Cerebral Development Research Articles

ASSESSMENT OF JUXTA-APICAL RADIOLUCENCY WITH CONE BEAM CT

Aim: This study aimed to investigate the association of JAR with third molar status and mandibular canal and also describe its radiologic features through cone beam computed tomography (CBCT).
 Methods: CBCT images of 100 individuals (153 mandibular third molars) were evaluated for the presence of JAR. Than, the CBCT images were analysed to evaluate the position of the JAR and its relationship to the impacted teeth, mandibular canal and buccal-lingual cortical plates. Descriptive statistical analyses were used.
 Results: JAR was identified in 70 individuals and 95 mandibular third molars (48 right side, 47 left side). 22 of the individuals with JAR were male and 48 were female. It was found that 26 (27,4%) of the 95 third molars were erupted, 10 (10,5%) were partially erupted, 59 (62,1%) were impacted. 74,7 % were on the apical third of the root and the rest was located along the mesial or distal surfaces of root. Close proximity to the buccal cortical plate was seen in 25,35 % of JAR located apically, whereas it was seen only 25% of JAR located along the root surface. Only 23.4 % were associated with the mandibular canal.
 Conclusion: The present study gives an insight into the relationship of JAR with mandibular canal and cortical plates using CBCT. However, future studies are warranted that use a larger sample size to validate the above findings.

INTRAOSSEOUS SCHWANNOMA AFFECTING THE MANDIBLE: CASE REPORT AND IMMUNOHISTOCHEMICAL ANALYSIS

Schwannomas are neoplasms arising from differentiated Schwann cells. These tumors most often affect the soft tissues of the head and neck and rarely occur in intraosseous location. To date, approximately 90 cases of schwannoma affecting the jaws have been reported. A 52-year-old female patient was referred for evaluation of an asymptomatic mandibular lesion. Imaginologic analysis showed a large radiolucent lesion involving the mandibular body and ramus with expansion of the buccal and lingual cortical plates. An incisional biopsy was performed, which microscopically revealed hypercellular and myxoid hypocellular areas composed of spindle cells with ill-defined cytoplasm. Nuclear palisading around cellular areas was evident. Immunohistochemistry showed positivity for S-100, CD56, and CD34 (weak). The Ki-67 labeling index was <3%. Schwannomas in an intraosseous location affecting the jaws may mimic odontogenic and nonodontogenic cysts and tumors; thus, a strict clinicopathologic correlation is required for a correct diagnosis.

Assessment of Bone Mineral Density in Type 2 Diabetes: A Cone Beam Computed Tomography (CBCT) Study.

IntroductionThe main purpose of the study was to assess and compare bone mineral density (BMD) at prospective implant sites in the mandible in type 2 diabetes mellitus (T2DM) and non-diabetic patients using cone beam computed tomography (CBCT).Material and methodologyA total of 40 patients were included in this type of cross-sectional study. They were divided into two groups, A and B, according to their haemoglobin A1c values. Group A consisted of patients with HbA1c between the range of 6.1%-8% and group B had patients with no history of T2DM. CBCT scans were made of the mandibular arches of both the patients to evaluate the BMD at lingual and buccal cortical plates and the trabecular regions in two successive slices with the assistance of PlanMeca Romexis software (PlanMeca Romexis®, Helsinki, Finland). The Shapiro-Wilk test was used to determine the normality of continuous data. The Mann-Whitney U test was used to compare the groups.ResultsThere were no differences that were statistically significant between the two cohorts according to the Mann-Whitney U test at buccal cortical plate points 1 and 2. However, the diabetes group's mean bone density at implant sites-A, B, C, D, and E at trabeculae points 1 and 2 was considerably (7p>0.001) lower than the non-diabetic groups. The mean bone density of the diabetes group was marginally but significantly (p=0.009) lower than the non-diabetic group at lingual cortical plates.ConclusionIndividuals with type 2 diabetes mellitus show significantly lower bone mineral density in the lingual cortical plate and trabecular region, however, implant therapy can be performed with certain mentioned guidelines in such regions. In the buccal cortical region, the bone mineral density is seen to be unaffected.

