The IL-1ß-p65 axis stimulates quiescent odontogenic epithelial cell rests via TGF-ß signalling to promote cell proliferation of the lining epithelia in radicular cysts: A laboratory investigation.

AIM: Cyst formation of the jaws is frequently accompanied by the proliferation of odontogenic epithelial cells located in the periodontal ligament (PDL), which consists of heterozygous cells and includes the most fibroblasts. The lining epithelium of radicular cyst, an odontogenic cyst of inflammatory origin, is derived from the proliferation of the remnants of the Hertwig epithelial root sheath (odontogenic epithelial cell rests of Malassez; ERMs) in the PDL. ERMs are maintained at a lower proliferative state under physiological conditions, but the regulatory mechanisms underlying the inflammation-dependent enhanced-proliferative capabilities of ERMs are not fully understood. The aim of this study was to evaluate the effects of cytokine pathway association between TGF-ß signalling and IL-1ß signalling on the regulation of odontogenic epithelial cell proliferation using radicular cyst pathological specimens and odontogenic epithelial cell lines. METHODOLOGY: Immunofluorescence analyses were performed to clarify the expression levels of Smad2/3 and Ki-67 in ERMs of 8-week-old mouse molar specimens. In radicular cyst (n = 52) and dentigerous cysts (n = 6) specimens from human patients, the expression of p65 (a main subunit of NF-κB), Smad2/3 and Ki-67 were investigated using immunohistochemical analyses. Odontogenic epithelial cells and PDL fibroblastic cells were co-cultured with or without an inhibitor or siRNAs. Odontogenic epithelial cells were cultured with or without TGF-ß1 and IL-1ß. The proliferative capabilities and Smad2 phosphorylation levels of odontogenic epithelial cells were examined. RESULTS: Immunohistochemically, Smad2/3-positivity was increased, and p65-positivity and Ki-67-positivity were decreased both in ERMs and in the epithelial cells in dentigerous cysts, a non-inflammatory developmental cyst. In contrast, p65-positive cells, along with the expression of Ki-67, were increased and Smad2/3-positive cells were decreased in the lining epithelia of radicular cysts. Co-culture experiments with odontogenic epithelial cells and PDL fibroblastic cells revealed that PDL cells-derived TGF-ß1/2 and their downstream signalling suppressed odontogenic epithelial cell proliferation. Moreover, TGF-ß1 stimulation induced Smad2 phosphorylation and suppressed odontogenic epithelial cell proliferation, while IL-1ß stimulation reversed these phenotypes through p65 transactivation. CONCLUSIONS: These results suggest that IL-1ß-p65 signalling promotes odontogenic epithelial cell proliferation through suppressing TGF-ß-Smad2 signalling, which would be involved in the pathogenesis of radicular cysts.

Immunohistochemical Comparison of Ki-67 and MCM-3 in Odontogenic Cysts: An Observational Study.

Odontogenic cysts are a diverse group of pathologic entities with different proliferation potential, leading to variations in their biological behavior. One of the most cited proliferation markers used in diagnostic histopathology is Ki-67. Another group of proteins recently investigated is minichromosome maintenance (MCM-3) and its expression has been evaluated in several odontogenic lesions but the results were controversial. Thus, the present study endeavored to compare the expression of MCM-3 and Ki-67 in odontogenic cysts. Furthermore, a pioneer attempt was made to evaluate the sensitivity of these markers to inflammation. A total of 101 cases (37 dentigerous cysts, 37 odontogenic keratocysts, and 27 radicular cysts) were included. Immunohistochemical expression of Ki-67 and MCM-3 were investigated using a labeling index (LI). In addition, they were scored for inflammation, followed by correlation with both markers. The data obtained were subjected to statistical analysis ( P <0.05). Overall, a higher LI of MCM-3 than Ki-67 was obtained in all study groups along with a positive correlation of Ki-67 LI with inflammation. Thus, MCM-3 proteins proved to be a more accurate means to determine the proliferation potential and were not sensitive to external stimuli like inflammation than conventional markers, such as Ki-67.

