scanners not used in the training data was examined to evaluate its out-of-distribution performance. The DLS had a statistically significant difference (p < 0.001) with lower variability to the radiologists with 0.74 mm than the interobserver variability of 0.77 mm and generalised to new devices with 0.63 mm, 0.67 mm and 0.87 mm (p < 0.001). For the radiologists’ consensus segmentation, used as a gold standard, the DLS showed a symmetric mean curve distance of 0.39 mm, which was statistically significantly different (p < 0.001) compared to those of the individual radiologists with values of 0.62 mm, 0.55 mm, 0.47 mm, and 0.42 mm. These results show promise towards integration of DLS into clinical workflow to reduce time-consuming and labour-intensive manual tasks in implantology.

SUMMARY: A recent study found that the mandibular canal might be preferably called the inferior alveolar canal in recent publication years, certain journal categories, countries and departments with which the authors were affiliated. The canal can also be called the inferior dental canal that was not included in that study. This bibliometric analysis was conducted to evaluate the entire relevant literature, and to investigate if inferior alveolar canal was trending over the years. The Web of Science Core Collection electronic database was searched to identify publications exclusively mentioning mandibular canal, inferior alveolar canal, inferior dental canal, and publications mentioning them in combinations. Publication year, country of contributing authors, journal category, journal title, and citation count were recorded for the resultant publications. There were 1152 publications analyzed. Mandibular canal has always been the dominating term since the 1990s, whereas inferior alveolar canal seemed to become slightly more popular in the 2010s than in the past. Journals from dentistry, surgery, radiology, anatomy, and medicine all showed a preference towards mandibular canal. Leading dental surgery journals had a higher ratio of inferior alveolar canal usage than their dental radiology counterparts. Top 20 countries showed a preference towards mandibular canal except Saudi Arabia, which had 57.7 % of publications using inferior alveolar canal exclusively. Publications mentioning mandibular canal, inferior alveolar canal, and inferior dental canal did not differ in averaged citation count. The term mandibular canal was still dominating in all academic fields. The term inferior alveolar canal showed increased usage in the 2010s without an increasing trend. The argumentation of renaming mandibular canal as inferior alveolar canal has yet to accumulate considerable traction.

The present study aimed to assess whether anatomical variations of the mandibular canal are associated with neurosensory disturbances of the inferior alveolar nerve (IAN) following mandibular third molar removal. Two observers compared the detection of third molar root-nerve relations and bifurcations of the mandibular canal on panoramic radiographs and CBCT images of 201 patients undergoing removal of 357 mandibular third molars. Potential neurosensory disturbances of the IAN were surveyed ten days after surgery. Fisher’s Exact was performed to correlate presence of canal variations to postoperative neurosensory disturbances. Positive and negative predictive values (PPV, NPV) and likelihood ratios (LR + , LR–) were calculated. Thirteen patients reported postoperative altered sensation of the lower lip, with 2 of them having mandibular canal bifurcations on the ipsilateral side of the injury. Fisher’s Exact showed that the studied mandibular canal variations were not related to postoperative neurosensory disturbances. CBCT was superior in visualization of anatomical variations of the mandibular canal. Prevalence of bifurcations was 14% on CBCT and 7% on panoramic radiographs. In both imaging modalities and for all parameters, PPVs were low (0.04 − 0.06) and NPVs were high (0.92 − 0.98), with LR ranging around 1. In the present study, the assessed mandibular canal variations had limited predictive value for IAN neurosensory disturbances following third molar removal. While a close relation between the third molar and the mandibular canal remains a high risk factor, mandibular canal variations did not pose an increased risk of postoperative IAN injury after third molar removal.

© 2021, The Author(s), under exclusive licence to Japanese Society for Oral and Maxillofacial Radiology and Springer Nature Singapore Pte Ltd.Objectives: The aim of this study is to evaluate the mandibular trabecular and cortical bone structure of patients using systemic glucocorticoid (GC) and compare to control group with the fractal analysis (FA) and radiomorphometric indices. Methods: Two researchers retrospectively investigated 192 dental panoramic radiographs to compare individuals using systemic GCs to healthy controls. FA was performed in 4 different regions; geometrical center of the mandibular ramus (ROI1), cancellous bone on supracortical mandibular angle area inferior to the mandibular canal (ROI2), cancellous bone on mesial to the mental foramen (ROI3), basal cortical bone extending mental foramen to the first molars’ distal root in the mandibular corpus (ROI4). Panoramic mandibular index (PMI), mandibular cortical width (MCW) and mandibular cortical index (MCI) were performed for evaluate cortical thickness and porosity. The Shapiro–Wilk test was used to determine the normal distribution of the data, the independent t test for comparison of values and the chi-square test for descriptive statistics. Results: There were statistically significant differences in ROI4 and MCW. The fractal dimension (FD) values in ROI4 and MCW were significantly lower in study group. There were no significant differences in FD values in ROI1, ROI2, ROI3 and PMI and MCI measurements between both groups. Conclusions: FA and radiomorphometric measurements is an efficient method to detect early changes in bone mass. In our study, ROI4 and MCW were significantly lower in study group. Osteoporosis prevention should be considered in patients using systemic GCs.

Purpose Dental implants are widely used for the rehabilitation of edentulous sites. This study investigated the occurrence of dental implant malpositioning as shown on post-implantation cone-beam computed tomography (CBCT) and to identify related factors. Materials and methods Samples with at least 1 malpositioned dental implant were collected from a central radiology clinic in Tehran, Iran from January 2017 to January 2019. Variables such as demographic characteristics, length and diameter of implants, type of implant, sites of implant insertion, different types of implant malpositioning problems (cortical plate perforation, interference with anatomical structures), angulation of the implant, and the severity of malpositioning were assessed. In addition, the incidence of implant fracture and over-drilling was evaluated. Data were statistically analyzed using the chi-square test, 1-sample t-test, and Spearman correlation coefficients. Results In total, 252 patients referred for implant postoperative CBCT evaluations were assessed. The cases of implant malpositioning included perforation of the buccal cortical plate (19.4%), perforation of the lingual cortical plate (14.3%), implant proximity to an adjacent implant (19.0%), implant proximity to an adjacent tooth (3.2%), interference with anatomical structures (maxillary sinus: 18.3%, mandibular canal: 11.1%, nasal cavity: 6.3%, mental foramen: 5.6%, and incisive canal: 0.4%). Implant fracture and over-drilling were found in 1.6% and 0.8% of cases, respectively. Severity was categorized as mild (9.5%), moderate (35.7%), severe (37.7%), and extreme (17.1%), and 52.4% of implants had inappropriate angulation. Conclusion CBCT imaging is recommended for detecting dental implant malpositioning. The most common and severe type of malpositioning was buccal cortex perforation.

