Presence of Porphyromonas gingivalis in gingival squamous cell carcinoma

Periodontal disease has been recently linked to a variety of systemic conditions such as diabetes, cardiovascular disease, preterm delivery, and oral cancer. The most common bacteria associated with periodontal disease, Porphyromonas gingivalis (P. gingivalis) has not yet been studied in the malignant gingival tissues. The objective of this study was to investigate the presence of P. gingivalis in specimens from squamous cell carcinoma patients. We have performed immunohistochemical staining to investigate the presence of P. gingivalis and Streptococcus gordonii (S. gordonii), a non invasive oral bacteria, in paraffin embedded samples of gingival squamous cell carcinoma (n = 10) and normal gingiva (n = 5). Staining for P. gingivalis revealed the presence of the bacteria in normal gingival tissues and gingival carcinoma, with higher levels (more than 33%, P < 0.05) detected in the carcinoma samples. The staining intensity was also significantly enhanced in the malignant tissue by 2 folds (P < 0.023) compared to specimens stained for the non-invasive S. gordonii. P. gingivalis is abundantly present in malignant oral epithelium suggesting a potential association of the bacteria with gingival squamous cell carcinoma.

The association between periodontal disease and cancer: a review of the literature

OBJECTIVES

Periodontal disease has long been linked to many systemic diseases, and recently a link between periodontal disease and cancer has been established. The purpose of this paper is to review the literature to explore the evidence to date of a relationship between periodontal disease and cancer. In addition, the main hypotheses for the association are discussed along with challenges in evaluating the evidence.

DATA/SOURCES/STUDY SELECTION

In this review, English-language papers studying the relationship between periodontal disease or tooth loss in humans and increased risk of several types of cancers along with overall cancer risk between 1990 and April 2009 were reviewed.

CONCLUSIONS

The most consistent increased risk was noted in studies of oral and esophageal cancers and periodontal disease. Gastric and pancreatic cancers had an association in most but not all studies. Lung, prostate, hematologic and other cancers were less consistently associated or did not have sufficient studies to determine a predictable pattern. Studies to date indicate a positive correlation between several forms of cancer and periodontal disease.

Association between periodontal pockets and elevated cholesterol and low density lipoprotein cholesterol levels

BACKGROUND

Periodontitis is associated with increased prevalence of cardiovascular morbidity and mortality; however, the nature of this association is unclear. There is a rationale that indicates that the presence of periodontal pockets which can harbor pathogenic microorganisms and evoke a host response could elicit a systemic effect. The hypothesis of this study is that periodontal pockets may be associated with elevated blood lipid levels, a known risk factor for atherosclerotic disease.

METHODS

The periodontal health of 10,590 Israeli military service men and women was assessed using the Community Periodontal Index of Treatment Needs (CPITN). The relationship of blood lipids and periodontal disease and CPITN index was tested, controlling for factors that are related to elevated cholesterol levels, including high body mass index (BMI), age, diastolic blood pressure, and smoking.

RESULTS

The presence of periodontal pockets was positively associated with higher cholesterol and low density lipoprotein (LDL) cholesterol blood levels in men. No significant association was found in women.

CONCLUSIONS

In this large cohort study, the presence of periodontal pockets as measured by CPITN was positively associated with total cholesterol and LDL-cholesterol. The findings of the study support the reports linking increased prevalence of cardiovascular mortality among patients with periodontal disease.

Expression of the receptor of advanced glycation end products in gingival tissues of type 2 diabetes patients with chronic periodontal disease: a study utilizing immunohistochemistry and RT-PCR

OBJECTIVES

Relationship between diabetes and periodontal disease is well established. It has been shown that advanced glycation end-products (AGEs) might exert noxious effects on gingival tissues through its receptor. Evidence for the role of receptors of AGE (RAGE) in periodontal disease was verified in a murine model for diabetes. However, the presence of RAGE in human gingival tissues has not been demonstrated previously. In this study we demonstrate the presence of RAGE in human periodontium in patients with chronic periodontitis with and without type 2 diabetes.