A novel pilot animal model for bone augmentation using osseous shell technique for preclinical in vivo studies.

Bone grafting is commonly used to reconstruct skeletal defects in the craniofacial region. Several bone augmentation models have been developed to evaluate bone formation using novel bone substitute materials. The aim of this study was to evaluate a surgical animal model for establishing a three-dimensional (3D) grafting environment in the animal's mandibular ramus for bone augmentation using the osseous shell technique, as in humans. Osteological survey of New Zealand white (NZW) rabbit skull (Oryctolagus cuniculus): Initial osteological and imaging surveys were performed on a postmortem skull for a feasibility assessment of the surgical procedure. Postmortem pilot surgery and cone beam computed tomography imaging: a 3D osseous defect was created in the mandibular ramus through a submandibular incision. The osseous shell plates were stabilized with osteosynthesis fixation screws, and defects were filled with particular bone grafting material. In vivo surgical procedure: surgeries were conducted in four 8-week-old NZW rabbits utilizing two osseous shell materials: xenogeneic human cortical plates and autogenous rabbit cortical plates. The created 3D defects were filled using xenograft and allograft bone grafting materials. The healed defects were evaluated for bone formation after 12 weeks using histological and cone beam computed tomography imaging analysis. Clinical analysis 12 weeks after surgery revealed the stability of the 3D grafted bone augmentation defects using the osseous shell technique. Imaging and histological analyses confirmed the effectiveness of this model in assessing bone formation. The proposed animal model is a promising model with the potential to study various bone grafting materials for augmentation in the mandibular ramus using the osseous shell technique without compromising the health of the animal. The filled defects could be analyzed for osteogenesis, quantification of bone formation, and healing potential using histomorphometric analysis, in addition to 3D morphologic evaluation using radiation imaging.

CHRONIC SUPPURATIVE OSTEOMYELITIS OF MANDIBULAR CONDYLE- A RARE CASE REPORT

Osteomyelitis is dened as inammation of the bone marrow with a tendency to progression and involves the adjacent cortical plates and periosteal tissues. It develops in the jaws after a chronic odontogenic infection or from other reasons such as trauma, incomplete management of fracture, following irradiation of the Mandible. It is more common in Mandible than maxilla. However, involvement of Mandibular condyle is very rare. Hereby we report a case of chronic suppurative osteomyelitis of condyle in a 16 years old female treated with course of antibiotics followed by Sequestrectomy, condylectomy and subsequent follow up.

Human–rat integrated microRNAs profiling identified a new neonatal cerebral hypoxic–ischemic pathway melatonin‐sensitive

Neonatal encephalopathy (NE) is a pathological condition affecting long‐term neurodevelopmental outcomes. Hypothermia is the only therapeutic option, but does not always improve outcomes; hence, researchers continue to hunt for pharmaceutical compounds. Melatonin treatment has benefitted neonates with hypoxic–ischemic (HI) brain injury. However, unlike animal models that enable the study of the brain and the pathophysiologic cascade, only blood is available from human subjects. Therefore, due to the unavailability of neonatal brain tissue, assumptions about the pathophysiology in pathways and cascades are made in human subjects with NE. We analyzed animal and human specimens to improve our understanding of the pathophysiology in human neonates. A neonate with NE who underwent hypothermia and enrolled in a melatonin pharmacokinetic study was compared to HI rats treated/untreated with melatonin. MicroRNA (miRNA) analyses provided profiles of the neonate's plasma, rat plasma, and rat brain cortexes. We compared these profiles through a bioinformatics tool, identifying Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways common to HI brain injury and melatonin treatment. After evaluating the resulting pathways and the literature, to validate the method, the key proteins expressed in HI brain injury were investigated using cerebral cortexes. The upregulated miRNAs in human neonate and rat plasma helped identify two KEGG pathways, glioma and long‐term potentiation, common to HI injury and melatonin treatment. A unified neonatal cerebral melatonin‐sensitive HI pathway was designed and validated by assessing the expression of protein kinase Cα (PKCα), phospho (p)‐Akt, and p‐ERK proteins in rat brain cortexes. PKCα increased in HI‐injured rats and further increased with melatonin. p‐Akt and p‐ERK returned phosphorylated to their basal level with melatonin treatment after HI injury. The bioinformatics analyses validated by key protein expression identified pathways common to HI brain injury and melatonin treatment. This approach helped complete pathways in neonates with NE by integrating information from animal models of HI brain injury.

