Differentiation of radicular cysts and radicular granulomas via texture analysis of multi-slice computed tomography images.

OBJECTIVES: This study aimed to establish a method for differentiating radicular cysts from granulomas via texture analysis (TA) of multi-slice computed tomography (CT) images. METHODS: A total of 222 lesions with multi-slice computed tomography images acquired at our hospital between 2013 and 2022 that were pathologically diagnosed were included in this study. Cases of contrast-enhanced images, severe metallic artefacts, and lesions that were not sufficiently large to be analysed were excluded. The images were chronologically divided into a training group and a validation group. The radiological characteristics were determined. Subsequently, a TA was performed. Pyradiomics software was used for the TA of three-dimensionally segmented volumes extracted from 2 mm slice thickness images with a soft-tissue algorithm. Features that differed significantly between the two lesions in the training group were extracted and used to create machine-learning models. The discriminative ability of these models was evaluated in the validation group using receiver operating characteristic curve analysis. RESULTS: A total of 131 lesions, comprising 28 radicular cysts and 103 granulomas, were analysed. Forty-three texture features that exhibited significant variations were extracted. A support vector machine and decision tree model, with areas under the curves of 0.829 and 0.803, respectively, were created. These models showed high discriminative abilities, even for the validation group, with areas under the curve of 0.727 and 0.701, respectively. Both models showed superior performance compared with that of the models based on radiographic findings. CONCLUSION: Discriminatory models were established for the TA of radicular cysts and granulomas using CT images.

Nlrp3 inflammasome drives regulatory T cell depletion to accelerate periapical bone erosion.

AIM: Apical periodontitis is an inflammatory disorder triggered by an immune response to bacterial infection, leading to the periapical tissue damage and alveolar resorption. However, the underlying mechanisms driving this process remain elusive, due to the complex and interconnected immune microenvironment within the local lesion site. In this study, the influence of Nlrp3 inflammasome-mediated immune response on the apical periodontitis was investigated. METHODOLOGY: RNA sequencing, immunohistochemistry and ELISA assay were performed to investigate the activation of Nlrp3 inflammasome signalling pathways in the human periapical tissues, including radicular cysts, periapical granulomas and healthy oral mucosa. A mouse model of apical periodontitis was established to study the role of Nlrp3 knockout in periapical bone resorption and Treg cell stability, and the underlying mechanism was explored through in vitro experiments. In vivo Treg cell adoptive transfer was performed to investigate the effects of Treg cells on the progression of apical periodontitis. RESULTS: Our findings find that the hyperactivated Nlrp3 inflammasome is present in human periapical lesions and plays a vital role in the immune-related periapical bone loss. Using a mouse model of apical periodontitis, we observe that Nlrp3 deficiency is resistant to bone resorption. This protection was accompanied by elevated generation and infiltration of local Treg cells that displayed a notable ability to suppress RANKL-dependent osteoclast differentiation. In terms of the mechanism of action, Nlrp3 deficiency directly inhibits the osteoclast differentiation and bone loss through JNK/MAPK and NF-κB pathways. In addition, Nlrp3 induces pyroptosis in the stem cells from apical papilla (SCAPs), and the subsequent release of cytokines affects the stability of Treg cell in periapical lesions, leading indirectly to enhanced bone resorption. In turn, adoptive transfer of both Nlrp3-deficient and wild-type Treg cells effectively prevent the bone erosion during apical periodontitis. CONCLUSIONS: Together, our data identify that the Nlrp3 inflammasome modulates the Treg cell stability and osteoclastogenesis in the periapical inflammatory microenvironment, thus determining the progression of bone erosion.

Correlation Between Proinflammatory Cytokine Expression and Clinical Data in Apical Granuloma.

INTRODUCTION: This study was intended to evaluate the expression of inflammatory cytokines commonly secreted by CD4+ T cells (IL-2, IL-5, IL-17, TGF-ß, TNF-α, and IFN-γ) in apical granulomas and correlate with the clinical conditions and time elapsed since root canal treatment. METHODS: Eighteen biopsy specimens obtained by periradicular surgery of teeth with post-treatment apical periodontitis and diagnosed as apical granuloma were available from the oral pathology laboratory. Silanized slides containing paraffin sections were used for immunohistochemical reactions. Images were analyzed by using an optical microscopy and each slide was subdivided into 5 fields at high magnification. RESULTS: IFN-γ and TGF-ß were the cytokines with the highest expression levels. There were statistically significant differences when comparing IL-2 and IFN-γ (P < .05), and IL-2 and TGF-ß (P < .05). Comparison between the detected cytokines and clinical data and time of treatment demonstrated significant correlation (P < .05) between lower expression of IL-2 and the presence of painful symptoms, absence of sinus tract, and treatments performed more than 4 years before. It was also possible to observe a significant correlation between lower expression of IL-5 and treatments performed less than 4 years before (P < .05). CONCLUSION: IFN-γ and TGF-ß were highly expressed in apical granulomas. However, only IL-2 and IL-5 levels were associated with clinical data and time since previous root canal treatment.

Prevalencia de cristales de colesterol en granulomas perirradiculares de origen endodóntico / Prevalence of cholesterol crystals in periradicular granulomas of endodontic origin

Objetivos: Identificar y determinar la prevalencia de cristales de colesterol (CRCo) en granulomas perirradiculares de origen endodóntico y el tipo de reacción que provocan en los tejidos circundantes. Material y métodos: Se estudiaron con microscopía óptica 75 preparados histológicos de archivo pertenecientes a lesiones perirradiculares humanas correspondientes a piezas dentarias que habían recibido un tratamiento endodóntico pre- vio y que, según los informes que acompañaban las muestras, habían sido obtenidas mediante una apicectomía. Del total, 68 muestras fueron diagnosticadas como granulomas, mientras que los 7 restantes se diagnosticaron como quistes inflamato- rios y fueron descartadas. Resultados: 39 granulomas pertenecían a pacientes de sexo femenino con presencia de CRCo en el 58,97% de los ca- sos. Los 29 granulomas restantes pertenecían al sexo mascu- lino y presentaron CRCo en un 41,37%. La mayor proporción de CRCo fue hallada en granulomas pertenecientes a pacien- tes mayores de 62 años. Los CRCo se observaron rodeados de macrófagos y células gigantes multinucleadas, provocando una reacción a cuerpo extraño. También se observaron células espumosas en áreas circundantes. Conclusiones: La presencia de CRCo en granulomas perirradiculares de origen endodóntico provoca una reacción a cuerpo extraño que puede interferir con el proceso de re- paración posendodóntico especialmente en pacientes de edad avanzada (AU)