MATERIAL AND METHODS

Gingival biopsies from eight patients with both type 2 diabetes and chronic periodontitis and 14 healthy control subjects with chronic periodontitis were immunohistochemically stained for RAGE. Five samples from the study groups and four controls were subjected to reverse transcriptase coupled to polymerase chain reaction (RT-PCR) for quantitative determination of mRNA for RAGE.

RESULTS

On immunohistochemistry, positive staining for RAGE was seen in the endothelium and the basal and spinous layer of the inflamed gingival epithelium in both type 2 diabetes and non-diabetes tissue with no statistically significant difference between both groups. RT-PCR, however, showed a 50% increase in mRNA for RAGE in the gingiva of diabetic patients when compared with controls (p<0.05).

CONCLUSIONS

Although there was no change in the staining intensity for RAGE between both groups, the increase in the mRNA for RAGE in the type 2 diabetes gingival epithelium may indicate a possible involvement of this receptor in the periodontal destruction in type 2 diabetes.

Localization of P. gingivalis in preterm delivery placenta

Increasing evidence suggests an association between periodontal disease and adverse pregnancy outcomes. Although infection is considered as a risk factor for preterm delivery, the localization of oral bacteria or their antigens in chorioamnionitis placental tissue has never been demonstrated. This study was devised to test the hypothesis that periodontal pathogens may be present and affect human placenta in cases of chorioamnionitis. Using immunocytochemistry, we have identified the presence of Porphyromonas gingivalis antigens in placental tissues. The antigens were detected in the placental syncytiotrophoblasts, chorionic trophoblasts, decidual cells, and amniotic epithelial cells, as well as the vascular cells. There was a substantial increase in immunostaining intensity of the tissues sectioned from women with chorioamnionitis compared to those experiencing normalterm pregnancy, p < 0.019 (Mann-Whitney test). These results suggest that P. gingivalis may commonly colonize placental tissue, and that the presence of the organism may contribute to preterm delivery.

On the association between hypercholesterolemia, cardiovascular disease and severe periodontal disease

BACKGROUND

Premature death in men is known to be significantly associated with coronary heart disease (CHD). More and more studies are pointing toward a possible association between periodontal disease and increased risk of cardiovascular disease. The association of poor oral hygiene and atherosclerosis can be explained by the effect of chronic inflammatory disease on blood rheology. The purpose of the present study was to assess the relationship between CHD and periodontal disease.

PATIENTS AND METHODS

The study population included 1094 Israeli army service men aged 26-53 years (mean: 39+/-5 years). The study group comprised 151 subjects classified as having coronary heart disease CHD, i.e., myocardial infarction, and or anginal syndrome with angiographic evidence of significant coronary disease, or suffer from atherosclerotic risk factors, i.e., diabetes (fasting glucose) and HTN according to strict, well-established criteria. Blood levels of cholesterol and triglycerides were also determined. The severity of periodontal disease was assessed by the aid of CPITN. The control group comprised 943 healthy subjects. Statistical analysis was performed with chi2 test.

RESULTS

Statistical analysis showed a significant association of CPITN score 4 with hypercholesterolemia and a possible association with CHD.

CONCLUSIONS

The generation of higher cholesterol blood levels is proposed as a possible link between chronic periodontal inflammation and atherosclerosis.

High resolution of microRNA signatures in human whole saliva

OBJECTIVE

Identifying discriminatory human salivary RNA biomarkers reflective of disease in a low-cost non-invasive screening assay is crucial to salivary diagnostics. Recent studies have reported both mRNA and microRNA (miRNA) in saliva, but little information has been documented on the quality and yield of RNA collected. Therefore, the aim of the present study was to develop an improved RNA isolation method from saliva and to identify major miRNA species in human whole saliva.

DESIGN

RNA samples were isolated from normal human saliva using a combined protocol based on the Oragene RNA collection kit and the mirVana miRNA isolation kit in tandem. RNA samples were analysed for quality and subjected to miRNA array analysis.