Objectives. This study aimed to assess the radiographic position of impacted mandibular third molars (IMTMs) and their association with pathological conditions. Materials and Methods. The impaction depth, relationship with ramus, and angulation of 1600 IMTMs and their association with 2nd molar distal caries and root resorption, pathological conditions, and proximity to the mandibular canal were evaluated on panoramic radiographs. The IMTM position was determined based on the depth of impaction according to the Pell and Gregory classification, relationship with ramus according to the Pell and Gregory classification, and angulation according to the Winter’s classification. The classical and Bayesian logistic regressions were applied to analyze the effect of IMTM position on the associated complications using the odds ratio (OR) and 95% confidence interval (credible interval for Bayesian models). Two-tailed P value

Impacted mandibular third molar extraction is one of the most frequent procedures performed in the field of oral surgery. Oral surgeons sometimes face cases that cannot be extracted using the conventional procedure because of atypical tooth structure or irregular tooth position in the mandible. Here, we report an unusual impacted third mandibular molar with atypical root form, which was extracted by buccal cortex osteotomy of the mandibular ramus. A 42-year-old Japanese female presented with a complaint of discomfort in the left molar region. Radiographical examination showed an impacted third molar with a mushroom-like root overlapping the mandibular canal. This lesion was radiographically diagnosed as cemental hyperplasia. The tooth could not be extracted using the conventional procedure, and buccal cortex osteotomy was applied. Briefly, bones necessary for extraction were removed once from the mandibular ramus. After extraction, the bony fragment was repositioned in the original position. The patient experienced no postoperative complications such as nerve paralysis, mandibular angle fracture, and infections. Buccal cortex osteotomy is a simple and easy technique to extract impacted mandibular third molars that cannot be extracted by conventional methods.

The anatomical variations of the mandibular canal have been described according to the number of additional branches it presents, bifid and trifid. Within the bifids we can also find subtypes of variations such as the retromolar mandibular canal. These anatomical variations can have important clinical implications for the work of dental professionals. A systematic search of the literature was carried out in different databases that met the following criteria: articles published between 2000 and 2020, and articles that established a clinical correlation with variations in the mandibular canal. After applying inclusion and exclusion criteria, 32 articles were obtained, in which the variations of the mandibular canal were identified, their prevalence and incidence, which was very varied between the different articles, it was also found that the CBCT was the main technique to identify the anatomical variations of the mandibular canal. Lastly, the anatomical variations of the mandibular canal have a direct clinical correlation with pre-surgical, intra-surgical and postsurgical complications in pathologies that require surgical intervention. The anatomical variations of the mandibular canal have a high incidence, so knowing them is of vital importance both for clinicians and anatomy professors who provide morphological training. We believe that research should focus on describing and diagnosing the causes of these anatomical variations. That said, there is also a continuous challenge for all health professionals to learn about the different anatomical variations that the human body presents and how these can affect clinical practice.

Background: Periapical and Orthopantomogram (OPG) are the most commonly used radiographs for assessment of the relationship of lower 3rd molar roots with the inferior alveolar canal. Panoramic radiographs provide inadequate information of the buccolingual relationship between the roots of the 3rd molar & mandibular canal being two-dimensional (2D) in nature. To verify the relationship in three (3D) dimensions and to make a predictable treatment plan, traditional investigations may be supplemented by using CBCT. Cone-beam computerized tomography (CBCT) is an office-based radiography technique used to assess the three-dimensional relationship of lower 3rd molar roots with inferior alveolar nerve. Patients and methods: This comparative-cross sectional study was conducted at the Department of Oral and Maxillofacial Surgery, Fatima Memorial Hospital (FMH), Lahore from 1st January 2019 till 30th June 2019. A total of 124 patients requiring removal of lower wisdom tooth were enrolled and then divided into two groups (62 in each) randomly. OPG was used for diagnosis of impacted lower 3rd molars in Group A patients while CBCT for diagnosis in Group B patients. A self-designed Performa was used to collect the data and final information was collected after 3 months of follow-up. Data analysis was performed using SPSS 20. A chi-square test was used to compare the postoperative paraesthesia between the OPG group and CBCT group patients. A p-value

Introduction This study aimed to evaluate the mandibular canal course in individuals with cleft lip palate (CLP) and mandibular prognathism in terms of the sagittal split-ramus osteotomy using cone-beam computed tomography. Materials and methods Individuals with CLP older than 16 years of age and planned to undergo Le fort I + SSR osteotomies and those with class III occlusion planned to undergo Le fort I + SSR osteotomies were included. The measurements on the cleft side of CLP patients were compared with both their noncleft sides and those with class III occlusion. The course of the inferior alveolar nerve and its position in the mandible were evaluated starting from the mandibular foramen, the first entrance to the mandible, to the mental foramen, the exit from the mandible. Results The distance between the mandibular canal and the buccal surface of the mandible (B3) on the plane tangent to the distal of the mandibular first molar and perpendicular to the occlusal plane was found to be greater in individuals with CLP (P = 0.011). Buccal cortex thickness (C4) at the level of the mandibular canal on the plane tangent to the distal of the mandibular second molar and perpendicular to the occlusal plane was found to be lower in individuals with CLP (P = 0.021). Conclusions The buccal cortex thickness of the mandible corpus and the distance of the mandibular canal to the buccal surface is different in patients with CLP compared to class III individuals' posterior to the mandible. Surgeons should take these differences into consideration during mandibular osteotomy.