Aim: Identify and determine the prevalence of cholester- ol crystals (CRCo) in periradicular granulomas of endodontic origin and the type of reaction they produce in the surround- ing tissues. Material and methods: 75 archival histological preparations were studied with optical microscopy. They be- longed to human periradicular lesions corresponding to teeth that had received a previous endodontic treatment and that, according to the reports accompanying the samples, had been obtained by an apicoectomy. Of the total, 68 samples were diagnosed as granulomas, while the remaining 7 were diag- nosed as inflammatory cysts and were discarded. Results: 39 granulomas corresponded to female patients in which the presence of CRCo was observed in 58.97% of the cases. The remaining 29 granulomas were from male patients and showed CRCo in 41.37% of the cases. The highest pro- portion of CRCo was found in patients over 62 years of age. The CRCo were surrounded by macrophages and multinucle- ated giant cells causing a foreign body reaction. Foam cells were also observed in the surrounding areas. Conclusions: The presence of CRCo in periradicular granulomas of endodontic origin could be a factor interfering with periapical healing after conventional endodontic thera- py, especially in elderly patients (AU)

Imunoexpressão de ING 4, VEGF e NF-κB em lesões periapicais inflamatórias / Immunoexpression of ING 4, VEGF and NF-κB in inflammatory periapical lesions

As lesões periapicais inflamatórias (LPIs) são condições patológicas decorrentes de infecções de origem odontogênica, principalmente representadas pelos granulomas periapicais (GPs) e cistos radiculares (CRs). Sua patogênese está associada a mecanismos imunológicos e angiogênicos. O presente estudo, do tipo retrospectivo, teve como objetivo analisar, de forma semiquantitativa, a expressão imuno-histoquímica de ING-4, VEGF e NF-κB em LPIs, e correlacionar o padrão de expressão dessas proteínas. A amostra consistiu de 26 GPs, 17 CRs e 19 cistos radiculares residuais (CRRs). Foram avaliados espessura epitelial e infiltrado inflamatório, e a associação desses achados com o padrão de expressão das proteínas ING-4, VEGF e NF-κB nas LPIs selecionadas. Para a realização da análise estatística, foram utilizados os testes de qui-quadrado, Kruskal-Wallis, Mann-Whitney e correlação de Spearman (p < 0,05). O infiltrado inflamatório exibiu maior intensidade no GP, seguido pelo CR, e por último, o CRR (p < 0,05). Apesar de não haver associação estatisticamente significativa ao associar a expressão de ING-4 nas células inflamatórias do tecido conjuntivo ou cápsula fibrosa entre os grupos de LPIs, o GP e CR evidenciaram, através da média de postos, maior expressão dessa proteína. Não foi evidenciada associação estatisticamente significativa de ING-4 com a intensidade do infiltrado inflamatório. A imunoexpressão de VEGF no núcleo das células inflamatórias do tecido conjuntivo ou cápsula fibrosa exibem associação significativa com as LPIs, que ocorre maior expressão dessa proteína nos cistos (p= 0,002). A maior expressão de NF-κB foi evidenciada nos casos de GPs, tanto a nível nuclear quanto citoplasmático das células inflamatórias (p = 0,005; p = 0,002). Não houve associação estatisticamente significativa quando comparada a expressão de NF-κB entre os cistos, mas a mediana da expressão dessa proteína foi maior para os CRs. Na cápsula fibrosa, a imunoexpressão nuclear e citoplasmática de NF-κB nas células inflamatórias foi superior nas lesões periapicais com intenso infiltrado inflamatório (p < 0,001). Portanto, sugere-se que ING-4, VEGF e NF-κB participam do desenvolvimento das LPIs, e apesar de ocorrer relação diretamente proporcional entre a expressão dessas proteínas, ING-4 não exerceu atividade reguladora na inflamação associada a essas lesões (AU).

Inflammatory periapical lesions (IPLs) are pathological conditions resulting from infections of odontogenic origin, being mainly represented by periapical granulomas (PGs) and radicular cysts (RCs). Its pathogenesis is associated with immunological and angiogenic mechanisms. This retrospective study, semi-quantitative and comparative aimed to analyze the immunohistochemical expression of ING-4, VEGF and NF-κB in IPLs, and to correlate the pattern of expression of these proteins. The sample consisted of 26 were PGs, 17 RCs and 19 residual radicular cysts (RRCs). Epithelial thickness and inflammatory infiltrate were evaluated, and the correlation of these findings with the expression pattern of ING-4, VEGF and NF-κB proteins in selected IPLs. To perform the statistical analysis, the chi-square, Kruskal-Wallis, Mann-Whitney and Spearman correlation tests were used (p < 0.05). The inflammatory infiltrate exhibited greater intensity in the PG, followed by the RC, and finally, the RRC (p < 0.05). Although there was no statistically significant association when associating the expression of ING-4 in inflammatory cells of the connective tissue or fibrous capsule the groups of IPLs, the PG and RC showed higher expression of this protein. There was no statistically significant association between ING-4 and the intensity of the inflammatory infiltrate. Immunoexpression of VEGF in the nucleus of inflammatory cells in the connective tissue or fibrous capsule shows a significant association with IPLs, in which there is greater expression of this protein occurring in cysts (p= 0,002). The highest expression of NF-κB was evidenced in cases of PGs, both at the nuclear and cytoplasmic level of inflammatory cells (p=0,005; p= 0,002). There was no statistically significant association when comparing the expression of NF-κB between the cysts, but the median expression of this protein was expression was higher for the RCs. In the fibrous capsule, nuclear and cytoplasmic NF-κB immunoexpression in inflammatory cells was higher in periapical lesions with intense inflammatory infiltrate (p<0.001). Therefore, it is suggested that ING-4, VEGF and NF-κB participate in the etiopathogenesis of IPLs, and that there is a directly proportional relationship between the expression of these proteins. ING-4 did not exert regulatory activity in the inflammation associated with these lesions (AU).

