Craniomandibular transverse tomographic evaluation after anterior open bite orthodontic treatment with miniplates anchorage.

BACKGROUND: Skeletal anterior open bite (SAOB) represents one of the most complex and challenging malocclusions in orthodontics. Orthodontic treatment supported by miniplates enable to reduce the need for orthognathic surgery. Transverse dimension may be affected by intrusion biomechanics. This study aims to assess transverse bone alterations in patients with SAOB who underwent orthodontic treatment with absolute anchorage using four miniplates. METHODS: A total of 32 patients of both sexes, with an average age of 33.8 years, diagnosed with SAOB and treated orthodontically with four miniplates (one in each hemiarch), were selected for this study. Tomographic examinations were performed before (T1) and after (T2) orthodontic treatment. Linear measurements (width of the maxillary base, maxillary alveolar, maxillary root, maxillary dental cusp, mandibular alveolar) and angular measurements (maxillary intermolar angle) were assessed in these images. The Shapiro-Wilks normality tests were applied to verify data distribution, and the paired t-test was used to compare the initial and final measures obtained. RESULTS: Among the evaluated parameters, the maxillary alveolar width, maxillary dental cusp width, mandibular alveolar cusp width, and intermolar angle showed statistically significant differences between T1 and T2 (p < 0.05). However, maxillary base and maxillary root widths showed no significant difference (p > 0.05). CONCLUSIONS: Intrusion and distalization with miniplates in SAOB therapy may lead to significant expansive changes, due to molars cusps width and buccal inclination increase restricted at the alveolar level.

Prevalence of orofacial alterations in patients with sickle-cell disease: Systematic review and meta-analysis.

OBJECTIVE: The aim of this study was to identify the prevalence of orofacial alterations in sickle-cell disease (SCD) and to compare it with the general population. STUDY DESIGN: This review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2020 guidelines. The search was conducted on PubMed, Embase, Scientific Electronic Library Online, Web of Science, Cochrane Library, gray literature, and references of the included articles. RESULTS: A total of 770 records were found, and 28 studies were selected. In SCD, the prevalence of decreased bone density was 57% (95% CI: 35%-80%), with Q: P < .01 and I2 = 95%; for stepladder pattern was 30% (IC: 13%-47%), Q: P < .01 and I²: 93%; for delayed eruption was 20% (95% CI: 6%-34%), with Q: P < .01 and I2 = 86, Q: P < .01 and I2 = 99%; and for malocclusion, 66% (95% CI: 39%-92%), Q: P < .01 and I2 = 98%. A high risk of bias was observed in relation to the sample size of the studies. A limited number of articles compared the prevalence of orofacial alterations in patients with SCD and healthy individuals. CONCLUSIONS: Decreased bone density, malocclusion, orofacial pain, tooth necrosis, eruption delay, periodontal disease, and neuropathies may be present in patients with SCD with variable prevalence.

Application of the London Atlas Software App 2nd edition for the radiographic assessment of dental development.

Background: Assessing the dental development of children and adolescents is an important part of treatment planning. The radiographic visualization of dental developmental stages prior to age estimation is currently feasible by means of digital software apps. Testing the existing software tools is necessary to safeguard application in practice. This study applied the London Atlas Software App 2nd edition™ for dental age estimation in Brazilian children. Material and Methods: The software was applied to 1.104 digital panoramic radiographs of females (n = 509) and males (n = 595) with ages between 6 and 15.99 years (mean = 10.88 ± 2.84 years). The sample included at least 100 individuals similarly distributed based on sex within 10 age categories of one year each (6├ 15.99) years. Metrics of errors were quantified between the estimated (EA) and chronological (CA) ages. Results: The mean absolute errors among females and males were 0.56 and 0.60 years, respectively (overall = 0.58 years for the combined sample). The lower error values were observed in the age interval of 6 ├ 9.99 years. Error values above one year were detected in older age intervals (10 ├ 15.99 years). Statistically significant differences in dental development were not observed between females and males (p> 0.05). Conclusions: The London Atlas Software App 2nd edition led to specific error rates that can be acceptable for case-specific clinical applications. In the forensic field, caution is advised if the application is planned in the transition between late childhood and early adolescence - when third molars play a major role among the scarce developing teeth. Key words:Brazil, children, dental age estimation, forensic dentistry, radiology.