Aim: Detection of the prevalence of bifid mandibular canal and classification of its types in the Egyptian population. Methodology: Radiographic examination of 329 mandibular sides was done using Planmeca Promax 3D Mid CBCT machine. The scans varied depending on patients’ sizes (according to the manufacturer’s recommendations) using different FOVs with the same voxel size (0.4 mm (400 μm)). The bifid the mandibular canal was observed and classified according to Naitoh`s classification (retromolar, dental, forward, and buccolingual canals). In addition, the prevalence of location of accessory canal types and the mean distance to the alveolar ridge and teeth were reported. Results: In 329 hemimandibles, there were 101 bifid canals (30.7%) and 37 trifid canals (11.2%). The dental canal type was the most common (43.3%), followed by retromolar canal type (33.7%), forward canal type (17.2%), and buccolingual canal type (5.7%). The forward canals and the dental canals had statistically similar mean distances of 11.1 ±2.1 and 11.1±2.5 mm respectively. The accessory canals were at a significantly longer mean distance (12.1±1.6 mm) to the alveolar crest in the premolar area compared to distance in the molar area (10.9 ± 2.3 mm). Retromolar canals showed a significantly longer distance of 13.8± 4.4 mm. Conclusions: Examination of the mandibular canal is mandatory by surgeons to minimize the chance of missing any accessory branches, since its prevalence was more than 40% with 21.3 % presented with bilateral manifestation.

Aim: The present study was done to evaluate the accuracy of panoramic radiography (OPG), conventional cross sectional tomography (CCST) and cone beam computed tomography (CBCT) to precisely portray structures in the posterior mandible. Materials and Methods: The present in-vitro study was performed on 42 edentulous human mandibles. A region 2cm behind the mental foramen was imaged using an OPG machine followed by imaging the same region using CCST function of the same OPG machine and CBCT. The distances from the alveolar crest to superior margin of the mandibular canal and alveolar crest to the lower border of mandible were measured in radiographs obtained by the three modalities. This step was followed by the comparison of the measurements performed in the cut-section of the mandible considered as Gold Standard. Results: The measurements done in the images obtained by OPG machine exceeded the values of gold standard by a mean of 2.69 mm ± 2.27 mm and 5.84 mm± 0.89 mm respectively. Similarly in CCST function and CBCT images, the measurements exceeded by 4.95 mm ± 2.35mm, 9.55mm ±1.25mm and 0.24mm ±0.20mm, 0.20mm ± 0.13mm respectively. The differences between the measurements made in radiographs and cut section were statistically significant. Conclusions: It was concluded that the measurements made by CBCT images were more precise, in addition CBCT images were also helpful in accurate three dimensional localization of the mandibular canal.

Background: Cone beam computed tomography (CBCT) is a diagnostic imaging modality for implant and surgical procedures in anterior and posterior mandibular area. It provides adequate information concerning maxillofacial regions, optimum image quality, excellent geometric accuracy, and low radiation dose. Aim: The aim of this study was to evaluate prevalence and anatomical variations in Mandible (Mandibular Incisive canal, Lingual Foramen, Mental Foramen, and Mandibular canal) in CBCT scans of the maxillofacial region. Methodology: All CBCT cross-sectional images of 40 study participants was analyzed for the presence of anatomical landmarks. All the anatomical parameters were compared with respect to age groups, dentition, gender, and right and left side and their respective distances from the inferior border of mandible and alveolar crest were measured using CS 3D imaging software (Kodak). Results: Lingual Foramen, Mental Foramen, and Mandibular Foramen were seen in all (100%) study samples, incisive foramen 83% and anterior loop in 25% of study samples. On statistical analysis, the difference of the mean distance of incisive foramen, mental foramen, anterior loop and mandibular foramen from lower border of mandible and alveolar crest was significant with relation to gender (P = 0.006) and with relation to dentate, partially dentate, and edentulous were found to be significantly different (P < 0.001). Conclusions: Careful assessment of the anatomical landmarks is essential to avoid neurosensory and bleeding complications using CBCT.

Introduction. Mandibular canal with the associated neurovascular bundle may be closely related to the apices of mandibular teeth. In order to avoid injuries and damages to the inferior alveolar nerve during invasive dental procedures, it is important to know its localization. The aim of this study was to determine the average vertical distances of the root apices of second premolars, first molars and second molars mesially and distally from the upper projection of the mandibular canal on the sagittal section of CBCT images, and determine if there were statistically significant differences between the age and gender groups. Material and methods. The research was conducted at the Faculty of Medicine of the University of Banja Luka, and the sample consisted of 146 CBCT images of patients. CBCT images were obtained using Planmeca ProMax 3D Mid instrument (Planmeca, Helsinki, Finland) and analyzed using Planmeca Romexis Viewer software. In the sagittal section, the vertical distance from the root apex to the upper projection of the mandibular canal was measured for each examined tooth. Results. The distal root of the first molar (4.88 mm) had the greatest average vertical distance of the root apex from the mandibular canal, and the distal root of the second molar had the smallest average vertical distance (2.76 mm). There was statistically significant difference between certain age groups in the values of individual roots, for the second molar mesially and distally (p < 0.05), while for the first molar mesially the value of p was at the limit of significance (p = 0.05). Conclusion. The results of this study showed that distal root of the mandibular second molar had the smallest vertical distance from mandibular canal, therefore an extra caution during a root canal treatment and careful planning of oral surgery in this region is recommended.

Objective: This diagnostic accuracy study aimed to evaluate the relationship between mandibular third molars (M3) and mandibular canal (MC) using panoramic radiographs (PR) and cone-beam computed tomography (CBCT) and to assess the effect of CBCT on treatment decision. Materials and Methods: CBCT scans of 150 patients with close association between MC and M3 on PR were included in the study. The degree of superimposition, Buccolingual position (buccal, central and lingual) and physical relationship (separation, contact and involved) were measured on CBCT images. Fisher's Exact test was used to evaluate differences between PR and CBCT. Results: All M3 were directly superimposed on the MC on PR; however, CBCT showed separation from the canal in 10% of M3 roots. Evaluation of CBCT images revealed that the probability to observe an involvement was significantly higher when the MC was in the lingual position (57.6%) than in other positions. Conclusion: Three-dimensional imaging is very useful to clarify the true relationship between M3 and MC relative to two-dimensional panoramic images, and the clinician may decide to change the treatment plan based on CBCT images in patients with high risk. Nevertheless, PR can be considered an acceptable diagnostic method with low radiation dose compare with CBCT.