The evaluation of the effect of performing guided lid surgery with enucleation of a cystic lesion; a case report.

Introduction and importanceDentigerous cysts are benign odontogenic cysts of developmental origin. Enucleation and marsupialization are still considered the blueprint of cystic lesion treatment.Case presentationA 23-year-old male patient presented complaining of a minimal swelling in his upper jaw with slight tenderness in his upper anterior teeth. Cone Beam Computed Tomography (CBCT) on the maxilla was requested. The cystic lesion was found to be minimally expansile with intact cortical plates of the maxilla in the affected area. The CBCT was used to fabricate a cutting guide to determine the exact location of the bony window to fully access the lesion. Root canal treatment was done for the affected non-vital teeth. The cuts were done using a piezo-electric device. Complete enucleation was done for the lesion followed by fixation of the cortical bone lid using micro-plates and screws. The case was followed up after 6 months for new bone deposition using CBCT and 1 week, 1 month, and 6 months postoperatively for postoperative pain using the Visual Analogue Scale (VAS).Clinical discussionPiezo-electric surgery was used due to the selective cutting merit to cut through bone while preserving the cystic lining intact. Lid surgery aims to maximize the volume of bone deposited in place of the defect by converting the cavity of the cystic lesion into a contained defect.ConclusionGuided lid surgery using a piezo-electric device could be a useful technique for cystic enucleation regarding the new bone formation and pain level.

A miraculous outcome of the conservative treatment of odontogenic keratocyst: A unique case report

Background: The odontogenic keratocyst (OKC), earlier referred as the keratocystic odontogenic tumor, is a distinctive form of developmental odontogenic cyst. OKC is unique because of its distinguishing clinical features, including potentially aggressive behavior, high recurrence rate and an association with the nevoid basal cell carcinoma syndrome. Treatment options includes from conservative approach to extensive surgeries including marsupialization, enucleation or segmental resection. We hereby report a case of a massive OKC of mandible, which was treated conservatively with outstanding results.Methodology: A 27 year old male patient presented with the complaint of swelling of the lower jaw since one year. His past history revealed trauma to the lower jaw due to self fall 15 years ago. Examination revealed a single, well-defined, irregular swelling seen over the lower jaw extending from one angle to the other with both buccal and lingual cortical plate expansion along with egg shell crackling. Radiographical examination revealed unilocular radiolucency extending from one angle to the other with a paper thin lower border. On histopathological examination it was diagnosed as odontogenic keratocyst. The patient was managed with enucleation under local anaesthesia followed up by iodoform dressing every week and Carnoy’s solution application every alternate week.Results: On regular follow up of one year, significant improvement and formation of healthy bone with respect to the cortical plates and floor of the defect was noted.Conclusion: Conservative management with meticulous regular follow ups can successfully manage a massively extensive OKC with overwhelmingly miraculous results.