Assessment of cone beam computed tomography for determining position and prognosis of interradicular mini-implants.

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.

Effect of decompression and online transmission on the dimensional changes of .stl files generated by intra-oral scanning.

Intraoral scans became part of the virtual planning in Dentistry. In the new scenario of digital workflows, dental clinics and laboratories had to establish an online communication that requires the compression, decompression, and transmission of 3D files. Knowledge about the effects of these procedures on the dimensional properties of the files is fundamental to ensure a more realistic virtual planning. The aim of this study was to assess the influence of 3D file compression, decompression, and online transmission on the dimensional properties of dental models from intraoral scanning. Intraoral scan files in.stl format of 50 patients were selected from the database of a dental radiology clinic, with 25 of these patients with mixed dentition and 25 with permanent dentition. The maxilla and mandible scans of each patient were included in the study, generating a total of 100 files. A folder with the 100 files was created and replicated six times with different labels (A, B, C, D, E, F), totaling a sample number of 600 files. Folder A was compressed by WinZip and then decompressed. Folder B went through the same process, but the step of compression and decompression by WinZip was repeated 10 times. The folders C, D, E, F were sent, respectively, through the platforms WeTransfer, Dropbox, Google Drive, and OneDrive, then each of them was downloaded in their respective platforms. After the six folders went through the compression process and were sent by the platforms, each file in the folder was compared with its original file by superimposing the 3D images and identifying the dimensional deviation in the compressed file in relation to the original file. We observed that there were no differences between the six groups regarding dimensional changes from the compression, decompression and online transmission processes. The lack of dimensional changes was observed for the sets of permanent and deciduous. teeth We concluded that it is possible to compress, decompress, and transfer.stl format files online without causing dimensional distortions in the 3D model.

Two-dimensional radiographs versus cone-beam computed tomography in planning mini-implant placement: A systematic review.

Background: This study aimed to compare two-dimensional radiographs and cone beam computed tomography (CBCT) images for mini-implant planning. Material and Methods: A search was performed in PubMed, Embase, Web of Science, Cochrane Library and Google Scholar electronic databases according to PIRD strategy, on September 11, 2021. In vivo studies that compared two-dimensional imaging with CBCT for mini-implant planning were selected. The methodological quality of each study was assessed using the QUADAS-2 tool. Results: The initial search identified 441 papers. Five studies were added following a manual research. Of the total 446 studies, 40 were selected after title evaluation, 29 remained after abstract evaluation, and 11 were left after full-text analysis. Final screening yielded a total of four studies that composed the narrative synthesis of this systematic review. When comparing the imaging systems for palatal mini-implants, lateral radiographs (LRs) showed approximately the same measurements of bone quantity as those of CBCT, hence bearing no influence on placement site selection. In determining image suitability for interradicular mini-implants, two-dimensional radiographs underestimated the available space. Conclusions: Lateral radiography is sufficient to quantify the available bone for planning mini-implants installed on the palate, in the median region of upper first premolars. CBCT enhances interradicular mini-implant planning by aiding in implantation site selection, and improving the installation success rate. Key words:Systematic Review, Cone beam computed tomography, Radiography, Orthodontic mini-implant, Dental planning.

Evaluation of the dosimetry and centralization of scout-view function in CBCT.

