Simultaneous presentation of dual pathologies within the oral cavity: an unusual and diagnostically challenging presentation.

Necrotising sialometaplasia (NS) is a rare condition, with a limited scientific evidence base regarding its aetiology and pathophysiology. Diagnosing NS demands extensive investigatory tests. Their accuracy is vital in order to exclude oral malignancy and prevent unwarranted, invasive management.Within Birmingham Dental Hospital, a 22-year-old, South Asian woman presented with generalised pain from the lower right third molar extending to involve the palate, to which the patient's general medical practitioner previously attributed to a viral upper respiratory infection. Clinical examination revealed bilateral erythematous: non-ulcerated, palatal swellings (10 mm x 5 mm) at the greater palatine foramina. Following extensive investigations, the challenging definitive diagnoses of two distinct pathologies were made: non-ulcerative NS and pericoronitis.This case report describes the successful diagnosis and management of non-ulcerating NS, an 'atypical' presentation of a rare condition, that was confounded by a simultaneous episode of pericoronitis - a presentation not previously documented within scientific literature.

Quorum Sensing in Oral Biofilms: Influence on Host Cells.

Quorum sensing molecules (QSMs) in the oral cavity regulate biofilm formation, the acquisition of iron, stress responses, and the expression of virulence factors. However, knowledge of the direct QSM-host interactions in the oral environment is limited, although their understanding could provide greater insight into the cross-kingdom communication occurring during oral disease development. This review aims to explore the literature on oral QSM-host interactions and to highlight areas of advancement in this field. The studies included in this review encompass an array of cell types and oral QSMs, with particular emphasis on immune cells and their relationship to periodontal diseases. It can be inferred from the current literature that QSMs are utilised by host cells to detect bacterial presence and, in the majority of cases, elicit an immune response towards the environmental QSMs. This may provide a base to target QSMs as a novel treatment of oral diseases. However, N-acyl homoserine lactone (AHL) detection methods remain an area for development, through which a greater understanding of the influence of oral QSMs on host cells could be achieved.

Under pressure-mechanisms and risk factors for orthodontically induced inflammatory root resorption: a systematic review.

BACKGROUND: The application of orthodontic forces causes root resorption of variable severity with potentially severe clinical ramifications. OBJECTIVE: To systematically review reports on the pathophysiological mechanisms of orthodontically induced inflammatory root resorption (OIIRR) and the associated risk factors based on in vitro, experimental, and in vivo studies. SEARCH METHODS: We undertook an electronic search of four databases and a separate hand-search. SELECTION CRITERIA: Studies reporting on the effect of orthodontic forces with/without the addition of potential risk factors on OIIRR, including (1) gene expression in in-vitro studies, the incidence root resorption in (2) animal studies, and (3) human studies. DATA COLLECTION AND ANALYSIS: Potential hits underwent a two-step selection, data extraction, quality assessment, and systematic appraisal performed by duplicate examiners. RESULTS: One hundred and eighteen articles met the eligibility criteria. Studies varied considerably in methodology, reporting of results, and variable risk of bias judgements.In summary, the variable evidence identified supports the notion that the application of orthodontic forces leads to (1) characteristic alterations of molecular expression profiles in vitro, (2) an increased rate of OIIRR in animal models, as well as (3) in human studies. Importantly, the additional presence of risk factors such as malocclusion, previous trauma, and medications like corticosteroids increased the severity of OIIRR, whilst other factors decreased its severity, including oral contraceptives, baicalin, and high caffeine. CONCLUSIONS: Based on the systematically reviewed evidence, OIIRR seems to be an inevitable consequence of the application of orthodontic forces-with different risk factors modifying its severity. Our review has identified several molecular mechanisms that can help explain this link between orthodontic forces and OIIRR. Nevertheless, it must be noted that the available eligible literature was in part significantly confounded by bias and was characterized by substantial methodological heterogeneity, suggesting that the results of this systematic review should be interpreted with caution. REGISTRATION: PROSPERO (CRD42021243431).

The role of the host-Neutrophil biology.

