Oral fungal infections can be caused by certain species of fungi among which candida albicans is the most implicated. Oral candidiasis is correlated with multiple conditions, such as coronavirus disease-2019, oral leukoplakia and oral erythroplakia. Tenascin is a glycoprotein and is present at the site of tissue injury and chronic inflammation, and tends to be over-expressed in cases of malignancy. Matrix metalloproteinase-9 belongs to a family of zinc-dependent endopeptidases and is involved in the degradation of extracellular matrix, leading to tissue invasion and metastasis. The current narrative review was planned to shed light on the fungal co-infections of coronavirus disease-2019 and molecular mechanisms of matrix metalloproteinase-9 and tenascin involved in the pathogenesis of fungus-associated oral leukoplakia and oral erythroplakia. Key Words: Oral, fungal, COVID-19, Tenascin, MMP-9.

<p>Diabetes mellitus is a disorder of the metabolic system that is diagnosed by hyperglycemia and glucose intolerance. Diabetic patients are frequently prone to developing oral health complications, such as being at a higher risk for developing oral precancerous conditions like lichen planus, leukoplakia, and erythroplakia. Insulin-like growth factor-I (IGF-I) is a peptide hormone with a structure similar to insulin and belongs to the family of growth factors that play a vital role in the development of embryonic, postembryonic, and normal physiological functions of the human body. IGF-I, through autophosphorylation of its receptor, activates the mitogen-activated protein kinases pathway that leads to the expression of IGF-I hormone. In oral premalignant conditions, like lichen planus, submucous fibrosis, leukoplakia, and erythroplakia, the levels of the IGF-I hormone are increased. Subsequently, IGF-I can be used as a marker for early detection of malignancy in oral premalignant lesions.</p>