This study evaluated the centralization of the region of interest (ROI) in acquisition of the CBCT images, when the freely positionable scout-view (SV) function is applied. Additionally, the dosimetry of the acquired images was assessed in the SV function alone as well as in complete tomographic image in two different fields of view (FOV) (50x50 and 78x150mm). A three-location device was created to accommodate the dosimeters and the specimens, in the right, middle and left location during image acquisition. For dose assessment, thermoluminescent dosimeters were irradiated within the FOV and analyzed in a portable reader. For ROI evaluation, three specimens of gutta-percha stick were placed on the same device and the CT scans were acquired (CBCT OP 300 Maxio device, 90kV, 13mA, 85 µm voxel size, FOV of 50X50mm), with and without the SV, in three positions (3-9, 1-7 and 5-11 o'clock), simulating different regions of the mouth. Two image evaluations were performed, an objective and subjective. There was a slight percentage increase (1.36% to 1.40%) of the radiation dose with the use of SV. The distances were significantly greater in the images acquired without SV (p < 0.05). Every image obtained with SV was classified as being at the FOV's center. In conclusion, the results demonstrated that SVs function is effective to centralize the ROI in the FOV, increasing the scan precision and avoiding repetitions due to positioning errors.

Finite element analysis of a newly designed miniplate for orthodontic anchorage in the maxillary anterior region.

INTRODUCTION: Multiple force vector applications may be indicated when an arch segment or en masse intrusion is needed. This finite element method study aimed to evaluate the total deform the stress yielded in the bone and the miniplate when forces with different directions and magnitudes were applied. METHODS: First, the prototyped skull model was fabricated on the basis of computed tomography (CT) scans. On this model, the miniplate was fixed, and orthodontic appliances were attached. Then, a 3-dimensional finite element model was constructed by reproducing the characteristics of the physical model. Seven situations were investigated, which diverged in the point of force application, the direction and the number of force vectors, and the force magnitudes. RESULTS: When the force was applied at 1 point, similar behavior could be observed concerning the deformation and the stress in the miniplate, the maxilla, and the screw holes. Most deformation and stress appeared in the transmucosal arm below the step bend and at the force application point. The angled vectors (-45° and 30°) presented smaller values concerning the vertical vectors. Similar or better performances could be observed when the forces were simultaneously applied at the 2 points. CONCLUSIONS: The newly designed miniplate showed similar or improved performances when multiple vectors were applied at the 2 points simultaneously compared with the force applied at 1 point. This newly designed miniplate may present improved performance in a clinical situation when multiple forces are demanded.

Evaluation of the dosimetry and centralization of scout-view function in CBCT

Abstract This study evaluated the centralization of the region of interest (ROI) in acquisition of the CBCT images, when the freely positionable scout-view (SV) function is applied. Additionally, the dosimetry of the acquired images was assessed in the SV function alone as well as in complete tomographic image in two different fields of view (FOV) (50x50 and 78x150mm). A three-location device was created to accommodate the dosimeters and the specimens, in the right, middle and left location during image acquisition. For dose assessment, thermoluminescent dosimeters were irradiated within the FOV and analyzed in a portable reader. For ROI evaluation, three specimens of gutta-percha stick were placed on the same device and the CT scans were acquired (CBCT OP 300 Maxio device, 90kV, 13mA, 85 µm voxel size, FOV of 50X50mm), with and without the SV, in three positions (3-9, 1-7 and 5-11 o'clock), simulating different regions of the mouth. Two image evaluations were performed, an objective and subjective. There was a slight percentage increase (1.36% to 1.40%) of the radiation dose with the use of SV. The distances were significantly greater in the images acquired without SV (p < 0.05). Every image obtained with SV was classified as being at the FOV's center. In conclusion, the results demonstrated that SVs function is effective to centralize the ROI in the FOV, increasing the scan precision and avoiding repetitions due to positioning errors.

Resumo Este estudo avaliou a centralização da região de interesse (ROI) na aquisição das imagens de TCFC, quando a função scout-view (SV) posicionável livremente é aplicada. Adicionalmente, a dosimetria das imagens adquiridas foi avaliada isoladamente na presença da função SV, bem como após aquisição de imagem tomográfica completa em dois diferentes campos de visão (FOV) (50x50 e 78x150mm). Um dispositivo de três localizações foi criado para acomodar os dosímetros e os espécimes, na localização direita, central e esquerda, durante a aquisição das imagens. Para avaliação da dose, dosímetros termoluminescentes foram irradiados dentro dos campos de visão e analisados em leitor portátil. Para avaliação da ROI, três espécimes de guta percha foram colocados no mesmo aparelho e as tomografias foram adquiridas (CBCT OP 300 Maxio, 90kV, 13mA, 85 μm tamanho de voxel, FOV de 50X50mm), com e sem a SV, em três posições (3-9, 1-7 e 5-11 horas), simulando diferentes regiões da boca. Foram realizadas duas avaliações de imagem, uma objetiva e outra subjetiva. Houve um leve aumento percentual (1,36% para 1,40%) da dose de radiação com o uso de SV. As distâncias foram significativamente maiores nas imagens adquiridas sem SV (p < 0,05). Todas as imagens obtidas com SV foram classificadas como sendo do centro do FOV. Em conclusão, os resultados do presente estudo demonstraram que a função scout view é eficaz para centralizar a ROI no FOV, aumentando a precisão do escaneamento e evitando repetições devido a erros de posicionamento.