Introduction: Atrophic mandibular jaws have been challenging to treat, using long implants. Techniques as jaw ridge augmentations, mandibular canal lateralization, and osseous distraction were proposed to allow the insertion of long Implants. However, complications as nerve injuries, tissue morbidity and prolonged healing have been inconvenient. Therefore, short implants with advanced surface treatments have been suggested. Objectives: Clinical and radiographic evaluation of splinted and single short implants, before and after loading, for teeth replacement in atrophic posterior mandibular alveolar ridges. Materials and Methods: A prospective study was done on 16 Patients with missing posterior teeth, with 6-8 mm of crestal height above the mandibular canal, and at least 7mm of bone width. Group A: 8 patients received 2 short implants loaded by splinted crowns. Group B: 8 patients received single short implants loaded by single crowns. Osstell and CBCts were used for implant stability and bone condition assessment. Results: Both groups maintained high implant stability with a mean of (68.79±4.61) for group A and (71.71±3.55) for group B, 6 months postoperative. Mean marginal bone loss for group A and group B was (0.11±0.04) and (0.16±0.10) respectively; however the difference is insignificant with P value 0.535. A remarkable increase in bone density for both groups among the follow up time with P value Conclusions: Short Implant is a useful solution for teeth replacement in atrophic posterior mandibular ridges, with an 87.5% of success recorded.

Objective: The aim of this study was to assess the relation between radiographic findings in large field of view (FOV) cone beam computed tomography (CBCT) exams and clinical findings of mandibular third molars in relation to the pre-operative patient information. Material and Methods: Two hundred and nine mandibular third molars in 134 orthognathic patients examined with CBCT were removed. Three observers assessed tooth- and mandibular canal-related variables in CBCT images, and the findings were correlated to clinical findings during surgery for all observers: tooth angulation, number and morphology of roots and close relationship between the tooth and the mandibular canal. Moreover, positive (PPV) and negative (NPV) predictive values and positive (LR+) and negative (LR-) likelihood ratios were calculated for the canal-related variables. Inter- and intra-observer reproducibility was expressed as percentage accordance and kappa-statistics. Results: Generally, there was high correlation between radiographic and clinical tooth-related variables. The opposite was true for the canal-related variables, since the PPV and LR + were low. The highest PPV and LR + were found when the mandibular canal was positioned between the roots of the third molar. Conclusions: Tooth-related findings in CBCT are reliable, whereas mandibular canal-related findings should not affect the information provided to the patient pre-operatively.

There are many reported anatomical variations of the mandibular canal. Consequently, there is great variation in the retromolar area, such as the quantity, size, and location of the retromolar foramen (RMF), the bony entrance of the retromolar canal (RMC). These variations allow for different accessory innervations to the mandibular molars and their adjacent buccal tissue because the RMC contains neurovascular bundles. Consideration of these anatomical variations is crucial for avoiding complications in anesthesia, implant placement, and surgery. However, the rarer canal types are often only imaged by computed tomography (CT) or cone beam computed tomography (CBCT). We present a rare case with bilateral RMF and a unilateral trifid mandibular canal in a cadaver.

Objectives: To evaluate impacted mandibular third molar tooth region and obtain linear measurements using CBCT images and to assess the relationship between the impacted third molar and the mandibular canal. Methods: CBCT scans of 351 patients (208 females, 143 males) were assessed. Age, gender, and impaction site were recorded for each patient. The relationship of third molars with the vertical axis of second molars, 2nd molar resorption and the relationship between third molar apices and the mandibular canal were assessed. In addition, the distance between ramus and second molar, mesiodistal width of the third molar, the angle between third molar and second molar, and width of the third molar capsule were measured. Binary Logistic Regression, Chi-Square Test, and General Linear Model were used for statistical analysis. Results: The highest percentage of impaction was found for mesioangular followed by transversal and vertical. The transversal impacted third molars revealed a significant association with adjacent second molar root resorption (p Conclusion: CBCT assessment of the third molar region provided useful information regarding impacted mandibular third molar surgery operations.

Mandibular foramen is an irregular foramen located just above the center of the medial surface of the ramus of the mandible. Mandibular foramen is leading to mandibular canal through which inferior alveolar nerve and vessels will transmit and supply the teeth of lower jaw.1 The inferior alveolar nerve block is the commonest local anesthetic technique which is used for anaesthetizing the lower jaw in various surgical & dental operations on the mandible and mandibular teeth such as removal of impaction, reductions of fractures and extraction of teeth. The success of this technique highly depends on the proximity of the needle tip to the MF at the time of the anesthetic injection. The aim of the study was to find exact location of mandibular foramen from different anatomical landmark. In present study we took 60 dry human mandibles & all the distances were measured from center of mandible to different landmark on both sides. The mean of MF-AB distance on right side is 15.6mm & on left side is 15.3mm. Mean of MF-PB distance are 12.0mm & 11.0mm on right side and left side respectively. MF-MB distance 23.4 mm and 22.9 mm are the mean of MF-MN on right and left side respectively. The mean of MF-AG is 23.2mm on right side & 24.2mm on left side. There is great variation found in the position of MF in previous studies. The present study helps in dental anaesthesia and also would help dental surgeons to avoid complications. Keywords: Mandibular foramen, Landmark, Inferior alveolar nerve distance.

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

Introduction The purpose of this study is to determine the 3-dimensional location of mandibular canal (MC), thickness of the cortical and cancellous bone at distal of 1st and 2nd mandibular molars in patients with Class 3 dentofacial deformity and compare with the dentoskeletal Class I individuals in relevance to sagittal split ramus osteotomy. Methods The study was conducted on CBCT images of 30 dentoskeletal Class I patients with a mean age of 22.9 years and 30 dentoskeletal Class III patients with a mean age of 21.27 years. Results The comparison of the measurements in the distal root of the first molar area showed that: thickness of the buccal cancellous bone, the distance from buccal aspect of MC to outer buccal cortical margin of mandible and the distance between superior aspect of MC and alveolar crest were significantly greater in Class I patients. The comparison of the measurements in the distal root of the second molar area showed that; the distance between superior aspect of MC and alveolar crest was significantly greater in Class I patients. However, the distances from the distal margin of mental foramen was significantly lower in Class I patients (P Conclusion In case of deviated skeletal development, position and size of anatomical structures can vary significantly. Prognathic mandibles has increased risk of neurovascular complications and bad splits. Morphologic data provided in this study may help practitioners for better surgical planning to reduce complications.

