Periapical Granulomas Research Articles

Evaluation of concordance between clinical and histopathological diagnoses in periapical lesions of endodontic origin

Background/purpose: Periapical lesions of endodontic origin are often diagnosed based on the clinical and radiological presentations that may be different from the histological diagnoses. The purpose of this study was to assess the concordance between the clinical diagnosis of these lesions and the histopathological diagnoses and to analyze their clinical and pathological features. Materials and methodsBiopsies of periapical lesions of endodontic origin diagnosed in the histopathology laboratory between 2006 and 2017 were retrieved from the database and used to conduct this retrospective review. Clinical data were obtained, and tissue samples were re-evaluated. The overall agreement between the clinical and histological diagnoses was tested utilizing the Cohen kappa (k). ResultsA total of 317 periapical biopsy specimens were included in this study which consisted of 137 periapical granulomas, 174 periapical cysts, and six periapical scars. Generally there was weak overall agreement between the clinical and histological diagnoses of periapical granuloma and periapical cysts (Cohen kappa, k = 0.059). ConclusionThe findings of this study indicate that clinical/radiographic examinations are not able to preoperatively determine whether a periapical lesion is a cyst or a granuloma and highlights the importance of developing a reliable nonsurgical diagnostic method to differentiate periapical lesions.

A Retrospective Brazilian Multicenter Study of Biopsies at the Periapical Area: Identification of Cases of Nonendodontic Periapical Lesions

IntroductionThe purpose of this study was to analyze the features of lesions obtained from biopsies at the periapical area of teeth with a radiographic or clinical initial diagnosis of apical periodontitis. MethodsA retrospective study was conducted on biopsies obtained from 1953–2018 at 3 Brazilian oral and maxillofacial pathology centers. Cases of endodontic and nonendodontic periapical lesions (NPLs) with a clinical diagnosis of endodontic pathoses were retrieved. Data regarding patient age, sex, and anatomic location were obtained from patients’ records. The frequency and percentage of cases with clinical diagnoses of a periapical cyst, periapical granuloma, or dentoalveolar abscess were recorded, and the final histopathologic diagnosis was documented. ResultsAmong 66,179 oral biopsies, 7246 (10.94%) were clinically diagnosed as periapical disease, 306 (4.22%) of which were histopathologically diagnosed as NPLs. The most frequent NPLs were odontogenic keratocysts (n = 107, 34.96%) followed by dentigerous cysts (n = 48, 15.68%). The mean age at diagnosis was 39.68 years with a range of 6–80 years. A total of 159 (51.96%) cases occurred in females and 147 (48.03%) in males (female to male ratio = 1.08:1). Most lesions (137, 44.77%) were located in the posterior mandible. ConclusionsA wide variety of histopathologic diagnoses, including benign odontogenic and nonodontogenic cystic and tumorous lesions, infectious diseases, and malignant neoplasms, was reported in the present survey. The features presented in this study were consistent with previous findings reported in the literature.

Histopathological features of chronic periapical lesions

Chronic periapical inflammation, the sequela of necrotic pulp, is one of the most common diseases in dental practice. The diagnosis of these lesions is based on clinical presentation, radiological features and histopathological examination. The aim of this study was to evaluate the clinico-pathological features of chronic inflammatory periapical lesions. 92 periapical lesions were collected at HCMC Odonto-Stomatology Hospital and HCMC National Odonto-Stomatology Hospital at HCM from June 2019 to January 2020. Male to female ratio was 1:1.6, the age range was 10-70 with average age was 35.5 years old. In terms of clinical features, 30.4% of patients were asymptomatic, 28.3% had percussion sensitivity, 27.2% had swelling, 12% had cortical expansion, 18.5% had intraoral fistula and 3.3% had tooth mobility. The most frequently- involved locations were the anteria maxilla and posterior mandible. Histopathological results confirmed 49 radicular cysts and 43 periapical granulomas. In most cases of radicular cyst (47 cases, 96%), the cyst was lined with nonkeratinized stratified squamous epithelium, with two cases containing mucous cells, 3 cases were observed with cholesterol clefts and 3 cases with Hyaline bodies. In 43 cases of periapical granulomas, the lesions included chronic inflammatory cells and 3 cases with cholesterol clefts. The collagen fibers in fibrous stroma of radicular cysts appeared to be thicker and more linearly arranged while they seemed to be thinner in scattered pattern in periapical granulomas. There was no significant difference between the prevalence of radicular cysts (53.3%) and periapical granulomas (46.7%), no case of chronic periapical abscess was recorded. The ratio of radicular cysts (67.3%) was significantly higher than periapical granulomas (41.9%) at the posterior areas (p<0.05).