Detección y cuantificación de células plasmáticas (plasmocitos) en granulomas periapicales inducidos experimentalmente en ratas / Detection and quantification of plasma cells in experimentally induced rat periapical granulomas

Objetivo: En los granulomas periapicales, los plasmocitos (PL) participan activamente mediante la liberación de inmunoglobulinas. El propósito de este ensayo fue identificar y contar el número de PL en diferentes períodos de tiempo en lesiones periapicales experimentales en ratas. Materiales y métodos: Mediante la exposición al medio oral de la pulpa de los primeros molares inferiores izquierdos, se indujeron granulomas periapicales en ratas a las que previamente se les suministró anestesia. La pulpa de los primeros molares inferiores derechos no fue expuesta, y estos dientes se utilizaron como control. Los animales fueron eutanasiados a los 10, 30 y 60 días de la exposición. Los maxilares inferiores fueron removidos, y los primeros molares, junto con los tejidos circundantes, se procesaron para su estudio histológico. Se obtuvieron secciones semiseriadas, posteriormente coloreadas con verde de metilo-pironina (VMP). Cada tres secciones, las tres siguientes fueron coloreadas con hematoxilina y eosina (H-E). Los controles también fueron coloreados con H-E. Resultados: Todos los especímenes experimentales coloreados con H-E revelaron la presencia de granulomas periapicales. Luego de la exposición pulpar, el número de PL que reaccionó positivamente al VMP se incrementó de manera progresiva desde el día 10 hasta los días 30 y 60. A pesar de que a los 60 días el número de PL fue ligeramente menor que a los 30 días, no hubo diferencias estadísticamente significativas entre estos dos períodos. Los especímenes del grupo control coloreados con H-E mostraron que los tejidos periapicales se encontraban dentro de los parámetros normales en todos los períodos de observación. Conclusiones: Los resultados de este estudio revelaron que el número de plasmocitos VMP positivos se incrementa progresivamente en función del tiempo transcurrido pero se estabiliza al finalizar el experimento. También sugieren que el empleo de la coloración de VMP es un procedimiento adecuado para la identificación y la cuantificación de plasmocitos en los granulomas periapicales inducidos experimentalmente en ratas (AU)

Aim: Plasma cells (PL) release immunoglobulin in periapical lesions. The purpose of this assay was to identify and count the number of plasmocytes observed in periapical lesions in rats. Materials and methods: By exposing the pulp of the lower left first molars to the oral environment, periapical granulomas were induced in rats previously anesthetized. The pulp of right mandibular first molars was not exposed and these teeth were used as negative controls. The animals were euthanized at 10, 30 and 60 days after pup exposure. The mandibles were removed and specimens of the molar teeth along with the surrounding tissues were prepared for histology. Semi serial sections of the left first molar were stained with methyl green pyronine (MGP). Every three sections, the following three sections were stained with hematoxilyn and eosin (H-E). Negative control samples were stained with H-E. Results: All the H-E stained experimental samples revealed the presence of periapical granulomas. After pulp exposure, the number of PL increased from day 10 to 30 and 60. In the 60-day samples the number of PL was slightly less than that of the 30-day samples, with no statistically significant difference. The H-E stained control samples showed normal periapical tissues in all observation periods. Conclusions: The results of this study revealed that the number of VMP positive PL, increased progressively with time but it was stabilized at the end of the experiment. In addition, the results suggest that the use of VMP stain is a suitable procedure for the identification and counting of PL in experimentally induced periapical granulomas in rats (AU)

Manejo cirúrgico de granuloma central de células gigantes em região de seio maxilar: relato de caso / Surgical management of central giant cell granuloma in the maxillary sinus: a case report

Introducão: O granuloma central de células gigantes é uma lesão intraóssea incomum com predileção pela região mandibular e sexo feminino. Classifica-se como agressivo ou não agressivo de acordo com seu comportamento clínico. O tratamento de eleição para este tipo de lesão varia desde modalidades não cirúrgicas até a ressecção óssea. Relato de caso: Paciente do sexo masculino, 21 anos, com lesão osteolítica agressiva em região de parede anterior de seio maxilar direito, tratada com excisão cirúrgica e reconstrução imediata com malha de titânio sem interferências estéticas ou funcionais no pósoperatório. Considerações finais: O granuloma central de células gigantes tem apresentação clínica diversa e o tratamento deve levar em consideração as características da lesão em cada paciente, em lesões agressivas, o manejo cirúrgico é sempre o indicado... (AU)

Introduction: Central giant cell granuloma is an uncommon intraosseous lesion with a predilection for the mandibular anterior region and females. It is classified as aggressive or non-aggressive according to its clinical behavior. The treatment of choice for this type of pathology ranges from non-surgical modalities to bone resection. Case report: Male patient, 21 years old with an aggressive osteolytic lesion in the anterior wall of the right maxillary sinus, treated with surgical excision and immediate reconstruction with titanium mesh without aesthetic or functional disturbances in the postoperative period. Final considerations: The Central giant cell granuloma may have differents clinical presentations and treatment must take into account the characteristics of the lesion in each patient, in aggressive lesions, surgical management is always indicated... (AU)

Análise fractal de lesões periapicais de origem inflamatória por meio de tomografia computadorizada de feixe cônico / Fractal analysis of inflammatory periapical lesions using Cone-Beam Computed Tomography

O desenvolvimento das periodontites apicais está associado à infecção por microrganismos e migração de seus subprodutos através do sistema de canais radiculares para a região periapical, onde induzem uma resposta inflamatória que pode ser visualizada em imagens tomográficas como áreas hipodensas, circunscritas, associadas ao ápice radicular, podendo ou não demonstrar um halo radiopaco circundante. A análise fractal (AF) é um método quantitativo capaz de descrever o padrão estrutural de formas geométricas complexas, sendo expressa numericamente como dimensão fractal (DF). Quanto maior o valor da DF, mais complexa é a estrutura avaliada. O diagnóstico diferencial entre as lesões apicais ainda é dado preferencialmente pelo exame histopatológico. O objetivo do trabalho foi avaliar a AF como método preditor do diagnóstico diferencial entre cistos e granuloma periapicais em exames de tomografia computadorizada de feixe cônico (TCFC). Foram selecionados 12 pacientes, dentre os quais 6 com diagnóstico histopatológico de cisto periapical e 6 com diagnóstico de granuloma periapical, que possuíam exames de TCFC nos bancos de dados analisados. As imagens foram padronizadas e analisadas por meio do software Fiji e a DF de cada lesão foi determinada com o auxílio do plugin BoneJ. O ponto de corte para diferenciação das lesões foi determinado para os dois grupos analisados: grupo I, com número de cortes padrão e grupo II, com número máximo de cortes englobando a lesão. Os resultados evidenciaram que os cistos e granulomas periapicais acometem de forma semelhante ambos os sexos e são mais prevalentes entre a terceira e a sexta décadas de vida. Para o grupo I, o valor de DF para o ponto de corte entre as lesões foi de 2,09 e para o grupo II o valor foi de 2,28, sendo que valores abaixo do ponto de corte apontam para o diagnóstico de cisto periapical. A AF foi considerada como uma ferramenta diagnóstica útil e não invasiva, para distinção entre as periodontites apicais.