A Case of Respiratory Epithelium-Lined Cyst with Enriched Nociceptor Innervation.

Apical lesions of endodontic origin can be classified as either granulomas or cysts. In rare cases, respiratory epithelium can proliferate and encapsulate a lesion, forming a cyst. Moreover, the innervation of apical lesions has only been previously reported in animal models of apical periodontitis. This report demonstrates an unusual case in which tooth #15 was initially treated with nonsurgical root canal therapy. Still, the patient remained in moderate to severe pain for several days following the procedure. Next, an intentional replantation was performed in which a periapical cyst was curetted from the alveolus. The patient experienced immediate pain relief following the procedure. Histological analysis revealed that the periapical cyst was lined entirely with respiratory epithelium, and immunohistochemical analysis showed it to be densely innervated. In addition, these nerve fibers expressed the LPS receptor, TLR4. This is the first demonstration of the innervation pattern of a periapical cyst. Further studies are warranted to evaluate innervation in apical lesions and its correlation with pre- and intra-operative symptoms and their participation in the pathogenesis of apical periodontitis.

The Dilemma Of Management Of Cystic Lesions; An Uncertain Way Forward: A Case Report.

Periapical diseases ranges from mild granulomatous lesions to large cystic ones, with the treatments corresponding to their respective pre-operative diagnoses. However, the determination of cause of periapical radiolucency is impossible on pre-operative clinical and radiographic examinations. We present a case highlighting the difficulties encountered in treating a periapical cyst using the current evidence in literature. It demonstrates the uncertainty involved in treating such lesions, owing to the impossible nature of determining the histopathological nature of the cyst, i.e., being either true cysts or pocket cysts. This case includes orthograde re-treatment; decompression of the cystic lesion, followed by peri-apical surgery of two teeth over a course of three years; and the uncertain outcomes encountered after each phase of the treatment.

Utility of Ultrasonography for Diagnosing and Differentiating Periapical Granuloma from Radicular Cyst.

RATIONALE AND OBJECTIVES: This study aimed to investigate the reliability and accuracy of high-resolution ultrasonography (US) for diagnosing periapical lesions and differentiating radicular cysts from granulomas. MATERIALS AND METHODS: This study included 109 teeth with periapical lesions of endodontic origin from 109 patients scheduled for apical microsurgery. Ultrasonic outcomes were analyzed and categorized after thorough clinical and radiographic examinations using US. B-mode US images reflected the echotexture, echogenicity, and lesion margin, while color Doppler US assessed the presence and features of blood flow of interested areas. Pathological tissue samples were obtained during apical microsurgery and subjected to histopathological examination. Fleiss' κ was used to measure interobserver reliability. Statistical analyses were performed to assess the diagnostic validity and the overall agreement between US and histological findings. The reliability of US compared to histopathological examinations was assessed based on Cohen's κ. RESULTS: The percent accuracy of US for diagnosing cysts, granulomas, and cysts with infection based on histopathological findings was 89.9%, 89.0%, and 97.2%, respectively. The sensitivity of US diagnoses was 95.1% for cysts, 84.1% for granulomas, and 80.0% for cysts with infection. The specificity of US diagnoses was 86.8% for cysts, 95.7% for granulomas, and 98.1% for cysts with infection. The reliability for US compared to histopathological examinations was good (κ = 0.779). CONCLUSION: The echotexture characteristics of lesions in US images correlated with their histopathological features. US can provide accurate information on the nature of periapical lesions based on the echotexture of their contents and the presence of vascularity. It can help improve clinical diagnosis and avoid overtreatment of patients with apical periodontitis.

A deep learning approach for radiological detection and classification of radicular cysts and periapical granulomas.

