ISOLATION AND IDENTIFICATION OF ORAL MICROBIOTA IN HEAD AND NECK CANCER PATIENTS BEFORE AND AFTER RADIOTHERAPY

Head and neck cancer (HNC) is one of the most common malignancies worldwide and is associated with significant oral complications following radiotherapy. Radiotherapy alters the oral environment by reducing salivary flow, changing oral pH, and disrupting the normal microbial ecosystem, thereby increasing the risk of dental caries and opportunistic infections. The present hospital-based analytical study evaluated changes in oral microflora and dental problems in head and neck cancer patients before and after radiotherapy. Twenty patients diagnosed with HNC were recruited after informed consent. Oral swabs were collected from the buccal mucosa, tongue, and dental plaque before and after radiotherapy. Samples were cultured on nutrient agar, and bacterial isolates were identified using Gram staining and biochemical tests. Dental status was assessed using the Decayed, Missing, and Filled Surfaces (DMFS) index. Healthy individuals were included for comparison. The predominant microorganisms isolated were Streptococcus mitis, Streptococcus mutans, Ligilactobacillus salivarius, Staphylococcus aureus, Staphylococcus epidermidis, Micrococcus luteus, Actinomyces spp., Proteus vulgaris, and Bacillus subtilis. Candida species were isolated from two patient samples. A reduction in bacterial colony counts after radiotherapy and an increase in DMFS scores in most patients indicated deterioration of oral health following treatment. These findings emphasize the importance of preventive dental care, maintenance of oral hygiene, and microbiological monitoring in patients undergoing radiotherapy.