The effect of Rutin hydrate on Glucocorticoids induced osteoporosis in mandibular alveolar bone in Albino rats (Radiological, histological and histochemical study)

BackgroundGlucocorticoids are used in different conditions such as autoimmune disorders and organ transplantation and their administration is the most common cause of secondary osteoporosis. Rutin is a flavonoid found in many plants. Flavonoids are natural products with various therapeutic and biological effects. ObjectiveIs to investigate the effect of Rutin Hydrate as a form of Rutin on glucocorticoid induced osteoporosis in mandibular alveolar bone radiologically, histologically and histochemically. MethodsTwenty-one adult male Albino rats were randomly divided into three groups. Group I (control), group II (osteoporotic) and group III (Rutin Hydrate treated). In both group II and III rats received 21 mg/kg of methylprednisolone daily for four weeks. Then group III received 50 mg/kg of rutin hydrate in distilled water daily for another four weeks. At the end of the experiment, mandibles were dissected for radiographic assessment, then processed for histological and histochemical examination and statistical analysis. ResultsRadiologically, administration of Rutin Hydrate was able to enhance bone density than osteoporotic group. Histological examination revealed preserved cortical bone thickness that had been statistically proved. Apparently normal sized marrow cavities, some plump osteoblasts and normal osteocytes were seen in group III. Histochemical examination showed statistical increase in the area percentage of newly formed collagen in group III than group II. ConclusionsRutin Hydrate was able to modify the radiological and histological picture of osteoporotic alveolar bone. This was achieved by the ability of Rutin Hydrate to increase bone density, preserve cortical plates thickness and enhance new collagen formation that was proved histochemically.

A radiographic analysis of Mandibular Symphysis dimension in black South African adult patients with differing skeletal patterns

Orthodontic treatment often involves planned tooth movement within the confined spaces of the alveolar bone trough. Tooth movement within the alveolar trough may be limited by thin labial and lingual cortical plates. Moving lower incisors beyond the mandibular symphysis dimensions may result in damage to roots and alveolar bone.4 Aim and objective The aim of the study was to evaluate limitation of treatment in different skeletal patterns due to mandibular symphysis dimension in order to evaluate limitations of tooth movement within the confines of the mandibular alveolar trough.The objective was to determine the mandibular symphysis dimensions in subjects with differing skeletal patterns Design The design was a retrospective, cross-sectional study. Methods A sample of 180 pre-treatment lateral cephalometric radiographs of black South African subjects were stratified into three groups based on their skeletal classification. Each Class was further divided into equal numbers of males and females. Descriptive statistics, Student’s t-test, ANOVA test and Pearson correlation coefficient were used to analyse the data and p-values of &lt;0.05 were considered statistically significant. Results Subjects with skeletal Class I pattern had a greater LA compared to subjects with skeletal Class II pattern. Subjects with skeletal Class I pattern had a greater LH and LA in females than in males. Subjects with skeletal Class III pattern had greater LH in males than in females.

AGA White Paper: Challenges and Gaps in Innovation for the Performance of Colonoscopy for Screening and Surveillance of Colorectal Cancer

In 2018, the American Gastroenterological Association's Center for GI Innovation and Technology convened a consensus conference, entitled "Colorectal Cancer Screening and Surveillance: Role of Emerging Technology and Innovation to Improve Outcomes." The conference participants, which included more than 60 experts in colorectal cancer, considered recent improvements in colorectal cancer screening rates and polyp detection, persistent barriers to colonoscopy uptake, and opportunities for performance improvement and innovation. This white paper originates from that conference. It aims to summarize current patient- and physician-centered gaps and challenges in colonoscopy, diagnostic and therapeutic challenges affecting colonoscopy uptake, and the potential use of emerging technologies and quality metrics to improve patient outcomes.

