Assessing the Impact of the Metal Artifact Reduction Tool on Detecting Furcation Lesions in Maxillary Molars with Different Intracanal Posts: An Ex Vivo Cone-beam Computed Tomography Study.

INTRODUCTION: Considering the potential image compromise and diagnostic challenges posed by metals, this study aimed to assess the efficacy of the metal artifact reduction (MAR) tool in cone-beam computed tomography examinations for detecting furcation lesions in upper molars treated endodontically and restored with different intracanal posts. METHODS: This ex vivo study used 45 endodontically treated maxillary first molars, categorized into the following3 groups (n = 15): control (without intracanal post), metal post, and fiberglass post. Simulations were conducted in the laboratory to replicate alveolar bone, periodontal ligament, and grade I, II, and III furcation lesions. Cone-beam computed tomography scans were obtained with and without the MAR tool, and the furcation lesions were evaluated considering a 5-point Likert scale. Data were analyzed at 5%. RESULTS: In the control group, there was no influence of MAR (P > .05); grade II lesions were not diagnosed, and grade III lesions were the most detected (P < .05). In the metal post group with MAR, grade III lesions were diagnosed more frequently than I and II (P < .05) and grade III without MAR (P < .05). In the fiberglass post group, the diagnosis of grade I lesions decreased with MAR (P < .05), and without MAR, grade III was most diagnosed (P < .05); grade III lesions were the most diagnosed (P < .05). CONCLUSIONS: The MAR tool was only effective for diagnosing grade III furcation lesions, regardless of the intracanal material. Its application for grade I and II lesions did not contribute to improved diagnosis. Furthermore, in the fiberglass post group with grade I lesions, the MAR tool negatively affected the detection of the lesions.

The mandibular bone structure in children by fractal dimension and its correlation with pixel intensity values: a pilot study.

OBJECTIVES: To identify a normal pattern of mandibular trabecular bone in children based on the fractal dimension (FD), and its possible correlation with pixel intensity (PI) values, to facilitate the early diagnosis of possible diseases and/or future bone alterations. MATERIALS AND METHODS: The 50 panoramic images were selected and divided into two groups, according to the children's age: 8-9 (Group 1; n = 25) and 6-7 (Group 2; n = 25). For FD and PI analyses, three regions of interest (ROIs) were selected, and their mean values were evaluated for each ROI, according to each group, using the t test for independent samples and the model of generalized estimation equations (GEE). Subsequently, these mean values were correlated by the Pearson test. RESULTS: Comparing the groups, FD and PI did not differ from each other for any of the measured regions (p > 0.00). It was observed that in the mandible branch (ROI1), FD and PI means were 1.26 ± 0.01 and 81.0 ± 2.50, respectively. In the mandible angle (ROI2), the means were 1.21 ± 0.02 (FD) and 72.8 ± 2.13 (PI); and in the mandible, cortical (ROI3) values of FD = 1.03 ± 0.01 and PI = 91.3 ± 1.75 were obtained. There was no correlation between FD and PI in any of the analyzed ROI (r < 0.285). The FD means of ROI1 and ROI2 did not differ from each other (p = 0.053), but both were different from ROI3 (p < 0.00). All PI values differed from each other (p < 0.00). CONCLUSION: The bone trabeculate pattern in 6-9-year-old children presented FD between 1.01 and 1.29. Besides that, there was no significant correlation between FD and PI.

3D analysis of maxillomandibular morphology in hyperdivergent and hypodivergent individuals: A cross-sectional study.

