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Objective: To investigate whether the curve markings performed prior to panoramic and cross-sectional reconstructions can influence the planning of oral implants., Methods: Twenty oral radiologists landmarked the reference panoramic curves in 25 CBCT scans of the mandible. Bone height was measured on the resulting cross-sectional slices in the edentulous region of the lower first molar. The following data were recorded: (1) number of landmarks used to build each reference curve; (2) shape of the reference curve (inverted "U", inverted "V" or "horseshoe"); and (3) measurement in the first molar region. The data were assessed for variability based on the number of landmarks, the shape of the reference curve, and the measurements obtained., Results: The number of landmarks used to guide the panoramic reconstruction varied among radiologists (p < 0.05), but most of them draw curves in inverted "U" shape (68-100%). The reproducibility of the measurements taken in the edentulous mandibular first molar region was excellent (84.7%). The number of landmarks and the shape of the curve did not have a significant influence on the reproducibility of the measurements (p > 0.05)., Conclusion: Variations of the operator-dependent steps during the panoramic reconstructions occur but do not play a significant part changing the measurements taken for oral implant planning., (© 2023. The Author(s) under exclusive licence to Japanese Society for Oral and Maxillofacial Radiology.)

Background and Objectives: A comprehensive understanding of the position of third molar roots and adjacent structures, such as the maxillary sinus (MS), is essential for safe extractions. Diagnostic imaging plays a fundamental role in achieving accurate treatment planning. This study aimed to compare panoramic radiography (PR) and cone-beam computed tomography (CBCT) for the evaluation of maxillary third molar roots and their relationship with the MS. Materials and Methods: Two trained radiologists evaluated third molar images. The number of roots, morphology (fused/conical, divergent, dilacerated, or atypical), and their relationship with the MS in PR and CBCT were registered. Descriptive and inferential statistics were performed using the weighted Kappa test. Results: Regarding the number and morphology of the roots, Kappa values showed moderate (κ = 0.42) and fair agreement (κ = 0.38), respectively. Regarding the proximity with the MS, most of the roots showed close contact (30.6%), or 1/3 of root superimposition (35%), in PR evaluation, while in CBCT, the third molars were in contact with the MS floor (32%), and with alveolar domes (27.2%). Conclusions: PR is a moderately reliable image technique to identify the number of roots and root morphology of maxillary third molars. PR, however, does not provide any radiographic signs that clearly indicate the anatomical relationship between the maxillary third molar roots and the maxillary sinus detected in CBCT images.

Objective: To investigate the influence of dynamic visualization of cone beam computed tomography (CBCT) scans on orthodontist's assessment of positioning status and prognosis of interradicular mini-implants (MI)., Methods: Three MI positions were virtually simulated in thirty CBCT volumes: (1) MI 1 mm from the lamina dura (LD), (2) MI touching the LD and (3) MI overlapping the LD. Each position was exposed to orthodontists (n = 35) as panoramic reconstruction, sagittal reconstruction and a sequence of axial slices. Each orthodontist evaluated the MI position (relationship with the LD) and scored the prognosis using a four-point scale (the higher the score, the better the prognosis). Kappa, Friedman and Nemenyi statistics were used., Results: Statistically significant associations were detected between the prognosis scores and the type of image visualized (p<0.05). The dynamic visualization of the CBCT volume (axial slices) was associated with higher scores for prognosis and more reliable evaluation of MI positioning. Inconsistent outcomes were more frequently associated with panoramic and sagittal reconstructions., Conclusion: The dynamic visualization of axial slices allowed orthodontists to perform better assessment of MI position and considerably affected prognosis judgment.