The development of apical periodontitis is associated with infection by microorganisms and migration of their subproducts through the root canal system to the periapical region, where they induce an inflammatory response that can be seen on tomographic images as hypodense, circumscribed image, associated with the root apex, which may or may not demonstrate a surrounding radiopaque halo. Fractal analysis (FA) is a quantitative method capable of describing the structural pattern of complex geometric shapes, being expressed numerically as fractal dimension (FD). The higher the DF value, the more complex is the evaluated structure. Differential diagnosis between apical lesions is still preferentially given by histopathological examination. The aim of this study was to assess FA as a differential diagnostic predictor method between periapical cysts and granuloma in cone beam computed tomography (CBCT) exams. Twelve patients were selected, including 6 with a histopathological diagnosis of periapical cyst and 6 with a diagnosis of periapical granuloma, who had CBCT exams in the analysed databases. Images were standardized and analysed using the Fiji software and the FD of each lesion was determined with the aid of the BoneJ plugin. The cutoff point for differentiation of lesions was determined for the two groups analysed: group I with standard number of slices and group II with maximum number of slices encompassing the lesion. The results showed that periapical cysts and granulomas affect both genders similarly and are more prevalent between the third and sixth decades of life. For group I, the FD value for the cutoff point between lesions was 2.09 and for group II the value was 2.28, since values below the cutoff point were representative for periapical cyst. FA was considered a useful and non-invasive diagnostic tool to distinguish between apical periodontitis.

Chronic inflammatory periapical diseases: a Brazilian multicenter study of 10, 381 cases and literature review

Abstract The aim of this study was to investigate the epidemiological and clinical characteristics of chronic inflammatory periapical diseases in different regions of Brazil and to compare with data from the literature. A multicenter study was carried out in four Brazilian referral centers in oral diagnosis. Histopathological records were reviewed, and all cases diagnosed microscopically as periapical granuloma, radicular cyst, and periapical abscess were included. Demographic and clinical data were collected. Descriptive statistics and Pearson's chi-square test were performed. A total of 10,381 cases of chronic inflammatory periapical diseases were found (13.8% of 74,931 archived specimens) over a period of 65 years. Radicular cysts were the most common lesion (59.9%). Women (56.1%) with a mean age of 37.01 years old (range 13 to 100 ± 14.42) and people of white skin color (59.2%) were the most affected individuals by chronic inflammatory periapical diseases. The lesions were generally asymptomatic (28.1%), located in the maxilla (60.1%), and posterior region (49.8%). The radicular cysts were larger when compared to periapical granulomas (p < 0.001). The disagreement between the clinical and histopathological diagnoses was higher when the final diagnosis was a periapical granuloma (p < 0.001). Chronic inflammatory periapical diseases continue to be common lesions affecting mainly adults. This should be a consequence of the burden of untreated caries in permanent teeth. Women are more affected and radicular cyst was the most common lesion.

Metaloproteinases da matriz: papel no desenvolvimento das lesões periapicais e modulação após tratamento endodôntico / Matrix metalloproteinases: role in the development of apical periodontitis and modulation after endodontic treatment

Introduction: Apical periodontitis represents a local immune response directed against the progression of microorganisms from the dental pulp to the apical foramen and periapical tissues, which results in bone and dental resorption. The aim of this review is to describe the expression of this group of proteases in apical periodontitis and its modulation during the periapical healing phase following root canal treatment. Literature review: The pathogenesis of apical periodontitis involves degradation of several extracellular matrix components. Matrix metalloproteinases (MMPs) are expressed in response to specific stimuli by resident cells of connective tissue during tissue remodeling and by inflammatory cells that arrive into the surrounding tissues during inflammatory events. MMPs have been reported in apical periodontitis, either experimentally induced or obtained from humans and there is evidence that these enzymes show diff erent expression patterns in granulomas and periapical cysts. Root canal therapy is important for the reduction of periapical inflammation as well as the synthesis of MMPs, especially when using a calcium hydroxide-based dressing. Conclusion: Apical periodontitis show high expression of matrix metalloproteinases and root canal treatment results in less expression of MMPs when compared to untreated apical periodontitis.

Introdução: A lesão periapical representa a resposta imunoinflamatória devido ao aumento do número e progressão de micro-organismos advindos dos canais radiculares contaminados em direção aos tecidos apicais e periapicais, resultando em reabsorção óssea. O objetivo desta revisão será abordar a importância das metaloproteinases da matriz no desenvolvimento das lesões periapicais e sua modulação durante a fase de reparação tecidual depois de instituído o tratamento endodôntico. Revisão da literatura: A patogênese da lesão periapical envolve a degradação progressiva de diversos componentes da matriz extracelular. Dentre as proteases responsáveis pela degradação destes componentes estão as metaloproteinases da matriz (MMPs). Estas proteinases são expressas em resposta a estímulos específicos pelas células residentes do tecido conjuntivo durante o processo de remodelação tecidual e por células inflamatórias que invadem os tecidos durante eventos inflamatórios. As MMPs foram descritas em lesões periapicais experimentais e em humanos e existem evidências de que estas enzimas apresentam padrões de expressões diferentes em granulomas e cistos periapicais. A terapia endodôntica é importante para a redução da inflamação periapical assim como da síntese das MMPs, principalmente quando utilizado um curativo de demora à base de hidróxido de cálcio. Conclusão: As lesões periapicais apresentam alta expressão de metaloproteinases da matriz e o tratamento endodôntico em dentes com lesão periapical resulta em menor expressão de MMPs quando comparado às lesões periapicais não tratadas.