RESULTS

RNA samples isolated from twenty healthy donors ranged from 2.59 to 29.4 μg/ml saliva and with 1.92-2.16OD(260/280 nm) ratios. RNA yield and concentration of saliva samples were observed to be stable over 48 h at room temperature. Analysis of total salivary RNA isolated from these twenty donors showed no statistical significance between sexes; however, the presence of high-, medium-, and low-yield salivary RNA producers was detected. MiRNA array analysis of salivary RNA detected five abundantly expressed miRNAs, miR-223, miR-191, miR-16, miR-203, and miR-24, that were similarly described in other published reports. Additionally, many previously undetected miRNAs were also identified.

CONCLUSION

High quality miRNAs can be isolated from saliva using available commercial kits, and in future studies, the availability of this isolation protocol may allow specific changes in their levels to be measured accurately in various relevant diseases.

Human leukocyte antigen (HLA) DR4. Positive association with rapidly progressing periodontitis

The relationship between human leukocyte antigens (HLA) determinants and periodontitis has been examined by several authors without showing any particular pattern. However, no study has investigated the HLA-D determinants, which are generally associated with immune disorders, and rapidly progressive periodontitis (RPP). The HLA profile of 10 RPP patients was compared with that of a healthy control population (n = 120). Although no significant difference was found for HLA-A, HLA-B, and HLA-C, HLA-DR4 of the HLA-D group was found in 80% of patients but only in 38.3% of controls. A high frequency of HLA-DR4 has been reported in rheumatoid arthritis (RA) patients. This finding may be significant in light of previous reports highlighting similarities between RA and periodontal disease.

Genetic polymorphisms and other risk factors associated with bisphosphonate induced osteonecrosis of the jaw

Bisphosphonate induced osteonecrosis of the jaw (BONJ) is a complication in patients taking bisphosphonate (BP) that affects their quality of life and compliance. In this cohort study, patients with multiple myeloma (MM) on intravenous BP therapy were enrolled over 1 year. Demographic and clinical data and genotyping of 10 single nucleotide polymorphisms (SNPs) from seven candidate genes associated with drug or bone metabolism were determined. Of the 78 patients enrolled, 12 had BONJ. The median time to developing BONJ was 28 months. Univariate and multivariate analysis revealed a significant association between BONJ and smoking (p=0.048) and type of BP treatment (p=0.03). A trend for higher odds for BONJ was found for SNPs in five genes: COL1A1 (rs1800012), RANK (rs12458117), MMP2 (rs243865), OPG (rs2073618) and OPN (rs11730582). Considering all five SNPs together, patients with genotype scores ≥ 5 had a BONJ event rate of 57%; those with scores < 5 had a rate of 10%. The adjusted odds ratio was 11.2 (95% confidence interval of 1.8-69.9; p value 0.0097). Smoking, type of BP and combined genotype score of COL1A1, RANK, MMP2, OPG and OPN were significantly associated with BONJ in MM patients undergoing BP therapy.

Osteonecrosis of the Jaw in the United States Food and Drug Administration's Adverse Event Reporting System (FAERS)