Stafne bone cyst: Report of a case and review of the literature

Stafne bone cyst is a rare and asymptomatic bone depression usually discovered incidentally on routine radiographs of the jaws. This pseudocyst could mimic odontogenic pathologies, especially sequelae of dental caries. We present a 25-year-old male with painful right mandibular swelling due to carious teeth on the right side of the mandible which the patient claimed was noticed 3 months prior to presentation. Panoramic radiograph showed grossly carious lower right first molar with periapical granuloma. In close relation with this, periapical pathology was a rounded well-defined radiolucency below the inferior alveolar canal. The patient had an extraction of the right lower first molar and was prescribed antibiotics. The apical pathology resolved completely after the extraction. A diagnosis of Stafne bone cyst was made as incidental finding following further investigation of the radiolucency below the inferior alveolar canal with computed tomographic scan.

Assessment of effectiveness of integrated teaching in oral radiology among dental students: A comparative study

Background: Basic science subjects are usually taught during the first and second academic years of the Undergraduate training with minimum or no integration with the clinical subjects, thereby creating a compartmentalization within the curriculum. The students have difficulty in understanding the concepts and depend on their ability to memorize facts for diagnosing various disease conditions. Aims and Objectives: To evaluate and compare the Effectiveness of Integrated teaching on diagnostic accuracy in Oral radiology among dental students. Material and Methods: A total of 46 students were randomly divided into 2 groups – Integrated basic science group (BSG) and segregated group (SG). Learning materials included sets of intraoral periapical radiographs and lecture based classes on radiographic features of a normal tooth, periapical abscess, periapical granuloma and periapical cyst. BSG students were taught regarding the radiographic appearance and the cause for such appearance in the radiograph. SG students were only explained regarding the radiographic features of these entities. Following the discourse, two tests - Diagnostic test (multiple-choice questions) on the day of lecture, followed by a memory test (spot diagnosis and match the following) one week later - were done to assess the level of understanding among the students. Statistical analysis was done using Students's t – test. Results: BSG students outperformed both in diagnostic test and memory test when compared to SG students. Conclusions: Integrated teaching has been found to be an effective method in enhancing diagnostic accuracy in Oral radiology and also improving the ability to memorize concepts among dental students.

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

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.

Epstein-Barr virus reactivation by persistent apical periodontal pathogens.

To assess whether Epstein-Barr virus (EBV) reactivation is triggered by persistent apical periodontitis-related microbes using in vitro and ex vivo methodologies. Surgically removed human periapical granulomas (n=50) and healthy gingival tissues (n=10) were analysed to determine the presence of EBV and seven persistent apical periodontitis-related microbes. In addition, real-time polymerase chain reaction was used to detect the mRNA expression of BZLF-1, an immediate-early gene of EBV. Expression of latent membrane protein (LMP)-1 and ZEBRA, an early lytic protein of EBV encoded by BZLF-1, was also examined using triple-colour immunofluorescence staining. n-Butyric acid produced by the microbes was quantified, and luciferase assays were performed in association with bacterial lysates. In addition, Daudi cells were cultured with bacterial lysates, and the expression levels of BZLF-1 mRNA and ZEBRA protein were determined. EBV DNA and BZLF-1 mRNA were detected in 47 out of 50 periapical granulomas, but not in healthy gingival tissues. The EBV DNA copy number and the number of Fusobacterium nucleatum were significantly positively correlated with BZLF-1 expression in periapical granulomas. The number of Prevotella intermedia was slightly correlated with BZLF-1 expression; however, the other microbes were not. CD79a-positive B cells in periapical granulomas, but not those in healthy gingival tissues, expressed both LMP-1 and ZEBRA. n-Butyric acid production was the highest in F. nucleatum and the lowest in P. intermedia. Enterococcus faecalis, Candida albicans and the other tested microbes did not produce n-butyric acid. An F. nucleatum lysate exhibited significantly increased BZLF-1-luciferase activity in the same manner of commercial butyric acid, whereas P. intermedia did not. F. nucleatum also induced the expression of BZLF-1 mRNA and ZEBRA protein by Daudi cells, indicating that EBV reactivation was induced. Among the persistent apical periodontitis-related bacteriathat were tested, F. nucleatum most strongly reactivated latent EBV, whereas E. faecalis and C. albicans as well as the other microbes did not.