Assessment of cone beam computed tomography for determining position and prognosis of interradicular mini-implants

ABSTRACT 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.

RESUMO Objetivo: Analisar se a avaliação dinâmica de volumes de tomografia computadorizada de feixe cônico (TCFC) influencia a percepção de ortodontistas quanto à determinação da posição e do prognóstico de mini-implantes (MIs) inter-radiculares. Material e Métodos: Foram selecionados 30 volumes de TCFC, nos quais foram simuladas três formas de instalação de MIs: 1) MI a 1 mm de distância da lâmina dura (LD); 2) MI tocando a LD; e 3) MI sobreposto à LD. As imagens foram examinadas por 35 ortodontistas na forma de reconstruções panorâmicas, reconstruções sagitais e uma sequência de reconstruções axiais. Os examinadores avaliaram a relação entre o MI e a LD, e indicaram o prognóstico dos MIs instalados, usando uma escala de 4 pontos (quanto maior o escore, mais favorável o prognóstico). Os dados foram submetidos à análise estatística, por meio dos testes de Kappa, Friedman e Nemenyi. Resultados: Houve associação significativa entre o prognóstico, os tipos de imagem e as três formas de inserção dos MIs (p<0,05). A visualização dinâmica dos volumes de TCFC (reconstruções axiais) foi associada a maiores escores para o prognóstico e a avaliações mais confiáveis da posição dos MIs. Escores mais inconsistentes e discordantes foram mais associados às reconstruções panorâmicas e sagitais. Conclusão: A análise do volume tomográfico em reconstruções axiais pode melhorar a avaliação do ortodontista quanto à posição dos MIs inter-radiculares, apresentando impacto significativo na determinação do prognóstico do caso.

Dosimetric evaluation for temporomandibular joint cone beam computed tomography exams using different field of view.

Objectives.To optimize the absorbed organ dose in relation to the field of view for temporomandibular joint examinations in four cone beam computed tomography devices.Methods.An anthropomorphic adult head and neck phantom, and 192 LiF dosimeters (TLD-100) were used. The dosimeters were placed in the region corresponding to the lens, parotid glands, submandibular glands, and thyroid. Small, medium and large FOVs were selected on Orthopantomograph OP300 Maxio, PaX-i3D Smart, ORTHOPHOS XG, and i-CAT Next Generation device when it was possible.Results.A wide range of absorbed dose values was recorded for all organs due to the different exposure parameters of each device. The radiosensitive organ with the highest dose was the parotid glands. The devices with 5 × 5 cm FOV recorded a lower dose in this protocol, while for the device without a small FOV (≤5 × 5 cm), the lowest dose was observed with the large FOV (6 × 16 cm).Conclusions.We recommend a double exposure with an FOV of 5 × 5 cm in the OP300 Maxio, PaX-i3D Smart, and ORTHOPHOS XG device, while in the i-CAT Next Generation device, a single exposure FOV of 6 × 16 cm is indicated.

Negligible tooth resorptions after anterior open bite treatment using skeletal anchorage with miniplates.