OBJECTIVES: Dentists and oral surgeons often face difficulties distinguishing between radicular cysts and periapical granulomas on panoramic imaging. Radicular cysts require surgical removal while root canal treatment is the first-line treatment for periapical granulomas. Therefore, an automated tool to aid clinical decision making is needed. METHODS: A deep learning framework was developed using panoramic images of 80 radicular cysts and 72 periapical granulomas located in the mandible. Additionally, 197 normal images and 58 images with other radiolucent lesions were selected to improve model robustness. The images were cropped into global (affected half of the mandible) and local images (only the lesion) and then the dataset was split into 90% training and 10% testing sets. Data augmentation was performed on the training dataset. A two-route convolutional neural network using the global and local images was constructed for lesion classification. These outputs were concatenated into the object detection network for lesion localization. RESULTS: The classification network achieved a sensitivity of 1.00 (95% C.I. 0.63-1.00), specificity of 0.95 (0.86-0.99), and AUC (area under the receiver-operating characteristic curve) of 0.97 for radicular cysts and a sensitivity of 0.77 (0.46-0.95), specificity of 1.00 (0.93-1.00), and AUC of 0.88 for periapical granulomas. Average precision for the localization network was 0.83 for radicular cysts and 0.74 for periapical granulomas. CONCLUSIONS: The proposed model demonstrated reliable diagnostic performance for the detection and differentiation of radicular cysts and periapical granulomas. Using deep learning, diagnostic efficacy can be enhanced leading to a more efficient referral strategy and subsequent treatment efficacy. CLINICAL SIGNIFICANCE: A two-route deep learning approach using global and local images can reliably differentiate between radicular cysts and periapical granulomas on panoramic imaging. Concatenating its output to a localizing network creates a clinically usable workflow for classifying and localizing these lesions, enhancing treatment and referral practices.

Immunohistochemical evaluation of cyclooxygenase-2 and mast cell density in periapical lesions.

AIM: Periapical granuloma (PG) and cyst (PC) are formed as a protective response consequent to pulpal infection leaching through the apical foramen and lateral canals. Various inflammatory mediators like mast cells and cyclooxygenase (COX)-2 are involved in this intricate process. This pilot study aimed to evaluate and compare the immunoexpression of tryptase and COX-2 in periapical granuloma and periapical cyst, and also correlate them with intensity of inflammatory infiltrate and thickness of cystic epithelial lining. METHODOLOGY: An observational and cross-sectional study was conducted on paraffin-embedded tissue sections of 50 PGs and 50 PCs submitted for morphological and immunohistochemical analysis using anti-tryptase and anti-COX-2 antibodies. The mean number of mast cells (total, granulated and degranulated), mean COX-2 expression and inflammatory score was calculated. The data obtained were analysed using Mann Whitney U, Student's T, Chi-square and Spearman correlation test (p < .05). RESULTS: The inflammatory score, total mast cells and COX-2 expression were similar in PGs and PCs (p = .352, .339 and .352) however, the degranulated mast cells were highly significant in PC while granulated mast cells were highly significant in PG respectively (p < .001 in both). Although a non-significant correlation existed between COX-2 and total mast cells in both groups but, total mast cells were significantly correlated with epithelial thickness in PC (p = .029). CONCLUSIONS: Mast cells and cyclooxygenase-2 proved to be independent inflammatory markers in periapical lesions. Further studies should be planned on mast cell and COX-2 inhibitors as treatment modalities of periapical lesions.

Pediatric Oral Pathology: Odontogenic Cysts.

Cysts encountered in the head and neck typically arise from epithelium that would normally be programmed to form teeth or tooth-supporting structures (odontogenic epithelium). These cysts come with a confusing array of similar-sounding names and histopathologic features that are sometimes shared between conditions. Here we describe and contrast the relatively-common lesions: hyperplastic dental follicle, dentigerous cyst, radicular cyst, buccal bifurcation cyst, odontogenic keratocyst, glandular odontogenic cyst, and the less-common gingival cyst of the new-born and thyroglossal duct cyst. The goal of this review is to help clarify and simplify these lesions for the general pathologist, pediatric pathologist, and surgeon.