Neutrophilic polymorphonuclear leukocytes (neutrophils) are myeloid cells packed with lysosomal granules (hence also called granulocytes) that contain a formidable antimicrobial arsenal. They are terminally differentiated cells that play a critical role in acute and chronic inflammation, as well as in the resolution of inflammation and wound healing. Neutrophils express a dense array of surface receptors for multiple ligands, ranging from integrins to support their egress from bone marrow into the circulation and from the circulation into tissues, to cytokine/chemokine receptors that drive their navigation to the site of infection or tissue damage and also prime them for a second stimulus, to pattern recognition receptors and immunoglobulin receptors to facilitate the destruction and removal of infective agents or debridement of damaged tissues. When afferent neutrophil signals are proportionate and coordinated they will phagocytose opsonized and unopsonized bacteria, activating the nicotinamide adenine dinucleotide phosphate oxidase (respiratory burst) to generate reactive oxygen species, which augment the proteolytic destruction of microbes secured within the phagosome. A highly orchestrated process of apoptosis follows, forming membrane-bound substructures that are removed by macrophages. Neutrophils are capable of various other forms of programmed cell death, such as NETosis and pyroptotic cell death, as well as nonprogrammed cell death by necrosis. In recent years, research has revealed that neutrophils are capable of far more subtle cell-cell interactions than previously thought possible. This includes synthesis of various inflammatory mediators and also myeloid cell training within bone marrow, where epigenetic and metabolic signals associated with returning neutrophils that undergo reverse egress from tissues into the vasculature and back to bone marrow program a hyperreactive subset of neutrophils during myelopoiesis that are capable of hypersensitive reactions to microbial aggressors. These characteristics are evident in various neutrophil subsets/subpopulations, creating broad heterogeneity in the behavior and biological repertoire of these seemingly schizophrenic immune cells. Moreover, neutrophils are critical effector cells of adaptive and innate immunity, binding to opsonized bacteria and destroying them by extracellular and intracellular methods. The former creates substantial collateral host tissue damage, as they are less specific than T-cytotoxic cell-killing mechanisms, and in conditions such as peri-implantitis, where plasma cells and neutrophils dominate the immune infiltrate, bone and tissue destruction are rapid and appear relentless. Finally, the role of neutrophils as conduits for periodontal-systemic disease connections and for oxidative damage to act as a causal link between the two has only recently been realized. In this chapter, we attempt to expand on these issues, emphasizing the contributions of European scientists throughout a detailed appraisal of the benefits and side effects of neutrophilic inflammation and immune function.

Current concepts in the pathogenesis of periodontitis: from symbiosis to dysbiosis.

The primary etiological agent for the initiation and progression of periodontal disease is the dental plaque biofilm which is an organized aggregation of microorganisms residing within a complex intercellular matrix. The non-specific plaque hypothesis was the first attempt to explain the role of the dental biofilm in the pathogenesis of periodontal diseases. However, the introduction of sophisticated diagnostic and laboratory assays has led to the realisation that the development of periodontitis requires more than a mere increase in the biomass of dental plaque. Indeed, multispecies biofilms exhibit complex interactions between the bacteria and the host. In addition, not all resident microorganisms within the biofilm are pathogenic, since beneficial bacteria exist that serve to maintain a symbiotic relationship between the plaque microbiome and the host's immune-inflammatory response, preventing the emergence of pathogenic microorganisms and the development of dysbiosis. This review aims to highlight the development and structure of the dental plaque biofilm and to explore current literature on the transition from a healthy (symbiotic) to a diseased (dysbiotic) biofilm in periodontitis and the associated immune-inflammatory responses that drive periodontal tissue destruction and form mechanistic pathways that impact other systemic non-communicable diseases.

Pre-conditioning of gingival epithelial cells with sub-apoptotic concentrations of curcumin prevents pro-inflammatory cytokine release.