INTRODUCTION: When miniplates are used as anchoring for orthodontic mechanics for anterior open bite correction by retraction of anterior teeth and posterior teeth intrusion and retraction, orthodontically induced inflammatory external apical root resorption is clinically negligible. METHODS: A homogeneous sample of 32 patients was used, and the roots of the teeth were compared on CT scans performed before and after orthodontic treatment. RESULTS: The observed root resorption was minimal, and this can be explained by the uniform distribution of forces in several teeth, simultaneously, in the set of the dental arch and in the bone that supports the teeth. CONCLUSION: The most important thing to prevent root resorption in orthodontic practice, besides being concerned with the intensity of the applied forces, is to be careful with its distribution along the roots of each tooth, in the dental arch and in the bone that supports the teeth.

Negligible tooth resorptions after anterior open bite treatment using skeletal anchorage with miniplates

ABSTRACT Introduction: When miniplates are used as anchoring for orthodontic mechanics for anterior open bite correction by retraction of anterior teeth and posterior teeth intrusion and retraction, orthodontically induced inflammatory external apical root resorption is clinically negligible. Methods: A homogeneous sample of 32 patients was used, and the roots of the teeth were compared on CT scans performed before and after orthodontic treatment. Results: The observed root resorption was minimal, and this can be explained by the uniform distribution of forces in several teeth, simultaneously, in the set of the dental arch and in the bone that supports the teeth. Conclusion: The most important thing to prevent root resorption in orthodontic practice, besides being concerned with the intensity of the applied forces, is to be careful with its distribution along the roots of each tooth, in the dental arch and in the bone that supports the teeth.

RESUMO Introdução: Quando são utilizadas miniplacas como ancoragem para a mecânica ortodôntica de correção da mordida aberta anterior por meio da retração dos dentes anteriores e intrusão e retração dos dentes posteriores, as reabsorções radiculares apicais externas inflamatórias induzidas ortodonticamente são clinicamente irrelevantes. Métodos: Usou-se uma amostra homogênea de 32 pacientes, e comparou-se as raízes dos dentes em tomografias realizadas antes e depois do tratamento ortodôntico. Resultados: As reabsorções radiculares observadas foram mínimas, e isso pode ser explicado pela distribuição uniforme das forças em vários dentes, simultaneamente, no conjunto da arcada dentária e no osso que suporta os dentes. Conclusão: O mais importante para se prevenir as reabsorções radiculares na prática ortodôntica, além de se preocupar com a intensidade das forças aplicadas, é tomar cuidado com a sua distribuição ao longo das raízes de cada dente, na arcada dentária e no osso que suporta os dentes.

Dental students' perceptions of case-based learning method and the impact of clinical information in imaging diagnosis.

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.

Odontogenic infection as a predisposing factor for pathologic disorder development in maxillary sinus.

OBJECTIVE: To investigate an association between odontogenic infections (OI) and maxillary sinuses pathologic disorder (MSPD). The distance between the sinus floor and the root apex of upper posterior teeth was also assessed. METHODS: Out of 4,402 cone beam computed tomography scans, 230 were selected, and 431 teeth were evaluated regarding the presence of OI: bone loss with furcation involvement, periapical and endodontic-periodontal lesions. The maxillary sinuses were assessed regarding the presence of MSPD, which was considered as mucosal thickening, opacification of the sinus and mucous retention cyst. RESULTS: There was a significant association between OI and MSPD (p < .001). Periodontal bone loss with furcation involvement, periapical lesions and endodontic-periodontal lesions increased the risk of opacification of the sinuses by 11.6, 34.1 and 228.8 times, respectively. The frequency of the different types of MSP showed not to be associated with a group of teeth or dental root. Conversely, the presence of MSP was associated with a significant shorter distance between the palatine root apex and the sinus floor (p < .001). CONCLUSION: There is a relationship between infectious process of teeth and MSPD. The proximity between the apex of palatine roots and the maxillary sinus floor showed to be a predisposing factor for MSPD.

