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The aim of this study was to evaluate the position of the mandibular canal (MC) before and after bilateral sagittal split ramus osteotomy (BSSRO) using cone-beam computed tomography (CT), and to compare the position of the MC in Class II and Class III patients in the preoperative period. Patients were divided into two groups: Class II (n = 38) and Class III (n = 41). Measurements of the superior, inferior, buccal, and lingual distances of the MC in relation to the cortical bone were taken at three levels in the proximal segment of the mandible. Results were analysed using the Kruskal-Wallis test (p < 0.05). In the Class II group the superior distance of the MC at levels 2 and 3, and the inferior distance at level 3 significantly decreased after BSSRO. In the Class III group, no significant differences were found at any level, and the inferior distances at all levels were smaller preoperatively than those in the Class II group. In the Class II group the position of the MC altered in relation to superior and inferior cortical bone after BSSRO. However, the position of the MC remained stable in the Class III group. Our results also suggest a deeper cut in inferior cortical bone in Class III patients.

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

PURPOSE The present study aimed to evaluate which factors were statistically associated with a greater probability of inferior alveolar nerve (IAN) damage during lower third molar surgery. METHODS A prospective observational study was performed at the Oral Surgery Unit of the Umberto I Hospital on 92 patients who underwent surgical extraction of a lower third molar that was radiographically overlapped with the mandibular canal. All surgeries were performed by the same expert surgeon. A principal component analysis and the exact 2-tailed Fisher exact test were used. RESULTS Temporary IAN damage occurred in 10 cases (10.9%). Symptoms lasted from 18 to 180 days (73 ± 49.15). IAN damage was more frequent in difficult and long-lasting surgeries, in the presence of many risk factors and in patients with a reduced maximum mouth opening. CONCLUSION Such factors should be accurately evaluated before surgery to assess and discuss the overall surgical risk of IAN damage with the patient especially when they are over the maximum limit of their significant variability range found in the present study, that is, >12 for difficulty index, >2 for number of orthopantomography risk markers and

PURPOSE Since cone-beam computed tomography was developed, a number of radiological studies on the bifid mandibular canals (BMCs) and trifid mandibular canals (TMCs) have been reported. However, many of the suggested subtypes of the BMC described in the literature seem to be normal branches of the inferior alveolar nerve. This might be due to a lack of revisiting classic anatomical studies in the field of radiology. Therefore, such studies are revisited here. METHODS A database search using PubMed and Google Scholar was conducted on BMC and TMC. Eighty-nine articles underwent full-text assessment. The reported three classifications of BMC and the six modified classifications were reviewed and compared to the intramandibular inferior alveolar nerve branches. RESULTS Some subtypes of BMC and TMC simply represent normal inferior alveolar nerve branches, i.e., retromolar branch, molar branch (alveolar branch/dental branch), large mental branch, or communicating branch. Others such as Naitoh's type III BMC and forward canal might be a true BMC. CONCLUSION We found that the bifid mandibular canal is an additional intramandibular canal running parallel to the mandibular canal with/without confluence with the main canal through comparison of classifications of BMC/TMC between the radiology and anatomy fields.

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

The mandibular canal is a single canal that runs in the mandible carrying inferior alveolar neuro vascular bundle and splitting of the mandibular canal into in its course is rare occurrence. With the advent of 3-dimensional imaging modalities like computed tomography or cone-beam computed tomography better visualization becomes possible. As a result, more cases of this nature are being reported in the recent past giving rise to increased prevalence than in the past where two-dimensional imaging like digital panoramic tomography were dominating. This article also appreciates the radiological anatomy of three cases with bifurcation of the mandibular canal incidentally diagnosed in the cone-beam computed tomography and also discusses the clinical significance of this rare anatomical entity.

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.