The SARS-Cov-2 (COVID-19) pandemic changed the educational structure of dentistry courses and highlighted the importance of online tools. Understanding students' perception regarding these changes is essential to establishing future teaching-learning strategies to accommodate students' needs in higher education. The aim of this study was to assess students' perceptions of the Oral Radiology teachinglearning process before and during the COVID-19 pandemic. The sample consisted of students (n = 111) of the 2nd, 4th and 6th semesters of the dentistry course, who answered a questionnaire with 21 items: A) Students' demographic data (5 questions); B) Students' teaching-learning experiences during the pre-pandemic period (8 questions); and C) Students' teaching-learning experiences during the post-pandemic period (8 questions). Stuart-Maxwell tests revealed statistically significant differences between students' opinions before and during the pandemic when they were asked about the structure of the Oral Radiology module (p = 0.008); their previous experience with e-learning and teaching (p < 0.001); their thoughts about the importance of e-learning in Oral Radiology (p < 0.05); and the time they spent online for academic purposes (p < 0.05). Students seem to prefer on-campus activities (before COVID-19), but the pandemic increased their awareness of the importance of e-learning, the time they spent on online studies, and their knowledge of online educational tools., Competing Interests: The authors declare no potential conflicts of interest regarding the research, authorship, and/or publication of this article., (Sociedad Argentina de Investigación Odontológica.)

Background: The mandibular incisive canal (MIC) is an anatomic structure to be considered in treatment planning for surgeries in the anterior region of the mandible. Awareness of the MIC increased with the use of 3D imaging for treatment planning, such as cone beam computed tomography (CBCT). This study aimed to use CBCT to assess the prevalence, morphology and position of the MIC among North-Brazilians., Material and Methods: The sample consisted of CBCT scans of 100 hemi-mandibles (50 individuals) that were assessed for the absolute (n) and relative frequency of the MIC. The morphological component of this study was the diameter (mm) of the detected MIC in five anatomic sites between the mental foramen and the midline. Within the interformainal region, the position of the MIC was assessed by measuring (mm) the distances between the MIC and the basal, vestibular and lingual cortical bone surfaces., Results: The prevalence of the MIC was >76% considering the different anatomic regions screened in CBCT. The mean diameter of the MIC progressively reduced from 1.29 mm to 0.86 throughout the five anatomic regions measured. The position of the MIC showed a downward trajectory away from the lingual cortical bone surface., Conclusions: MIC was a highly prevalent anatomic structure in the studied sample. The funnel-shaped outline of the MIC and its trajectory into the interforaminal region highlighted a major risk of damage to the neurovascular bundle in surgeries (e.g. implant placement) that are close to the mental foramen and the vestibular cortical bone. Key words: Anatomy, cone beam computed tomography, imaging, mandibular incisive canal, oral radiology., Competing Interests: Conflicts of interest The authors state that there are no conflicts of interest related to this work., (Copyright: © 2022 Medicina Oral S.L.)

Objective: To investigate whether the use of cone beam CT (CBCT) changes the diagnosis of external root resorption (ERR) or marginal bone loss (MBL) involving a second molar adjacent to an impacted third molar., Methods: A systematic search was applied in PubMed, EMBASE, Scopus, Web of Science, LILACS, Google Scholar, OpenGrey, and ProQuest. Studies assessing the detection of ERR or MBL in a second molar adjacent to an impacted third molar through CBCT and panoramic radiography (PAN) were included. Prevalence and agreement between PAN and CBCT on the detection of ERR and MBL were collected. The risk of bias was assessed using the MAStARI., Results: A total of 593 papers were identified, and after a 2-phase selection, 5 studies were included in the narrative synthesis. Regarding ERR, its prevalence in PAN was reported from 5.31 to 19.5% and from 22.8 to 62.0% in CBCT. The percentage of agreement varied from 28.5 to 74.0%. The prevalence of MBL varied from 21.9 to 62.9% in PAN, while those values varied from 21.6 to 80% in CBCT images. The percentage of agreement between PAN and CBCT for the detection of MBL ranged from 66.0 to 85.0%. Four studies presented low risk of bias and one had moderate risk., Conclusions: More ERR and MBL are assessed in CBCT compared to PAN. There is a considerable agreement between PAN and CBCT assessment of ERR and MBL, however, mostly related to the absence of the pathology rather its presence.