The success of orthodontic treatment quite often depends on cooperation between the orthodontist and the dental surgeon. An integrated approach, including orthodontic treatment of dento-maxillary anomalies in combination with using the latest surgical techniques can provide quick defect correction of the maxillofacial region and ensure better stability of the results achieved; in most cases of teeth crowding, there is no alternative to the removal of the third lower molars. The purpose of this study was to analyze the surgical interventions performed on for surgical extraction of wisdom teeth for orthodontic reasons and the approach to their choice. Materials and methods. During 2016-2020 years, 158 patients were subjected to 241 surgical interventions for surgical extraction of the third lower molars for orthodontic reasons. We performed on 160 (66.4%) standard operations of atypical tooth extraction, 43 (17.8%) germectomies and 38 (15.8%) coronectomies. The patients' age ranged from 12 to 26 years. All patients were examined by applying the standard technique including orthopantomogram. In cases then it was impossible to clearly assess the ratio between the roots of the wisdom tooth and the mandibular canal as a result of the superposition of their projections on the obtained pantomograms, we used computed tomography. Based on the data obtained from the examination of the patient, the optimal safest surgical intervention was chosen for removal: the surgical extraction of the wisdom tooth, germectomy, or coronectomy. Conclusions: 1. Operations on surgical extraction of the lower wisdom teeth require mandatory planning and an individual approach to each patient based on a thorough preliminary examination. 2. In cases when it is impossible to clearly assess the ratio between the roots of the wisdom tooth and the mandibular canal as a result of overlapping their projections on the pantomograms, patients are recommended to undergo computed tomography, and then based on the assessment of CT findings to determine the topographic and anatomical relationship of the mandibular canal and roots. 3. The operation of surgical extraction of the lower wisdom tooth can be performed as a standard operation, germectomy can be recommended for patients with underdeveloped roots, coronectomy is a good option when the roots of the wisdom tooth are very close to the mandibular canal.

Conventional intraoral removal of deeply impacted or ectopic mandibular third molar is challenging for limited surgical access. Because there are potential risks of inferior alveolar nerve (IAN) injury or iatrogenic mandibular fracture, several methods for the removal have been proposed. As minimally invasive and safe surgery, we report image-guided removal of deeply impacted mandibular third molar using navigation system. A 32-year-old male was referred to our department with right mandibular pain and swelling. Panoramic radiograph showed right mandibular third molar was deeply impacted and interrupted the white line of the mandibular canal. Computed tomography (CT) showed deep impacted right mandibular third molar with root projection from the lingual cortical bone, and there was resorption of lingual cortical bone and passing of mandibular nerve between roots. For mandibular navigation surgery, a resin occlusal splint with titanium markers and handle was manufactured to fix reference frame to the mandible. CT was performed preoperatively after the occlusal splint was fixed with patient’s mandibular teeth, and the patient underwent image-guided removal of mandibular third molar with navigation system under general anesthesia. After reference frame was attached to the handle of the occlusal splint fixed with patient’s mandibular teeth, point-based registration was performed. The crown was removed after the sectioning, and the root sectioning with calibrated bur was performed carefully to avoid injury of the IAN under navigational guidance. The roots were completely removed, and the IAN was exposed in the lingual cortical bone defect. Postoperative course was uneventful without paresthesia of the IAN.

Background and Objectives: The presence of bifid mandibular canals are among the anatomical variations in the inferior mandibular canals. Lack of attention to these canals can lead to complications, such as anesthesia and bleeding during dental treatments. This study aimed to investigate the prevalence of bifid canals and its relationship with the position and width of the main canal in the population-based panoramic radiographs in Qom, Iran. Methods: This analytical-descriptive, cross-sectional, and retrospective study investigated 2415 panoramic radiographs of 1320 females and 1095 males (age range: 18-86 years) who refereed to Dentistry School and Salamat Clinic in Qom, Iran, during 2019. The radiographs were evaluated regarding the presence of bifid mandibular canals on the right and left as well as canal width and distance using Scanora software. The data were analyzed in SPSS software through descriptive statistics (i.e., frequency, mean±SD) and analytical statistics (i.e., Chi-square, independent t-test, and Mann-Whitney test). A p-value less than 0.05 was considered statistically significant. Results: According to the results, the prevalence of the bifid mandibular canal was observed in 64 (2.6%) cases. Moreover, three (0.1%) individuals had bilateral bifid mandibular canals; therefore, the total number of the bifid mandibular canals was estimated at 67 cases. Furthermore, type 2 bifid mandibular canals were the most common type. In addition, the presence of bifid mandibular canals had no significant relationship with age, gender, width, and distance to the inferior border of the mandible. Conclusion: The presence of bifid mandibular canal in panoramic images had no significant relationship with age, gender, width, and distance to the inferior border.

Purpose The mandibular canal is damaged by the growth of cysts, and remodeling of the mandibular canal is observed as the size of the cyst decreases after decompression procedures. This study aimed to estimate changes in cyst volume and mandibular canal length using cone-beam computed tomography (CBCT) before and after decompression surgery. Materials and methods A retrospective cohort study was conducted in patients with a diagnosis of mandibular cyst invading the mandibular canal between 2012 and 2018. All patients underwent CBCT at the initial visit and after decompression. The predictor variable was the period before decompression and before enucleation surgery. The outcome variables were changes in cyst volume and mandibular canal length, which were evaluated 3-dimensionally. The initial volume of the cyst, initial length of the mandibular canal, and patient's age were set as variables of interest that affected the outcome. Results Decompression was performed in 20 patients (18 male and 2 female patients), and the mean decompression duration was 8.81 ± 2.94 months. The average volume reduction rate after decompression was 60.23%, with an average volume reduction speed of 0.72 mL/month. The average length increase rate after decompression was 50.88%, and the average speed of length increase was 2.68 mm/month. The initial volume of the cyst and initial length of the mandibular canal were the important variables affecting the results. Complete separation of the mandibular canal from the cyst was observed in 11 cases, and incomplete separation was found in 9. Conclusions Separation from the cyst and regeneration of the mandibular canal using decompression were observed using 3-dimensional CBCT analysis. The results of this study suggest that decompression is effective in separating and preserving important anatomic structures invaded by the cyst.

Calcium hydroxide (Ca (OH)2) paste is widely used as a provisional root canal filling material. This report describes a case of inferior alveolar nerve paresthesia caused by overfilling of Ca (OH)2 paste. A 53-year-old woman had previously undergone root canal filling in the left lower second molar with Ca (OH)2 paste. Immediately after the treatment, she felt sharp pain and paralysis in the left lower lip and chin area and visited our hospital four days later. X-ray examination showed a large radiopacity associated with the left mandibular canal and around the bone marrow from the lower left second premolar to the lower left third molar. We planned a tooth extraction and surgical removal of the Ca (OH)2 paste. However, she declined surgery, and we performed conservative treatment with administration of vitamin B12 and root canal therapy. Approximately one year after her first visit, we filled the root canal with gutta-percha and sealer. The tooth was preserved and paresthesia of the left lower lip and chin largely decreased except for a small remaining numb area. Therefore, it is important to pay scrupulous attention to ensure no extrusion of Ca (OH)2 paste beyond the root apex to avoid complications.