Detection Rate and Variability in Measurement of Mandibular Incisive Canal on Cone-Beam Computed Tomography: A Study of 220 Dentate Hemi-Mandibles from Italy

The mandibular incisive canal (MIC) is a small bony channel located in the interforaminal region; it represents the anterior continuation of the mandibular canal. Cone-beam computed tomography (CBCT) is the most commonly utilized radiological technique for assessing the MIC. The main purpose of this study was to evaluate the detectability and variability in measurements of the MIC on CBCT. A total of 220 dentate hemi-mandibles were retrospectively selected for this study. For each hemi-mandible, the detectability, diameter, and distance of the MIC from anatomical landmarks (cortical plates and tooth apices) were evaluated in consensus by two observers. The analysis was performed at four different levels (first premolar, canine, lateral incisor, and central incisor) and was repeated after one month. The variability of MIC measurements was expressed as the coefficient of repeatability (CR), obtained from the Bland–Altman analysis. The MIC detection rate reduced from the first premolar to the central incisor (from 82.3% to 0.5%). The CR of MIC measurements (diameter and distances from anatomical landmarks) was ≤0.74 mm. Although the MIC is difficult to detect in a non-negligible percentage of cases, the limited variability in measurements confirms that CBCT is an effective technique for the assessment of the MIC.

Meta-Learning Analysis of Ultrasonic Guided Waves for Coated Cortical Bone Characterization.

Due to its sensitivity to geometrical and mechanical properties of waveguides, ultrasonic guided waves (UGWs) propagating in cortical bones play an important role in the early diagnosis of osteoporosis. However, as impacts of overlaid soft tissues are complex, it remains challenging to retrieve bone properties accurately. Meta-learning, i.e., learning to learn, is capable of extracting transferable features from a few data and, thus, suitable to capture potential characteristics, leading to accurate bone assessment. In this study, we investigate the feasibility to apply the multichannel identification neural network (MCINN) to estimate the thickness and bulk velocities of coated cortical bone. It minimizes the effects of soft tissue by extracting specific features of UGW, which shares the same cortical properties, while the overlaid soft tissue varies. Distinguished from most reported methods, this work moves from the hand-design inversion scheme to data-driven assessment by automatically mapping features of UGW to the space of bone properties. The MCINN was trained and validated using simulated datasets produced by the finite-difference time-domain (FDTD) method and then applied to experimental data obtained from cortical bovine bone plates overlaid with soft tissue mimics. A good match was found between experimental trajectories and theoretical dispersion curves. The results demonstrated that the proposed method was feasible to assess the thickness of coated cortical bone plates.

Review on Applications of Object Detection using Deep Learning

Abstract: Human cerebral mantle not requires a second to separate the area of thing inside the image similarly as recall it when it ensures; in spite of that, machine requires a time and large amount of data to perform a similar task. Deep neural network dependent on convolution neural network allows high accuracy and better results in object discovery .To develop deep neural networks, large amount of information such as images, video recordings are required and also it requires large amount of time. As computational cost of PC vision is incredibly high, highly learning methodology, where a model ready on one endeavor is reused on one more associated task, gives improved results. Through the survey and investigation of deep learning-based article recognition techniques recently, this work integrates the going with parts: spine interconnection, setback limits and planning procedures, customary thing distinguishing proof plans, multi-layered issues, the datasets and appraisal aspects, applications, and future headway headings. We belief this overview paper will be helpful for experts in the field of object detection. Keywords: Artificial Intelligence, Deep Learning, Neural Network, Object Detection

Conservative Management of Unicystic Ameloblastoma- A Case Report

Ameloblastoma is the most common benign odontogenic tumor of the jaws that constitutes about 1% of all cysts and tumors of the jaws1,2. It is generally a painless, slow growing, locally aggressive tumor causing expansion of the cortical bone, perforation of the lingual or the buccal cortical plate and infiltration to the soft tissues. It has peak incidence in third and fourth decade of life but can be found in any age group with equal gender predilection (1:1)1,5. The relative frequency of mandible to maxilla is reported to be varying from 80% -20% to 99–1%. In the mandible majority of Ameloblastoma are found in the molar ramus region1,3. In a conventional radiograph, Ameloblastoma can present as either unilocular or multilocular corticated radiolucency. The bony septae results in a honey comb, soap bubble or tennis racket appearance. In some places, cortical plates are spared and expanded where as in other region they are destroyed; root resorption is a common finding6. Buccal and lingual cortical plate expansion is more common in Ameloblastoma than in other tumour7. Conventional radiograph is sufficient for small mandibular lesions but maxillary lesions and extensive lesions require CBCT, CT and MRI to establish the extent of the lesion7. The challenge in managing Ameloblastoma is by attaining complete excision and reconstruction of the defect when the tumor is large. Ameloblastoma is treated by enucleation, curettage or surgical excision depending on size and type of the lesion and conservative therapy also.&#x0D; This report gives a comprehensive knowledge regarding the conservative therapy using a Iodoform and paraffin paste which has been a boon in treatment of odontogenic tumor.