INTRODUCTION: The aim of this cross-sectional study was to investigate maxillomandibular morphology in hyperdivergent and hypodivergent individuals, using 3D surface models generated by cone-beam computed tomography (CBCT). METHODS: The sample consisted of 60 CBCTs (30 males, 30 females) patients aged 12-30 years, divided into two groups comprising hyperdivergent (≥35°) and hypodivergent (≤30°) individuals, according to the mandibular plane (MP) angle. Multiplanar reconstructions were used to mark the landmarks, and 3D surface models were created to evaluate structures of the maxillomandibular complex, including condyle, ramus, symphysis and palatal height. Intergroup comparisons were performed by independent t-test. Pearson's correlation test was used (P < .05) to evaluate the correlation of the MP angle with the angles and linear measurements of other structures. RESULTS: Significant differences were found between the groups regarding condylar width, ramus height, condylar plus ramus height, mandibular length, gonial angle, palatal plane angle and palatal-mandibular angle. No differences (P > .05) were found for the condylar height, symphysis inclination angle or palatal height. Correlations (P < .05) were found between the MP angle and structures of the maxillomandibular complex. CONCLUSIONS: Hyperdivergent (MP ≥ 35°) and hypodivergent (MP ≤ 30°) individuals present different skeletal morphology regarding condylar width, ramus height, condylar plus ramus height, mandibular length, gonial angle, palatal plane angle and palatal-mandibular angle. There is a significant correlation between MP angle and morphological structures such as condyle, ramus, symphysis, palatal plane angle and palatal-mandibular angle.

Comparison Between Radiographs, White and Fluorescent Images in the Diagnosis and Treatment Decisions for Occlusal Caries: An Ex Vivo Study

ABSTRACT Objective: To compare the agreement of images in white light (WL), fluorescence (FL), and digital radiographs (DR), on the diagnosis and treatment decisions for occlusal caries lesions against a micro-CT gold standard. Material and Methods: Ten extracted third molars, with enamel and/or dentin caries (ICDAS 2-4), were included. Occlusal surface images were acquired with an intraoral camera (SoproLife®) in WL and FL modes. DR was obtained using an intraoral X-ray and a semi-direct digital system. A total of 780 images were needed, organized in a template, to be later examined by twenty-six dentists invited to compose the study. The Generalized Estimation Equations model was used to compare the proportions of the correct answers between the three methods and the gold standard. When significant, Bonferroni post-hoc test was used to identify differences (α=5%). Results: Most of the examiners were specialists (76.9%) with 14.5 years of experience. All diagnostic methods were similar and showed low agreement (DR 12.7%, WL 16.5%, and FL 16.5%) compared with gold standard caries diagnostic scores. Regarding treatment decisions, mean agreement for all diagnostic methods was higher (43.2%; p<0.001), and among all methods, WL (48.1%) and FL (51.2%) modes performed better than DR (30.4%, p<0.001). Conclusion: SoproLife® images could help clinicians to propose rational, minimally invasive treatments for occlusal caries lesions.

Eficácia da intervenção educacional à distância na capacitação de cirurgiões-dentistas da rede pública sobre o uso consciente da tomografia computadorizada de feixe cônico: um ensaio clínico controlado quase-experimental / Efficacy of distance educational intervention in training public dentists on the conscious use of cone beam computed tomography: a quasi-experimental controlled clinical trial

Objetivo: Verificar a eficácia da intervenção educacional por videoconferência, para dentistas de um serviço público de saúde, sobre aquisição de conhecimentos em tomografia computadorizada de feixe cônico. Materiais e Métodos: Trata-se de um ensaio clínico controlado, com aplicação de questionários estruturados sobre uso criterioso da tomografia computadorizada de feixe cônico, antes e depois da intervenção educacional. Os participantes do estudo foram divididos em grupos controle (aula presencial) e experimental (aula por videoconferência). Participaram desta pesquisa 133 dentistas no pré-teste (questionário aplicado antes da intervenção) e 129 no pós-teste (questionário aplicado após a intervenção). As análises foram executadas para avaliar as variáveis da metodologia de ensino e comparar a proporção das respostas corretas e "não sei" entre os tempos, discriminadas pela especialidade odontológica dos participantes. O nível de significância adotado foi de 0,05. Foram utilizados os testes de qui-quadrado e o modelo de regressão logística binária e, quando significativo, foi aplicado o teste post-hoc de Bonferroni. Resultados: A análise das respostas "não sei" e respostas corretas entre as modalidades de ensino presencial e por videoconferência demonstrou que não houve mudança significativa dos resultados. O resultado das respostas "não sei" evidenciou uma grande diferença entre os tempos, onde o percentual dessas respostas, após a intervenção, variou de 23,6% para 4,7% (p<0,001). Em todas as especialidades, essa redução foi significativa nas questões referentes ao conhecimento sobre radioproteção. O aumento de respostas corretas foi de quase 10% (p<0,001). Conclusão: A capacitação profissional através do método de videoconferência mostrou-se eficaz e comparável ao método presencial para a aquisição de conhecimentos em tomografia computadorizada de feixe cônico.