Introduction: The use of teaching resources and digital objects has gradually been incorporated into dental schools. This study aimed to evaluate the digital anatomy table in teaching-learning process of the temporomandibular joint (TMJ) anatomy and the student's perception regarding this resource., Materials and Methods: A cross-sectional study was conducted on 41 undergraduate dental students. Knowledge assessment tests were applied at different time intervals: before and after the TMJ theoretical class, after the practical class on prosected specimens and after the use of digital anatomy table. The medians of the scores obtained in the three groups (theoretical class, practical class and digital table) were descriptively analysed and submitted to Wilcoxon, Kruskal-Wallis and Student-Newman-Keuls statistical tests. The perception survey was conducted at the end of the study., Results: When the teaching strategies were compared amongst each other, the medians of the scores with the digital anatomy table were significantly higher than after the theoretical and practical classes. At the end of the research, there were no differences amongst the three groups (theoretical class, practical class and digital table). Regarding the perception, the majority of the students reported that the digital anatomy table helped them to understand the content of the theoretical class., Conclusion: It was concluded that learning with the use of the digital anatomy table did not increase the knowledge of dental students with respect to the TMJ anatomy. The students' perceptions of the digital anatomy table were positive and that it could be used as an additional resource in the teaching-learning process., (© 2021 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Dose optimisation has been revisited in the literature due to the frequent use of cone beam computed tomography (CBCT). Although the reduction of the field-of-view (FOV) size has shown to be an effective strategy, this indirectly increases the negative effect from the exomass. The aim of this study was to evaluate the diagnostic accuracy of an optimised CBCT protocol in the detection of simulated vertical root fracture (VRF) in the presence of metal in the exomass and/or inside the FOV. Twenty teeth were endodontically instrumented and VRF was induced in half of them. All teeth were individually placed in a human mandible covered with a soft tissue equivalent material, metallic materials were placed at different dispositions in the exomass and/or endomass, and CBCT scans were obtained at two dose protocols: standard and optimised. Five radiologists evaluated the images and indicated the presence of VRF using a 5-point scale. Area under the ROC curve (AUC), sensitivity, and specificity were calculated and compared using ANOVA (α = 0.05). Overall, AUC, sensitivity, and specificity did not differ significantly (p > 0.05) between the dose protocols. In conclusion, optimised dose protocols should be considered in the detection of simulated VRF irrespective of the occurrence of artefacts from metallic materials in the exomass and/or inside the FOV., (© 2021. The Author(s).)

Objectives: This review aimed to present studies that prospectively investigated biological effects in patients following diagnostic dentomaxillofacial radiology (DMFR)., Methods: Literature was systematically searched to retrieve all studies assessing radiobiological effects of using X-ray imaging in the dentomaxillofacial area, with reference to radiobiological outcomes for other imaging modalities and fields., Results: There is a lot of variability in the reported radiobiological assessment methods and radiation dose measures, making comparisons of radiobiological studies challenging. Most radiological DMFR studies are focusing on genotoxicity and cytotoxicity, data for 2D dentomaxillofacial radiographs, albeit with some methodological weakness biasing the results. For CBCT, available evidence is limited and few studies include comparative data on both adults and children., Conclusions: In the future, one will have to strive towards patient-specific measures by considering age, gender and other individual radiation sensitivity-related factors. Ultimately, future radioprotection strategies should build further on the concept of personalized medicine, with patient-specific optimization of the imaging protocol, based on radiobiological variables.

Objectives: To evaluate the influence of exomass-related metal artefacts on the detection of simulated vertical root fracture (VRF) in cone-beam computed tomography (CBCT)., Methods: 20 teeth were endodontically instrumented and VRF was induced in half of them. All teeth were individually placed in an empty socket of a human mandible. Metallic materials were differently arranged in the exomass [zone outside of the field of view (FOV) but between the X-ray source and the receptor] and/or endomass (zone inside of the FOV), and CBCT scans were obtained. Four radiologists evaluated the presence of VRF using a 5-point scale. Sensitivity, specificity, and area under the receiver operating curve (AUC) were compared using ANOVA. Also, the tooth of interest was replaced with a tube filled with a radiopaque solution and all CBCT scans were repeated to analyse the data objectively. Mean grey and noise values were obtained from the tube and compared using ANOVA followed by Tukey's test (α = 0.05)., Results: Mean grey values were significantly lower and noise was significantly higher when metallic materials were present in the endomass or both the exomass and endomass. Sensitivity, specificity, and AUC were not influenced by the artefacts from the metallic materials irrespective of the arrangement condition., Conclusions: Exomass-related metal artefacts did not influence the diagnosis of simulated VRF in CBCT.