Osteonecrosis of the jaw (ONJ) is a serious adverse drug event that was initially reported with intravenous bisphosphonates (BPs) and more recently with other classes of drugs such as receptor activator of NF-κB ligand (RANKL) inhibitor, antiangiogenic agents, and mammalian target of rapamycin (m-TOR) inhibitors. The purpose of this study is to analyze the ONJ cases and the associated drugs in the US Food and Drug Administration's adverse event reporting system (FAERS). The FAERS database was queried for the adverse drug events reported from the first quarter of 2010 to the first quarter of 2014. The reporting odds ratios (ORs) and 95% confidence intervals (CIs) were calculated for each queried drug. A total of 17,119 unique ONJ cases were identified. In the overall analysis, the drugs with the highest reporting ORs were BPs: pamidronate (OR = 498.9), zoledronate (OR = 171.7), and alendronate (OR = 63.6), whereas denosumab had lower ORs than all the BPs except for etidronate. The antiangiogenic and m-TOR inhibitors had the lowest ORs. In cancer patients who were treated for prevention of skeletal-related events (SREs), the reporting ORs for zoledronate and denosumab were 125.2 and 4.9, respectively. In patients with osteoporosis, the ORs were 1.1 (1.0-1.18) for zoledronate and 0.63 (0.56-0.70) for denosumab, respectively. Our analysis of the FAERS database showed that the intravenous BPs were associated with the highest risk for ONJ, RANKL inhibitor was associated with risk comparable to BPs used for osteoporosis such as etidronate, and the antiangiogenic agents and m-TOR inhibitors were associated with the lowest risk for ONJ. The high risk for ONJ with zoledronate and denosumab was mainly observed in those who were treated for prevention of SREs, whereas there was limited evidence for such risk in those who were treated for osteoporosis.

Receptor for advanced glycation end product (RAGE) upregulation in human gingival fibroblasts incubated with nornicotine

BACKGROUND

Clinical and epidemiological data strongly support a link between smoking and periodontal disease. The mechanism by which smoking contributes to the destruction of periodontal tissue is not clear and cannot be attributed solely to the vasoconstrictive effects of nicotine. Our hypothesis is that nornicotine, a metabolite of nicotine, upregulates the expression of the receptor for the advanced glycation end products (RAGE) in the gingiva of smokers and triggers the proinflammatory effects of AGE by stimulating the secretion of cytokines and reactive oxygen species which directly cause destruction of the periodontal apparatus.

METHODS

Human gingival cells grown in tissue culture were exposed to 1 microM nornicotine for 72 hours. Following the nornicotine pretreatment, some of the cells were also treated with AGE that was generated with nornicotine for 48 hours and another group was continued on nornicotine only for 48 hours. Control cells that were not exposed to either nornicotine or AGE were also cultured. The cells were harvested and RNA was extracted for reverse transcription-polymerase chain reaction (RT-PCR) and RAGE mRNA was amplified.

RESULTS

The nornicotine-treated cells increased their expression of RAGE by approximately 4-fold (P <0.05, Student t test). These data suggest that nornicotine, a byproduct of cigarette smoke, can induce RAGE expression in gingival tissues. Therefore, our data support the hypothesis that RAGE potentially plays a significant role in the progression of periodontal disease exacerbated by smoking.

CONCLUSION

Nornicotine, AGE, and upregulation of RAGE may be involved in the pathogenesis of periodontal disease associated with smoking.

Oral manifestations of Wegener's granulomatosis: a report of three cases and a literature review

BACKGROUND

Hyperplastic granular gingivitis or "strawberry gingivitis" is a rare manifestation of Wegener's granulomatosis (WG), but it is nearly pathognomonic for this multisystem autoimmune vasculitis. The dentist may be the first health care professional to see patients with symptoms and findings of this condition. Early diagnosis and treatment is the most important factor in the management of this potentially fatal disease.

METHODS

The authors present three case reports that demonstrate the disease spectrum and conducted a literature review focused on current understanding of this disease.

RESULTS

The first patient had only the classic gingival manifestations of the disease. The second patient had simultaneous typical gingival lesions, as well as dermatologic findings. The third patient had an atypical oral presentation of aphthous ulcers and erythematous gingiva, as well as respiratory and genital involvement. Reaching a definitive diagnosis sometimes is challenging owing to the subtle onset of the disease and variable clinical and laboratory findings.

CONCLUSION AND CLINICAL IMPLICATIONS

Clinicians should be familiar with the broad variety of oral and systemic components of WG, as well as strategies to facilitate prompt disease recognition and to provide continued oral health care to these medically complex patients.

Oral signs and symptoms in relation to disease activity and site of involvement in patients with inflammatory bowel disease

OBJECTIVE

An assessment of oral symptoms and signs in patients with inflammatory bowel disease (IBD).