Accuracy of computer-assisted image analysis in the diagnosis of maxillofacial radiolucent lesions: A systematic review and meta-analysis.

This study aimed to search for scientific evidence concerning the accuracy of computer-assisted analysis for diagnosing maxillofacial radiolucent lesions. A systematic review was conducted according to the statements of Preferred Reporting Items for Systematic Reviews and Meta-analyses Protocols and considering 10 databases, including the gray literature. Protocol was registered at the International Prospective Register of Systematic Reviews (CRD42018089945). The population, intervention, comparison and outcome strategy was used to define the eligibility criteria and only diagnostic test studies were included. Their risk of bias was assessed by the Joanna Briggs Institute Critical Appraisal tool. Random-effects model meta-analysis was performed and heterogeneity among the included studies was estimated using the I2 statistic. The grade of recommendation, assessment, development, and evaluation (GRADE) tool assessed the quality of evidence and strength of recommendation across included studies. Out of 715 identified citations, four papers, published between 2009 and 2017, fulfilled the criteria and were included in this systematic review. A total of 191 lesions, classified as periapical granuloma and cyst, dentigerous cyst or keratocystic odontogenic tumor, were analyzed. All selected articles scored low risk of bias. The pooled accuracy estimation, regardless of the classification method used, was 88.75% (95% CI = 85.19-92.30). Heterogeneity test reached moderate values (I2 = 57.89%). According to the GRADE tool, the analyzed outcome was classified as having low level of certainty. The overall evaluation showed all studies presented high accuracy rates of computer-aided diagnosis systems in classifying radiolucent maxillofacial lesions compared to histopathological biopsy. However, due to the moderate heterogeneity found among the studies included in this meta-analysis, a pragmatic recommendation about the use of computer-assisted analysis is not possible.

Determining the frequency of Epstein-Barr virus (EBV) in two inflammatory lesions of the periapical cyst and dental granuloma

BackgroundOne of the significant problems of Partial root canal therapy is periapical cyst and granuloma. Microorganisms contribute to the creation of periapical lesions, causing chronic illness and dental granuloma. This study aims to determine the effect of Epstein-Barr virus (EBV) on the exacerbation of the disease using the PCR technique. MethodsParaffin tissue samples containing 25 periapical cysts, and 25 dental granulomas underwent DNA extraction. The extracted DNA quality was confirmed by the β-globin component replication using polymerase chain reaction (PCR). Moreover, the samples were evaluated using the nested-PCR technique in terms of the frequency of EBV using dedicated primers. The data analysis was performed using chi-squared, Fischer, and independent t-tests. ResultsEBV was detected in 4% (1/25) of the periapical sample and 4% (1/25) of the 25 dental granuloma samples. Despite the above observations, there was no statistically significant difference in the frequency of EBV between the periapical cyst and dental granuloma samples. ConclusionBased on the results of the study, EBV is likely to affect the pathogenesis or the growth of periapical lesions. Given that there is not a lot of research in this area and the results of the studies are conflicting, the findings attract more research.

Clinical and Histopathological Concordance of oral Bone Lesions. Retrospective Study

Bone lesions of the jaws have their origin from odontogenic and non-odontogenic structures. They can be benign or malignant, asymptomatic, they can be located around the root of the tooth, around the crown and in the interradicular area or they may not be related to the teeth. OBJECTIVE: to determine the frequency of the different bone lesions and the concordance between the clinical and histopathological diagnosis, in the clinical internship of the Faculty of Dentistry of the University of Costa Rica (UCR). METHODOLOGY: retrospective study of bone lesions recovered from the biopsy archive of the Faculty of Dentistry of the UCR from 2008 to 2015. Information on sex, age, location of the lesion, clinical diagnosis and diagnosis were evaluated and described. The agreement between the clinical and histopathological diagnosis was verified by the Kappa test. RESULTS: The 77 cases of oral bone lesions preferentially affected men 53.8% (n=41), the average age was 34.7 years (s.d.±19.6) and with lesions predominantly located in the posterior jaw 36.4% (n=28) and anterior maxilla 35.1% (n=27). Odontogenic cysts (OC) 42.9% (n=33), non-specific or unclassified diagnosis 28.6% (n=22) and inflammatory lesions of pulp and periapical origin 14.2% (n=11). TOs accounted for 7.8% (n=6) of the lesions. The four most predominant lesions were the radicular cyst, nonspecific diagnosis, dentigerous cyst and periapical granuloma. Concordance with the first diagnostic hypothesis was presented in 24 (31.2%) cases, the value of Kappa was 0.274 (discrete concordance) and 20.8% without clinical diagnosis only a description of the lesion. CONCLUSIONS: The OC were the predominant; being individually the radicular cyst the most frequent lesion. The clinical and histopathological concordance was discrete.

