Interactions between systemic diseases and oral microbiota shifts in the aging community: A narrative review.

As a gateway to general health and a diverse microbial habitat, the oral cavity is colonized by numerous microorganisms such as bacteria, fungi, viruses, and archaea. Oral microbiota plays an essential role in preserving oral health. Besides, the oral cavity also significantly contributes to systemic health. Physiological aging influences all body systems, including the oral microbial inhabitants. The cited effect can cause diseases by forming dysbiotic communities. Since it has been demonstrated that microbial dysbiosis could disturb the symbiosis state between the host and the resident microorganism, shifting the condition toward a more pathogenic one, this study investigated how the oral microbial shifts in aging could associate with the development or progression of systemic diseases in older adults. The current study focused on the interactions between variations in the oral microbiome and prevalent diseases in older adults, including diabetes mellitus, Sjögren's syndrome, rheumatoid arthritis, pulmonary diseases, cardiovascular diseases, oral candidiasis, Parkinson's disease, Alzheimer's disease, and glaucoma. Underlying diseases can dynamically modify the oral ecology and the composition of its resident oral microbiome. Clinical, experimental, and epidemiological research suggests the associations of systemic disorders with bacteremia and inflammation after oral microbial changes in older adults.

Photodynamic Therapy in Oral Cancer: A Narrative Review.

Methods: A comprehensive search in PubMed, Scopus, and Google Scholar was performed using relevant keywords to structure this narrative review. Only English articles were included and assessed according to titles, abstracts, and full texts. Background: Photodynamic therapy (PDT) is applied for targeting pre-malignancy and malignancies in the head and neck, skin, lungs, and gastrointestinal tract and has been greatly promising in reducing disfigurement and morbidity. This method includes a light-sensitive medicine known as a photosensitizer and a light source used through a minimally invasive surgical tool. Objective: This study aimed to review the application of PDT in managing head and neck cancers (HNCs) and provide an overview of the most recent advances in PDT and its efficiency in increasing the long-term life quality of patients with HNC. Results: The light source irradiates light at an appropriate wavelength that can be absorbed by the sensitizer and produce cytotoxic free radicals that can kill tumor cells, impair microvasculature in the tumor microenvironment, and stimulate further inflammatory responses of the immune system. Patients with either early lesions or advanced disease conveniently accept to receive PDT in outpatient clinics. Therefore, this simple technique is considered a novel and promising approach that can be used either individually or in association with other methods. However, its application as a management method in oral malignancies has yet to be studied. PDT is also suggested as a promising adjuvant treatment with better functional results. Then, it is possible to conclude that PDT's effectiveness in treating various tumors has been shown to depend on the depth of the lesion location. Its safety is acceptable, but its limited irradiation depth confines its application in the advanced stages of cancer. Conclusions: PDT is critically applicable in the early diagnosed cancers and superficial tumors where many heads and neck lesions settle as an ideal candidate for PDT because of the possibility of accurate evaluation of lesions and providing appropriate irradiation at these sites.