METHODS

Fifty-four patients with IBD, 34 with Crohn's disease (CD) and 20 with ulcerative colitis (UC) participated in the study. Forty-two patients without gastrointestinal disease or complaints attending the orthopedic clinic served as controls. Each patient completed a written questionnaire and was subjected to an oral examination.

RESULTS

The main findings of this study were the higher prevalence of halitosis (50% vs 10% P < 0.0008), nausea (30% vs 7%, P < 0.017) and reflux (regurgitation) (45% vs 17%, P < 0.017) in patients with UC, and nausea (50% vs 7%, P < 0.026), dry mouth and halitosis (29% vs 10%, P < 0.026) and vomiting (41% vs 5%, P = 0.01) in patients with CD, compared with controls. Patients with active CD had a higher prevalence of dry mouth, nausea and vomiting compared with controls (46, 69 and 54% vs 10, 7 and 5%, respectively, P < 0.001) and of reflux compared with non-active CD (46% vs 5%, P < 0.001). Patients with active UC had a higher prevalence of halitosis and regurgitation (50 and 60% vs 10 and 17%, P < 0.001) compared with controls.

CONCLUSIONS

The present study demonstrates increased frequency of oral signs and symptoms in patients with IBD. Patients with active CD had more oral signs compared with non-active CD patients. Manifestations such as nausea, vomiting, regurgitation and dry mouth may have detrimental effects on teeth and soft tissues of the oral cavity. Communication between gastroenterologists and dentists is imperative for success of the overall treatment of their patients.

Increased risk for COVID-19 in patients with vitamin D deficiency

OBJECTIVE

The 2019 coronavirus disease (COVID-19) pandemic has disproportionally affected a variety of patients with underlying risk factors such as respiratory and cardiovascular diseases, diabetes, obesity, and black race. Vitamin D deficiency, which can result in a compromised immune response, has been also linked to increased risk and increased morbidities associated with COVID-19. In the absence of large-scale longitudinal studies to determine the strength of association between vitamin deficiency and COVID-19, cross-sectional studies of large patient cohorts can be used.

METHODS

We used the i2b2 patient's registry platform at the University of Florida Health Center to generate a count of patients using the international classification of diseases (ICD)-10 diagnosis codes for the period of October 1, 2015, through June 30, 2020. Logistic regression of the aggregates was used for the analysis.

RESULTS

Patients with vitamin D deficiency were 4.6 times more likely to be positive for COVID-19 (indicated by the ICD-10 diagnostic code COVID19) than patients with no deficiency (P < 0.001). The association decreased slightly after adjusting for sex (odds ratio [OR] = 4.58; P < 0.001) and malabsorption (OR = 4.46; P < 0.001), respectively. The association decreased significantly but remained robust (P < 0.001) after adjusting for race (OR = 3.76; P < 0.001), periodontal disease status (OR = 3.64; P < 0.001), diabetes (OR = 3.28; P < 0.001), and obesity (OR = 2.27; P < 0.001), respectively. In addition, patients with vitamin D deficiency were 5 times more likely to be infected with COVID-19 than patients with no deficiency after adjusting for age groups (OR = 5.155; P < 0.001).

CONCLUSIONS

Vitamin D deficiency is significantly associated with increased risk for COVID-19.

Prevention of recurrent aphthous stomatitis with colchicine: an open trial

BACKGROUND

Recurrent aphthous stomatitis (RAS) is a common disorder with hitherto unsatisfactory drug therapy.

OBJECTIVE

Our purpose was to evaluate the prophylactic effect of colchicine in the treatment of RAS.

METHODS

An open, prospective, 4-month study was conducted in 20 patients with RAS who served as their own controls. During the first 2 months of the study no medications were given and in the last 2 months colchicine, 1.5 mg/day, was prescribed.

RESULTS

The mean number of aphthae per week and the subjective daily pain scores were reduced by 71% and 77%, respectively, during colchicine treatment as compared with the previous period (p < 0.001 for both). No serious side effects of colchicine were noted.