Ex vivo detection of lipopolysaccharide immunopositivity in Rushton bodies.

AIM: Our aim was to investigate how bacterial lipopolysaccharide (LPS) is immunoexpressed in periapical lesions. By surprise we detected Rushton bodies (RBs) whose origin has been debatable to be positive for LPS. METHODOLOGY: Samples of radicular cysts (N=70) were stained in order to identify variations in LPS immunoexpression indicating bacterial background. For immunostaining, we used an anti-LPS antibody from Escherichia coli, and for visualization Horse Radish Peroxidase labeled polymer as the secondary antibody. RESULTS: RBs showed positivity for LPS in radicular cysts. After collection of radicular cyst samples (70 in total), we noted that all RBs (N=25) histologically detected in tissue samples were positive for LPS. Furthermore, calcification in the cyst capsule showed immunopositivity. CONCLUSION: We demonstrate for the first time that LPS is present in RBs, indicating that host response to bacteria might be the initial cause of the formation of these hyaline bodies in the cyst epithelium and cyst capsule calcifications.

The expression of cyclic GMP-AMP synthase in human apical periodontitis: A laboratory investigation.

AIM: As a key DNA sensor, cyclic GMP-AMP synthase (cGAS) has emerged as a major mediator of innate immunity and inflammation. Human apical periodontitis has yet to be studied for the presence of cGAS. This investigation was conducted to determine if cGAS is involved in the pathological process of human apical periodontitis. METHODOLOGY: Sixty four human periapical lesions, comprising 20 periapical granulomas and 44 radicular cysts, were employed in this investigation. Healthy gingiva (n = 6), dental pulp (n = 3), and apical papilla (n = 3) were used as control samples. The expression of cGAS in the periapical tissues was discovered using immunohistochemical staining. mRNA-Sequencing and qRT-PCR were utilized to determine the differentially expressed genes (DEGs) associated with DNA-sensing signalling in periapical lesions compared to the healthy control. Immunofluorescence labelling was used to identify the co-expression of cGAS, interleukin-1ß, and interleukin-18. RESULTS: A significantly greater expression level of cGAS was discovered in the periapical lesions, with no significant difference between radicular cysts and periapical granulomas. mRNA-Sequencing analysis and qRT-PCR identified differentially expressed mRNA, such as cGAS and its downstream DEGs, between periapical lesions and healthy control tissues. Immunofluorescence labelling further revealed that cGAS, interleukin-1, and interleukin-18 were co-localized. CONCLUSIONS: These observations imply that along with the synthesis of interleukin-1 and interleukin-18, cGAS may be involved in the aetiology of apical periodontitis.

Expression pattern of hypoxia-related genes in odontogenic cysts.

OBJECTIVE: The aim of the present study was to reveal the effects of hypoxia-associated signaling in odontogenic cysts. DESIGN: The expression levels of genes involved in the hypoxia-associated signaling pathway were determined by quantitative Polymerase Chain Reaction (PCR) method. RESULTS: As a result, it was found that phosphatase and tensin homolog (PTEN) expression was low (p = 0.037), and the expression levels of phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA) (p = 0.0127), hypoxia inducible factor 1 alpha (HIF1A) (p < 0.001), and HIF1A antisense RNA 1 (HIF1A-AS1) (p = 0.0218) were higher in cyst tissue compared to normal tissue. HIF1A gene expression was found to be significantly altered according to the pathologic subtypes of odontogenic keratocyst, dentigerous cyst, and radicular cyst. CONCLUSIONS: Odontogenic cysts were found to have higher expression of HIF1A and HIF1A-AS1, which may be related to the increased hypoxia in these lesions. In addition, PI3K/Akt signaling may be stimulated by increased PIK3CA and decreased PTEN expression, which promote cell survival and support the mechanism of cyst formation.

