Studying host genetic background effects on multimorbidity of intestinal cancer development,type 2 diabetes and obesity in response to oral bacterial infection and high‐fat diet using the collaborative cross (CC) lines

BackgroundMultimorbidity of intestinal cancer (IC), type 2 diabetes (T2D) and obesity is a complex set of diseases, affected by environmental and genetic risk factors. High‐fat diet (HFD) and oral bacterial infection play important roles in the etiology of these diseases through inflammation and various biological mechanisms.MethodsTo study the complexity of this multimorbidity, we used the collaborative cross (CC) mouse genetics reference population. We aimed to study the multimorbidity of IC, T2D, and obesity using CC lines, measuring their responses to HFD and oral bacterial infection. The study used 63 mice of both sexes generated from two CC lines (IL557 and IL711). For 12 weeks, experimental mice were maintained on specific dietary regimes combined with co‐infection with oral bacteria Porphyromonas gingivalis and Fusobacterium nucleatum, while control groups were not infected. Body weight (BW) and results of a intraperitoneal glucose tolerance test (IPGTT) were recorded at the end of 12 weeks, after which length and size of the intestines were assessed for polyp counts.ResultsPolyp counts ranged between 2 and 10 per CC line. The combination of HFD and infection significantly reduced (P < .01) the colon polyp size of IL557 females to 2.5 cm², compared to the other groups. Comparing BW gain, IL557 males on HFD gained 18 g, while the females gained 10 g under the same conditions and showed the highest area under curve (AUC) values of 40 000‐45 000 (min mg/dL) in the IPGTT.ConclusionThe results show that mice from different genetic backgrounds respond differently to a high fat diet and oral infection in terms of polyp development and glucose tolerance, and this effect is gender related.     

The “oral” history of COVID-19: Primary infection,salivary transmission,and post-acute implications

Severe acute respiratorysyndrome coronavirus 2 (SARS-CoV-2), the causative agent of COVID-19, has led to more than 3.25 million recorded deaths worldwide as of May 2021. COVID-19 is known to be clinically heterogeneous, and whether the reported oral signs and symptoms in COVID-19 are related to the direct infection of oral tissues has remained unknown. Here, we review and summarize the evidence for the primary infection of the glands, oral mucosae, and saliva by SARS-CoV-2. Not only were the entry factors for SARS-CoV-2 found in all oral tissues, but these were also sites of SARS-CoV-2 infection and replication. Furthermore, saliva from asymptomatic individuals contained free virus and SARS-CoV-2-infected oral epithelial cells, both of which were found to transmit the virus. Collectively, these studies support an active role of the oral cavity in the spread and transmission of SARS-CoV-2 infection. In addition to maintaining the appropriate use of personal protective equipment and regimens to limit microbial spread via aerosol or droplet generation, the dental community will also be involved in co-managing COVID-19 “long haulers”—now termed Post-Acute COVID-19 Syndrome. Consequently, we propose that, as SARS-CoV-2 continues to spread and as new clinical challenges related to COVID-19 are documented, oral symptoms should be included in diagnostic and prognostic classifications as well as plans for multidisciplinary care.     

Dental therapy in the United States: Are developments at the state level a reason for optimism or a cause for concern?

Access to dental care continues to be a challenge for millions of vulnerable Americans. In more than 50 nations worldwide, dental therapists (DTs), mid‐level providers who deliver a limited scope of dental care under the supervision of a dentist, have helped increase access to needed care. Since 2003, when the Alaska Native Tribal Health System introduced DTs as part of the Federally authorized Alaska Community Health Aide Program, a total of 13 states have adopted the role. However, as of April 2020, there are fewer than 150 DTs in practice throughout the country, and educational and licensing requirements as well as scope of practice vary between each state. Such heterogeneity makes the training and recruitment of future DTs a challenge. This article summarizes the current state of the DT workforce in the United States and discusses the possible future of the profession as other states contemplate adopting the model in the face of ongoing oral health disparities.     