CONCLUSION

These findings suggest a role for continuous colchicine therapy in the prevention of RAS.

Central giant cell granulomas: a systematic review of the radiographic characteristics with the addition of 20 new cases

OBJECTIVES

The radiographic characteristics of central giant cell granuloma (CGCG) vary to a great extent. This study sought to relate the radiographic and clinical features of several cases, which were confirmed histopathologically, as central giant cell granulomas, and to systematically review the relevant literature.

METHODS

Twenty cases with an established histopathological diagnosis of CGCG were received from the Department of Oral Pathology. The correlation between any two categorical variables was tested using Chi-square or Fischer's test, with alpha=0.01. A systematic review of the literature was performed using electronic and manual searches.

RESULTS

There was no gender predominance. Nearly 81% of the lesions were located in the deciduous tooth bearing area of the mandible and in 35% of the cases the lesions crossed the midline. The correlation between the size of the lesion and its appearance was statistically significant with larger lesions assuming a multilocular appearance. Most lesions (55%) were radiolucent while wispy opacification and trabeculation was evident in 50% of the lesions. The borders of the lesions were well defined in 65% of the cases and scalloping was seen in 53%. Displacement of teeth and/or other anatomic structures was seen in 50% of the cases while root resorption was found in 37%. The lesions perforated the cortex in 50% of the cases. Two cases, presented with paresthesia of the lip.

CONCLUSIONS

Central giant cell granuloma demonstrates clinical and radiographic features of a benign lesion with some aggressive characteristics.

Expression of the receptor of advanced glycation end products in the gingival tissue of smokers with generalized periodontal disease and after nornicotine induction in primary gingival epithelial cells

BACKGROUND

The association between smoking and periodontal disease is well established; however, the mechanism by which smoking augments the destruction of periodontal tissue is not clear. We hypothesize that smoking is related to an increased expression of receptor of advanced glycation end products (RAGE) in gingival tissues of smokers.

METHODS

Gingival biopsies from five smokers and five age- and gender-matched non-smokers were examined. In addition, gingival epithelial cells (GECs) were reacted with 1 muM nornicotine for 4, 16, 24, and 48 hours for mRNA for RAGE and an additional 72 hours for protein expression. RAGE mRNA was amplified by reverse transcriptase-polymerase chain reaction (RT-PCR), and expression of RAGE at the protein level in GECs was studied with Western blots.

RESULTS

In the gingival biopsies from all 10 subjects, RT-PCR with RAGE-specific primers produced a band of the predicted size. For all pairs, the smoker biopsies expressed a greater level of RAGE compared to the matched non-smokers. When viewed as groups, analysis of the band intensity indicated that RAGE mRNA in smokers was approximately 1.4-fold of the expression in non-smokers (Wilcoxon test; P = 0.031). In GECs treated with nornicotine, there was a time-dependent increase in RAGE expression up to two-fold at 48 hours. RAGE protein levels initially were reduced but increased to 1.4-fold after 48 hours.

CONCLUSION

The ability of nornicotine to elevate RAGE expression in GECs, along with increased RAGE expression in inflamed gingival tissue from smokers, indicates that RAGE may be associated with periodontal disease linked to smoking.

Porphyromonas gingivalis invades human trophoblasts and inhibits proliferation by inducing G1 arrest and apoptosis