The bifid mandibular canal (BMC) is an anatomical variation with reported prevalence ranging from 0.08 to 65%. Identifying anatomical variations of mandibular canal is very important in order to prevent possible complications during oral surgical and other dental procedures. Objectives: The aim of this study was to determine the prevalence and to classify the morphology of BMCs using digital panoramic radiographs. Material and methods: A retrospective study was conducted that included 1008 digital panoramic radiographs (412 female and 596 male) used to identify the type of BMC. Panoramic radiographs were analyzed by three oral surgeons and one dentist, and BMCs were classified into six different types, 4 types according to Langlais et al. (types 1-4), and two new types (types 5 and 6) described by authors. Results: The prevalence of BMC was 4.66% (n=47), with no significant differences in gender between BMC types (P=0.947; χ2=0.74). The prevalence of type 1 BMC was 0.79 % (n=8), type 2 2.08 % (n=21), type 3 0.30 % (n=3), type 4 0% (n=0), type 5 0.89 % (n=9) and type 6 0.60% (n=6). Conclusion: This study revealed a relatively high prevalence of BMCs among Zagreb citizens. Furthermore, two new types of BMCs were described. These results stress the importance of a careful and thorough radiographic analysis prior to each invasive procedure in the mandible., Dvostruki mandibularni kanal (DMK) anatomska je varijacija s učestalošću u rasponu od 0,08 do 65 %. Njegovo uočavanje iznimno je važno kako bi se prevenirale moguće komplikacije tijekom oralnokirurških i drugih dentalnih zahvata. Svrha: Cilj istraživanja bio je ustanoviti morfološke klasifikacije i učestalost dvostrukoga mandibularnog kanala koristeći se ortopantomogramskim snimkama. Materijali i metode: Obavljena je retrospektivna analiza 1008 digitalnih ortopantomograma (412 od žena i 596 od muškaraca) kako bi se identificirao tip i učestalost DMK-a. Tri oralna kirurga i jedan stomatolog analizirali su ortopantomogramske snimke i dvostruki mandibularni kanal klasificirali su u šest različitih tipova – četiri prema Langlaisu i suradnicima (tipovi 1 4) i dva nova (tip 5 i 6) koje su opisali autori ovoga istraživanja. Rezultati : Učestalost DMK bila je 4,66 % (n = 47), bez statistički značajne razlike prema spolovima (P = 0,947; χ2= 0,74). Učestalost tipa 1 iznosila je 0,79 % (n = 8), tipa 2 bila je 2,08 % (n = 21), tipa 3 – 0,30 % (n = 3), tipa 4 – 0 % (n = 0), tipa 5 – 0,89 % (n = 9) i tipa 6 – 0,60 % (n = 6). Zaključak: U ovom istraživanju utvrdili smo razmjerno visoku učestalost DMK-a među stanovnicima Zagreba. Nadalje, opisana su i dva nova tipa. Rezultati istraživanja pokazuju koliko je važna temeljita i temeljita analiza ortopantomograma prije svakoga invazivnog zahvata na donjoj čeljusti.

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.

Introduction The general principles of anatomical terminology indicate that the "mandibular canal" should be named the "inferior alveolar canal" as it accommodates the inferior alveolar neurovascular bundles. Therefore, we performed a Delphi study to evaluate the current understanding and use of the terminology in different geographical regions and areas of expertise and to determine the appropriate terminology for this bony canal. Methods A Delphi panel was formed and questions sent and answered via email about: field of expertise (anatomy, oral surgery/oral and maxillofacial (OMF) surgery, oral radiology/OMF radiology, plastic surgery, ENT surgery, or dentistry with the exception of oral/OMF surgery and oral/OMF radiology), years of experience in the field of expertise, country currently working in, "what is the name of the bony canal that contains the inferior alveolar neurovascular bundle," and "what should the structure above be called, in general?" Results A total of 52 participants responded to the questionnaire. Half or more of the experts in anatomy, oral/OMF surgery, and ENT/Plastic surgery considered "mandibular canal" to be the most appropriate name for this bony canal. In contrast, more than half of all experts in oral/OMF radiology and dentistry, i.e., most fields of dentistry, considered "either mandibular canal or inferior alveolar canal" to be the appropriate name. Conclusions The results of the Delphi study and general principles suggest that an alternative term for the "mandibular canal" should be "inferior alveolar canal." This article is protected by copyright. All rights reserved.

