A buccal smear is a diagnostic procedure in which cells are gently collected from the inner lining of the cheek (buccal mucosa) using a sterile spatula, brush, or swab. The collected cells are then spread onto a glass slide, fixed, and stained for microscopic examination. This test is used to evaluate the cellular morphology of the oral mucosa, detect infections, assess epithelial changes, screen for precancerous or cancerous lesions, and monitor systemic diseases.