Poor oral hygiene is a big contributor to gastrointestinal cancer. Oral environment is affected by dental plaque, tarter, teeth alignment, occlusion, prosthesis, bad lifestyle, systematic factors obesity, stress, heredity and eating habits. Poor oral hygiene led to periodontal diseases such as gingivitis, tooth loss, clinical attachment loss, pocket formation and weak periodontium such as alveolar bone. This provides perfect conditions for the growth of certain dominant destructive bacteria in high quantities which activate the inflammatory process hence lead to cancerous growth in cells.