Diversity and compositional differences in the oral microbiome of oral squamous cell carcinoma patients and healthy controls: a scoping review

ObjectivesThe human oral microbiome may play a role in the development of oral squamous cell carcinoma. The aim of this scoping review was to examine microbial diversity and differences in the composition of the oral microbiome between OSCC patients and healthy controls.MethodsA literature search (in PubMed and Embase.com) was performed on January 9, 2023. The outcome variables used from the included studies of this review were alpha- and beta diversity and oral microbiome composition profiles for each taxonomic level (phylum-, class-, order-, genus- and species level).ResultsThirteen out of 423 studies were included in this review compromising 1,677 subjects, of which 905 (54.0%) were OSCC patients and 772 (46.0%) were healthy controls. Most studies found a higher alpha diversity in the OSCC patient group and significantly different beta diversities between OSCC patient samples and healthy control samples. Studies reported more abundant Fusobacteria (on phylum level), Fusobacterium (on genus level), Fusobacterium nucleatum, Porphyromonas endodontalis and Prevotella intermedia (on species level) in OSCC patients. The healthy control group had more abundant Actinobacteria (on phylum level), Streptococcus and Veilonella (on genus level) and Veilonella parvula (on species level) according to most studies.ConclusionsOur findings show differences in oral microbiome diversity and composition in OSCC patients. Clinical implications demand continuing study. Development of internationally accepted standard procedures for oral sample collection and oral microbiota analysis is needed for more conclusive and clinically relevant comparisons in future research

Haematopoietic stem cell transplantation and oral complications

De ontwikkeling van nieuwe procedures heeft ertoe geleid dat een hematopoëtische stamceltransplantatie tegenwoordig ook kan worden toegepast bij patiënten die vroeger niet hiervoor in aanmerking kwamen, zoals ouderen. Tevens leiden deze ontwikkelingen tot verschuivingen in het spectrum van complicaties als gevolg van hematopoëtische stamceltransplantatie. In dit artikel komen de belangrijkste principes van hematopoëtische stamceltransplantatie aan de orde en de verschillende orale complicaties die hierbij kunnen optreden: mucositis, infecties, bloedingen, graft-versus-hostziekte, xerostomie, hyposialie, smaakverandering, secundaire tumoren, osteoporose, osteonecrose en groei- en ontwikkelingsstoornissen. Tot slot wordt aandacht besteed aan de rol van mondzorgverleners bij een hematopoëtische stamceltransplantatie.New haematopoietic stem cell transplantation procedures make the treatment available to patients who previously did not qualify, such as the elderly. In addition, the spectrum of oral complications associated with haematopoietic stem cell transplantation has altered as a result of the recent developments. This article is a review of the main principles of haematopoietic stem cell transplantation and provides information on oral complications which may develop, such as mucositis, infections, bleeding, graft-versus-host disease, xerostomia, hyposalivation, altered taste, secondary tumors, osteoporosis, osteonecrosis and growing and developing disturbancies. Finally, the role of dental care providers in cases of haematopoietic stem cell transplantation is addressed.</p

Haematopoietic stem cell transplantation and oral complications

De ontwikkeling van nieuwe procedures heeft ertoe geleid dat een hematopoëtische stamceltransplantatie tegenwoordig ook kan worden toegepast bij patiënten die vroeger niet hiervoor in aanmerking kwamen, zoals ouderen. Tevens leiden deze ontwikkelingen tot verschuivingen in het spectrum van complicaties als gevolg van hematopoëtische stamceltransplantatie. In dit artikel komen de belangrijkste principes van hematopoëtische stamceltransplantatie aan de orde en de verschillende orale complicaties die hierbij kunnen optreden: mucositis, infecties, bloedingen, graft-versus-hostziekte, xerostomie, hyposialie, smaakverandering, secundaire tumoren, osteoporose, osteonecrose en groei- en ontwikkelingsstoornissen. Tot slot wordt aandacht besteed aan de rol van mondzorgverleners bij een hematopoëtische stamceltransplantatie.New haematopoietic stem cell transplantation procedures make the treatment available to patients who previously did not qualify, such as the elderly. In addition, the spectrum of oral complications associated with haematopoietic stem cell transplantation has altered as a result of the recent developments. This article is a review of the main principles of haematopoietic stem cell transplantation and provides information on oral complications which may develop, such as mucositis, infections, bleeding, graft-versus-host disease, xerostomia, hyposalivation, altered taste, secondary tumors, osteoporosis, osteonecrosis and growing and developing disturbancies. Finally, the role of dental care providers in cases of haematopoietic stem cell transplantation is addressed.</p