The present study correlated the mineralization of third molars to chronological age using a modified classification based on Demirjian's stages in a Brazilian subpopulation and compared with the original classification. A total of 1082 patients with age ranging from 6 to 26 years were included in the sample, with at least one third molar on panoramic radiographs. The third molars were classified according to the original Demirjian classification (8 stages) and a new model based on the Demirjian method, where the original stages were grouped into four stages: AB-enamel mineralization; CD-crown dentin mineralization; EFG-root formation; and H-complete development. Statistical analyses were performed by Kruskal-Wallis/Dunn tests (α = 0.05) and the multinomial logistic regression model. Data were analyzed according to percentiles for the probability of an individual being over 18 years old. The mean ages of the stages in both classifications did not present a significant difference between superior and inferior arches (p < 0.05). The differences in mean ages between all the stages of mineralization were statistically significant (p < 0.001) only for the 4-stage classification. Males attained root formation and complete formation earlier than females (p < 0.05) in the 4-stage classification. The modified classification system showed dependence between chronological age and mineralization stages of third molars, simplifying the age estimation process. At stage H, females present a 95.7% chance of being over 18, while for males, this probability is 89.6%. This modified classification system simplifies the dental age estimation process based on third molars and can be used as a reference for future studies.

Objectives: To present the ballistic gelatin as a new material capable of simulating the soft tissues in cone-beam CT (CBCT) images., Methods: CBCT images of three piglet heads were acquired with their soft tissues intact (standard group). Subsequently, the piglet heads were fixed in a container using metallic pins and moulded with acrylic resin; the soft tissues were then removed and replaced by ballistic gelatin, with the same thickness of the original soft tissues. The images were evaluated by two oral radiologists, to check the adaptation on bone surfaces, thickness and density, penetration into large bone cavities and cancellous bone, and the presence of air bubbles using a 5-score scale. Additionally, an objective analysis was carried out by one oral radiologist. For each CBCT scan, three axial reconstructions were selected to represent the mandibular, occlusal, and maxillary levels. The mean and standard deviation (SD) of the grey values were calculated in four regions of interest determined on soft tissue areas and compared by two-way ANOVA., Results: The ballistic gelatin showed subjective scores ranging from good to excellent for all parameters evaluated. There was no significant difference in the mean and SD values of the grey values between ballistic gelatin and the gold standard groups for all levels ( p > 0.05). Higher SD values were observed in the occlusal level for both groups ( p < 0.05)., Conclusions: Ballistic gelatin has visual and objective similarity with the gold standard. Thus, the ballistic gelatin is a promising material capable of simulating soft tissues in CBCT images.