BACKGROUND AND OBJECTIVE: Plaque-induced gingival inflammation (gingivitis) is ubiquitous in humans. The epithelial barrier reacts to the presence of oral bacteria and induces inflammatory cascades. The objective of this study was to investigate the mechanism by which the small molecule micronutrient curcumin could decrease inflammatory response in vitro to oral bacterium heat-killed Fusobacterium nucleatum as curcumin could be a useful compound for combatting gingivitis already consumed by humans. METHODS: H400 oral epithelial cell line was pre-conditioned with curcumin and the production of cytokines was measured by enzyme-linked immunosorbent assay (ELISA) and translocation of transcription factors was used to monitor inflammatory responses. Haem oxygenase (HO-1) expression and molecules that HO-1 releases were evaluated for their potential to reduce the quantity of cytokine production. Immunofluorescence microscopy and Western blotting were used to evaluate changes in transcription factor and enzyme location. RESULTS: Pre-conditioning of H400 cells with a sub-apoptotic concentration of curcumin (20 µM) attenuated secretion of Granulocyte-Macrophage - Colony-Stimulating Factor (GM-CSF) and reduced NFkB nuclear translocation. This pre-conditioning caused an increase in nuclear Nrf2; an initial drop (at 8 h) followed by an adaptive increase (at 24 h) in glutathione; and an increase in haem oxygenase (HO-1) expression. Inhibition of HO-1 by SnPPIX prevented the curcumin-induced attenuation of GM-CSF production. HO-1 catalyses the breakdown of haem to carbon monoxide, free iron and biliverdin: the HO-1/CO anti-inflammatory pathway. Elevations in carbon monoxide, achieved using carbon monoxide releasing molecule-2 (CORM2) treatment alone abrogated F. nucleatum-induced cytokine production. Biliverdin is converted to bilirubin by biliverdin reductase (BVR). This pleiotropic protein was found to increase in cell membrane expression upon curcumin treatment. CONCLUSION: Curcumin decreased inflammatory cytokine production induced by Fusobacterium nucleatum in H400 oral epithelial cells. The mechanism of action appears to be driven by the increase of haem oxygenase and the production of carbon monoxide.

Antioxidant Micronutrients and Oxidative Stress Biomarkers.

Chronic inflammatory diseases are the major causes of mortality in humans and recent research has improved our understanding of the major impact of lifestyle factors upon inflammatory diseases and conditions. One of the most influential of these is nutrition, which may drive both pro-inflammatory as well as anti-inflammatory cascades at molecular and cellular levels. There are a variety of model systems that may be employed to investigate the impact of micronutrients and macronutrients upon inflammatory pathways, many of which operate through oxidative stress, either at the level of controlling the redox state of the cell and downstream redox-regulated gene transcription factors, and other acting as free radical generating or scavenging agents. This chapter focuses upon biological sample preparation prior to assay and details methods for analyzing certain antioxidant micronutrients and biomarkers of oxidative stress.

Oral Epithelial Cell Culture Model for Studying the Pathogenesis of Chronic Inflammatory Disease.

The interactions between bacteria, epithelium, and neutrophilic polymorphonuclear leukocytes (neutrophils) are the key to the initiation and progression of many chronic inflammatory-immune diseases. In addition, all can be influenced by external factors, such as micronutrients, thereby providing potentially novel approaches to therapy. This chapter will therefore provide detailed methods for core techniques involved in studying cellular and molecular epithelial responses to a bacterial challenge in relation to chronic inflammatory disease pathogenesis and therapy.

Characterization, Quantification, and Visualization of Neutrophil Extracellular Traps.

Following the discovery of neutrophil extracellular traps (NETs) in 2004 by Brinkmann and colleagues, there has been extensive research into the role of NETs in a number of inflammatory diseases, including periodontitis. This chapter describes the current methods for the isolation of peripheral blood neutrophils as well as of oral neutrophils for subsequent NET experiments, including approaches to quantify and visualize NET production, the ability of NETs to entrap and kill bacteria, and the removal of NETs by nuclease-containing plasma.

Impact of Gingivitis on Circulating Neutrophil Reactivity and Gingival Crevicular Fluid Inflammatory Proteins.