Detection of bone marrow edema in differential diagnoses of odontogenic cysts using dual-energy computed tomography.

PURPOSE: In this study, we prospectively investigated the relationship between bone marrow edema (BME) and odontogenic cysts and explored the possibility of using dual-energy computed tomography (DECT) as an auxiliary tool for the diagnosis of odontogenic cysts. METHODS: This cross-sectional study included 73 patients who underwent the DECT scan and surgery for odontogenic cysts or odontogenic tumors. The virtual noncalcium (VNCa) computed tomography (CT) values and CT values were measured at several sites. The predictor variable was diagnosis, and the other variables included age, sex, and sites. The primary outcome was VNCa CT value. Variables were tested using the chi-square test or the Kruskal-Wallis test. The VNCa CT and CT values were tested using the Scheffe test for multiple comparisons. All variables were analyzed as independent variables affecting the VNCa CT values around the lesion in the multiple regression analysis. RESULT: There were 35 men and 38 women. The mean patient age was 50.0 ± 19.5 years (range: 8-86). The VNCa CT values (- 6.2 ± 34.3) around the lesion in patients with RCs were significantly higher than those in patients with dentigerous cysts (- 44.4 ± 28.6) and odontogenic keratocysts (- 67.3 ± 19.5). In multiple regression analysis, the VNCa CT values around the lesion showed a significant positive correlation with histological results (regression coefficient: - 0.605, P < 0.001). CONCLUSION: The presence of BME is associated with radicular cysts, and DECT can be used as an auxiliary tool for radicular cyst diagnosis.

The Prevalence of EBV and KSHV in Odontogenic Lesions.

OBJECTIVES: Odontogenic lesions evolve as a result of altered dental development. This study aimed to evaluate the prevalence and the coinfection of Epstein-Barr virus (EBV) and Kaposi sarcoma-associated herpesvirus (KSHV) in radicular cysts, dentigerous cysts, odontogenic keratocysts, and ameloblastomas. METHODS: Polymerase chain reaction (PCR) was used to analyse 66 cases of odontogenic lesions for the presence of EBV-DNA and KSHV-DNA. These lesions were 15 radicular cysts, 16 dentigerous cysts, 18 odontogenic keratocysts, and 17 ameloblastomas. RESULTS: EBV-DNA was detected in 24 (36.4%) of the studied samples as follows: 6 samples (40.0%) of radicular cysts, 4 (25.0%) of dentigerous cysts, 10 (55.6 %) of odontogenic keratocysts, and 4 (23.5%) of ameloblastomas (P = .168). KSHV-DNA was found in 16 (24.2%) of the studied samples as follows: 1 sample (6.7%) of radicular cysts, 6 (37.5%) of dentigerous cysts, 8 (44.4 %) of odontogenic keratocysts, and 1 (5.9%) of ameloblastomas (P = .001). Additionally, EBV and KSHV were positively correlated in all studied samples (P = .002). CONCLUSIONS: Both EBV and KSHV are found in odontogenic cysts and ameloblastomas. KSHV and EBV are more prevalent in odontogenic keratocysts than in other studied odontogenic lesions. Further, there is a high prevalence of EBV and KSHV coinfection in odontogenic cysts and ameloblastomas.

The Potential Immunomodulatory Roles of Semaphorin 4D in Human Periapical Lesions.