Introduction: Education in oral imaging diagnosis is provided early in most dental curricula worldwide. Stressing the importance of clinical and radiographic information for oral diagnosis is of utmost importance for dental students. In this context, active learning methods, such as case-based learning (CBL), represent contemporary tools in the armamentarium of dental education. This study aimed to investigate (a) dental students' perceptions on CBL and (b) the importance of clinical data for image-based diagnosis., Methods: Fifteen cases of bone lesions were presented to 56 undergraduate students; group 1 (n = 24) was provided with the imaging data alone from each case, while group 2 (n = 32) received clinical information followed by the imaging data. Students' performance and perception on the teaching approach were assessed using a structured questionnaire. Their differential diagnoses for each of the lesions figured as variables to be compared with the known diagnosis., Results: All the students reported a positive experience with the case-based teaching method and confirmed this approach as a valuable tool in dental education. The diagnosis of a simple bone cyst, a periapical cyst or an ameloblastoma improved when they were provided with clinical data prior to the complementary images. No significant difference was detected, however, when the total amount of correct diagnoses were combined together and compared between groups (P > .05)., Conclusion: Case-based learning was corroborated as an optimal method for educating undergraduate dental students. Clinical data might contribute to diagnostic imaging, especially regarding lesions with multiple differential diagnoses., (© 2020 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Objective: To investigate the validity of micro-CT for in vitro caries detection in comparison with histology as the reference standard., Methods: A systematic search was conducted in the databases Latin American and Caribbean Health Sciences (LILACS), LIVIVO, PubMed, Scopus and Web of Science from their inception to 16 January 2019. Grey literature was searched on Open Grey, ProQuest Dissertations and Theses Database and Google Scholar. In vitro studies assessing the validity of micro-CT for caries detection were included when compared with histology as the reference standard were included. Two authors independently collected the information and sensitivity, specificity, positive and negative likelihood ratios, as well as diagnostic odds ratios were calculated. The risk of bias of the included studies was assessed using the QUADAS-2 tool. Certainty of evidence was assessed with GRADE., Results: A total of 270 papers were identified, and after a 2-phase selection, 12 studies were included in qualitative and three in quantitative synthesis. For enamel caries diagnostic, sensitivity values ranged from 29.0 to 84.0% indicating high variability while specificity varied from 88.0 to 95.0% indicating good to excellent micro-CT capability do identify the true negative. For dentine caries diagnostic, sensitivity values ranged from 61.0 to 77.0% indicating fair-to-good probability of micro-CT to identify the true positives, while specificity varied from 88.0 to 94.0%. The majority of the included studies presented low risk of bias and moderate certainty of evidence., Conclusions: This study demonstrated the validity of micro-CT for in vitro caries detection in comparison with histology.

Objectives: To assess, objectively to determine the deterioration of the photostimulable phosphor plates (PSPs) after several acquisitions., Methods: Two new PSPs without preliminary use were exposed with an intraoral X-ray unit, and the EXPRESS ® (Instrumentarium Imaging, Tuusula, Finland) unit was used for scanning of the PSPs. A 12-stepwedge aluminum scale were used superimposed with the PSPs during the X-rays exposures to perform the objective analyses. Objective analysis was carried out by mean gray values using the Image J software through a region of interest (ROI) of 0.1 × 0.1 mm, and the data were analyzed statistically using ANOVA., Results: For each, the Express ® PSP a total of 1800 images were acquired during 60 days. The objective analysis showed loss of the mean gray values between the initial and final images. Besides, the percentage of mean gray values' loss was between 0.7%, for the thickest step, and 8.4%, for the lowest thickness step., Conclusion: After many X-ray exposures of the Express ® PSP a singular deterioration in the mean gray values could be observed.

Cone beam CT (CBCT) for dentomaxillofacial paediatric assessment has been widely used despite the uncertainties of the risks of the low-dose radiation exposures. The aim of this work was to investigate the clinical performance of different CBCT acquisition protocols towards the optimization of paediatric exposures. Custom-made anthropomorphic phantoms were scanned using a CBCT unit in six protocols. CT slices were blinded, randomized and presented to three observers, who scored the image quality using a 4-point scale along with their level of confidence. Sharpness level was also measured using a test object containing an air/PMMA e,dge. The effective dose was calculated by means of a customized Monte Carlo (MC) framework using previously validated paediatric voxels models. The results have shown that the protocols set with smaller voxel size (180 µm), even when decreasing exposure parameters (kVp and mAs), showed high image quality scores and increased sharpness. The MC analysis showed a gradual decrease in effective dose when exposures parameters were reduced, with an emphasis on an average reduction of 45% for the protocol that combined 70 kVp, 16 mAs and 180 µm voxel size. In contrast, both "ultra-low dose" protocols that combined a larger voxel size (400 µm) with lower mAs (7.4 mAs) demonstrated the lowest scores with high levels of confidence unsuitable for an anatomical approach. In conclusion, a significant decrease in the effective dose can be achieved while maintaining the image quality required for paediatric CBCT.

