Ans.Bad breath is also called halitosis. It is a common problem and caused by the build-up of bacteria in the mouth. It is persistence, unpleasant smell in exhaled breath, generally not serious but still not easy to live with.

Bad breath can be because of following causes:

• Food: Some kind of food may produce odour after eating, for example, garlic, onion, cheese, fish, sodas, coffee, and alcohol often leave behind traces of odour until they are flushed out from the body.
• Plaque formation: it is a yellowish/colourless thin film on the tooth surface and gums. Actually, it is a layer of bacteria and occurs due to poor oral hygiene.
• Dry mouth: also called xerostomia, it is a medical condition where mouth becomes dry out due to insufficient saliva and dehydration. It can happen due to fasting, diet control, intake of certain medicine and habit of sleeping with an open mouth. Saliva production almost stops during sleeping that why we get a bad morning breath.
• Smocking and tobacco chewing: the chemical in it causes the drying of the mouth and leads to heavy bad breath.
• Health issues, infections and allergies: infections like decay, gum disease, sinus infection, cough and cold, diabetes, digestion issues, respiratory infections, liver and kidney disease, dehydration etc. often lead to bad breath.

Braces and denture: Due to braces, oral hygiene is compromised and causes bacterial infections and leaves behind an odour.