Medication-related osteonecrosis of the jaws (MRONJ) is a rare and serious adverse effect of anti-resorptive and/or antiangiogenic therapy that can cause necrotic bone exposure in the oral cavity, which affects patients’ quality of life. The present study aimed to review literature regarding MRONJ with special focus on diagnostic and treatment. The databases PubMed, Scielo and Google Scholar were searched for reports regarding diagnostic and treatment of MRONJ. Even though this disorder shows poor response to treatment, there is an increase in cure rates when early diagnosed and treated. In this way, systematic dental follow-up of patients under anti-resorptive and/or antiangiogenic therapy is essential for the identification of signs and symptoms suggestive of MRONJ like pain, swelling or dental mobility. Radiographic and tomographic features like increase of bone density, bone sclerosis or osteolysis, persisting alveolar socket, periosteal neoformation, lamina dura widening and mandibular canal widening may indicate bone necrosis. Since there is no universally accepted treatment to cure MRONJ, the management involves symptom palliation and control of associated infection, and surgical excision of necrotic bone is recommended for more severe cases. Each case must be individually evaluated by a multidisciplinary team, allowing dental and medical discussion. The prevention of MRONJ by patients education, elimination of risk factors and oral health maintenance is still the most important measure in the management of these patients. A osteonecrose maxilar relacionada a medicamentos (MRONJ) é um raro e grave efeito adverso de terapia antirreabsortiva e/ou antiangiogênica que pode causar exposição de osso necrótico em cavidade bucal, o que implica na qualidade de vida dos pacientes. O presente trabalho teve por objetivo revisar a literatura sobre MRONJ enfatizando os critérios de diagnóstico e tratamento. As bases de dados PubMed, Scielo e Google scholar foram consultadas em busca de artigos que abordassem o tema. Embora apresente baixa resposta ao tratamento, o diagnóstico e tratamento precoce aumentam a chance de cura. Dessa forma, o acompanhamento odontológico sistemático de pacientes que estejam em terapia antirreabsortiva e/ou antiangiogênica é fundamental para a identificação de sinais ou sintomas sugestivos de MRONJ como dor, tumefação ou mobilidade dentária. Alterações radiográficas ou tomográficas como aumento da densidade óssea, esclerose óssea ou osteólise, persistência de alvéolo dentário, neoformação periosteal, espessamento da lâmina dura e estreitamento do canal mandibular podem ser indicativos da presença de necrose óssea. Como ainda não existe um tratamento universalmente aceito capaz de curar a MRONJ, a abordagem envolve paliação de sintomas e controle da infecção associada, reservando-se a remoção cirúrgica da área necrótica para casos mais graves. Salienta-se que cada caso deve ser avaliado individualmente por uma equipe multidisciplinar que permita a discussão entre a equipe de saúde bucal e equipe médica. A prevenção da MRONJ por meio da educação dos pacientes, eliminação dos fatores de risco e manutenção da saúde bucal constitui ainda a medida mais importante no manejo desses indivíduos.

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.

Background: The aim of this study was to introduce a new radiological classification that could be normally used in clinical practice to assess the relationship between an impacted third molar and mandibular canal on cone beam CT (CBCT) images. Material and Methods: The relationship between the third molar teeth and the mandibular canal, the distance of the third molar to the inferior alveolar canal, buccal-apical-lingual position of the canal relative to the tooth, and the presence of contact between the canal and the third molar teeth were evaluated according to the classification. According to these criteria, a total of eight classifications and two subtypes , class A and B, were made. CBCT images of 50 patients were independently studied all the possible relationships between third molar and IAN on the cross-sectional images. The SPSS software version 24.0 was used for the statistical analysis. Results: For the lower left third molar teeth (38), it was found to be that the most common class was 1A (48,6%) in gender-free examination. For the third molar teeth (48) in the lower right mandibula, it was found to be that the most common class was 1A (45%) regardless of the gender. Conclusion: The use of this classification could be a valid support in clinical practice to obtain a common language among operators in order to define the possible relationships between an impacted third molar and the mandibular canal on CBCT images.