Primary intraosseous squamous cell carcinoma arising in odontogenic cysts: A report of five cases and a review of the literature

Primary intraosseous carcinoma (PIOC) is rare entity with an estimated incidence of 0.01-0.02% of all oral cancer. To date, 133 PIOC cases have been reported with most occurring in the setting of periapical/residual cysts. Distinc- tion from carcinomas arising from the oral or antral mucosa may be difficult, especially when the cortical plates have been destroyed. Therefore, signs of oral ulceration preclude the diagnosis of PIOC. Identification of a benign cystic structure exhibiting transition to a squamous cell carcinoma may be of help in establishing the diagnosis and etiology of the tumor. The aim of our study was to evaluate the cases of only primary intraosseous squamous cell carcinomas arising in odontogenic cysts diagnosed in the Oral Pathology Laboratory at New York Presbyterian Queens between 1995-2019 with the goal of adding valuable information to the literature for this uncommon en- tity. Five cases of PIOC were identified. For each case the histology, demographics, radiographic descriptions and radiographs when possible were reviewed. In all cases, transition from a cystic structure to infiltrating carcinoma was identified. In no case did the overlying surface mucosa exhibit dysplastic changes or transition to carcinoma. Four cases occurred in the maxilla and one in the mandible. The average age of patients in this study was 67.6 years with a range of 37 to 81. Three patients were males and two were female. Three cases presented as ill-defined radiolucencies and one was described as a cystic expansion. Two PIOCs arose in the setting of a periapical cyst, one in the setting of a residual cyst and one in the setting of a dentigerous cyst. Two cases had associated bone loss. While uncommon, the possibility of carcinoma arising in what appears clinically to be a cyst, supports the need to submit all tissue for microscopic examination.

The effect of orthodontic treatment on the periodontal tissues

INTRODUCTION Reduced periodontal support is a challenge that clinicians often face during rehabilitation of compromised dentition. The close and intricate relationship between the periodontal tissues and the processes of tooth movement suggest that adjunct orthodontic therapy may play an important role in overcoming these problems. On the other hand, excessive movement of teeth beyond the anatomic boundaries of the alveolar process is commonly believed to contribute to further destruction of the periodontal tissues PURPOSE: To highlight the importance the periodontium health and root of the tooth during the orthodontic treatment METHOD: A literature review for the last five years was performed, with keywords such as: orthodontic appliances, healthy periodontium, recessions, systemic reviews. RESULTS: Root resorption can be observed during the orthodontic treatment which can follow up to tooth mobility as well as losing the tooth due to the treatment CONCLUSIONS: The correction of some orthodontic problems, such as excessively tipped molars, traumatic deep-bites and flared and spaced incisors, maybe particularly beneficial in periodontally compromised patients who are motivated to undergo treatment and demonstrate stable periodontal conditions. However, several factors may contribute to a harmful periodontal response including the use of heavy forces, inappropriate force systems and poor oral hygiene. Excessive and unrealistic tooth movements are also likely to result in reduced alveolar bone thickness, especially in patients with thin cortical plates. On the other hand, the response of the soft tissues is less predictable and likely to be influenced by multiple factors.

