Tomographic, microbiological and histological characterization of secondary apical periodontitis: case series

This case series included a tomographic, microbiological, and histopathological description of 15 secondary apical periodontitis (SAP) lesions obtained by apical microsurgery performed in 10 patients to better understand the etiology and pathogenesis of SAP. Preoperative tomographic analyses were performed through Cone beam computerized tomography - Periapical index (CBCT-PAI), and apical microsurgeries were then carried out. The removed apices were used for microbial culturing and for molecular identification using PCR for the detection of 5 strict anaerobic bacteria (P. gingivalis, P. intermedia, P. nigrescens, T. forsythia, and T.denticola) and 3 viruses Herpes simplex viruses (HSV), Cytomegalovirus (CMG) and Epstein-Barr Virus (EBV) by nested PCR. The removed apical lesions were histologically described. Univariate statistical analyses were performed by using STATA MP/16 (StataCorp LLC, College Station, TX, United States). CBCT-PAI analyses revealed PAI 4 and PAI 5 score lesions that involved cortical plate destruction. Eight SAPs were positive by culture, while nine SAP lesions were positive by PCR. Fusobacterium species were the most frequently cultured organisms in 7 SAP lesions, followed by D. pneumosintes in 3. In contrast, by single PCR, T. forsythia and P. nigrescens were detected in 5 lesions, T. denticola in 4 lesions, and P. gingivalis in 2 lesions. Twelve periapical lesions were granulomas, and the remaining three SAP lesions were radicular cysts. In conclusion, this case series study revealed that secondary apical lesions presented tomographic involvement of PAI 3 to 5, and that most SAP lesions were apical granulomas containing anaerobic and facultative microorganisms.

Human cytomegalovirus is present in the odontogenic epithelium of ameloblastoma

Background: The factor behind the activation of the remnant odontogenic tissues and development of odontogenic cysts and tumors is poorly understood.This study aimed to investigate the presence of human cytomegalovirus (HCMV) in dentigerous cyst (DC), odontogenic keratocyst (OKC), and ameloblastoma (AB). Methods: The study included 41 samples, which distributed into DC (n=13), OKC (n=12), and AB (n=16). Conventional PCR assay and IHC analysis were used to detect the HCMV-DNA and HCMV glycoprotein B (HCMV-gB) respectively. Results: HCMV-DNA was detected in 10 samples (62.5%) of AB, four samples (30.8%) of DC, and three samples (25 %) of OKC respectively (χ² test = 1.195, p= 0.247). Meanwhile, HCMV-gB was found in 12 (75%) of AB, in 2 (15.4%) of DC, and absent in OKC (0.0%) (χ² test = 4.122, p= 0.042). Conclusions: The high prevalence of HCMV inside the odontogenic epithelium of AB could indicate a possible role of the virus in the oncogenesis and/or oncomodulation of the AB. Additionally, we recommend the IHC for the detection of HCMV in the odontogenic tumors like AB.

Cytomegalovirus infection: friend or foe in rheumatoid arthritis?

Human cytomegalovirus (HCMV) is a β-herpesvirus that causes inflammation and remains for life in a latent state in their host. HCMV has been at the center of many hypotheses regarding RA.

We have recently shown that HCMV infection impairs bone erosion through the induction of the mRNA-binding protein QKI5. Latently infected RA patients display a slower progression of bone erosion in patients from a national cohort. Our observations question the possible association between HCMV and the pathophysiology of RA. In this review, we examine the possibility that HCMV may be an aggravating factor of inflammation in RA while protecting from bone erosion. We also assess its relationship with other pathogens such as bacteria causing periodontitis and responsible for ACPA production.

This review thus considers whether HCMV can be regarded as a friend or a foe in the pathogenesis and the course of RA.

Epithelioid cell granuloma with caseating necrosis possibly caused by periapical periodontitis: a case report

Background

Epithelioid cell granuloma with caseating necrosis is a typical pathological finding in tuberculosis. While specific inflammation, including that related to tuberculosis, can induce caseating granuloma formation, there have been very few reports on the induction of caseating granuloma by non-specific inflammation. Chronic periapical periodontitis is usually related to bacterial biofilm formation as well as fungal or viral infection in the periapical lesion. However, it is difficult to eliminate these extraradicular pathogenic microbes by normal endodontic therapy alone, and more invasive surgical removal is almost always required.

Case presentation

Here we describe the case of a 30-year-old Japanese woman who had suffered from dull pain related to periapical periodontitis for approximately 10 years. Although the causal tooth had been previously extracted at the Department of Oral Surgery of another hospital in 2015, inflammation of the surrounding tissue had not abated. She was referred to our hospital in May 2016 and underwent surgical debridement via an intra/extraoral approach under general anesthesia. A caseating granuloma accompanied by a small amount of fungi was histopathologically confirmed in the excised specimen. Her inflammation has not been exacerbated since the operation.