Cirurgia do periápice para remoção de lesões granulomatosas: relato de caso / Periapical surgery to remove granulomatous lesion

Periapical granuloma is a histological term that refers to the formation of a mass of granulomatous tissue around the apex of a tooth resulting from inflammation and necrosis of the pulp tissue. It consists of an infiltrate of inflammatory cells such as macrophages, plasmocytes and lymphocytes, as well as fibroblasts, collagen fibers and capillaries. Periapical surgery is an alternative for preserving the tooth in the oral cavity in cases where periapical inflammation is persistent even after treatment of root canals. The objective of this study was to report a clinical case in which the surgical technique was used to remove granulomatous lesions from a patient, female, with a history of recurrent periapical abscess without painful symptomatology in the region of the anterior 11,12 and 13 teeth. The histopathological exam demonstrated the presence of a granulomatous tissue with intense inflammatory infiltrate mixed, permeated with lymphocytes and high number of plasmocytes, confirming the diagnosis of periapical granuloma. The treatment was considered successful since the patient remained asymptomatic and there was incorporation of the inorganic bovine bone graft and initiation of bone neoformation in the periapical region.

Granuloma periapical é um termo histológico que refere-se à formação de uma massa de tecido granulomatoso ao redor do ápice de um dente, decorrente da inflamação e necrose do tecido pulpar. É constituído por um infiltrado de células inflamatórias como macrófagos, plasmócitos e linfócitos, além de fibroblastos, fibras colágenas e capilares. A cirurgia do periápice é uma alternativa para preservação do dente na cavidade bucal nos casos em que a inflamação periapical é persistente mesmo após tratamento dos canais radiculares. O objetivo desse trabalho é relatar um caso clínico no qual a técnica cirúrgica do periápice foi utilizada para remoção de lesões granulomatosas de uma paciente, do sexo feminino, com histórico de abscesso periapical recidivante sem sintomatologia dolorosa na região dos dentes anteriores superiores 11, 12 e 13. O exame histopatológico demonstrou a presença de um tecido granulomatoso com intenso infiltrado inflamatório misto, permeado com linfócitos e elevado número de plasmócitos, confirmando o diagnóstico de granuloma periapical. O tratamento foi considerado exitoso, visto que a paciente se manteve asintomática e houve incorporação do enxerto ósseo bovino inorgânico e início da neoformação óssea na região periapical.

Presence of langerhans cells, regulatory T cells (Treg) and mast cells in asymptomatic apical periodontitis

Abstract Asymptomatic Apical Periodontitis is essentially an inflammatory disease of microbial aetiology. Association and function of the cell components involved, or specific inductive factors and growth mediators associated with development, maintenance and resolution of the periapical lesions are still unknown. The objective of this study was to evaluate the concentration of Regulatory T cells (FoxP3+; Treg), Langerhans cells (CD1a+; LC) and mast cells in asymptomatic apical periodontitis. 73 cases were selected: 30 periapical granulomas, 29 radicular cysts and 14 residual cysts. All groups were submitted to morphological analysis for classification of inflammatory infiltrate and thickness of the epithelial lining as well as to immunohistochemical analysis for detection of LC and Treg cells. Toluidine blue staining was used for detecting mast cells. Analysis showed higher mean numbers of LC (8.2 cells/0.2mm2), and Treg cells in radicular cysts (5.910 cells/0.2mm2). As for mast cells, it was found that radicular cysts had a higher mean number of these cells compared to other periapical lesions (12.68 cells/0.2mm2). The association between thickness of the epithelial lining and inflammatory cells showed that the presence of hypertrophic epithelium in radicular cysts presented higher density of LC. The number of LC and Treg cells play an important role in the control of the inflammatory micro-environment in periapical granulomas and radicular cysts, respectively. The presence of mast cells in radicular cysts may be associated with progression of the lesion. Knowledge regarding the inflammatory cell profile is therefore essential for a better understanding of the pathogenesis of asymptomatic periapical periodontitis.

[Artigo Parcialmente Retratado] Prevalência da infecção por Helicobacter pylori em pacientes dispépticos e associação com fatores de riscos clínicos para o desenvolvimento de adenocarcinoma gástrico / [article partial retraction] prevalence of helicobacter pylori infection in dyspeptic patients and its association with clinical risk factors for developing gastric adenocarcinoma

ABSTRACT BACKGROUND: In Brazil, particularly in the underdeveloped localities, the prevalence of Helicobacter pylori (H. pylori) infections can range up to 90%. These rates are higher in older individuals and vary by country region. H. pylori infections are linked to the development of gastric pathologies, namely mild to moderate gastritis, gastroenteritis, peptic ulcer, intestinal metaplasia, and gastric cancer. In 1994, this organism was classified by the International Agency for Research on Cancer (IARC) as pertaining to the Group 1 carcinogen for gastric adenocarcinoma etiology. Gastric cancer represents a significant public health problem, being the fourth most common malignant tumor and the second largest cause of cancer-related deaths. OBJECTIVE: To investigate the prevalence of H. pylori infection in dyspeptic patients and determine the link between clinical risk factors and gastric adenocarcinoma diagnosis. METHODS: Polymerase chain reaction (PCR) analysis was employed for molecular diagnosis of gastric tissue biopsies collected from 113 dyspeptic patients at the University Hospital of Federal University of Goiás. Molecular analyses allowed the identification of H. pylori infections. Furthermore, histopathological examinations were performed to determine the clinical risks of developing gastric malignancies. RESULTS: The test results identified 69 individuals older than 44 years, from 75 (66.4%) positive H. pylori infection samples. The prevalence of gastric adenocarcinoma in this study was 1.3%. Among the infected patients, six (8.2%) had high risk, and 67 (91.8%) had a low risk of developing gastric cancer (P<0.05). CONCLUSION: This study shows a high prevalence of H. pylori infection and identifies its contribution to gastric inflammations, which in the long term are manifested in high-risk clinical factors for the development of gastric adenocarcinoma.

