when you look up the following in your coding book
swelling
- mouth
you get code 784.2
Also called the oral cavity, the mouth is the first part of the gastrointestinal tract (or alimentary canal). The boundaries of the mouth are formed by the lips, cheeks, floor of the mouth, and palate. The mouth contains the teeth and tongue and receives secretions from the salivary glands. It performs three main functions, which have to do with digestion, breathing, and speech
hope this helps explain why 784.2 would be appropriate code.