INTRODUCTION: Semaphorin 4D (SEMA4D) is an important immunoregulator in the development of inflammatory diseases. Currently, the role of SEMA4D in human apical periodontitis remains unclear. This study aims to investigate the expression of SEMA4D and its potential immunomodulatory roles in apical periodontitis. METHODS: A total of 31 periapical tissues and 6 healthy gingival tissues were used in this experiment. Hematoxylin-eosin staining, immunohistochemical staining, and multiplex immunofluorescence staining were performed for histologic examination and immunochemical analysis. For data processing, the number of SEMA4D+, CD4+, CD8+, and CD20+ cells was analyzed by QuPath. In addition, the colocalization of SEMA4D with CD4, CD8, and CD20 was detected. RESULTS: Radicular cysts (RCs) (n = 18) and periapical granulomas (PGs) (n = 13) were identified by histologic evaluation. The number of SEMA4D+ cells in PGs was significantly greater than that in RCs (P < .05). T-cell and B-cell infiltration did not differ significantly between RCs and PGs. An increased number of CD20+ cells was observed in both types of apical periodontitis compared to CD8+ cells and CD4+ cells. Additionally, the presence of SEMA4D/CD4 and SEMA4D/CD20 double-positive cells was also markedly higher in PGs than in RCs. CONCLUSION: The expression of SEMA4D and related immune cells showed different characteristics between RCs and PGs. The disparate expression patterns indicated the possible different pathologic states of the 2 types of periapical lesions. This study provides a new perspective on the description of the comprehensive microenvironment of periapical lesions.

Immunoexpression of CXCL12 and CXCR4 in Radicular Cysts, Dentigerous Cysts, and Odontogenic Keratocysts.

The aim of this study was to evaluate the immunoexpression of chemokine CXCL12 and its receptor CXCR4 in radicular cysts (RCs), dentigerous cysts (DCs), and odontogenic keratocysts (OKCs), and to correlate the findings with morphologic parameters of RCs (inflammatory infiltrate and cystic epithelium). Twenty RCs, 20 DCs, and 20 OKCs were submitted to immunohistochemistry. The percentages of cytoplasmic (CXCL12 and CXCR4) and nuclear (CXCR4) staining in epithelial and fibrous capsule cells were determined. RCs and DCs exhibited higher epithelial expression of CXCL12 than OKCs ( P <0.05). The expression of CXCL12 in the fibrous capsule was higher in DCs than in RCs and OKCs ( P <0.05). Higher cytoplasmic expression of CXCR4 was observed in the epithelial lining and fibrous capsule of RCs and DCs compared with OKCs ( P <0.05). In the fibrous capsule, DCs exhibited higher nuclear expression of CXCR4 than OKCs ( P <0.05). No significant differences in the immunoexpression of CXCL12 or CXCR4 were observed according to the morphologic parameters of RCs ( P >0.05). Strong positive correlations were found between cytoplasmic and nuclear expression of CXCR4 in the epithelial lining of RCs and DCs and in the fibrous capsule of all groups ( P <0.05). The results suggest the participation of CXCL12 and CXCR4 in the pathogenesis of RCs, DCs, and OKCs. These proteins may be particularly relevant for the development of odontogenic cysts with less aggressive biological behavior, irrespective of their nature (inflammatory or developmental). In RCs, the expression of CXCL12 and CXCR4 may not be related to the intensity of the inflammatory infiltrate or the status of cystic epithelium.

Variability in the Epithelial Expression of Ki67 and Polarization Characteristics of Collagen in Odontogenic Cysts and Tumours

ABSTRACT Objective: To assess the proliferation of epithelium (using the Ki67 index) and the polarization pattern of collagen in selected odontogenic cysts and tumours. In addition, an exploratory analysis of the effect of inflammation on the proliferation rate was done. Material and Methods: Following immunohistochemical staining, the labelling/proliferation index of Ki67 was calculated. The thickness and corresponding polarization colour of 100 juxta-epithelial picrosirius red-stained collagen fibers were assessed using linear micrometry with an eyepiece reticule under × 1000 magnification. Inflammation was graded subjectively as mild, moderate, and severe. Results: Overall Ki-67 expression was higher in the radicular cyst, Odontogenic Keratocyst, Ameloblastoma, while suprabasal Ki-67 positivity was maximum in Odontogenic Keratocyst. The stromal collagen fibers in Ameloblastoma showed predominantly green birefringence, whereas Odontogenic Keratocyst had orange birefringence. There was no significant association of inflammation with Ki-67 expression or birefringence patterns. Conclusion: The highest Ki67 expression in the radicular cyst, followed by Odontogenic Keratocyst and Ameloblastoma. Differences in the collagen maturation pattern were noted innately in five lesions studied and were further influenced by inflammatory changes. Epithelial proliferation and concomitant expression of thickness and maturity of the stromal collagen are innate features of the lesion further influenced by inflammation in various odontogenic cysts and tumours and may, in turn, guide the clinical behavior.