Purpose Significant displacement of the mandibular canal (MC), which occurs frequently in extensive mandibular cystic lesion cases, may raise the risk of inferior alveolar neurovascular bundle injury in surgery. The aim of the present study was to measure the association between positional changes of the MC and the direction (in the coronal plane) of bone expansion of cystic lesions in the mandible. Patients and Methods We performed a retrospective study of patients who had undergone decompression and enucleation surgery from January 2014 to December 2018. Based on coronal planes of cone-beam computerized tomography, the centroids of the expanded mandibles were calculated and considered markers for evaluation of the directions of bone expansion. In addition, the changes in the position of the MC before decompression and enucleation were measured and compared. A Cartesian coordinate system was introduced in this study to illustrate the relationship of positional changes between the displacement of the MC and expansion of the mandible in a straightforward manner. Statistical analysis was performed using the paired t test, unpaired t test, one-way analysis of variance or linear regression as appropriate. Results Thirty-six patients with an average age of 29.8 years (14 men, 22 women) who received treatment of decompression and enucleation for mandibular cystic lesions were included in this study. The MCs were displaced in the direction toward the lower edge of the mandible and opposite to the direction of mandibular expansion. In addition, the MCs were relocated close to their original location by 1.67 ± 1.45 mm (mean ± standard deviation) approximately 1 year after decompression, accounting for 22.66% of the total displacement. Conclusions In mandibular cystic lesion cases, the MCs tend to displace opposite to the direction of mandibular expansion and relocate less after decompression.

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

Objective: This study was designed to determine the ossification time and pattern of the mandible. Methodology: Three hundred and fifty (350) wasted fetuses consisting of 70 Balami, 140 each of Uda and Yankasa breeds whose crown vertebral rump length ranged from 3.0-15 cm were used. The fetuses were processed using the Alizarin technique and the mandible was dissected from the head for stereography. Result: The result revealed that the first part of the mandible to develop was the body and mental foramina at the 42 nd –44 th days of gestation while the coronoid process, rami, and condyloid process develop later at different time points. In addition, the mandibular foramina remained undeveloped in all age groups. Interestingly, the mandibular canal began ossification earlier in the Yankasa breed compared to other breeds. It was shown to arise from a cartilaginous tissue at the medial and lateral surfaces of the body and dorsally remained opened and undifferentiated from the teeth alveoli of the lower jaws in the 7 age groups. Conclusion: It was therefore concluded that the mandible arises from three ossification centres at the body, rami, and coronoid process. These segments develop at different time intervals in the three breeds of sheep with Yankasa mandible ossifying and progressing faster than in Balami and Uda. Doi: 10.28991/SciMedJ-2021-0301-3 Full Text: PDF

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.

It is difficult to correlate the direction of mandibular canal branches (MCBs) with altered sensation in dental treatments. In contrast, calcitonin gene–related peptide (CGRP) is related to vasodilation, bone formation, and the interaction with the peripheral nervous system. Therefore, we investigated the detailed morphological characteristics of MCBs using cone-beam computed tomography (CBCT) and observation of the CGRP distribution around the MCB. The MCB measurements were evaluated using principal component analysis (PCA) to identify morphological correlations. A total of 168 sides of mandibles from 84 cadavers were analyzed in this study. Most of the MCBs were primarily in the direction of the clock model from X to XI in sagittal sections and XII to I in coronal sections of the mandible. The structure of the MCB was divided into the fine canal branch (60.4%, 223/369), partial branch (24.4%, 90/369), and no canal branch (15.2%, 56/369). PCA indicated that the measurement element with the MCB and its structures were correlated in contrast to tooth factors. Positive CGRP reactions were clearly observed in the no-canal branch group compared to other groups. These data provide useful suggestions for MCB dynamics and information for clinical dental treatment.