Objective: To verify the effectiveness of an educational intervention by videoconference, for dentists of a public health service, on acquiring knowledge in cone-beam computed tomography. Materials and Methods: This is a controlled clinical trial with structured questionnaires on the judicious use of cone-beam computed tomography, before and after the educational intervention. Study participants were divided into control (faceto-face class) and experimental (videoconference class) groups. A total of 133 dentists participated in the pre-test (questionnaire applied before the intervention) and 129 in the post-test (questionnaire applied after the intervention). The analyzes were performed to evaluate the variables of the teaching methodology and to compare the proportion of correct and "I do not know" answers between times, broken down by the dental specialty of the participants. The level of significance adopted was 0.05. The chi-square tests and the binary logistic regression model were used and, when significant, the Bonferroni post-hoc test was applied. Results: The analysis of the answers "I don't know" and correct answers between the teaching modalities showed no significant change in the results. The result of the "I don't know" answers showed a significant difference between the times, where the percentage of these answers, after the intervention, varied from 23.6% to 4.7% (p<0.001). In all specialties, this reduction was significant in questions related to knowledge about radioprotection. The increase incorrect answers were almost 10% (p<0.001). Conclusion: Professional training through the videoconference method proved effective and comparable to the face-to-face method for acquiring knowledge in cone-beam computed tomography.

Oral manifestations arising from oral piercings: A systematic review and meta-analyses.

OBJECTIVE: The aim of this study was to perform a systematic review of oral manifestations arising from oral piercings. STUDY DESIGN: Literature was searched through January 2022 in PubMed, Scopus, Embase, Web of Science, Cochrane Library and Virtual Health Library, OpenGrey, and Google Scholar to address the question, "Is there an association between oral piercings and oral alterations, complications, or lesions?" Quality was assessed using the Joanna Briggs Institute appraisal tools. Meta-analyses were performed, and certainty of evidence was assessed through Grading of Recommendations Assessment, Development and Evaluation (GRADE). Reporting followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. RESULTS: Fifty-four studies were included, with 15 achieving good methodological quality. Periodontal and tooth damage were the most reported, followed by soft tissue/mucosal injuries, speech disorders, chewing, soft plaque, and saliva. Pain was the most reported complication, followed by infection, swelling, bleeding, inflammation, allergy, and adornment aspiration. Meta-analyses revealed that 33% of participants with piercings had gingival recession (GR) (event rate [ER] = 0.329). In participants with piercings, ER values for nonspecified dental damage (NSDD), tooth chipping, wear/abrasion, and dental fracture (DF) were 27% (ER = 0.270), 22% (ER = 0.219), 34% (ER = 0.344), and 34% (ER = 0.338), respectively. Certainty of evidence was very low. CONCLUSIONS: Alterations, complications, and lesions were associated with oral piercings and adornments, of which GR, DF, and NSDD were the most prevalent.

Tomographic analysis of midpalatal suture prior to rapid maxillary expansion.

