Mucositis is a frequent and important side effect of radio/chemotherapy treatment. Understanding the possible participation of viruses in the mechanism of this condition is important to develop strategies for treatment and prevention.

Background Patients with chronic kidney disease (CKD) have inability to maintain the normal levels of protein metabolism products, blood pressure and hematocrit. Periodontal disease involves an inflammatory destructive process. Identification of opportunistic viruses is extremely important as they are associated with co‐morbidities. The objective of this study was to analyse the presence of human herpesviruses in saliva and gingival crevicular fluid (GCF) from patients with CKD. Methods One hundred and thirty one individuals were divided depending on the stage of CKD: Group 1 (clearance of creatinine > 75 mL/min) patients with no renal disease (n = 24); Group 2 (clearance of creatinine of 11‐75 mL/min) patients with renal disease (n = 67); Group 3 (clearance of creatinine < 10 mL/min) patients on hemodialysis (n = 40). The parameters of periodontal disease were evaluated. The viral detection was assessed by PCR. Results considering the three groups, the prevalence of herpes simplex virus 1 (HSV‐1) were 9% in saliva and 5% in GCF; Epstein‐Barr virus 36% in saliva and 39% in GCF; human cytomegalovirus (HCMV) 11% in GCF; varicella zoster virus 6% in saliva and 3% in GCF; of human herpesvirus‐6 (HHV‐6) 6% in saliva and 2% in GCF; and HHV‐7 44% in saliva and 8% in GCF. Of these patients, 46.48% presented with severe periodontitis. A statistically significant association between HSV‐1 and HCMV was found in hemodialysis patients and severe periodontitis was also more frequent among them. Conclusion These findings show the importance of evaluating the periodontal disease and detecting herpesviruses in patients with CKD as the inflammatory process observed in these clinical conditions may worsen the course of both periodontal disease and CKD.

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/0.2mm 2), and Treg cells in radicular cysts (5.910 cells/0.2mm 2). 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/0.2mm 2). 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.

The present findings support other longitudinal studies evaluating the relationship between oral shedding of human herpesviruses and clinical presence of active infection and renal transplant failure.

Objective This study aimed to investigate the use of texture analysis for characterization of radicular cysts and periapical granulomas and to assess its efficacy to differentiate between both lesions with histological diagnosis. Methods Cone beam computed tomography (CBCT) images were obtained from 19 patients with 25 periapical lesions (14 radicular cysts and 11 periapical granulomas) confirmed by biopsy. Regions of interest were created in the lesions from which 11 texture parameters were calculated. Spearman's correlation analysis was performed and adjusted with Benjamini-Hochberg false discovery rate procedure (FDR <0.005). Results The texture parameters used to differentiate the lesions were assessed by using a receiver operating characteristic analysis. Five texture parameters were predictive of lesion differentiation for eight positions: angular second moment; sum of squares; sum of average; contrast; correlation. Conclusion Texture analysis of CBCT scans distinguishes radicular cysts from periapical granulomas and can be a promising diagnostic tool for periapical lesions. Clinical significance Texture analysis can be used in diagnostic and treatment monitoring to provide supplementary information.

Renal transplant recipients excreted herpesviruses more often than control individuals, especially HSV-1. Decreased salivary flow and xerostomia were more frequent in patients who used tacrolimus, whereas those who used cyclosporine had more cases of DIGO.

Background COVID-19 is a disease affecting various human organs and systems, in which the virus seeks to interact with angiotensin-converting enzyme 2 receptors. These receptors are present in the oral cavity, but the direct relationship between such an interaction and possible oral manifestations of COVID-19 is still unclear. Aim The present study evaluated oral manifestations in a cohort of COVID-19 patients during the period of hospitalisation. Methods In total, 154 patients presenting moderate-to-severe forms of COVID-19 had their oral mucosa examined twice a week until the final outcome, either discharge or death. The oral alterations observed in the patients were grouped into Group 1 (pre-existing conditions and opportunistic oral lesions) and Group 2 (oral mucosal changes related to hospitalization). Results Oral lesions found in the patients of Group 1 are not suggestive of SARS-CoV-2 infection as they are mainly caused by opportunistic infections. On the other hand, oral alterations found in the patients of Group 2 were statistically ( P < 0.001) related to intubation and longer period of hospitalisation. Conclusion It is unlikely that ulcerative lesions in the oral cavity are a direct manifestation of SARS-CoV-2 or a marker of COVID-19 progression.

Pigmented squamous cell carcinoma in situ (PSCCIS) is very rare, being clinically described as a pigmented lesion with histological characteristics of an in-situ carcinoma presenting pigmentation within neoplastic cells. A 50-year-old Afro-descendant man came for clinical evaluation of a painful black and red lesion located on the right aspect of the oropharyngeal isthmus. After incisional biopsy, the resulting sample was described as a pigmented squamous cell carcinoma in situ, a diagnosis further confirmed by immunohistochemical analysis. Treatment consisted in total excision of the lesion, and no recurrence was observed after a 30-month follow-up. Clinicians and pathologists should be aware of PSCCIS as a differential diagnosis of melanoma, a lesion which significantly increases the morbidity and mortality rates among these patients. Key words:Pigmented squamous cell carcinoma in situ; oropharyngeal mucosa; immunohistochemistry.