Objectives: Previous studies have suggested a relationship between resorption in second molars and pressure from the eruptive force of the third molar. The aim of this study was to simulate functional forces in a mandible model by means of finite element analysis and then assess the biomechanical response produced by impacted third molars on the roots of the second molar., Materials and Methods: A cone beam computed tomography scan presenting an impacted mandibular third molar was segmented (Mimics V17 software). The modeling process was performed using the reverse engineering technique provided by the Rhinoceros 3D 5.0 software. The third molar position was changed in order to produce different inclinations of the impacted tooth. Bite forces were simulated to evaluate total deformation, the equivalent von Mises stress, minimum principal stress on hard tissue, and equivalent elastic strain on soft tissue., Results: Areas of high energy dissipation and compression stress were detected in the second molar root, independently of the inclination of the impacted third molar. In general, the horizontal position was the situation in which major stress and the amount of deformation occurred in the second and third molar regions., Conclusion: Impacted third molars in close proximity with the adjacent tooth can generate areas of compression concentrated at the site of contact, which suggests an involvement of mechanical factors in the triggering of resorption lesions., Clinical Relevance: The results of these computational experiments contribute to the understanding of the triggering and progression of resorptive lesions in the adjacent second molar.

Background: Children are more sensitive to ionizing radiation effects due to their high radiosensitivity., Purpose: To estimate doses and risks for dental radiological examinations in children., Material and Methods: A pediatric population consisting of 7150 children and young adults which underwent 12252 dental radiological examinations (4220 intraoral, 1324 cephalometric, 5284 panoramic radiographs and 1424 CBCTs) within two years were included. Two groups were studied: CBCT group (exposed to CBCT ± conventional radiographs) and 2D group (exposed only to 2D radiological examinations). The effective doses were corrected according to age at exposure and settings parameters (mA;FOV) by using logarithmic fit equations for dose interpolation. The individual cumulative dose, per-caput collective dose and radiation risk were calculated for each group., Results: The median effective and cumulative doses for conventional radiographs were lower than 20 μSv and did not vary with age. Children exposed to CBCT had a higher median effective dose (127.2 μSv) and cumulative dose (156.5 μSv) with a significant increased cumulative dose between 11 and 14 years. The CBCT contributed with 70% to the collective dose and per caput collective dose was 184 μSv for CBCT exposures. The Life Attributable Risk (LAR) and Relative Radiation Level (RRL) were significantly higher for children exposed to CBCT under the age of 18. The highest radiation dose for CBCT was equivalent with 34.1 days of natural background radiation and it was found for ages between 11 and 15., Conclusion: The CBCT doses and radiation risk vary but remain in the lower levels of the relative risk of medical exposures., (Copyright © 2018 Elsevier B.V. All rights reserved.)

DIMITRA (dentomaxillofacial paediatric imaging: an investigation towards low-dose radiation induced risks) is a European multicenter and multidisciplinary project focused on optimizing cone-beam CT exposures for children and adolescents. With increasing use of cone-beam CT for dentomaxillofacial diagnostics, concern arises regarding radiation risks associated with this imaging modality, especially for children. Research evidence concerning cone-beam CT indications in children remains limited, while reports mention inconsistent recommendations for dose reduction. Furthermore, there is no paper using the combined and integrated information on the required indication-oriented image quality and the related patient dose levels. In this paper, therefore, the authors initiate an integrated approach based on current evidence regarding image quality and dose, together with the expertise of DIMITRA's members searching for a state of the art. The aim of this DIMITRA position statement is to provide indication-oriented and patient-specific recommendations regarding the main cone-beam CT applications in the pediatric field. The authors will review this position statement document when results regarding multidisciplinary approaches evolve, in a period of 5 years or earlier.