INTRODUCTION: In Orthodontics and Facial Orthopedics, the timing of treatment onset may be critical and individual analysis should be applied to promote a favorable treatment planning. In this study, individual analysis of midpalatal suture (MS) and palatal measurements were performed in teenagers and young adult patients treated with rapid maxillary expansion (RME). DESCRIPTION: Twenty-six patients submitted to RME with a tooth-supported appliance (Hyrax) were evaluated. The inclusion criteria were: minimum age of 14 years, presenting all posterior teeth, diagnosed with transverse maxillary discrepancy, and with a clinical indication for maxillary expansion. The pretreatment CBCT scans of these patients were assessed to obtain the stages of MS maturation (MSM); density ratio (MSD); and palatal length, thickness (anterior, intermediate and posterior) and sagittal area. RESULTS: The maturation stages present were C, D or E; the density ranged from 0.6 to 1, and lower density (MSD < 0.75) and higher density (MSD ≥ 0.75) groups were determined. Individuals with higher MSD presented smaller sagittal area, compared to the lower density group. Individuals in D and E MSM stages presented smaller sagittal area and intermediate thickness, compared to stage C. CONCLUSIONS: Smaller palatal sagittal area was observed in the high MSD groups and in the stages D and E of MSM.

Missed canals in endodontically treated maxillary molars of a Brazilian subpopulation: prevalence and association with periapical lesion using cone-beam computed tomography.

OBJECTIVES: To evaluate the prevalence of missed canals in endodontically treated maxillary molars through cone-beam computed tomography (CBCT) images and to verify their association with the presence of periapical lesions. MATERIAL AND METHODS: Three oral radiologists evaluated 633 maxillary molars in CBCT exams regarding number of roots, number of root canals, number of missed canals, anatomic identification of missed canals, presence of periapical lesions, and root location of the periapical lesions. Data were statistically analyzed at a 5% significance level. RESULTS: Descriptive statistical analysis showed that among 395 first molars, 218 had at least one missed canal, and 186 (46.5%) had a missed canal and periapical lesion simultaneously. Of these, 72.4% (134) of the missed canals were only mesiobuccal 2 (MB2). Among 238 s molars evaluated, 121 presented at least one missed canal, and 104 (43.6%) had a missed canal and periapical lesion simultaneously. Of these, 81.7% (85) of the missed canals were only MB2. The chi-squared test showed an association between the presence of missed canals and periapical lesions for 1st and 2nd maxillary molars. Teeth that presented a missed canal showed an odds ratio (OR) of 2.57 (p < 0.0001) of being associated with a periapical lesion. Missed canal occurrence was positively related to the number of root canals (z = 13.06, p < 0.0001), meaning when the number of root canals is higher, there is a higher probability of missed canal occurrence. According to the model calculated prediction, for a one-unit increase in the number of canals, the probability of missed canals increases by 4.22%. CONCLUSIONS: It was concluded that MB2 was the most frequently missed canal, associated with the presence of periapical lesions in endodontically treated maxillary molars. CLINICAL RELEVANCE: Professionals' negligence of anatomical root variations has been contributed to the high prevalence of missed canals, leading to failures in endodontic treatment. Their association with periapical lesion occurrence emphasizes the importance of correct detection and instrumentation of these canals.

Evaluation of different teaching methods in the radiographic diagnosis of proximal carious lesions.

OBJECTIVES: To evaluate four different teaching methodologies in the radiographic diagnosis of proximal carious lesions and in the students' perception of these methodologies. METHODS: 71 undergraduate dental students were subdivided into 4 groups according to the teaching methodologies used (traditional, hybrid, e-learning and problem-based learning). All methods were applied by two properly trained researchers. Initially, students completed a pre-methodology test (index test). After applying the teaching methodologies, the students were submitted to a post-methodology test containing periapical radiographs for evaluation of proximal carious lesions. Then, the students answered a questionnaire to verify their perception of the different teaching methodologies. Statistical analysis was done. RESULTS: There were no relationship between the results of pre- and post-methodologies tests, irrespective of the teaching methodology employed (p > 0.05). No differences between the teaching methodologies studied (p > 0.05) were found regarding the amount of correct answers. However, the students who participated in the active (e-learning and problem-based learning) and hybrid teaching methodology reported a positive impact in relation to their diagnostic skills at the questionnaire. CONCLUSIONS: All the tested methodologies had a similar performance; however, the traditional methodology showed less acceptance by the students when analyzed subjectively and comparatively. The results of the present study increase comprehension about teaching methodologies for radiographic diagnosis of proximal carious lesions, and there is a potential to build on the knowledge base and provide practical support for students and educators.