Abordagem cirúrgica de cisto periapical abscedado na maxila: relato de caso / Surgical approach of absceded periapical cyst in the maxilla: case report / Abordaje quirúrgico de quiste periapical abscedido en la maxila: reporte de caso

O cisto radicular é uma lesão inflamatória associada à necrose pulpar que ocorre frequentemente em maxila. Objetivo: Descrever um caso cirúrgico detalhado de Cisto Periapical Abscedado. Relato de Caso: paciente gênero feminino, 40 anos, hipertensa, diabética Tipo II, compareceu à clínica queixando-se de dor ao ingerir alimentos frios e quentes na região da maxila, lado esquerdo. Ao exame físico, observou-se destruição coronária e presença de fístula na região do elemento dentário 23. Ao exame radiográfico, observou-se uma área radiolúcida ovalada bem circunscrita com halo radiopaco envolvendo a região apical do elemento dentário 23. Frente ao aspecto clínico e radiográfico, foram sugeridas as hipóteses diagnósticas de abscesso periapical crônico, granuloma periapical ou cisto apical abscedado. Foi realizada a exodontia do elemento 23 seguida de enucleação cística. O diagnóstico histopatológico final foi de cisto abscedado. Após 5 meses de evolução observa-se mucosa íntegra e reparo ósseo alveolar. Conclusão: É imprescindível um exame clínico cuidadoso associado ao exame radiográfico e histopatológico para analisar minuciosamente o caso a fim de oferecer ao paciente melhores condutas de tratamento. O diagnóstico de lesões intraósseas associado ao correto tratamento interrompe a evolução do processo patológico, evita danos maiores e restabelece a condição de saúde dos pacientes... (AU)

The radicular cyst is an inflammatory lesion associated with pulp necrosis that often occurs in the maxilla. Objective: To describe a detailed surgical case of Abscessed Periapical Cyst. Case Report: female patient, 40 years old, hypertensive, type II diabetic, came to the clinic complaining of pain when ingesting cold and hot foods in the left side of the maxilla. On physical examination, coronary destruction and the presence of a fistula in the region of the tooth 23 were observed. The radiographic examination showed a well-circumscribed oval radiolucent area with a radiopaque halo involving the apical region of the tooth 23. In view of the clinical and radiography, the diagnostic hypotheses of chronic periapical abscess, periapical granuloma or abscessed apical cyst were suggested. Element 23 extraction was performed followed by cystic enucleation. The final histopathological diagnosis was an abscessed cyst. After 5 months of evolution, intact mucosa and alveolar bone repair are observed. Conclusion: A careful clinical examination associated with radiographic and histopathological data is essential to systematically analyze the case in order to offer the patient better treatment. The diagnosis of intraosseous lesions associated with the correct treatment interrupts the evolution of the pathological process, avoids further damage and restores the patients' health condition... (AU)