Porphyromonas gingivalis is an oral pathogen that is also associated with serious systemic conditions such as preterm delivery. Here we investigated the interaction between P. gingivalis and a cell line of extravillous trophoblasts (HTR-8) derived from the human placenta. P. gingivalis internalized within HTR-8 cells and inhibited proliferation through induction of arrest in the G1 phase of the cell cycle. G1 arrest was associated with decreased expression of cyclin D and of CDKs 2, 4 and 6. In addition, levels of CDK inhibitors p15, p16, p18 and p21 were increased following P. gingivalis infection. The amount of Rb was diminished by P. gingivalis, and transient overexpression of Rb, with concomitant upregulation of phospho-Rb, relieved P. gingivalis-induced G1 arrest. HTR-8 cells halted in the G1 phase became apoptotic, and apoptosis was accompanied by an increase in the ratio of Bax/Bcl-2 and increased activity of caspases 3, 7 and 9. HTR-8 cells infected with P. gingivalis also exhibited a sustained activation of ERK1/2, and knock-down of ERK1/2 activity with siRNA abrogated both G1 arrest and apoptosis. Thus, P. gingivalis can invade placental trophoblasts and induce G1 arrest and apoptosis through pathways involving ERK1/2 and its downstream effectors, properties that provide a mechanistic basis for pathogenicity in complications of pregnancy.

The emerging role of the insulin-like growth factors in oral biology

The insulin-like growth factors (IGF) are a family of growth factors, receptors and binding proteins that are involved in numerous growth and differentiation processes, as well as in various pathological conditions. The aim of this review is to summarize data that has been accumulating in recent years linking the IGF system to a number of physiological and pathological oral processes. The IGF system fulfills an important role in growth and development of teeth, mandible, maxillae, and tongue. It has been postulated that IGF-I may be of great value in the treatment of periodontal defects and in tissue healing. Furthermore, IGF-II has been shown to be overexpressed in salivary gland adenomas, suggesting that aberrant IGF signaling may be a key factor in the etiology of oral malignancies. Understanding the role and regulation of IGF system components in salivary glands and other oral structures will be of significant basic and clinical relevance.

Periradicular radiographic assessment in diabetic and control individuals

OBJECTIVE

The purpose of this study was to investigate the prevalence of radiographic periradicular radiolucencies in endodontically treated and untreated teeth in patients with and without diabetes.

STUDY DESIGN

The records of 30 subjects with diabetes and 23 control subjects attending the Endodontic Graduate Clinic at the University of Florida, Gainesville, were reviewed. The number of teeth with root canal treatments with and without periradicular radiolucencies and the number of teeth without endodontic treatment but with periradicular lesions were recorded.

RESULTS

There were no main effects of sex, diabetes diagnosis, or age (the covariate) on the 3 outcomes of interest- nonsurgical endodontic treatment (NSE) with lesions, NSE without lesions, and no NSE with lesions. However, there were significant interactions between sex and diabetes diagnosis for both of the endodontic outcomes, NSE with lesions (F = 4.292; P <.05) and NSE without lesions (F = 4.241; P <.05). This meant that men with type 2 diabetes who had endodontic treatments were more likely to have residual lesions after treatment.

CONCLUSION

Type 2 diabetes is associated with an increased risk of ill response by the periradicular tissues to odontogenic pathogens.

Persistent orofacial muscle pain

The pathophysiology of persistent orofacial myalgia has been the centre of much controversy. In this article we suggest a novel descriptive term; 'persistent orofacial muscle pain' (POMP) and review current evidence that supports the hypothesis that the induction of POMP involves the interplay between a peripheral nociceptive source in muscle, a faulty central nervous system component and decreased coping ability. In this context it is widely accepted that a complex interaction of variable intrinsic and extrinsic factors act to induce POMP and dysfunction.

Trends in caries and associated variables among young Israeli adults over 5 decades

This study was conducted among a representative sample of 7,139 21-year-old Israeli adults, upon release from compulsory military service. Data were collected between 1994 and 1997. The average DMFT level found was 8.49+/-4.95. Untreated caries (according to the D component of DMFT) was 2.25+/-2.90 and significantly higher among males. Untreated caries was also significantly associated with geographic origin: higher among subjects of African or former USSR descent; and with family size: higher among subjects with four or more siblings; with education: caries was higher among subjects with less than 12 years of schooling; and with smoking: caries was more extensive among those who smoked (P<0.0001 for all the associations). Caries severity (DMFT) was found to be significantly associated with father's country of origin and number of siblings (highest among subjects of Asian and African descent and those who had four or more siblings). This is the largest and most representative Israeli survey of young adults to date. Data were compared with available data from studies conducted in 1956, 1966, 1973, and 1985. DMFT scores had previously increased from the 1950s until the 1980s. Treatment levels had increased since the 1980s. The present data, together with results of studies conducted among Israeli children, indicate a recent national decrease in caries experience. This study indicates a further increase in caries treatment level, but a persisting inequity according to social variables.