OBJECTIVE To characterize the CT findings and epidemiological features of acquired dental disease in rabbits. ANIMALS 100 client-owned rabbits (Oryctolagus cuniculus). PROCEDURES Medical records were searched to identify rabbits that underwent skull CT for any reason from 2009 to 2017. History, signalment, and physical examination findings were recorded. The CT images were reevaluated retrospectively for evidence of dental disease and graded according to a previously described system (from 1 [no evidence of disease] to 5 [severe dental disease]) for acquired dental disease in rabbits, and an overall (mean) grade was assigned. Descriptive analyses were performed. Factors were assessed for associations between dental disease grade and malocclusion stage. RESULTS Common findings included premolar or molar tooth curvature in transverse (n = 100 rabbits) and sagittal (95) planes, apical elongation of premolar or molar teeth (99), sharp dental points (93), deformation of the mandibular canal (82), and periodontal ligament space widening (76). Acquired dental disease was classified as grade 1 (n = 2 rabbits), 2 (60), 3 (14), 4 (4), or 5 (20). Most CT findings were significantly correlated with each other. Agreement of grades was fair between left- and right-sided quadrants and between maxillary and mandibular quadrants. Age was associated with increasing dental disease grade and malocclusion stage (proportional ORs, 1.21 and 1.32/y, respectively). CONCLUSIONS AND CLINICAL RELEVANCE Fair agreement in disease grades between dental quadrant pairs indicated a degree of asynchrony in the development of dental disease. Findings suggested premolar or molar tooth curvature in a sagittal plane, subtle elongation at premolar or molar tooth apices, and mandibular canal deformation should be added to the grading system.

Dental implantation is the most popular method of restoring lost teeth. There are risk factors for dental implantation. These risk factors include the localization of residual filling material in the lumen of the mandibular canal in the selected jaw segment for implantation. A rare clinical case of dental implant placement with preservation of the safety zone relative to the residual siler in the mandibular canal is presented. A surgical guide was used for precise positioning. The treatment protocol was carried out without an immediate loading stage to monitor the possible development of symptoms.

AIM: The objective of this study was to correlate the preoperative radiological findings and intraoperative surgical findings during removal of impacted mandibular 3rd molar with respect to the inferior alveolar canal. MATERIALS AND METHOD: The prospective study design included 100 patients between the age group of 20 years and 50 years who visited the Department of Oral and Maxillofacial Surgery at Vydehi Institute of Dental Sciences and Research Centre, Whitefield, Bengaluru. A preoperative panoramic radiograph was taken and the parameters were assessed and a normal surgical protocol was followed to extract the impacted mandibular 3rd molar with intra-operative assessment as well. RESULTS: Out of the 100 patients with definitive radiological signs showing close relation of the third molar to the mandibular canal who underwent surgical removal, only 12 patients presented with definitive clinical findings of the association. CONCLUSION: A true close relationship between the third molars and mandibular canal increases the risk of inferior alveolar nerve injury, and accurate evaluation of the relationship is essential to avoid the risk of surgery. The accuracy of the plain radiographs to diagnose an intimate relationship between the neurovascular bundle and the third molar root has its limitations, since only 12 of the 100 patients with positive radiological signs showed clinical evidence of involvement. Surgeons should be aware of the limitations of the radiographic markers of panoramic radiography and should consider more detailed imaging in more specific cases in which one or more radiographic marker is present.

The purpose of this study is to evaluate CBCT images of impacted mandibular canines in detail and to discuss implications for diagnosis and treatment. CBCT images of dental patients applied between December 2015 and December 2017 were evaluated retrospectively. 2591 CBCT images, including mandible in their field of view, were determined and evaluated regarding the presence of mandibular canine impaction. 66 impacted mandibular canines of 58 patients were analyzed in detail regarding their location, morphology, associated pathologies, and their relationship with the neighboring anatomic structures, the role of these factors on transmigration, as well as treatments applied. The Pearson Chi square test was used between the groups. Transmigration was observed in 53% of impacted mandibular canines. Teeth with transmigration were localized horizontally, below the apex of adjacent teeth frequently, and had no contact with mandibular cortical bone mostly. 62% of mandibular canines were in contact/proximity with the incisive mandibular canal. The most applied treatment for transmigrated teeth was surgical removal, followed by radiographic monitoring, but orthodontic traction was not preferred in any case. For non-transmigrated teeth, the most applied treatment options were surgical removal, orthodontic traction, and radiographic monitoring, respectively. Autotransplantation was not preferred in any case of impacted teeth. Vertical position of the crown tip (p

One of the most vital anatomical structure within the mandible is the mental foramen. The significance of this structure come since it is the anatomical opening of mandibular canal on the mandible bilaterally. The neuro-vascular complex leaving from the foramen has a critical and important role and giving supply to the skin and muscles of the chin, lower lip, the associated gingiva and mucosa following to the lower premolars. Subsequently, the location knowledge of the mental foramen considers an awfully significant for dental specialists to dodge harming this imperative structure via the dental working on this region, as in dental anaesthesia, dental surgery, dental anaesthesia and root canal treatment. The aim of study: The point of the think about: To assess the site of the mental foramen in relative to the mandibular premolars, depended on the panoramic and CBCT and O.P.G images. Materials and Methods: The current study involved the previous articles published from 1997 till 2019, with respect to the site of mental foramen in elderly and adult patients, in any case of the gender. All these studies were used on either the panoramic and cone-beam computed tomographic images for visualizing the site of the mental foramen. Results: Regarding the outcomes of the previous studies included in this review, the statistics appeared that the first common area of mental foramen was beneath the apices of lower second premolars in the percentage of 49.99%, the other second common area of mental foramen was between the apices of the lower first and second premolars in the percentage of 42.30%. Conclusion: The mental foramen was mostly found beneath the apices of lower first and second premolars and then between the apices of the lower first and second premolars.

