Smoking produces smoke which is drawn directly into the mouth. Approximately 4000 chemicals, 60 of which are carcinogenic, have been identified in this smoke. These include carbon monoxide, hydrogen cyanide and reactive oxidising radicals.
Some problems caused by smoking are obvious, such as stained teeth and bad breath. However, smoking is one of the greatest and most preventable risk factors for more severe oral disease including oral cancer, mouth lesions, gum disease, tooth decay, and cleft lip and palate.