RESUMO CONTEXTO: No Brasil, particularmente nas áreas mais pobres, a prevalência da infecção por Helicobacter pylori pode variar até 90%. Esses índices aumentam com o envelhecimento da população e são distintos entre as diferentes regiões do país. Podendo manifestar diferentes sintomatologias, essa infecção está diretamente relacionada com o desenvolvimento de patologias gástricas como gastrite leve a moderada, gastroenterites, úlcera péptica, metaplasia intestinal e principalmente, o câncer gástrico. Em 1994 a bactéria foi categorizada pela International Agency for Research on Cancer (IARC) como carcinógeno do Grupo 1 para adenocarcinoma gástrico, tipo de câncer que representa um importante problema de saúde pública, sendo o quarto tumor maligno mais comum e a segunda maior causa de mortes por câncer no mundo. OBJETIVO: Analisar a prevalência da bactéria em pacientes dispépticos e avaliar a associação de fatores de risco clínicos para desenvolvimento de adenocarcinoma gástrico. MÉTODOS: Biópsias de tecido gástrico coletadas de 113 pacientes dispépticos, atendidos no Hospital das Clínicas da Universidade Federal de Goiás, foram submetidas a diagnóstico molecular por meio de Reação em Cadeia da Polimerase, para identificação da infecção por Helicobacter pylori, e exame histopatológico, para avaliar o risco clínico de desenvolvimento de adenocarcinoma gástrico. RESULTADOS: Foram diagnosticadas 75 (66,4%) amostras positivas para infecção por Helicobacter pylori, sendo 69 indivíduos maiores de 44 anos de idade. A prevalência do adenocarcinoma gástrico nesse estudo foi de 1,3% e dentre os pacientes positivos para a infecção bacteriana seis (8,2%) possuem alto risco e 67 (91,8%) baixo risco de desenvolver esse tipo de câncer (P<0,05). CONCLUSÃO: Esse estudo mostra uma alta prevalência da infecção por H. pylori na população estudada e identifica sua intrínseca contribuição para inflamações gástricas, que a longo prazo se manifestam em fatores clínicos de alto risco para o desenvolvimento de adenocarcinoma gástrico.

Macrophages subpopulations in chronic periapical lesions according to clinical and morphological aspects

Abstract: The aim of this study was to evaluate macrophage M1 and M2 subpopulations in radicular cysts (RCs) and periapical granulomas (PGs) and relate them to clinical and morphological aspects. M1 macrophages were evaluated by the percentage of CD68 immunostaining associated with the inflammatory cytokine TNF-α, and M2 macrophages, by its specific CD163 antibody. The CD68+/CD163+ ratio was adopted to distinguish between the two macrophage subpopulations. Clinical, radiographic, symptomatology, treatment, and morphological parameters of lesions were collected and a significance level of p = 0.05 was adopted for statistical analysis. The results showed that the CD68+/CD163+ ratio was higher in the RCs (median = 1.22, p = 0.002), and the highest TNF-α immunostaining scores were found in RCs (p = 0.018); in PGs, the CD68+/CD163+ ratio was lower and associated with a greater CD163+ immunostaining (median = 1.02, p <0.001). The TNF-α in cyst epithelium had a score of 3 in 10 cases and predominance of M1 macrophages by CD68+/CD163+ (median = 2.23). In addition, CD68+ cells had higher percentage of immunostaining in smaller RCs (p = 0.034). Our findings suggest that increased CD68 immunostaining associated with TNF-α cytokine in RCs results in a greater differentiation of the M1 phenotype. The higher CD163 immunostaining in PGs results in greater differentiation of the M2 phenotype. Therefore, the inflammatory state promoted by M1 macrophages is related to growth and progression of RCs; on the other hand, the immunomodulatory state of M2 macrophages is related to maintenance of PGs.

Periapicopatias inflamatórias de origem endodôntica: estudo multicêntrico na população brasileira / Endodontic periapical lesions: A multicenter study in the Brazilian population

Introdução: as periapicopatias inflamatórias de origem endodôntica são as doenças mais frequentes dos ossos maxilares e ocorrem principalmente como consequência da disseminação da infecção endodôntica. Apesar de vários estudos, não existem dados recentes sobre as características epidemiológicas e clínicas dessas lesões envolvendo uma amostra tão grande da população. Objetivo: Investigar as características epidemiológicas e clínicas das periapicopatias inflamatórias de origem endodôntica, incluindo o granuloma periapical, o cisto radicular e o abscesso periapical. Metodologia: foi realizado um estudo retrospectivo e multicêntrico em quatro instituições com centros de referência em diagnóstico oral no Brasil. Todos os registros histopatológicos foram revisados e foram incluídos todos os casos diagnosticados microscopicamente como granuloma periapical, cisto radicular e abscesso periapical. Foram coletados os seguintes dados demográficos e clínicos: sexo, idade e cor da pele dos pacientes, sintomas, duração, tamanho e localização das lesões e concordância entre o diagnóstico clínico e histopatológico. Análises estatísticas descritivas e bivariadas, utilizando o teste Qui-quadrado de Pearson, foram realizadas. Em casos de variáveis com mais de duas categorias, utilizou-se o teste Z para comparação das proporções de colunas e a correção de Bonferroni. Valores de p < 0,05 foram considerados estatisticamente significativos. Resultados: foram encontrados 10.381 casos de lesões periapicais entre 74.931 espécimes arquivados (13,8%) em 65 anos. Os cistos radiculares foram as lesões mais comuns (59,9%). As lesões periapicais acometeram principalmente mulheres (56,1%), com média de idade de 37,01 anos (13 a 100 ± 14,42 anos) e cor de pele branca (59,2%). As lesões eram geralmente assintomáticas (28,1%), persistindo por mais de um ano (13,3%), com tamanho de até 10 mm (25,2%) e localizadas na maxila (60,1%) e região posterior (49,8%). Os cistos radiculares foram maiores (p < 0,001), com maior ocorrência de sintomatologia (p < 0,027) e maior frequência na região posterior (p < 0,001) em relação aos granulomas periapicais. A possibilidade de discordância entre o diagnóstico clínico e histopatológico foi maior nos granulomas periapicais (p < 0,001). Conclusões: as periapicopatias inflamatórias de origem endodôntica foram comuns em serviços de Patologia Bucomaxilofacial, acometendo principalmente adultos. Isso deve ser uma consequência da carga de cáries não tratadas em dentes permanentes. As mulheres são mais afetadas e o cisto radicular é a lesão mais comum.