Objectives: The study aimed to assess the prevalence and morphology of bifid mandibular canal (BMC) using cone beam computed tomography (CBCT) among a group of Yemeni adults. Materials and Methods: The presence and type of BMC were evaluated among 400 CBCT images. Prevalence rate of BMC was also determined according to gender. Further, the diameter and length of BMCs were measured using Ez3D plus software. Chi-square analysis and the analysis of variance (one-way ANOVA) were used. Results: The study concluded that BMCs were found in 60 (15%) of total cases. There was no significant correlation between gender and BMC prevalence. Forward BMC was the most common type (48.3%), followed by retromolar BMC (35.0%) then dental BMC (16.7%); while not even one case of buccolingual BMC was observed. There was a significant difference in the mean diameter of BMC (P value = 0.016). There was a significant difference in the mean length of BMC (P = 0.001). Conclusion: The prevalence of BMCs in Yemeni adults is relatively high, and forward BMC was the most common type. Detecting BMCs by using CBCT imaging is highly recommended prior to any mandibular surgery.

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.

Introduction: Oral traumas and surgery frequently lead to injuries such as neuromas and hematomas.Materials and Methods: PubMed was searched up using the keywords: “oral traumatic neuroma”, “neuroma dental implant” and “oral hematoma”. Works about oral surgery were considered. Results: In some of the studies included in this review, traumatic neuroma was found following dental extraction; others following chin augmentation and sagittal osteotomy of the mandible. Implant surgery also appears to be linked to the development of traumatic neuromas. Bilateral bifid mandibular canal is a rare anatomic variation which, if present, can lead to the neuroma following surgery of the lower third molar and the placement of dental implants. The vast majority of cases of hematoma are consequent to oral surgery (rarely have spontaneous hematomas have been described in patients taking antiplatelets or anticoagulants).Conclusion: The literature shows a concrete risk of hematoma and traumatic neuroma following oral or maxillofacial surgery. Particular attention should be paid to patients with coagulation abnormalities.

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.

Background: Hypoesthesia occurs as a result of injuries resulting in injury to the nerve fibres. The causes of injury include direct harm from the needle injections, around the nerve fibres, mechanical injuries resulting in an indirect pressure into the mandibular canal, during the dental surgical procures, as well as the toxicity of the local anaesthetic agents. Methods: This cross-sectional research was conducted by recruiting N=79 adult individuals (>18 years), who had visited the district hospital for acquiring clinical assistance and treatment of facial muscles or nerve-related complications in August 2020. Data collection for this research was carried out by using a specially designed questionnaire, which facilitated in acquiring data related to aetiology of trauma, identification of the hypoesthesia area, as well as the clinical complications experienced by the respondents. The clinical reports of the patients were also collected for analysing the hypoesthesia area. SPSS was utilised for data analysis, and statistical tests were conducted for assessing the risk factors for hypoesthesia after repair of facial fractures. Results: The statistical tests revealed that only a small percentage of the sample population, i.e., (N=9) or 11.8% experienced the facial bone fracture, male respondents had more exposure to the facial bone fractures, as compared to the females (Mean=1.81, SD= 0.397), and the individuals below 25 years of age had high exposure of facial bone fracture (Mean=1.78, SD= 0.428). A significant majority of hypoesthesia cases were at mandible, and orbit region. Conclusion: The dental treatment resulting in nerve manipulation results in nerve elongation, nerve compression, contributing to transient hypoesthesia. Hypoesthesia might also lead to other clinical complications.