Gingivitis is an extremely common oral inflammatory condition and can be induced in humans using an acute 21-day experimental gingivitis model. Neutrophils are known to be highly prevalent in the gingival crevice during gingival inflammation; however, the effect of gingivitis and the associated biofilm on peripheral blood neutrophils (PBN) is not well characterised. Thus, the aim of this study was to examine the impact of inflammation induced by experimental gingivitis and its resolution upon the function of PBN. Fifteen systemically healthy volunteers undertook a split-mouth 21-day experimental gingivitis study followed by a resolution phase of 14 days. PBN function, including reactive oxygen species (ROS) production, neutrophil extracellular trap (NET) release, directional chemotactic accuracy and expression of host mediators in gingival crevicular fluid (GCF), were measured at baseline (day 0), on day 21 and on day 35. NET formation and ROS production were significantly elevated at day 21. Chemotactic speed was also elevated in response to bacterial peptide fMLP at day 21. At day 35, ROS production in response to an Fcgamma stimulant, opsonised Staphylococcus aureus, remained elevated. The data presented suggest a lasting biological impact of the experimental gingivitis on PBN function even after clinical symptoms have abated.

Discovery, validation, and diagnostic ability of multiple protein-based biomarkers in saliva and gingival crevicular fluid to distinguish between health and periodontal diseases.

AIM: To discover and validate differential protein biomarker expression in saliva and gingival crevicular fluid (GCF) to discriminate objectively between periodontal health and plaque-induced periodontal disease states. MATERIALS AND METHODS: One-hundred and ninety participants were recruited from two centres (Birmingham and Newcastle upon Tyne, UK) comprising healthy, gingivitis, periodontitis, and edentulous donors. Samples from the Birmingham cohort were analysed by quantitative mass spectrometry proteomics for biomarker discovery. Shortlisted candidate proteins were then verified by enzyme-linked immunosorbent assay in both cohorts. Leave-one-out cross validation logistic regression analysis was used to identify the best performing biomarker panels. RESULTS: Ninety-five proteins were identified in both GCF and saliva samples, and 15 candidate proteins were selected based upon differences discovered between the donor groups. The best performing panels to distinguish between: health or gingivitis and periodontitis contained matrix metalloproteinase-9 (MMP9), S100A8, alpha-1-acid glycoprotein (A1AGP), pyruvate kinase, and age (area under the curve [AUC] 0.970); health and gingivitis contained MMP9, S100A8, A1AGP, and pyruvate kinase, but not age (AUC 0.768); and mild to moderate and advanced periodontitis contained MMP9, S100A8, A1AGP, pyruvate kinase, and age (AUC 0.789). CONCLUSIONS: Biomarker panels containing four proteins with and without age as a further parameter can distinguish between periodontal health and disease states.

Fusobacterium nucleatum Subspecies Differ in Biofilm Forming Ability in vitro.

Development of dysbiosis in complex multispecies bacterial biofilms forming on teeth, known as dental plaque, is one of the factors causing periodontitis. Fusobacterium nucleatum (F. nucleatum) is recognised as a key microorganism in subgingival dental plaque, and is linked to periodontitis as well as colorectal cancer and systemic diseases. Five subspecies of F. nucleatum have been identified: animalis, fusiforme, nucleatum, polymorphum, and vincentii. Differential integration of subspecies into multispecies biofilm models has been reported, however, biofilm forming ability of individual F. nucleatum subspecies is largely unknown. The aim of this study was to determine the single-subspecies biofilm forming abilities of F. nucleatum ATCC type strains. Static single subspecies F. nucleatum biofilms were grown anaerobically for 3 days on untreated or surface-modified (sandblasting, artificial saliva, fibronectin, gelatin, or poly-L-lysine coating) plastic and glass coverslips. Biofilm mass was quantified using crystal violet (CV) staining. Biofilm architecture and thickness were analysed by scanning electron microscopy and confocal laser scanning microscopy. Bioinformatic analysis was performed to identify orthologues of known adhesion proteins in F. nucleatum subspecies. Surface type and treatment significantly influenced single-subspecies biofilm formation. Biofilm formation was overall highest on poly-L-lysine coated surfaces and sandblasted glass surfaces. Biofilm thickness and stability, as well as architecture, varied amongst the subspecies. Interestingly, F. nucleatum ssp. polymorphum did not form a detectable, continuous layer of biofilm on any of the tested substrates. Consistent with limited biofilm forming ability in vitro, F. nucleatum ssp. polymorphum showed the least conservation of the adhesion proteins CmpA and Fap2 in silico. Here, we show that biofilm formation by F. nucleatum in vitro is subspecies- and substrate-specific. Additionally, F. nucleatum ssp. polymorphum does not appear to form stable single-subspecies continuous layers of biofilm in vitro. Understanding the differences in F. nucleatum single-subspecies biofilm formation may shed light on multi-species biofilm formation mechanisms and may reveal new virulence factors as novel therapeutic targets for prevention and treatment of F. nucleatum-mediated infections and diseases.