Tomographic analysis of midpalatal suture prior to rapid maxillary expansion

ABSTRACT Introduction: In Orthodontics and Facial Orthopedics, the timing of treatment onset may be critical and individual analysis should be applied to promote a favorable treatment planning. In this study, individual analysis of midpalatal suture (MS) and palatal measurements were performed in teenagers and young adult patients treated with rapid maxillary expansion (RME). Description: Twenty-six patients submitted to RME with a tooth-supported appliance (Hyrax) were evaluated. The inclusion criteria were: minimum age of 14 years, presenting all posterior teeth, diagnosed with transverse maxillary discrepancy, and with a clinical indication for maxillary expansion. The pretreatment CBCT scans of these patients were assessed to obtain the stages of MS maturation (MSM); density ratio (MSD); and palatal length, thickness (anterior, intermediate and posterior) and sagittal area. Results: The maturation stages present were C, D or E; the density ranged from 0.6 to 1, and lower density (MSD < 0.75) and higher density (MSD ≥ 0.75) groups were determined. Individuals with higher MSD presented smaller sagittal area, compared to the lower density group. Individuals in D and E MSM stages presented smaller sagittal area and intermediate thickness, compared to stage C. Conclusions: Smaller palatal sagittal area was observed in the high MSD groups and in the stages D and E of MSM.

RESUMO Introdução: Em Ortodontia e Ortopedia Facial, o momento de início do tratamento pode ser crítico, e uma análise individual deve ser aplicada para promover um planejamento de tratamento favorável. No presente estudo, foram realizadas a avaliação individualizada da sutura palatina mediana (SPM) e medições no palato de adolescentes e adultos jovens tratados com expansão rápida da maxila (ERM). Descrição: Foram avaliados vinte e seis pacientes submetidos à ERM com aparelho dentossuportado (Hyrax). Os critérios de inclusão foram: idade mínima de 14 anos, apresentando todos os dentes posteriores, diagnosticado com discrepância transversa da maxila e com uma indicação clínica para expansão maxilar. A tomografia computadorizada de feixe cônico (TCFC) pré-tratamento desses pacientes foi avaliada para obter os estágios de maturação da SPM (MSPM), densidade da SPM (DSPM), comprimento do palato, espessura (anterior, intermediária e posterior) e área sagital. Resultados: Os estágios de maturação presentes foram C, D ou E; a densidade variou de 0,6 a 1, e foram determinados grupos de baixa (DSPM < 0,75) e alta densidade (DSPM ≥ 0,75). Indivíduos com maior DSPM apresentaram menor área sagital, em comparação com o grupo de densidade mais baixa. Indivíduos nos estágios D e E de MSPM apresentaram menor área sagital e espessura intermediária, comparados aos indivíduos no estágio C. Conclusão: Uma menor área sagital palatina foi observada nos grupos de alta DSPM e nos estágios D e E de MSPM.

Dental radiographic anatomy analysis for identification of a carbonized body: case report

Introduction: Dentistry imaging is responsible for providing paramount support for forensic odontologists in cases of cadaveric identification. Nevertheless, in some cases, this assistance becomes essential, as in cases in which all the crowns have proven to be in perfect health standards, and when the dentist is able to identify loss of crown structural integrity, which can occur due to intense thermal action. Objective: To report a case in which forensic odontologists identified acadaver through radiographic comparisons. Case report: In 2018, a carbonized bodyfound inside an incinerated vehicle was referred to an examination aim ingits identification. The comparative analysis used different types of bidimensional images: antemortem panoramic radiograph and postmortem periapical radiographs. There was a total agreement of the dental radiographic anatomy, with emphasis on the root angulation, morphology of root canals, furcation regions, root apexes, the shape of pulp chambers and regions of alveolar trabecular related to both arches, as well as a cavity located in the occlusal surface of the lower right first molar. Conclusion: The compatibility of dental anatomy analyzed through the radiographs was fundamental for a positive result of the dentistry identification process.