Introduction: Inflammatory periapical lesions are the most frequent diseases of maxillary bones and occur mainly as a consequence of the dissemination of endodontic infection. Despite several studies, there are no recent data on the epidemiological and clinical characteristics of these lesions involving such a large sample. Objective: To investigate the epidemiological and clinical characteristics of periapical lesions, including periapical granuloma, radicular cyst and periapical abscess. Methodology: A multicenter retrospective study was realized in four institutional reference centers in oral diagnosis in Brazil. Histopathological records were reviewed and included all cases diagnosed microscopically as periapical granuloma, radicular cyst and periapical abscess. Data on patient sex, age, skin color, symptoms, lesion duration, lesion size, lesion location and concordance between clinical and histopathological diagnosis were collected. Descriptive statistics and bivariate analyses using Pearson's Chi-square test were done. A z-test, to compare the column proportions, and Bonferroni correction were used, in the case of variables with more than two categories. P values < 0.05 were considered statistically significant. Results: Were found 10,381 cases of periapical lesions among 74,931 archived specimens (13.8%) in 65 years. Radicular cysts were the most common lesions (59.9%). Periapical lesions affected mainly women (56.1%), with a mean age of 37,01 years (range 13 to 100 ± 14,42) and white-skinned (59.2%). The lesions were generally asymptomatic (28.1%), persisting for more than one year (13.3%), size up to 10 mm (25.2%) and located in the maxilla (60.1%) and posterior region (49.8%). The radicular cysts were larger (p < 0.001), with a higher occurrence of symptomatology (p < 0.027) and higher frequency in the posterior region (p < 0.001) compared to periapical granulomas. The possibility of disagreement between clinical and histopathological diagnosis was higher in periapical granulomas (p < 0.001) than radicular cyst. Conclusions: Endodontic periapical lesions were common in the Bucomaxillofacial Pathology services affecting mainly adults. This should be a consequence of the burden of untreated caries in permanent teeth. Women are more affected and radicular cyst is the most common lesion.

Periodontitis apical: caracterización histológica y morfométrica de quistes radiculares y granulomas periapicales / Apical periodontitis: histological and morphometric characterization of radicular cysts and periapical granulomas

La periodontitis apical es una patología inflamatoria que afecta los tejidos periapicales de un diente desvitalizado. El objetivo de este estudio fue caracterizar histológica y morfométricamente las lesiones de quistes y granulomas utilizando microscopía óptica. Se analizaron seis biopsias obtenidas de dientes con indicación de exodoncia. El análisis histológico se realizó mediante microscopía óptica y microfotografías, con análisis de contraste de imágenes y conteo celular mediante ImageJ. Descripción de las características histológicas: en los quistes se observaron cavidades rodeadas de epitelio escamoso estratificado no queratinizado y una cápsula fibrosa compuesta de fibrocitos, fibroblastos e infiltrado inflamatorio crónico; en los granulomas se observaron capilares, una capsula fibrosa de fibrocitos/fibroblastos y un infiltrado inflamatorio de predominio linfocitario. Cuantificación del número celular de infiltrado inflamatorio: para quistes fue de 9,2 cel/10000 µm2, mientras que para granulomas fue de 20,8 cel/10000 µm2, sin diferencias estadísticas significativas entre ambos (p=0,654). Cuantificación del número celular de fibrocitos/fibroblastos: para quistes fue de 15,4 cel/10000 µm2, mientras que para granulomas fue de 18,5 cel/10000 µm2, sin diferencia estadística significativa (p=0,499). Porcentaje de colágeno tipo I: para los quistes fue de 37,8±19,2 %, mientras que para granulomas fue de 33,8±23,3 %, sin diferencias estadísticas significativas (p=0,704). Se observó una correlación negativa moderada para el infiltrado inflamatorio (R=0,637) y una correlación positiva baja para fibrocitos/fibroblastos (R=0,121), en relación a la cantidad de colágeno tipo I. Medición del área de las lesiones periapicales: el promedio total de las lesiones fue de 10,7±5,0 mm2, siendo el mayor tamaño un quiste de 18,1 mm2 y el menor un granuloma de 5,2 mm2. El análisis histológico permite realizar un diagnóstico diferencial de lesiones con características similares y así definir el tratamiento más adecuado.

Apical periodontitis is an inflammatory pathology that affects the periapical tissues of a devitalized tooth. The aim of this study was to histologically and morphometrically characterize lesions of cysts and granulomas using light microscopy. Six biopsies obtained from teeth with indication of exodontia were analyzed. The histological analysis was carried out by means of optical microscopy and microphotographs, with contrast analysis of images and cell count by ImageJ. A description of the histological characteristics was made, observing the cavities surrounded by stratified squamous non-keratinized epithelium and a fibrous capsule composed of fibrocytes, fibroblasts and chronic inflammatory infiltrate; in the granulomas, capillaries, a fibrous capsule of fibrocytes/fibroblasts and a predominantly lymphocytic inflammatory infiltrate were observed. In relation to quantification of the cellular number of inflammatory infiltrate, for cysts itwas of 9.2 cel / 10000 mm2, while for granulomas it was 20.8 cel / 10000 mm2, without significant statistical differences between both (p = 0.654). The quantification of the fibrocyte / fibroblast cell number was, for cysts, 15.4 cells / 10000 mm2, while for granulomas it was 18.5 cells / 10000 mm2, without significant statistical difference (p = 0.499). With respect to the percentage of collagen type I, for the cysts was 37.8 ± 19.2%, while for granulomas it was 33.8 ± 23.3%, without significant statistical differences (p = 0.704). A moderate negative correlation was observed for the inflammatory infiltrate (R = 0.667) and a low positive correlation for fibrocytes / fibroblasts (R = 0.121), in relation to the amount of type I collagen. Measurement of the area of the periapical lesions: the total average of lesions were 10.7 ± 5.0 mm2, the largest being a cyst of 18.1 mm2 and the smallest a granuloma of 5.2 mm2. The histological analysis allows to make a differential diagnosis of lesions with similar characteristics and thus define the most appropriate treatment.

Prevalência de granulomas, abscessos e cistos periapicais em inflamações de origem endodôntica / Prevalence of granulomas, abscesses and periapical cysts in inflammations of endodontic origin