Conclusions

This is the first report in which non-specific inflammation is shown to induce caseating granuloma arising in the jaw. Our report also highlights the importance of sufficient root canal treatment during the first stage of the procedure.

A bacterial genotoxin causes virus reactivation and genomic instability in Epstein-Barr virus infected epithelial cells pointing to a role of co-infection in viral oncogenesis

We have addressed the role of bacterial co‐infection in viral oncogenesis using as model Epstein–Barr virus (EBV), a human herpesvirus that causes lymphoid malignancies and epithelial cancers. Infection of EBV carrying epithelial cells with the common oral pathogenic Gram‐negative bacterium Aggregatibacter actinomycetemcomitans (Aa) triggered reactivation of the productive virus cycle. Using isogenic Aa strains that differ in the production of the cytolethal distending toxin (CDT) and purified catalytically active or inactive toxin, we found that the CDT acts via induction of DNA double strand breaks and activation of the Ataxia Telangectasia Mutated (ATM) kinase. Exposure of EBV‐negative epithelial cells to the virus in the presence of sub‐lethal doses of CDT was accompanied by the accumulation of latently infected cells exhibiting multiple signs of genomic instability. These findings illustrate a scenario where co‐infection with certain bacterial species may favor the establishment of a microenvironment conducive to the EBV‐induced malignant transformation of epithelial cells.

What's new?

Little is known about the influence of coinfections, especially of bacteria, on viral oncogenesis. Here, the authors examined the effect of the cytolethal distending toxin (CDT) of Aggregatibacter actinomycetemcomitans, a common oral pathogen, on epithelial cells infected with Epstein–Barr virus (EBV). Exposure of EBV+ cells to CDT induced viral reactivation, while exposure of EBV‐ cells to low amounts of CDT led to the accumulation of latently infected cells upon infection, pointing to a multi‐layered role of bacterial co‐infection in viral oncogenesis.

Periodontitis: facts, fallacies and the future

This volume of Periodontology 2000 represents the 25th anniversary of the Journal, and uses the occasion to assess important advancements in periodontology over the past quarter-century as well as the hurdles that remain. Periodontitis is defined by pathologic loss of the periodontal ligament and alveolar bone. The disease involves complex dynamic interactions among active herpesviruses, specific bacterial pathogens and destructive immune responses. Periodontal diagnostics is currently based on clinical rather than etiologic criteria, and provides limited therapeutic guidance. Periodontal causative treatment consists of scaling, antiseptic rinses and occasionally systemic antibiotics, and surgical intervention has been de-emphasized, except perhaps for the most advanced types of periodontitis. Plastic surgical therapy includes soft-tissue grafting to cover exposed root surfaces and bone grafting to provide support for implants. Dental implants are used to replace severely diseased or missing teeth, but implant overuse is of concern. The utility of laser treatment for periodontitis remains unresolved. Host modulation and risk-factor modification therapies may benefit select patient groups. Patient self-care is a critical part of periodontal health care, and twice-weekly oral rinsing with 0.10-0.25% sodium hypochlorite constitutes a valuable adjunct to conventional anti-plaque and anti-gingivitis treatments. A link between periodontal herpesviruses and systemic diseases is a strong biological plausibility. In summary, research during the past 25 years has significantly changed our concepts of periodontitis pathobiology and has produced more-effective and less-costly therapeutic options.

Orofacial granulomatosis: A case report of three cases may be caused by apical periodontitis

RATIONALE

Orofacial granulomatosis (OFG) is a rare disease characterized by noncaseating granulomatous inflammation. The most common clinical presentation is persistent swelling of the soft tissues in the oral and maxillofacial regions. The precise cause of OFG is unknown. Corticosteroids are the first-line and best treatment, but there is lack of uniform treatment prescription and standard. It is important to identify the pathogen in order to improve treatment specificity.

PATIENT CONCERNS

Three patients presented with recurring lip swelling and cobblestone formation on buccal mucosa, complained of toothache or dental caries for many years. They had very similar and characteristic clinical signs, especially the corresponding location with infected teeth, which suffered from apical periodontitis.

DIAGNOSES

The three patients were all diagnosed with typical clinical signs and non-caseating epithelioid cell granulomas histologically.

INTERVENTIONS

The teeth with apical periodontitis were extracted or treated and corticosteroids were prescribed locally or/and systematically.

OUTCOMES

A complete resolution of lip swelling and cobblestone formation were shown after treatment.

LESSONS

This is the first report to highlight that apical periodontitis may intrigue the pathogenesis of OFG, which suggested that dental infection may be the direct and initial etiology of OFG. Removal of infected teeth should be performed as soon as possible in order to reduce the dosage of corticosteroids and occcurence rate of OFG.