Introdução: Os exames de imagem odontológicos fornecem um importante auxílio para os odontolegistas em casos de identificação cadavérica. Porém, em alguns casos, tal auxílio se torna essencial, como nos casos em que todas as coroas dentárias se encontram hígidas e quando ocorre perda da estrutura coronária, podendo ser devido à ação térmica. Objetivo: Relatar um caso em que odontolegistas identificaram um cadáver através de comparações radiográficas. Relato do caso: Em 2018, um cadáver carbonizado no interior de um veículo incinerado foi encaminhado para exame visando sua identificação. A análise comparativa utilizou diferentes tipos de exames bidimensionais: uma radiografia panorâmica antemortem e radiografias periapicais postmortem. Houve total concordância da anatomia dentária radiográfica, destacando-se a angulação das raízes, morfologia dos condutos radiculares, regiões de furca, ápices radiculares, forma das câmaras pulpares e regiões do trabeculado alveolar relativos a ambas as arcadas, além de uma cavidade localizada na face oclusal do primeiro molar inferior direito. Conclusão: A compatibilidade da anatomia dentária observada através das radiografias foi primordial para um resultado positivo do processo de identificação odontológica.

Imaginological characterization of multiple myeloma lesions of the jaws through cone-beam computed tomography.

PURPOSE: To establish an evaluation protocol for the identification and description of the variations in multiple myeloma (MM) lesions of the jaws, by means of cone-beam computed tomography (CBCT). MATERIALS AND METHODS: Tomography exams from 33 MM patients were evaluated in this retrospective observational study. The reconstructions were analyzed simultaneously, according to the established protocol, with the following description criteria: anatomic location, size, margins, inner aspect, relationship with adjacent structures, and presence or absence of a punched-out aspect. The exams were further subdivided into groups of patients using, or not bisphosphonates. RESULTS: There were osteolytic lesions in 100% of cases, most of which were extended to more than one anatomical region. Poorly defined margins were more frequent in the maxilla than in the mandible. Extensive bone resorption presenting multilocular areas was the most frequently observed aspect, being 86.2% for maxilla and 87.9% for mandible. In relation to bisphosphonates, patients who used the medication had more poorly defined bone margins and contortions (68.6%) than those who did not undergo drug therapy (31.4%). No well-defined lesions were observed (p = 0.34%). CONCLUSION: It was possible to establish a protocol for evaluation of MM lesions in CBCT images and to identify that when evaluated three-dimensional, lesions tend to be poorly defined and have no pattern of description, as described in two-dimensional "punched-out".

Bisphophonate alterations of the jaw bones in individuals with multiple myeloma.

OBJECTIVES: To verify quantitative differences of the mandibular cortical and trabecular bone between patients with multiple myeloma (MM) under bisphosphonate (BP) therapy and a control group never exposed to BP. METHODS: Clinical and demographic characteristics were collected through medical records and interviews. Mandibular cortical thickness (MCT) and fractal dimension (FD) were measured on cone beam computed tomography (CBCT) images, on the molar region, in both groups. Additionally, FD was measured on periapical digital intraoral radiography and results were compared to CBCT measurements. RESULTS: There were 33 patients with MM under BP therapy and 28 controls, with no significant differences in gender and age between groups. Pamidronate was used by all MM patients, either associated or not to other types of BP. The median MCT was higher in MM group exposed to BP (5.20 mm) than in controls (3.50 mm, p < 0.001). There were no significant differences in the median FD between patients in the MM group and controls, on CBCT (0.95 vs 0.90, p = 0.814) and periapical digital intraoral radiography (0.98 vs 0.96, p = 0.963), respectively, even when more than one type of BP was used. CONCLUSIONS: The MCT represents an useful tool in the detection of bone dimensional changes caused by BP, in patients with MM. Additional studies are necessary to improve the knowledge on the quantitative evaluation of trabecular jaw bone, in individuals with MM, under BP therapy.