Prognostic performance of the 2017 World Workshop classification on staging and grading of periodontitis compared with the British Society of Periodontology's implementation.

BACKGROUND: The British Society of Periodontology (BSP) implemented a simplified version of the 2017 World Workshop Classification (WWC) on staging and grading of periodontitis, for use in UK clinical practice. The aim of this study was to assess the long-term (>10 years) prognostic capability of BSP's implementation (BSP-i) compared with the 2017 WWC, using periodontal-related tooth loss (TLP) as a disease outcome. METHODS: Data on medical history, smoking status, and clinical periodontal parameters were retrieved from 270 patients who received non-surgical and surgical periodontal therapy from 1966 to 2007. Each patient received a baseline diagnosis according to the 2017 WWC and the BSP-i guidelines for implementation. Univariate multilevel Cox regression frailty models were performed to analyze the association between variables with TLP. A post-hoc comparison with Bonferroni correction was performed to analyze interclass comparisons. The prognostic performance of both systems was analyzed using Harrell C index. RESULTS: The prognostic performance of both systems was very similar (0.922 for the 2017 WWC and 0.925 for the BSP-i). The singular prognostic performance of BSP stage was slightly higher than that of 2017 WWC stage (0.9212 versus 0.9188), while the 2017 WWC grade showed a slightly better performance than BSP grade (0.9175 versus 0.9155). BSP-i's extent performed better than the 2017 WWC extent (0.9203 versus 0.9098); however, in the 2017 WWC extent, the class "localized" was associated with a better prognosis than "generalized." CONCLUSION: The overall prognostic performance of the two systems was excellent, with both systems having a Harrell C index score of >0.92.

Patient acceptability of targeted risk-based detection of non-communicable diseases in a dental and pharmacy setting.

BACKGROUND: Non-communicable diseases [NCDs] are the major cause of mortality globally and are increasing in prevalence. Different healthcare professionals' access different population groups; and engaging allied healthcare professionals in risk-driven early case detection of certain NCDs may be beneficial, especially those who have not been tested for NCDs within the previous 12 months. The objectives of this study were to determine: whether NCD case finding in dental/community pharmacy settings is feasible in terms of patient acceptability, barriers to recruitment, impact on the existing service. Determine time taken to test for: type 2 diabetes risk [T2DM], chronic obstructive pulmonary disease [COPD], hypertension, vitamin D deficiency and chronic kidney disease [CKD]. Determine whether there is added benefit of point of care testing [POCT] to identify diabetes risk compared to a validated screening questionnaire alone. METHODS: An exploratory study was undertaken to explore issues associated with NCD assessment in one dental practice and one community pharmacy within the West-Midlands, UK. Fifty patients > 40 years-of-age were recruited per site. Participants undertook: a questionnaire providing demographic data, any previous NCD diagnosis or positive family history. Validated questionnaires for determining NCD risk [T2DM/COPD]. Chair-side capillary blood [finger-prick] samples for HbA1C, creatinine/eGFR, Vitamin-D. Prior work had been undertaken to measure the agreement between point of care testing [POCT] devices and a central laboratory method, and to gauge the opinions of participants regarding discomfort experienced using venous (antecubital fossa) and capillary (finger-prick) blood collection, via a 10 cm Visual-Analogue-Scale. The POCT devices demonstrated good concordance with laboratory testing and were acceptable methods of blood collection for participants. RESULTS: Recruitment rates demonstrated that 8 days were needed to recruit 50 participants and 60% of those approached opted to participate. The principal barrier to participation was time, with average time taken to test being 19mins. Utilising dental and pharmacy settings identified potential cases of previously undiagnosed disease. CONCLUSIONS: Risk-targeted testing for NCDs in high street dental and community pharmacies is both attractive and acceptable to patients.