Objectives: This report aims to describe the development of age-specific phantoms for use in paediatric dentomaxillofacial radiology research. These phantoms are denoted DIMITRA paediatric skull phantoms as these have been primarily developed and validated for the DIMITRA European research project (Dentomaxillofacial paediatric imaging: an investigation towards low-dose radiation induced risks)., Methods: To create the DIMITRA paediatric phantoms, six human paediatric skulls with estimated ages ranging between 4 and 10 years- old were selected, protected with non-radiopaque tape and immersed in melted Mix-D soft tissue equivalent material, by means of a careful procedure (layer-by-layer). Mandibles were immersed separately and a Mix-D tongue model was also created. For validation purposes, the resulting paediatric phantoms were scanned using a cone-beam CT unit with different exposure parameter settings., Results: Preliminary images deriving from all scans were evaluated by two dentomaxillofacial radiologists, to check for air bubbles, artefacts and inhomogeneities of the Mix-D and a potential effect on the visualization of the jaw bone. Only skulls presenting perfect alignment of Mix-D surrounding the bone surfaces with adequate and realistic soft tissue thickness density were accepted., Conclusions: The DIMITRA anthropomorphic phantoms can yield clinically equivalent images for optimization studies in dentomaxillofacial research. In addition, the layer-by-layer technique proved to be practical and reproducible, as long as recommendations are carefully followed.

Objective: To evaluate the relation of juxta-apical radiolucency (JAR) to the mandibular canal and cortical plates on cone beam computed tomography images, as well as to assess whether the presence of JAR is related to the position of the mandibular canal., Study Design: Forty-seven JAR cases were evaluated by cone beam computed tomography. JAR position and its relationship to the mandibular canal and cortical plates were investigated. The position of the mandibular canal was recorded and compared with a control group. Descriptive analyses and χ 2 tests were performed., Results: A significant association was established between JAR and the position of the mandibular canal (P = .0193), which was positioned lingually in 59.6% of JAR cases. In most cases, JAR was located distal to the tooth (66%) and in contact with the mandibular canal, either with (53.2%) or without (40.4%) preservation of the cortical border of the canal. In 22 cases (46.8%), thinning of cortical plates was observed, but no statistical differences were found between buccal and lingual sides (P = .5728)., Conclusions: The mandibular canal is located lingually in the third molar region in most JAR cases. JAR is located distal to the tooth and is generally in contact with the mandibular canal. These relations may increase the risk of nerve injury during surgical removal of third molars., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Objectives: The objective of this study is to assess the accuracy of the vertical tube shift method in identifying the relationship between the mandibular canal (MC) and third molars., Materials and Methods: Two examiners assessed image sets of 173 lower third molar roots (55 patients) using forced consensus. The image sets comprised two methods: PERI, two periapical radiographs (taken at 0° and -30°), and PAN, a panoramic radiograph (vertical angulation of -8°) and a periapical radiograph taken at a vertical angulation of -30°. Cone beam computed tomography (CBCT) was the reference standard in the study. The responses were recorded for position (buccal, in-line with apex and lingual) and contact (present or absent). The McNemar-Bowker and McNemar tests were used to determine if the PERI and PAN methods would disagree with the reference standard (α = 5 %)., Results: The PERI and PAN methods disagreed with the reference standard for both position and contact (p < 0.05)., Conclusion: The vertical tube shift method was not accurate in determining the relationship between lower third molars and the MC., Clinical Relevance: The vertical tube shift is not a reliable method for predicting the relationship between lower third molars and the MC.

Purpose: To investigate the presence of external root resorption (ERR) in second molars adjacent to horizontally and mesioangular impacted mandibular third molars by cone-beam computed tomography. In addition, patient characteristics (age and gender) and third molar depth were correlated with the presence of ERR., Materials and Methods: The sample consisted of 116 scans (58 acquired on the i-CAT Classic and 58 on the Picasso-Trio) of 70 women and 46 men (mean age, 23.7 yr). Two observers recorded the presence of ERR in the second molars, inclination and depth of third molars in relation to bone and soft tissues, third molars classification according to Pell and Gregory, and location and severity of ERR. Data were analyzed by analysis of variance, Mann-Whitney test, and χ(2) test. The κ test was used to analyze intraobserver agreement., Results: The overall prevalence of ERR was 49.43%. There were no statistically significant differences in the detection of ERR by gender, images from the 2 devices, or third molar inclination (P > .05). The κ test showed excellent reproducibility values (κ = 0.7778). There was a smaller proportion of affected patients 14 to 24 years old and ERR in teeth adjacent to Class C third molars., Conclusion: Mesially inclined third molars (mesioangular and horizontal) have a greater potential of being associated with ERR in second molars, which was shown by the high prevalence of the condition in the overall sample. Class A and B third molars in patients older than 24 years were more associated with the presence of ERR in adjacent teeth., (Copyright © 2015 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.)