Background Injury to the inferior alveolar nerve (IAN) is a severe complication of third molar (M3) surgeries that may interfere with speech, chewing, and social interactions, all of which affect quality of life. Factors such as direct IAN-M3 contact and interruption of the mandibular canal border (decorticalization) diagnosed from cone-beam computed tomography (CBCT) images have been reported as risk factors, although their relation to postoperative sensory impairment is controversial. The purpose of this study was to assess the association between postoperative nerve injury and direct contact between IAN and M3 or canal decorticalization defined with CBCT. Materials and methods Seventy-five patients with at least one M3 tooth (total of 126 teeth) in direct contact with the IAN were included in the study. All associations were confirmed with CBCT. Nerve injuries after surgery were confirmed and follow-ups were made with information given by patients, light touch, and pinprick tests. The relationship between sensory impairment and direct contact between IAN and M3 or canal decorticalization on CBCT images was statistically assessed. Results One M3 extraction (0.8%) presented with postoperative permanent sensory impairment. No correlation between nerve injury and direct contact with the IAN or canal decorticalization on CBCT could be established. Conclusion There is no association between nerve injury and direct IAN-M3 contact or canal decorticalization. Although orthopantomography is commonly used to plan M3 surgeries, consideration of CBCT as a viable alternative is warranted.

The bifid mandibular canal is an anatomical variation, which causes anesthetic failure and surgical accidents occasionally. The purpose of this study is to observe the prevalence and anatomical location of bifid mandibular canals, providing clinical value in reducing the occurrence of surgical accidents and postoperative complications. A total of 321 outpatients were selected in this study. Their CBCT images were observed, and the prevalence of bifid mandibular canals as well as the composition ratios of each branch type was evaluated according to the classification of Naitoh. The bifid mandibular canals and their branches’ diameter, length, horizontal distance to the buccal/lingual wall of the mandible, and vertical distance to the mandibular alveolar ridge were measured. Furthermore, 194 dry adult mandibles from the Department of Oral Anatomy and Physiology of Tianjin Medical University were observed to evaluate the prevalence and the average diameter of retromolar foramina. Of all the 321 patients, 84 (26.17%) cases of bifid mandibular canals and 105 (16.36%) sides of unilateral bifurcation were observed. Based on Naitoh’s classification, the retromolar canals were the most common types (46.67%), followed by the forward canals (40.00%), the dental canals (10.48%) and the buccolingual canals (2.86%). In 194 dry adult mandibles, 23 cases (11.86%) and 29 sides (7.47%) of retromolar foramina were found and the average diameter of retromolar foramina was 0.94 ± 0.30 mm. More than a quarter of the population has the bifid mandibular canal, which is a potential factor of the onset of surgery accidents. CBCT is an effective method to identify the branches of mandibular canals. Preoperative CBCT examination can help reduce various postoperative complications.

Summary Background The inferior alveolar nerve (IAN) courses through the mandibular foramen (MF) to enter the first segment of the mandibular canal (MC) in the mandibular ramus, to further supply with trigeminal fibers the lower teeth of that hemimandible. As the IAN also supplies the mylohyoid nerve, it is a mixed nerve. Methods Unusual morphologies of the mandibular ramus were encountered during a retrospective study of archived CBCT files. Results A previously unreported anatomic variation was found bilaterally in an edentulous mandible, consisting of a lowered position of the MF, with seemingly compensatory lengthening and enlargement of the sulcus colli, thus shortened MCs. Also, a rare neurovascular canal of the neck of the mandible was incidentally found unilaterally in another case and is reported here. Conclusions Such possibilities of variation could justify the individual effect of the IAN block.

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 computerized tomography (CBCT), for evaluating its position and exact location. Mandibular neurovascular canal contents may be vulnerable to damage during mandibular surgical procedure. Greater knowledge of the location and configuration of the mandibular canal can help in the safe performance of these procedure in the dental clinic. Cross-sectional CBCT imaging is a good modality for studying the course, location, configuration and accessory branches of the mandibular canal. Advanced cross-sectional imaging modalities especiallly CBCT is a suitable tool for observing anatomic characteristics of mandibular canal to preserve this vital structure in surgical procedure.

We sought to investigate the transport route for protein‐rich fluid from the apical area towards the draining lymph nodes. The first mandibular molar root canals in 24 female Wistar rats were instrumented and filled with radioactive‐labelled human serum albumin. The rats were sacrificed at different intervals beginning after 10 min (time 0) and continuing up to 72 h. Three jaw segments, gingiva around the first molar, blood samples, submandibular and cervical lymph nodes were collected and analyzed for radioactivity. The starting volume of tracer (control) for all experiments was calculated from measurements at time 0. At time 0, radioactivity was only detected in the jaw segments. Within lymph nodes and serum, the tracer was found after 4 h, with the highest amount recorded in serum up to 24 h. Lymphatics were found within the mandibular canal along blood vessels and nerves and exiting via foramen mandibularis, after immunohistochemical staining in four untreated rats. Our results show tracer distribution from the apical area towards the mandibular canal in a posterior direction. The tracer washout rate was low, and the fluid was mainly absorbed into blood vessels. The lymphatics in the mandibular canal may be more important for immune cell transport than for fluid drainage. publishedVersion

Background & aim: The mandibular canal is a canal within the mandible that contains the inferior alveolar nerve, inferior alveolar artery, and inferior alveolar vein. Surgery within the mandibular canal requires accurate knowledge of the intra-bone pathway and anatomy of the canal due to the possibility of damage to the mandibular canal. Considering the importance of being aware of the variability of the mandibular canal and the fact that few researches has been conducted in Iran through CBCT, the aim of this study was to determine the frequency of bifurcated mandibular canal and to investigate its relationship with the third molar in CBTT images. Methods: In the present retrospective descriptive cross-sectional study, the Cone Beam Computed Topographies (CBCTs) of 101 patients were evaluated and classified by sex, and by the presence or absence of bifurcation. The CBCT examination was employed from recorded CBCT of a private oral and maxillofacial radiology center (Yasuj, Iran) from 22 July to 22 September 2019.The type of bifurcation was identified using Langlais and Correr classification. The Data was evaluated using the SPSS software, and the BMC types and frequency were determined. The Chi square test was used to assess the relationship between sex and bifid canals. P≤0.05 were considered statistically significant. Result: The results displayed 50% of the identified cases of type 1(one bilateral branch stretched to the third molar or around) and 50% of type 2 (two bilateral unilateral branches that were stretched along the main canal and join in the mandibular Ramus). Based on the blind classification 20% (2) of type B (i.e., the close proximity between the two-branched mandibular canal and one-third of the third molar tooth crown) and 80% (8) cases were of type D. In the present study, the frequency of bifurcated mandibular canal was 9.9% and a significant relationship was observed between bifurcated mandibular canal and sex (p

Bone resorption in posterior mandibular region creates a challenge in placement of dental implants and prosthetic rehabilitation due to presence of inferior alveolar nerve (IAN). Several alternatives treatment modalities are suggested: the use of short implants, cortical implants, guided bone regeneration, appositional bone grafting (both autogenous and allograft), distraction osteogenesis, inclined implants tangential to mandibular canal, and the lateralization of the inferior alveolar nerve. In this paper, we will present IAN repositioning cases and simultaneous implant placement and asses the success of implants, severity of nuerosensory disturbances and its impact on present day implant dentistry. Keywords: Inferior alveolar nerve (IAN), Nerve repositioning, Dental implants, Mandibular atrophy, Nuerosensory disturbances.