The Importance of Connexin 43 in Enamel Development and Mineralization

During enamel development, formation of hydroxyapatite crystals and regulation of pH in the enamel matrix require massive transport of ions. Both ameloblasts and adjacent dental epithelial cells in the stellate reticulum co-express several transmembrane cotransporters/ion-exchangers for transport of ions across plasma membranes. Gap junctions (GJs) enable intercellular exchanges of ions between neighboring cells. This suggests that the ameloblasts and other cell layers of the enamel organ, form a functional unit. During the bell stage of tooth formation, the non-ameloblast dental epithelium highly expresses the Na-K-Cl cotransporter (Nkcc1). Nkcc1-null mice are associated with enamel hypomineralization and increased expression of GJ protein connexin 43 (Cx43), suggesting that reduced ion transport in the Nkcc1-null mouse is in part compensated by increased intercellular ion transport through GJs. To understand the role of GJs in ion transport and its effect on pH regulation, we examined in a mouse strain in which Cx43 was ablated selectively in DMP1 expressing cells (Cx43flox/flox mice crossed with DMP1-8kb-Cre mice), including ameloblasts. Micro-CT analysis showed that the mineral density at late maturation stage incisal enamel of the Cx43-null mice was 10% less than in controls, whereas that in dentin was unchanged. Maturation stage ameloblasts of mice lacking the pH regulating sodium/bicarbonate transporter NBCe1 (Nbce1-null), or chloride channel Cftr (Cftr-null) were found to have increased Cx43-immunostaining. These results support the possibility that GJs in the ameloblast–papillary complex at the maturation stage contribute to ion transport by enabling passage of ions directly from cells of the papillary layer into ameloblast layer. Increasing the number of GJs may partly compensate the reduction of ion-cotransporters and ion exchangers in dental epithelium

Risk factors for oral mucositis in paediatric oncology patients receiving alkylant chemotherapy

BACKGROUND: We describe the risk indicators for oral mucositis (OM) in paediatric oncology patients hospitalised in the Institut Gustave Roussy (Villejuif-Paris) and treated with alkylant chemotherapy with autologous peripheral blood progenitor cells. METHODS: The sample was selected using PIGAS software. Three groups of subjects received different chemotherapy regimens: A. Melphalan, B. Busulfan and C. other alkylant protocols. The degree of mucositis was recorded by CTC version 2.0 (Common Toxicity Criteria). Descriptive statistics were performed. The association between mucositis and risk indicator variables was tested using a χ(2 )test. The association between case status and covariates was tested using unconditional logistic regression analysis. RESULTS: Of the 337 children enrolled, 241 showed mucositis (group 1) and 96 did not show mucositis (group 2) during alkylant chemotherapy. There was a higher prevalence of male patients in both groups. The three different chemotherapy regimen groups are correlated with the appearance of oral mucositis (χ(2 )= 22.42, p < 0.01). Weight loss was higher in group 1 (χ(2 )= 6.31, p = 0.01). The duration of aplasia was lower in the Busulfan protocol (7.5 days) than in the Melphalan group (9.3 days) or the other regimens (8.6 days). The use of Bufulfan(® )was directly associated with case status (presence of oral mucositis): odds ratio [OR] = 2.1 and confidence interval [95%CI] = 1.3–3.0. Also, occurrences of germinal tumours and secondary bacterial infections were directly linked with case status: [OR] = 1.4 and 1.8, confidence interval [95%CI] = 1.2 – 1.7 and 1.1 – 2.5, respectively. CONCLUSION: The presence of OM was associated with the three different chemotherapy regimens considered; in particularly patients treated with Busulfan had the highest prevalence

MASCC/ISOO clinical practice guidelines for the management of mucositis secondary to cancer therapy.

BACKGROUND: Mucositis is a highly significant, and sometimes dose-limiting, toxicity of cancer therapy. The goal of this systematic review was to update the Multinational Association of Supportive Care in Cancer and International Society of Oral Oncology (MASCC/ISOO) Clinical Practice Guidelines for mucositis. METHODS: A literature search was conducted to identify eligible published articles, based on predefined inclusion/exclusion criteria. Each article was independently reviewed by 2 reviewers. Studies were rated according to the presence of major and minor flaws as per previously published criteria. The body of evidence for each intervention, in each treatment setting, was assigned a level of evidence, based on previously published criteria. Guidelines were developed based on the level of evidence, with 3 possible guideline determinations: recommendation, suggestion, or no guideline possible. RESULTS: The literature search identified 8279 papers, 1032 of which were retrieved for detailed evaluation based on titles and abstracts. Of these, 570 qualified for final inclusion in the systematic reviews. Sixteen new guidelines were developed for or against the use of various interventions in specific treatment settings. In total, the MASCC/ISOO Mucositis Guidelines now include 32 guidelines: 22 for oral mucositis and 10 for gastrointestinal mucositis. This article describes these updated guidelines. CONCLUSIONS: The updated MASCC/ISOO Clinical Practice Guidelines for mucositis will help clinicians provide evidence-based management of mucositis secondary to cancer therapy

Swallowing dysfunction in cancer patients

Purpose Dysphagia (swallowing dysfunction) is a debilitating, depressing, and potentially life-threatening complication in cancer patients that is likely underreported. The present paper is aimed to review relevant dysphagia literature between 1990 and 2010 with a focus on assessment tools, prevalence, complications, and impact on quality of life in patients with a variety of different cancers, particularly in those treated with curative chemoradiation for head and neck cancer. Methods The literature search was limited to the English language and included both MEDLINE/PubMed and EMBASE. The search focused on papers reporting dysphagia as a side effect of cancer and cancer therapy. We identified relevant literature through the primary literature search and by articles identified in references. Results A wide range of assessment tools for dysphagia was identified. Dysphagia is related to a number of factors such as direct impact of the tumor, cancer resection, chemotherapy, and radiotherapy and to newer therapies such as epidermal growth factor receptor inhibitors. Concomitant oral complications such as xerostomia may exacerbate subjective dysphagia. Most literature focuses on head and neck cancer, but dysphagia is also common in other types of cancer. Conclusions Swallowing impairment is a clinically relevant acute and long-term complication in patients with a wide variety of cancers. More prospective studies on the course of dysphagia and impact on quality of life from baseline to long-term follow-up after various treatment modalities, including targeted therapies, are needed