El quiste radicular es una lesión inflamatoria asociada a necrosis pulpar que frecuentemente se presenta en el maxilar. Objetivo: Describir un caso quirúrgico detallado de Quiste Periapical Absceso. Caso Clínico: paciente femenina, de 40 años, hipertensa, diabética tipo II, acudió a la consulta quejándose de dolor al ingerir alimentos fríos y calientes en el lado izquierdo del maxilar. Al examen físico se observó destrucción coronaria y la presencia de una fístula en la región del diente 23. El examen radiográfico mostró un área radiolúcida oval bien delimitada con un halo radiopaco que involucraba la región apical del diente 23. En vista de la clínico y radiográfico, se sugirieron las hipótesis diagnósticas de absceso periapical crónico, granuloma periapical o quiste apical abscesificado. Se realizó la extracción del elemento 23 seguida de enucleación quística. El diagnóstico histopatológico final fue de quiste abscesificado. A los 5 meses de evolución se observa mucosa intacta y reparación del hueso alveolar. Conclusión: Un examen clínico cuidadoso asociado con el examen radiográfico e histopatológico es fundamental para analizar a fondo el caso con el fin de ofrecer al paciente mejores enfoques de tratamiento. El diagnóstico de lesiones intraóseas asociado al correcto tratamiento interrumpe la evolución del proceso patológico, previene mayores daños y restablece el estado de salud de los pacientes... (AU)

EXPRESSION OF ALPHA-SMOOTH MUSCLE ACTIN IN ODONTOGENIC CYSTS AND TUMORS.

BACKGROUND: Odontogenic cysts and tumors exhibit different degrees of aggressiveness in their biological behavior. There has been evidence that the presence of myofibroblasts (MFs) at the invasion front promotes tumor invasion. Our study is based on the fact that MFs are important in the biological behavior of odontogenic cysts and tumors. AIM: To assess immunohistochemically expression of alpha-smooth muscle actin (α-SMA) of MFs in odontogenic cysts and tumors and correlate this expression to their biological behavior. MATERIALS AND METHODS: The archival tissues collected for 1.5 years were obtained from the Department of Oral Pathology & Microbiology, People's Dental Academy, Bhopal (India). A total of 40 cases consisting of 10 cases each of odontogenic keratocysts, radicular cysts, dentigerous cysts and ameloblastomas formed the study group. An immunohistochemical analysis of α-SMA expression and localization was carried out. RESULTS: Mean MF counts were the highest in odontogenic keratocysts which was followed by ameloblastomas, entigerous cysts and radicular cysts. Weak α-SMA-expression was found in 50% of cases, moderate in 22.5% of cases, and intense - in 10% cases. MFs were arranged in the spindle, focal, or network patterns in 35; 27.5 and 20% of cases, respectively. CONCLUSION: The analysis revealed that the MFs were distinctly heterogeneous in distribution and pattern of arrangement. This provided persuasive evidence that stroma of these lesions harbor MFs as reflected by α-SMA immunopositive cells.

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).

Prevalence of Nonendodontic Diagnoses in Periapical Biopsies: A 6-year Institutional Experience.

INTRODUCTION: The purpose of this study was to identify nonendodontic periapical lesions (NPLs) mimicking endodontic pathosis, which are most frequently encountered by clinicians. METHODS: A retrospective study was conducted on biopsies obtained from 2015-2020 at Texas A&M College of Dentistry's oral pathology laboratory. The online database was screened for cases submitted as suspected endodontic pathology using specific key words. Histologic diagnoses were collected to determine the prevalence of NPLs that were originally thought to be of endodontic origin. The frequency and percentage of endodontic pathology and NPLs were documented. RESULTS: Among 6704 biopsies clinically diagnosed as endodontic lesions, 190 (2.8%) were histopathologically diagnosed as NPLs. The most frequent NPLs were odontogenic keratocytes' (n = 70, 36.8%), cemento-osseous dysplasia (n = 27, 14.2%), and dentigerous cysts (n = 22, 11.6%). Of all NPLs, 3.7% were malignant neoplasms, with the most common diagnosis being squamous cell carcinoma. Of 6514 endodontic histologic diagnoses, the prevalence of periapical granulomas and cysts was 60.2% (n = 3924) and 39.1% (n = 2549), respectively. CONCLUSIONS: Although most endodontic submissions are likely to be histologically diagnosed as periapical granulomas or cysts, the clinician should be aware that a small portion of these lesions may be nonendodontic in origin and possibly neoplastic in nature. Histopathologic evaluation of biopsied specimens is critical to achieve a proper diagnosis to ensure the appropriate management of patients.