Investigation of the Mechanisms Underlying the Development and Evolution of the Cerebral Cortex Using Gyrencephalic Ferrets.

The mammalian cerebral cortex has changed significantly during evolution. As a result of the increase in the number of neurons and glial cells in the cerebral cortex, its size has markedly expanded. Moreover, folds, called gyri and sulci, appeared on its surface, and its neuronal circuits have become much more complicated. Although these changes during evolution are considered to have been crucial for the acquisition of higher brain functions, the mechanisms underlying the development and evolution of the cerebral cortex of mammals are still unclear. This is, at least partially, because it is difficult to investigate these mechanisms using mice only. Therefore, genetic manipulation techniques for the cerebral cortex of gyrencephalic carnivore ferrets were developed recently. Furthermore, gene knockout was achieved in the ferret cerebral cortex using the CRISPR/Cas9 system. These techniques enabled molecular investigations using the ferret cerebral cortex. In this review, we will summarize recent findings regarding the mechanisms underlying the development and evolution of the mammalian cerebral cortex, mainly focusing on research using ferrets.

Characteristics of Juxta-apical Radiolucency as Risk Factor of Inferior Alveolar Injury

Introduction: Juxta-apical radiolucency (JAR) is introduced as a new risk factor for inferior alveolar nerve (IAN) injury; following the removal of the third molar. Thus, the aim of the present study was to examine the relationship of JAR to IAN, cortical plates, and its position with regards to IAN and tooth angulation.&#x0D; Materials and Methods: The present case-control study comprising a sample of 545 Cone Beamed CT scans of mandibular third molars examined 75 JAR cases and 75 control teeth. The relationship of JAR to IAN, its position with regards to IAN, lingual cortical plate thinning, teeth position and angulation were investigated. Descriptive analyses, chi-square and fisher exact tests were performed with a value of 0.05 considered significant.&#x0D; Results: Mesioangular teeth were the most common in both groups. Based on tooth angulation, no significant difference was detected between case and control groups (p value = 0.346). There was no significant difference between the two groups, with regards to JAR and tooth proximity to IAN (p value = 0.578). Although, the most prevalent position in the JAR group was lingual and superior in the control group, but no significant difference was observed between them (p value = 0.122). Most cases of JAR (84.0%) and most cases of control group (77.3%) showed some degree of cortical thinning. Based on this, no significant difference was present between the JAR and control groups (p value = 0.626).&#x0D; Conclusion: JAR is generally in contact with mandibular canal and some degree of cortical thinning manifest in most of these cases. These findings suggest a possible increase in the risk of nerve injury during surgical removal of third molars.

Assessment of the relationship of the distance between mandibular first and second molars with the inferior alveolar canal and cortical bone plate in an Egyptian subpopulation: a CBCT study.

The aim of the current cone beam computed tomography (CBCT) study was to evaluate the proximity of mandibular first and second molar roots to the inferior alveolar canal (IAC) and mandibular cortex in an Egyptian subpopulation. Scans of 120 patients (480 molars, 960 roots) were obtained from the College of Dentistry database at the Suez Canal University, Egypt. Buccal and lingual bone plates and root thickness were measured at the specified resected root end 3 mm from the radiographic apex, and so was the proximity of the root apices to the IAC. Measurements of the right and left mandibular first and second molars were recorded for each root. Three examiners performed the measurements separately. ANOVA was used to compare the different roots. Bonferroni's post-hoc test was used for pair-wise comparisons when ANOVA was significant. The significance level was set at p ≤ 0.05. The findings displayed a closer proximity of the mandibular second molar apices to the IAC, as compared to the mandibular first molars. The mesial roots were at a shorter distance than the distal ones. Moreover, the mandibular second molars revealed the thickest total bone width including the root. So, it is beneficial for endodontists to be aware of the relation of the mandibular first and second molars to the surrounding cortical bone plates and the IAC before starting either nonsurgical or surgical endodontic treatment.