Effects of different pre-operative doses of dexamethasone on alveolar repair in rats.

Dexamethasone has been widly used in oral and maxillofacial surgery for controlling of postoperative surgical inflammation. Despite its clinical effectiveness, several studies have demonstrated the negative impact of this drug on the healing of soft and hard tissues. This study aimed to assess the effects of different pre-operative doses of dexamethasone on alveolar repair. Sixty rats were divided into four groups of 15 animals each. Single pre-operative doses of dexamethasone equivalent to human doses of 4 mg (Group 4 mg), 8 mg (Group 8 mg), and 12 mg (Group 12 mg), calculated by allometric dose extrapolation, were administered; and rats in the Control Group were injected with saline solution. The animals were anesthetized, and their left mandibular first molars (M1) were removed. After three, seven, and 40 days, 5 animals from each group were euthanized, and bone samples of M1 alveolus were collected for radipgraphic, histomorphological and histometric evaluation of the early and late phases of alveolar healing. At three days, Group 12 mg presented reduced radiographic density, percentage of collagen, and connective matrix compared with the Control Group. At 7 days, the percentage of bone was increased in the Control Group compared to Groups 8 mg and 12 mg (P < 0.05). It can be concluded that a single pre-operative dose of 12 mg of dexamethasone affected the early stages of alveolar repair in rats.

Double mandibular canal and triple mental foramina: detection of multiple anatomical variations in a single patient.

Having complete information about a patient's mandibular canal and mental foramen is fundamental to performing safer procedures and avoiding intraoperative and postoperative complications. Cone beam computed tomography (CBCT) produces accurate images for the analysis of maxillomandibular bone structures and is widely used in dentistry. The aim of this study is to report a case of mandibular bifid canal associated with triple mental foramina that was revealed with CBCT images. A 45-year-old woman was referred for a CBCT scan of remaining bone quantity to assist in preoperative implant planning. The patient had reported problems related to anesthesia during extraction of the mandibular right second and third molars. Examination showed bilateral bifurcation of the mandibular canal, from the mandibular foramen to the gonial angle. In addition, exteriorization of the mandibular canal was noticed in 3 regions; that is, there were 3 distinct mental foramina. Clinicians must be aware of these anatomical variations in the mandibular region during dental procedures to avoid complications such as difficulty in obtaining anesthesia or postoperative sensory dysfunction.

Imaginological exams of the frontal sinus in human identification

Introduction: Human identification is the process by which the identity of an individual is established by comparing data recorded at different times. In the case of the human skull, the most used areas for the individualization are the Turkish Chair, the sphenoid bone, the mastoid cells, and the frontal sinus. Objective: The aim of the present work was to identify and describe the main techniques developed for human identification through a literature review, based on imaging of the frontal sinuses, due to the potential contribution of dental radiology in this context. Sources of data: For this, a bibliographic search was performed in PUBMED, using the following terminologies: frontal sinus, radiology, and forensic. Articles published between 2007 and 2017 were included, literature articles, letters, and case reports were excluded. Synthesis of data: A total of twenty-three articles were selected, the sample was analyzed for the nationality, homogeneity, sex, and age of the individuals, as well as for the types of imaging tests that constituted this sample, whether of radiographic or tomographic origin and their different projections and modalities. In addition, the literature was classified as to the different techniques and parameters used for identification, whether quantitative or morphological. Conclusion: After this research, it was possible to conclude that the profile of the world scientific research aimed at human identification through imaging of the frontal sinuses, consists of homogenous samples, of both sexes, and a wide age group, using mostly posteroanterior extraoral radiographic examination and qualitative and quantitative parameters for identification.