Análise ético-jurídica da publicidade odontológica no Instagram / Ethical and legal analysis of Odontology-related advertisement on Instagram

A restrição à publicidade odontológica coíbe a mercantilização, resguarda a privacidade do paciente e o protege como consumidor. O objetivo deste estudo foi avaliar a adequação da publicidade na rede Instagram® ao regramento vigente. Numa amostra de 384 perfis profissionais, avaliaram-se postagens públicas à luz da Lei 5.081/1966, Código de Defesa do Consumidor e Código de Ética Odontológica. A identificação adequada não foi feita por 35,4%. Já 3,6% anunciaram especialidades não reconhecidas. A expressão "popular" foi utilizada por 27,1%. Houve publicidade abusiva (16,4%) ou enganosa (8,3%). Serviços gratuitos foram anunciados (9,4%), com divulgação de preços (5,5%). Usando a imagem do paciente (79,4%), constatou-se divulgação de resultados clínicos (72,9%). Houve identificação do paciente em 68,2%, com uso adequado da imagem em apenas 9,1% dos casos. As imagens de antes/depois foram usadas em 76,6% das postagens. As inadequações sem a imagem do paciente orbitam entre infração ética, exercício profissional ilícito e desrespeito ao direito consumerista. Conclui-se que a publicidade odontológica veiculada no Instagram® apresentou condutas ilícitas e antiéticas, com e sem o uso da imagem do paciente o que pode configurar prejuízos ao paciente, ao profissional e à Odontologia como profissão da área de saúde.

Association between the Root Canal Configuration, Endodontic Treatment Technical Errors, and Periapical Hypodensities in Molar Teeth: A Cone-beam Computed Tomographic Study.

INTRODUCTION: This study aimed to evaluate the association between the root canal configuration (RCC), endodontic technical errors, and periapical hypodensities in molars using cone-beam computed tomographic (CBCT) images. METHODS: Two hundred twenty-one roots were assessed from 79 patients referred for CBCT examination because of symptomatology in endodontically treated molars. Two oral and maxillofacial radiologists classified the RCC of each dental root according to Vertucci's classification. Root canals were assessed for the presence of technical errors from endodontic treatment. The presence of periapical hypodensity for each dental root and the coronal sealing condition of each tooth were also recorded. RESULTS: For RCC type I, the most prevalent technical error was underfilling (17.4%). For types II and VIII, nonfilled canals were found in 54% and 100% of the cases, respectively. For type III, underfilling, nonhomogeneous filling, and nonfilled canals were equally frequent (33.3%), whereas for type IV underfilling and nonfilled canals had a prevalence of 42%. In general, there was a higher prevalence of apical hypodensities among roots with technical errors. It was also observed for type I, with an increase from 41.2%-62.9% when a technical error was present. CONCLUSIONS: The prevalence of different endodontic technical errors varies depending on the RCC for molars. A greater complexity of RCC is related to a higher occurrence of errors and a higher prevalence of periapical hypodensity.

Pre-eruptive intracoronal resorption on cone beam computed tomography: two case reports / Reabsorção dentinária pré-eruptiva na tomografia de feixe cônico: dois relatos de caso

ABSTRACT Pre-eruptive intracoronal resorption (PIR) is a rare lesion that occurs within the dentin of the crown on unerupted teeth. The aim of this article is to report two rare cases of a PIR in impacted canine using cone beam computed tomography (CBCT). High resolution CBCT images (Prexion 3D) were indicated for evaluating of the non-erupted tooth, claiming no other related signs or previous historyto be considered. In the first case, the images revealed an impacted and mesioinclined superior canine. In the coronary portion, it was observed an irregular hypodense lesion, involving the dentin, enamel tissue, and communication with the external surface of the tooth. In the second case, the images showed an impacted superior canine in the vertical position. It also revealed a hypodense lesion with poorly defined limits envolving the dentin, which extends over the crown. In both cases, the tooth was not in contact with the adjacentlateral tooth. Therefore, PIR in impacted teeth is rare, which is frequently diagnosed through routine radiographs. Additionally, CBCT seems to be an invaluable tool for providing accurate information about the exact topography, relationships with adjacent structures, helping, therefore, on the appropriate treatment planning.