Introdução: a necrose do tecido pulpar seguida da colonização e infecção do canal radicular representa eventos determinantes na instalação, desenvolvimento e perpetuação da periodontite apical. Objetivo: avaliar a prevalência dos diferentes tipos de lesões inflamatórias periapicais de origem endodôntica. Métodos: a amostra do estudo foi proveniente da revisão de laudos histopatológicos de 805 espécimes cirúrgicos encaminhados ao Serviço de Patologia Bucal do Laboratório Público do estado de Mato Grosso, Brasil, entre os anos de 2008 e 2014. Os seguintes dados foram coletados dos laudos de cada paciente: gênero, faixa etária, grupo dentário, localização anatômica e diagnóstico histopatológico (granuloma periapical, abscesso periapical e cisto radicular). A análise estatística dos dados incluiu distribuição de frequência e teste de associação. A significância estatística para a associação entre as variáveis foi determinada pelo teste qui-quadrado. O nível de significância estabelecido foi de p < 0,05. Resultados: observou-se maior frequência de lesões periapicais em indivíduos do gênero masculino (n = 405; 50,31%) e com idade entre 21 e 30 anos (n = 212; 26,34%). Os dentes mais comumente envolvidos foram os molares inferiores (n = 293; 36,40%), seguidos pelos molares superiores (n = 213; 26,46%). O granuloma periapical (n = 458; 56,89%) foi a lesão inflamatória periapical mais prevalente. Foram observadas associações significativas entre tipo de lesão periapical e localização anatômica (p < 0,05). Conclusões: verificou- se maior ocorrência de lesões periapicais em indivíduos do gênero masculino; a faixa etária mais acometida foi entre 21 e 30 anos; o granuloma periapical foi a lesão mais comumente diagnosticada, sendo os dentes localizados na região posterior da mandíbula os mais afetados. (AU)

A retrospective analysis of oral and maxillofacial pathology in a pediatric population from Rio de Janeiro-Brazil over a 75-year period

BACKGROUND: The aim of this study was to analyze the distribution of oral and maxillofacial lesions affecting children and adolescents patients from a single oral pathology laboratory from Rio de Janeiro, Brazil. MATERIAL AND METHODS: Oral and maxillofacial lesions biopsied in patients younger than 19-years were retrieved from the oral pathology files of the Department of Oral Diagnosis and Pathology, School of Dentistry, Federal University of Rio de Janeiro over a 75-year period (1942-2017). The clinical data and the diagnoses of each case were included in a Microsoft Excel(R) database, being classified into 13 categories according to the etiology. A descriptive analysis of the variables age, gender and final diagnosis was made. RESULTS: From 19.095 lesions diagnosed in this period, 2408 (12.61%) were from patients aged 0 to19 years, with a higher incidence in females in the second decade. Salivary gland pathology was the most common group of lesions (24.30%), followed by reactive lesions (16.82%) and odontogenic cysts (14.66%). Mucocele was the most common lesion (21.72%), followed by dentigerous cyst (6.48%) and fibrous hyperplasia (6.44%). Malignant lesions were observed in 1.12% of all cases with Burkitt lymphoma as the most frequent. CONCLUSIONS: Our results were similar to previous studies and knowledge of these data may contribute to the understanding of oral lesions that most commonly affects children

Aspectos radiográficos de imágenes periapicales asociadas a incisivos primarios traumatizados / Aspectos radiográficos de imagens periapicais associadas a incisivos decíduos traumatizados / Radiographic aspects of periapical images associated with traumatized primary incisors

Las imágenes radiolúcidas periapicales que involucran dientes primarios traumatizados se pueden confundir entre sí y dar lugar a diagnósticos erróneos y tratamiento. Por lo tanto, es importante identi-ficar las características radiográficas de las imágenes radiolúcidas periapicales en los incisivos prima-rios traumatizados, principalmente debido al hecho de que la superposición de imágenes se produce en esta región. Además, es frecuente observar la expansión del folículo haciendo que el diagnóstico radiográfico sea aún más difícil. El objetivo de este estudio fue describir, a través de una revisión de la literatura, las características radiográficas de las imágenes periapicales asociadas con los incisivos primarios traumatizados.

Periapical radiolucencies involving traumatized primary teeth can be confused with each other and lead to misdiagnosis and treatment. Therefore, it is important to identify radiographic characteristics of periapical radiolucent images in traumatized primary incisors, mainly due to the fact that overla-pping of images occurs in this region. Besides, it is frequent to observe follicle expansion making the radiographic diagnosis even more difficult. The objective of this study was to describe, through a literature review, the radiographic characteristics of periapical images associated with traumatized primary incisors.

As radioluscências periapicais envolvendo dentes decíduos traumatizados podem ser confundidas entre si e levar a um erro de diagnóstico e tratamento. Por isso, é importante identificar características radiográficas de imagens radiolúcidas periapicais em incisivos decíduos traumatizados, principalmente pelo fato que nesta região ocorre sobreposição de imagens e, é frequente observar expansão do folículo, dificultando ainda mais o diagnóstico radiográfico. O objetivo deste trabalho foi descrever através de uma revisão de literatura as características radiográficas de imagens periapicais associadas a incisivos decíduos traumatizados.

Differentiation of periapical granulomas and cysts by using dental MRI: a pilot study / 国际口腔科学杂志·英文版

The purpose of this pilot study was to evaluate whether periapical granulomas can be differentiated from periapical cysts in vivo by using dental magnetic resonance imaging (MRI). Prior to apicoectomy, 11 patients with radiographically confirmed periapical lesions underwent dental MRI, including fat-saturated T2-weighted (T2wFS) images, non-contrast-enhanced T1-weighted images with and without fat saturation (T1w/T1wFS), and contrast-enhanced fat-saturated T1-weighted (T1wFS+C) images. Two independent observers performed structured image analysis of MRI datasets twice. A total of 15 diagnostic MRI criteria were evaluated, and histopathological results (6 granulomas and 5 cysts) were compared with MRI characteristics. Statistical analysis was performed using intraclass correlation coefficient (ICC), Cohen's kappa (κ), Mann-Whitney U-test and Fisher's exact test. Lesion identification and consecutive structured image analysis was possible on T2wFS and T1wFS+C MRI images. A high reproducibility was shown for MRI measurements of the maximum lesion diameter (intraobserver ICC = 0.996/0.998; interobserver ICC = 0.997), for the "peripheral rim" thickness (intraobserver ICC = 0.988/0.984; interobserver ICC = 0.970), and for all non-quantitative MRI criteria (intraobserver-κ = 0.990/0.995; interobserver-κ = 0.988). In accordance with histopathological results, six MRI criteria allowed for a clear differentiation between cysts and granulomas: (1) outer margin of lesion, (2) texture of "peripheral rim" in T1wFS+C, (3) texture of "lesion center" in T2wFS, (4) surrounding tissue involvement in T2wFS, (5) surrounding tissue involvement in T1wFS+C and (6) maximum "peripheral rim" thickness (all: P < 0.05). In conclusion, this pilot study indicates that radiation-free dental MRI enables a reliable differentiation between periapical cysts and granulomas in vivo. Thus, MRI may substantially improve treatment strategies and help to avoid unnecessary surgery in apical periodontitis.