Quantitative Analysis of CCL5 and ep300 in Periapical Inflammatory Lesions.

In silico bioinformatical analysis suggested that the expression of two genes, CCL5 (C-C Motif Chemokine Receptor 5) and ep300 (Histone acetyltransferase p300), could be used as potential new biomarkers in differentiation between periapical granulomas and radicular cysts. Thus, we hypothesized that gene expression of CCL5 and ep300 in periapical lesions would classify the lesions as either granuloma or cyst. Patient samples (n=122) included 46 periapical granulomas, 38 radicular cysts and 38 healthy gingival samples as controls. Real-time PCR analysis of CCL5 and ep300 transcripts was compared to SDHA (Succinate dehydrogenase complex, subunit A) as the reference. Clinical parameters (e.g., intensity of inflammation and lesion size) were measured and correlated with CCL5 and ep300 expression. ROC (Receiver operating characteristic) and logistic regression analyses were used to establish the diagnostic character of ΔCt values. Granulomas and radicular cysts had significantly higher expression of CCL5 and ep300 compared to controls (P<0.05). However, no differences were observed when comparing granulomas and radicular cysts. ROC analyses showed that CCL5 and ep300 have good diagnostic accuracy, but low accuracy for distinguishing between the lesions. This study confirmed that expression of CCL5 and ep300 is relevant for the pathogenesis of periapical inflammatory lesions but cannot be used as a distinctive marker between these lesions.

Overexpression of Cyclophilin A in Human Periapical Lesions

IntroductionCyclophilin A (CypA) is a cytosolic protein involved in multiple biological functions, such as inflammation, tissue remodeling, tumorigenesis, and vascular diseases. Human periapical lesions are induced by bacterial infections. However, the expression of CypA in human periapical lesions remains unclear. This study aimed to investigate the presence of CypA in human periapical lesions and the possible association of CypA with angiogenesis, inflammatory cell infiltration, and alveolar bone degradation during inflammatory development. MethodsFifty-eight human periapical tissues, including periapical granulomas (PGs, n = 28), radicular cysts (RCs, n = 24), and healthy control tissues (control group, n = 6) were collected. Samples were fixed and analyzed. CypA expression was detected and analyzed by immunohistochemistry in different cross sections. Double immunofluorescence was assessed to colocalize CypA with CD34, CypA with matrix metalloproteinase 9 (MMP-9), and CD147 with MMP-9. ResultsCypA was significantly overexpressed in the RC and PG groups compared with the control group (P < .05), but the difference between the RC and PG groups was insignificant (P > .05). CypA-positive cells were mainly lymphocytes, endothelial cells, epithelial cells, and plasma cells. The double-labeling analysis of CypA with CD34 suggested that CypA expression was associated with angiogenesis during periapical lesions. MMP-9 colocalized with both CypA and CD147 indicated that CypA may colocalize with CD147 and may be associated with the degradation of soft and hard tissues around human periapical lesions. ConclusionsCypA may be involved in the development of periapical lesions with an increase in inflammatory cell infiltration, angiogenesis acceleration, and alveolar bone degradation.

Analysis of oral pathology in an Australian paediatric population: A retrospective study

PurposeThere are very few published epidemiological studies that investigate oral pathology in the paediatric population in an Australian cohort. MethodsThe purpose of this study was to analyze data from histopathological specimens received over a period of 23 years at the Institute for Clinical Pathology and Medical Research (ICPMR), and to report on the frequency of oral pathology in the Australian pediatric population. Results obtained from ICPMR, were imported into an electronic database and data such as age, gender and histopathological diagnosis were used to determine the frequency of commonly occurring pathology in children. ResultsA total of 935 oral pathology specimens collected from paediatric patients aged 16 and under were included in the analysis. The most common pathology was salivary gland pathology (21.1%), followed by mucosal pathology (15.8%) and miscellaneous pathology (14.9%). The most frequently encountered lesion was the mucocele (19.1%), followed by periapical granuloma (5.9%), dentigerous cyst (5.1%) and the giant cell fibroma (5%). ConclusionIn the paediatric population, oral pathology shows an increasing tendency with age, with the majority of pathology being benign in nature comprising mainly of mucoceles and dental pathology particularly, periapical granuloma's and dentigerous cysts.