RESUMO A reabsorção intra-coronária pré-eruptiva (RIP) é uma alteração rara que ocorre na coroa de dentes não erupcionados. O objetivo desse trabalho é documentar dois casos raros de RIP em caninos inclusos nas imagens de tomografia computadorizada de feixe cônico (TCFC). As imagens de TCFC de alta resolução (Prexion 3D) foram solicitadas cuja indicação era avaliação topográfica de dente não irrompido alegando nenhuma outra causa relacionada ou história pregressa a ser considerada. Caso 1: As imagens apresentaram o dente 23 incluso e mesioangulado. Na porção coronária observa-se imagens hipodensas irregulares abrangendo o tecido dentinário, esmalte e comunicação com a superfície externa do dente. Caso 2: As imagens apresentaram o dente 13 incluso em posição vertical.Imagem hipodensa e de limites pouco definidos, que se estende por quase toda coroa e acomete principalmente a dentina. Ambos os casos não apresentavam íntimo contato com o dente lateral adjacente. Portanto, pode concluir, que a reabsorção coronária de dentes totalmente inclusos é um achado raro de etiologia desconhecida, onde a TCFC é um instrumento de grande valia para fornecerinformações da exata topografia, relações com estruturas adjacentes, e auxílio para o correto planejamento do tratamento. Portanto, RIP em dentes impactados é raro, o que é frequentemente diagnosticado através de radiografias de rotina. Além disso, CBCT parece ser uma ferramenta inestimável para fornecer informações precisas sobre a topografia exata, relações com estruturas adjacentes,ajudando, portanto, no planejamento do tratamento adequado.

Detection of Incomplete Root Fractures in Endodontically Treated Teeth Using Different High-resolution Cone-beam Computed Tomographic Imaging Protocols.

INTRODUCTION: The purpose of this study was to compare different high-resolution cone-beam computed tomographic (CBCT) imaging protocols in the diagnosis of incomplete root fractures of endodontically treated teeth. METHODS: Twenty single-rooted human teeth were endodontically treated, and an incomplete root fracture was induced. The teeth were scanned with the CBCT unit PreXion 3D (Teracom, San Mateo, CA) operating at 2 different protocols: high resolution/standard (HI-STD) (19 seconds and 512 basis images) and high resolution/high density (HI-HI) (37 seconds and 1024 basis images). Three oral radiologists evaluated all images using multiplanar reconstructions. The diagnostic tests and the receiver operating characteristic (ROC) curve were calculated. RESULTS: The HI-STD and HI-HI protocols presented an accuracy of 0.90 and 0.93, respectively, and both protocols had a sensitivity of 0.97. The HI-HI protocol showed a higher positive predictive value and slightly higher areas under the ROC curve. CONCLUSIONS: Both high-resolution imaging protocols presented high accuracy in the detection of incomplete root fracture of endodontically teeth. Thus, the HI-STD protocol should be indicated this reduces the radiation dose.

Maxillary canine morphology: comparative and descriptive analysis from periapical radiographs and cone beam computed tomography.

The anatomical characteristics of permanent maxillary canines were evaluated through visual examination, periapical radiography, and cone beam computed tomography (CBCT), and measurements obtained from the images and directly on the teeth were compared. Fifty extracted human maxillary canines were classified according to the side of the mouth. The direction of root curvature and location of the apical foramen were also verified. Periapical radiographs and CBCTs of the specimens were obtained. The number of root canals was verified. Tooth length and the mesiodistal and buccopalatal widths of the root were measured directly on the specimens as well as on the radiographs and CBCTs. Data were analyzed by chi-square testing and analysis of variance (α = 0.05). All teeth-26 (52%) from the right side of the dental arch and 24 (48%) from the left-had only 1 main canal each. The apical foramen was located exactly in the root apex in 34 teeth (68%). Root curvature toward the distal side was observed in the apical third in 23 teeth (46%). There were no statistically significant differences between the canines' arch side and either the foramen location (P = 0.104) or the root curvature (P = 0.215). No statistically significant differences were found in measurements of tooth length (P = 0.669), mesiodistal root width (P = 0.517), or buccopalatal root width (P = 0.672) obtained from specimens and images. Both CBCTs and periapical radiographs were reliable for determining the tooth length, mesiodistal root width, and buccopalatal root width of maxillary canines and produced statistically similar measurements.