Purpose: The aim of the present study was to compare panoramic radiography and cone beam computed tomography (CBCT) for the assessment of external root resorption (ERR) of second molars associated with impacted third molars. In addition, the prevalence of ERR in second molars and the inclinations of the third molars more associated with ERR were investigated in both imaging methods., Materials and Methods: The sample consisted of 66 individuals with maxillary and mandibular impacted third molars (n = 188) seen on panoramic radiographs and CBCT images. The presence of ERR on the adjacent second molar was investigated, and the position of the third molar was determined using Winter's classification (vertical, horizontal, mesioangular, distoangular, and transverse). Statistical analysis was performed using the χ(2) test, Fisher exact test, and 2-proportion Z test (the significance level was set at 5%)., Results: A significantly greater number of cases of ERR (P < .0001) was diagnosed from CBCT images (n = 43, 22.88%) than panoramic radiographs (n = 10, 5.31%). The agreement between the panoramic radiographs and CBCT scans for diagnosing ERR was 4.3%. Mandibular third molars in mesioangular and horizontal inclinations were more likely to cause resorption of the adjacent teeth., Conclusions: CBCT should be indicated for the diagnosis of ERR in second molars when direct contact between the mandibular second and third molars has been observed on panoramic radiographs, especially in mesioangular or horizontal impactions. Furthermore, considering the propensity of these teeth to cause ERR in second molars, third molar prophylactic extraction could be suggested., (Copyright © 2014 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.)

Horizontal root fractures (HRF) usually affect anterior teeth of male patients as a result of trauma. The consequences can be complex because of combined damage to different tissues, but it has been reported that root fractures undergo healing in majority cases. Diagnosis of HRF must be based on clinical findings, sensibility tests, and radiographic examination. The cone-beam computed tomography (CBCT) has already been proven to be superior among other radiographic modalities for diagnostic imaging of root fractures. However, CBCT in these cases needs to be used in a careful manner, and only when the radiation exposure should be justified by the potential diagnostic benefits and improvement of the treatment results. This case report describes a case of spontaneously healed horizontal root fracture with displacement of the fragments and discusses the usefulness of CBCT in the follow-up of root fractures cases., (© 2012 John Wiley & Sons A/S.)

This study investigated the viability of the cell block technique as an auxiliary method of diagnosing jawbone lesions. Thirty-three clinically diagnosed jawbone lesions with a cystic appearance were subjected to aspiration. The aspirated material was processed by the cell block technique, and the lesions were biopsied and treated. Cytological findings (cell block) and histopathology analyses (gold standard) were compared by the chi-square test. There were associations between cysts and cholesterol crystal clefts, between keratocystic odontogenic tumors (KOT) and epithelial cells, and between KOT and parakeratin. The occurrence of cholesterol crystal clefts in cell block slides was correlated with cystic lesions, and the parakeratin presence was a KOT indicator. The cell block technique proved to be fast, easy-to-handle, and low-cost, making it an attractive auxiliary method for the preliminary diagnosis of jawbone lesions.

Bifid mandibular condyle (BMC) is a rare asymptomatic morphological alteration with no predilection for age group or gender. Its morphology varies from a shallow groove to two condylar heads with separate necks, oriented mediolaterally or anteroposteriorly. This report describes an unusual case of anteroposterior bifid condyle in a 39-year-old female patient with the main complaint of mouth-opening limitation and a deviation of the mandible to the left side. Magnetic resonance imaging (MRI) findings revealed a bifid condyle on the left side and duplicated mandibular fossa, with the articular disc over the anterior head. The MRI images in the open-mouth position revealed minimal movement of the condyle. Despite the increased number of mediolateral bifid mandibular condyle cases described in the literature, none of previously reported cases of BMC included an anteroposterior bifid condyle case with two distinct mandibular fossa., (Copyright © 2012 Wiley Periodicals, Inc.)