The Validity of a Visual Basic Program in Learning Cone Beam Computed Tomography versus the PowerPoint Slides

Aims: the purpose of this study was to evaluate the validity of specially designed computer assisted learning (CAL) Visual Basic program containing images with multiple choice questions (MCQ) for learning the basics of CT and CBCT compared to lecture supplemented with PowerPoint presentation only.Methodology: The software contained one hundred images obtained from textbooks and internet web sites, the images included the basic principles of CT and CBCT, normal anatomical landmarks, caries, periapical granuloma, cyst and tumor interpretation. 30 postgraduate internship students’ participated and divided into two groups after attending a guiding lecture about the cone beam computed tomography including the study images, group I were given the program CD while group II were allowed to review the lecture only. After 2 weeks, both groups had OSPE exam.Results: it showed statistically significant mean student’s score in group I receiving the program CD after lecture compared to the other group II (traditional method only)Conclusion: The use of CAL Visual Basic program enhances the learning of the basics of CBCT

Vasoactive Intestinal Peptide Immunoregulatory Role at the Periapex: Associative and Mechanistic Evidences from Human and Experimental Periapical Lesions

IntroductionThe balance between the host proinflammatory immune response and the counteracting anti-inflammatory and reparative responses supposedly determine the outcome of periapical lesions. In this scenario, the vasoactive intestinal peptide (VIP) may exert a protective role because of its prominent immunoregulatory capacity. In this study, we investigated (in a cause-and-effect manner) the potential involvement of VIP in the development of human and experimental periapical lesions. MethodsPeriapical granulomas (n = 124) and control samples (n = 48) were comparatively assessed for VIP and multiple immunologic/activity marker expression through real-time polymerase chain reaction. Experimental periapical lesions (C57Bl/6 wild-type mice) were evaluated regarding endogenous VIP expression correlation with lesion development and the effect of recombinant VIP therapy in lesion outcome. CCR4KO and IL4KO strains and anti-glucocorticoid-induced TNFR-related protein inhibition were used to test the involvement of Treg and Th2 cells in VIP-mediated effects. ResultsVIP expression was more prevalent in periapical granulomas than in controls, presenting a positive association with immunoregulatory factors and an inverse association/correlation with proinflammatory mediators and the receptor activator of nuclear factor kappa B ligand/osteoprotegerin ratio. Endogenous VIP expression up-regulation was temporally associated with lesion immunoregulation and a decline of bone loss. VIP therapy in mice prompted the arrest of lesion development, being associated with an anti-inflammatory and proreparative response that limits the proinflammatory, Th1, Th17, and osteoclastogenic response in the periapex. The VIP protective effect was dependent of Treg migration and activity and independent of interleukin 4. ConclusionsOur results show that VIP overexpression in human and experimental periapical lesions is associated with lesion inactivity and that VIP therapy results in the attenuation of experimental lesion progression associated with the immunosuppressive response involving Treg cells.

Difficulties in the diagnosis of periapical translucencies and in the classification of cemento-osseous dysplasia

BackgroundCemento-osseous dysplasia is a benign fibro-osseous lesion of the tooth-bearing region of the jaws with a periodontal ligament origin. It appears predominantly in Black and Asian middle-aged females. Its importance is that it could mimic a periapical lesion in the early, translucent stage.Case presentationIn this report a rare case of familial cemento-osseous dysplasia is presented: a 50-years old Caucasian woman with labial paraesthesia and radiological translucency around the roots of the mandibular incisors and the first molar teeth. The lesion around the first molar was diagnosed as periapical granuloma and a root canal treatment was carried out. The diagnosis of florid cemento-osseous dysplasia and the treatment plan based on two- and three-dimensional radiographic examinations were certified histologically after surgical removal of the lesion. We screened the family members - including the patient’s mother, daughter and son - and identified a periapical version of cemento-osseous dysplasia in the daughter. Our case highlights the difficulties of differential diagnosis of cemento-osseous dysplasia and other periapical pathologies. The inconsistencies in the present classification of cemento-osseous dysplasia are also discussed with a proposal for a different classification based on new aspects that would be very helpful in setting up a correct treatment plan.ConclusionDifferentiation of endodontic and non-endodontic origin of radiolucency and distinguishing it from anatomical landmarks by appropriate clinical evaluation and using vitality testing can give an opportunity to prevent unnecessary endodontic treatment.The current categories of cemento-osseous dysplasia classification do not cover the early stage of a hereditary florid form of cemento-osseous dysplasia.Instead of anatomical location of the lesion, clinical and genetic features may be recommended as parameters of cemento-osseous dysplasia classification.