Stafne's bone cavity in the anterior mandible: a possible diagnostic challenge

Stafne was the first to report the presence of "bone cavities" in the angle of 35 mandibles. Such cavities generally appear in the area between the mandibular first molar and the mandibular angle, and are not considered rare. One of their primary radiological diagnostic features is the characteristic location below the mandibular canal. Stafne's bone cavity is relatively rare in the anterior mandible. The mandibular canal is not present in the anterior mandible. As a result, diagnosis in the anterior mandible may be missed. Needless treatment modalities such as endodontic treatment, bone trephining, and bone exploration may be conducted. The purpose of the present report is to describe a new case of Stafne's bone cavity in the anterior mandible and discuss the differential diagnosis process. The dental computerized tomography scan is suggested as the most suitable noninvasive diagnostic and follow-up modality for this bony configuration in the anterior mandible.

Herpes simplex and herpes zoster viruses in COVID-19 patients

BACKGROUND

Reactivation of herpes family viruses in immunocompromised patients may result in detrimental outcomes for the hosts; therefore, herpes simplex virus-1 and varicella zoster virus infections in the context of COVID-19 may have clinical and prognostic implications. Several reports associated this human herpes virus with COVID-19 infection and have claimed that it can be an indicator for latent COVID-19 infection. However, since most of these were case reports, it is impossible to assess the prevalence of these associations.

METHODS

The University of Florida patient registry i2b2 with ICD-10 diagnosis codes was used for retrieval of patients with diagnosis of COVID-19 and each of the other viruses over the period of October 2015-June 2020.

RESULTS

The prevalence of the herpes simplex-1 occurrence in the COVID-19 group was 2.81% compared to 0.77% in the hospital population odds ratio of 5.27. When adjusted for gender, race, and age, the odds were 5.18, 4.48, and 4.61, respectively. After adjustment for respiratory disease, endocrine disease, obesity, diabetes, circulatory disease, and smoking, the odds were 1.94, 3.18, 1.37, 3.54, 3.7, and 5.1, respectively. The prevalence of the varicella zoster virus in COVID-19 patients was 1.8% compared to 0.43% in the hospital population, odds ratio of 5.26 before adjustment, and 5.2, 5.47, and 4.76 after adjusting for gender, age, and race, respectively. When adjusted for respiratory disease, endocrine disease, obesity, diabetes, and circulatory and neurological diseases, the odds were 1.3, 2.2, 1.48, 2.33, 2.85, and 2.6, respectively.

CONCLUSION

Herpes simplex-1 and varicella zoster viruses are strongly associated with COVID-19 infection.

Small interfering RNA-mediated silencing induces target-dependent assembly of GW/P bodies

Gene silencing using small interfering RNA (siRNA) is a valuable laboratory tool and a promising approach to therapeutics for a variety of human diseases. Recently, RNA interference (RNAi) has been linked to cytoplasmic GW bodies (GWB). However, the correlation between RNAi and the formation of GWB, also known as mammalian processing bodies, remains unclear. In this report, we show that transfection of functional siRNA induced larger and greater numbers of GWB. This siRNA-induced increase of GWB depended on the endogenous expression of the target mRNA. Knockdown of GW182 or Ago2 demonstrated that the siRNA-induced increase of GWB required these two proteins and correlated with RNAi. Furthermore, knockdown of rck/p54 or LSm1 did not prevent the reassembly of GWB that were induced by and correlated with siRNA-mediated RNA silencing. We propose that RNAi is a key regulatory mechanism for the assembly of GWB, and in some cases, GWB may serve as markers for RNAi in mammalian cells.