Interexaminer Agreement in the Radiologic Identification of Apical Periodontitis/Rarefying Osteitis in the National Dental Practice-Based Research Network PREDICT Endodontic Study

IntroductionPeriapical images are routinely made in endodontics to support diagnosis and treatment decisions, but conventional imaging may not readily demonstrate inflammatory changes. This study aims to quantify disagreement in the radiologic interpretation of apical periodontitis/rarefying osteitis between 2 expert examiners and to determine if differences exist based on anatomic location.MethodsWe used 1717 pretreatment periapical images made before orthograde endodontic treatment as part of the Predicting Outcomes of Root Canal Treatment (PREDICT) study conducted within the National Dental Practice-Based Research Network. Periapical changes were assessed independently by 2 board-certified specialists, an oral and maxillofacial radiologist and an endodontist, blinded to other clinical information. If the examiners disagreed about whether a diagnosis of apical periodontitis/rarefying osteitis was justified, an adjudication was made by a third examiner.ResultsThe overall prevalence of this radiologic diagnosis in the periapical images was 55%, and interexaminer agreement measured with the Cohen kappa statistic was calculated to be 0.56 (95% confidence interval, 0.52–0.60). Diagnostic disagreements between the 2 examiners occurred for 377 teeth (22%), with disagreements more frequent for jaw location (P = .038) and tooth type (P = .021). Differences between root number (P = .058) and jaw location and tooth groups (P = .069) were found not to be statistically significant.ConclusionsThe variability of diagnostic disagreements across anatomic location and tooth type may reflect the inability of periapical images to reveal bone changes masked by the complexity and density of overlying anatomic structures, a limitation that could potentially be overcome with the use of 3-dimensional imaging.     

Is the addition of extranodal extension and lymph node yield of pN0 to the lymph node ratio useful as a prognostic parameter for patients with oral squamous cell carcinoma?

We investigated the value of the weighted lymph node ratio (WLNR), a new marker in pN0 patients that incorporates the number of metastatic lymph nodes with extranodal extension and the lymph node yield, for the prognosis and postsurgical management of oral squamous cell carcinoma (OSCC). We designed a retrospective study and enrolled patients with OSCC who were treated by neck dissection (ND). The predictor variable was WLNR, and the outcome variable was overall survival (OS). The Cox proportional-hazards model was used to identify independent prognostic factors. In 133 patients with OSCC, the WLNR cut-off value for predicting OS was 0.0363 (area under the curve 0.723, p<0.001). When stratified according to WLNR, there was a significant difference in OS (88.4% for low WLNR and 63.0% for high WLNR, p<0.001). Univariate analyses showed close associations between OS and age, dissection area, postoperative management, extranodal extension, number of positive lymph nodes, pN stage, WLNR, and nodal disease area. Cox multivariate analysis identified the WLNR as an independent predictive factor for OS (HR 3.273, 95% CI 1.227 to 8.731, p=0.018). As a predictive factor, a high WLNR (≥0.0363) in patients with pN0 disease, which included the addition of extranodal extension and lymph node yield to the LNR, was associated with diminished survival.     

Decreased recurrence of symptoms in oral lichen planus with intralesional injection of hyaluronic acid and triamcinolone

Oral lichen planus (OLP) is a chronic non-infectious, inflammatory, immunological disease. In contrast to skin lesions, which are often self-limiting, oral lesions rarely heal on their own and can be resistant to local and systemic treatments. In this clinical trial, hyaluronic acid (HA) was mixed with triamcinolone for intralesional injection to reduce side effects in the treatment of OLP. This randomized clinical trial with a split-mouth design was performed on 28 patients with OLP. The mouth was divided randomly into two sides: a test side, which received HA combined with triamcinolone, and a control side, which received triamcinolone alone. The rate of symptom recurrence was 74.1% on the control side and 11.1% on the test side (significant difference, P < 0.01). Pain scores did not differ between the two groups when assessed after 2 weeks. The group treated with a combination of HA and triamcinolone experienced a significantly better resolution of lesions and symptoms. Considering the role of HA in tissue healing and in regulating inflammatory responses, as well as its antioxidant and hydration properties, it appears that HA could be effective in improving of OLP and decreasing the rate of symptom recurrence.