Potential role of TP63 in apical periodontitis development.

To investigate the expression of TP63 in apical periodontitis (AP) tissues and the association of single nucleotide polymorphisms (SNPs) in the TP63 gene with AP using a case-control dataset. Expression of TP63 in human AP lesions (apical abscess, radicular cyst, periapical granuloma) was evaluated using immunohistochemistry. A case-control association study was performed to assess the association of TP63 polymorphisms in individuals having AP with or without associated pain. Cases were defined as subjects with deep caries and AP (n=151) and subjects with symptomatic apical periodontitis or acute apical abscess (n=124). Subjects without AP (n=169) and asymptomatic (n=196) were used as controls, respectively. Saliva samples were collected as source of genomic DNA. Twelve SNPs in the TP63 gene were selected for genotyping using Taqman chemistry in real-time PCR. Data analysis was performed using PLINK software. The Bonferroni method was applied to correct for multiple testing; α≤0.004 indicates significant differences between groups. TP63 expression was evident in apical abscesses and radicular cysts, while weaker expression was observed in periapical granulomas. Positive expression was observed in mononuclear cells in the granulation tissues of all AP lesions. Regarding the presence of AP, a trend for allelic association was observed for rs16864812 and rs9810322 (P=0.04) and rs9810322 genotypes were also nominally associated with AP under a dominant model (P=0.04). When considering the presence of periapical pain, a trend for allelic and genotypic association was observed for rs10155037 (P=0.03). Haplotypes were also associated with AP and periapical pain (P≤0.05). Apical periodontitis is a complex multifactorial condition and it is likely that multiple genes and environmental effects may influence its susceptibility, progression or both. TP63 variants may play a role in AP pathogenesis and susceptibility, individually or interactively with other genes. Additional studies in other populations and functional studies are needed to improve understanding of the role of TP63 in AP.

Mesenchymal Stem Cell Marker Expression in Periapical Abscess

IntroductionThere is evidence that acute periapical lesions present a greater potential for cyst formation. Recently, it was found that these lesions have cells with characteristics of pluripotent stem cells, which may influence cyst development. However, a more complete phenotype investigation of stem cells in a specific sample of periapical abscesses is required. The aim of this study was to analyze the immunohistochemical expression of mesenchymal stem cell (MSC) markers in periapical abscesses and to evaluate differences in their expression in relation to acute and chronic periapical lesions. MethodsImmunohistochemistry was used to access MSC marker expression (CD44, CD73, and CD105) in samples of periapical abscesses (n = 10), granulomas (n = 10), cysts (n = 10), and apical papillae (n = 10). Immunohistochemical expression was evaluated by a quantitative scoring system. The chi-square test was used to assess the association between MSC marker expression and the histopathological diagnosis at a 5% significance level. ResultsCD44 and CD73 immunostaining was observed in mesenchymal cells located in the outer portion of the abscess and periapical cyst specimens. CD105 immunoexpression was found predominantly in mesenchymal and vascular endothelial cells of the lesions studied. MSC marker expression was higher in the periapical abscesses, with a significant association between MSCs and the histopathological diagnosis of an abscess (P < .05). ConclusionsThe periapical region is a rich source of MSCs. The greater presence of MSCs in periapical abscesses found in this study could hold an important clue into understanding the pathological pathway of periapical cyst formation.

Endodontics: standard endodontic treatment of a discolored maxillary canine tooth in a dog

Pulpitis and subsequent pulp necrosis results in tissue degradation by-products causing staining of the dentin.This is a common cause of localised intrinsic staining of the teeth. Reversible pulpitis is a...

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

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.