This study reviewed the literature on the position of the mandibular canal (MC) relative to the root apices (RA) of neighbouring teeth using cone beam computed tomography (CBCT). The authors searched the PubMed, Scopus, EBSCO Dentistry and Oral Sciences Source, Cochrane and Lilacs databases for relevant English-language articles with no year limitations published through January 25, 2018. The search identified 888 articles, 12 of which met the inclusion criteria. Three groups were found based on the measuring method: the shortest distance from the RA to the MC, the vertical distance from the RA to the MC, or the distance from the RA to the superior cortical bone of the MC. In the first and second groups, the shortest distances to the canines, first premolars, second premolars, first molars, second molars, and third molars were 3.8 mm, 4.76 mm, 1.65 mm, 1.23 mm, 0.64 mm, and 1.28 mm, respectively. In the third group, the shortest distances to the second premolars, first molars, and second molars were 2.71 mm, 3.82 mm, and 1.4 mm, respectively. The distance from the MC to the RA was generally shorter in females and younger people, with decreasing distances in patients over 60 years old, and depended on the tooth type. The protocol for this systematic review was registered on PROSPERO (CRD42018085478).

Introduction: Dental implant is the most preferable option for the replacement of missing teeth because of its advantage of maintaining the structural and functional integrity of bone, like that of a natural tooth. Aim and Objectives of the Study: Aim of this study is to evaluate the depth of submandibular gland fossa and its relationship with the mandibular canal, based on gender and side of the mandible. Materials and Methods: 100 CBCT scans of both males and females were acquired. The deepest region of submandibular gland fossa and the superior, parallel, and the inferior relationship of the mandibular canal to submandibular gland fossae were obtained. Results: The mean ± SD of the depth of the submandibular gland fossa on the right side in males and females were 1.69 ± 0.73 mm and 1.62 ± 0.58mm, respectively, and those on the left were 1.69 ± 0.61 mm and 1.56 ± 0.42 mm, respectively. The deepest region in both the genders was above the infra-alveolar canal. Conclusion: Males showed greater depths when compared to females, Right side of the mandible showed greater depth when compared to the left side in both genders. Therefore, careful evaluation of alveolar bone thickness during implant placements is of great importance in males.

Background/Aim: The aim of the present study was to assess prevalence and morphologic mandibular canal variations in dry skulls. Material and Methods: Panoramic radiographs were obtained of 57 skulls among the academic collection at the University of Pittsburgh. Orthodontic wire was inserted through the mandibular canal as a reference point at panoramic images for localization of the course of the mandibular canal. Results: Double mandibular canals were present in 2 out of 57 skulls (3,5%); one of them was unilateral the other one was bilateral. Additionally, bifurcation of the mandibular canal and different types of configurations were assessed. In five of the specimens (8,8%) bifid canals were identified. Among them, one case (1,7%) was identified as a forward type. In one case additional canal (1,7%), was detected in the retromolar region, which joined the main canal. Three of the specimens (5,3%) showed accessory canal types. These were the canals that detached from the main canal and proceeded towards the molar teeth roots (dental type). All of these bifid canal types were unilateral. Conclusions: Our results depicted the anatomical variations of the mandibular canal. Dental practitioners should be aware of this underestimated but not a rare occurrence of mandibular canal variations in order to avoid complication during surgical procedures.

The dentigerous cyst is the second most frequent odontogenic cyst after the root, being typically asymptomatic and commonly incidentally diagnosed. The objective of this case was to describe a successful treatment of a dentigerous cyst associated with an unerupted lower third molar, which extended from the condyle to the premolar region, treated by decompression followed by surgical enucleation. That said, a 19-year-old female patient, black, without underlying pathologies, came to the dental office for extraction of the third molars, and after a preoperative orthopantomographic radiography, the displacement of the dental element was noted 38 for the condylar region, unilocular cystic lesion occupying the branch and mandibular body region, root resorption of the dental elements involved in the region and rejection of the mandibular canal. After cytopathological analysis of the material collected through fine needle aspiration, the diagnosis of infected dentigerous cyst was confirmed. Afterwards, extraction and decompression were performed followed by surgical enucleation. Thus, it is concluded that the treatment performed promoted a satisfactory result, given a spontaneous bone neoformation after decompression and surgical enucleation of the lesion.

Introduction: Third molars are common teeth to be impacted. The position of mandibular third molar is such that it is in close contact with inferior alveolar canal which may lead to nerve damage during its removal. So, this study was conducted to find out the prevalence of compression of inferior alveolar canal by mandibular third molars. Methods: This descriptive cross-sectional study was conducted on images collected from Dental Imaging Centers of Nepal from 25th June 2020 to 15th February 2021 after obtaining ethical clearance from Nepal Health Research Council (Reference number: 2100). A convenience sampling method was used to collect 433 cone-beam computed tomography images showing the relation between the third molars and inferior alveolar canal. Data were analyzed using the Statistical Package for the Social Sciences version 16. Point estimate at 95% confidence interval was calculated along with frequency and proportion for the binary data. Results: Out of 433 images, 135 (31.17%) (26.80-35.53 at 95% Confidence Interval) images showed compression of inferior alveolar nerve by mandibular third molar. The study result indicated that 16 (11.85%) buccally placed, 50 (37.03%) lingually placed and 69 (51.11%) inferiorly placed inferior alveolar canal were compressed by apices of mandibular third molars. Conclusions: The prevalence of compression of inferior alveolar canal by mandibular third molar was found to be similar to other studies done in similar settings. Compression of the canal was more evident when inferior alveolar canal is situated lingually.