Epidermolysis bullosa.

Epidermolysis bullosa (EB) is an inherited, heterogeneous group of rare genetic dermatoses characterized by mucocutaneous fragility and blister formation, inducible by often minimal trauma. A broad phenotypic spectrum has been described, with potentially severe extracutaneous manifestations, morbidity and mortality. Over 30 subtypes are recognized, grouped into four major categories, based predominantly on the plane of cleavage within the skin and reflecting the underlying molecular abnormality: EB simplex, junctional EB, dystrophic EB and Kindler EB. The study of EB has led to seminal advances in our understanding of cutaneous biology. To date, pathogenetic mutations in 16 distinct genes have been implicated in EB, encoding proteins influencing cellular integrity and adhesion. Precise diagnosis is reliant on correlating clinical, electron microscopic and immunohistological features with mutational analyses. In the absence of curative treatment, multidisciplinary care is targeted towards minimizing the risk of blister formation, wound care, symptom relief and specific complications, the most feared of which - and also the leading cause of mortality - is squamous cell carcinoma. Preclinical advances in cell-based, protein replacement and gene therapies are paving the way for clinical successes with gene correction, raising hopes amongst patients and clinicians worldwide.

Systemic disease or periodontal disease? Distinguishing causes of gingival inflammation: a guide for dental practitioners. Part 2: cancer related, infective, and other causes of gingival pathology.

Periodontitis and gingivitis are highly prevalent inflammatory diseases of the oral cavity, and typically are characterised by the presence of dental plaque. However, other causes of oral inflammation exist, which can resemble plaque-induced gingivitis and periodontitis, and may thus first be seen by a dental practitioner. This paper aims to provide dentists with an understanding of the manifestations of systemic diseases to the periodontium and highlights anamnestic and clinical clues important for distinguishing between plaque-induced and non plaque-induced lesions. In the first part of this series immune-mediated and hereditary conditions as causes of gingival lesions were discussed; this second part highlights cancer-related gingival lesions as well as those caused by specific pathogens, medication or malnutrition. A clear clinical, epidemiological and visual overview of the different conditions is provided. Early diagnosis of non plaque-related causes of gingival lesions can be vital for affected patients. Therefore, dental practitioners should be aware of the various manifestations of systemic diseases to the periodontium.

Systemic disease or periodontal disease? Distinguishing causes of gingival inflammation: a guide for dental practitioners. Part 1: immune-mediated, autoinflammatory, and hereditary lesions.

Periodontitis and gingivitis remain two of the most common diseases that affect the oral cavity. As they are caused by plaque, effective oral hygiene, elimination of plaque-retentive factors and successful periodontal treatment will result in resolution of gingival and periodontal inflammation. Certain systemic diseases can have a clinical appearance similar to periodontal diseases or exacerbate existing periodontitis/gingivitis and vice versa. This paper aims to provide the dental practitioner with an understanding of the manifestations of systemic diseases to the periodontium and highlights elements in the clinical assessment, which will aid in establishing a correct diagnosis. Additional anamnestic and clinical clues are important for distinguishing between plaque-induced and non-plaque-induced lesions. The first part of this compendium covers immune-mediated and hereditary conditions as causes of gingival lesions, which can resemble those caused by dental plaque. The different conditions are presented concisely and exemplified by clinical photographs. Dental practitioners should be aware of the various manifestations of systemic diseases to the periodontium in order to offer appropriate diagnosis and treatment, which can reduce both patient morbidity and mortality.