Introdução: A identificação humana é o processo pelo qual se estabelece a identidade de um indivíduo por meio da comparação entre dados registrados em momentos diferentes. Tratando-se do crânio humano, as regiões mais utilizadas na individualização do mesmo são as áreas da sela túrcica, no osso esfenoide, as células mastoides e o seio frontal. Objetivo: O presente trabalho teve como objetivo, através de uma revista da literatura, identificar e descrever as principais técnicas desenvolvidas para a identificação humana, a partir de exames de imagens dos seios frontais, em virtude da contribuição em potencial da radiologia odontológica nesse contexto. Fonte de dados: Para isso, foi realizada uma busca bibliográfica, no PUBMED, a partir do uso das seguintes terminologias: frontal sinus, radiology e forensic . Foram incluídos os artigos publicados entre 2007 e 2017 e excluídos artigos de revisão de literatura, cartas e relatos de caso. Síntese dos dados: Em um total de vinte e três artigos selecionados analisou-se a amostra quanto à nacionalidade, homogeneidade, sexo e faixa etária dos indivíduos, além dos tipos de exames de imagem que constituíram essa amostra, seja de origem radiográfica ou tomográfica, e suas diferentes projeções e modalidades. Além disso, classificou-se a literatura quanto às diferentes técnicas e parâmetros empregados para a identificação, sejam eles quantitativos ou morfológicos. Conclusão: Através desta busca, conclui-se que o perfil da pesquisa científica mundial, voltada para a identificação humana através de exames de imagem dos seios frontais, utiliza amostras homogêneas, de ambos os sexos e ampla faixa etária, empregando-se majoritariamente a Radiografia Extra-oral Póstero- Anterior e parâmetros qualitativos e quantitativos para a identificação.

Evaluation of different soft tissue-simulating materials in pixel intensity values in cone beam computed tomography.

OBJECTIVE: This study aimed to evaluate different materials as soft tissue simulators and the influence of soft tissues in cone beam computed tomography. STUDY DESIGN: Images of 5 piglet heads were acquired with intact soft tissues, with the tissues stripped, and with the use of different soft tissue simulators, following the same acquisition protocol. Four different materials were tested, individually or in combination: acrylic, water, utility wax, and expanded polystyrene (EPS). Pixel intensity values of 8 quadrangular regions, that is, upper and lower teeth and alveolar bone, were obtained. The mean values were used for comparison by analysis of variance (ANOVA; α = 5%). RESULTS: No differences were observed for the "No Material," "EPS," "Acrylic," and "EPS and Wax" groups for the lower anterior and posterior teeth, the upper posterior tooth, and the anterior and posterior bone, and for the "No Material," "EPS," and "EPS and Wax," groups for the lower posterior bone. All groups showed statistical differences for the lower anterior bone and the upper anterior tooth. CONCLUSIONS: Expanded 2-cm thick polystyrene, with or without 1-cm thick utility wax, was effective for most regions, followed by acrylic 0.5 cm. Soft tissues were not of great influence in most regions. Water was not an effective material for any of the regions.

Root canal segmentation in cone-beam computed tomography: comparison with a micro-CT gold standard

Aim: The purpose of this study was to compare root canal volumes (RCVs) obtained by means of cone beam computed tomography (CBCT) to those obtained by micro-computed tomography (micro-CT) after applying different segmentation algorithms. Methods: Eighteen extracted human teeth with sound root canals were individually scanned in CBCT and micro-CT using specific acquisition parameters. Two different images segmentation strategies were applied to both acquisition methods (a visual and an automatic threshold). From each segmented tooth, the root canal volume was obtained. A paired t-test was used to identify differences between mean values resulted from the experimental groups and the gold standard. In addition, Pearson correlation coefficients and the agreement among the experimental groups with the gold standard were also calculated. The significance level adopted was 5%. Results: No statistical differences between the segmentation methods (visual and automatic) were observed for micro-CT acquired images. However, significant differences for the two segmentation methods tested were seen when CBCT acquired images were compared with the micro-CT automatic segmentation methods used. In general, an overestimation of the values in the visual method were observed while an underestimation was observed with the automatic segmentation algorithm. Conclusion: Cone beam computed tomography images acquired with parameters used in the present study resulted in low agreement with root canal volumes obtained with a micro-CT tomography gold standard method of RCV calculation