Hi doc.....does chewing inside our own mouth cause mouth infection?????

Maybe.: If you break the skin bacteria can infect the lining. Usually not serious since the mouth has such good blood supply and saliva is pretty protective.

It can: If you are chewing on the inside of your mouth, you break down the normal barriers to infection. It would be a good idea to stop this if it is a habit. If you feel that the inside of your mouth is painful, swollen or red, see your doctor or dentist right away,

Infection or worse: A constant irritation to the inside of the mouth can create a precancerous condition or an infection if the tissue is often cut and exposed to mouth bacteria. Try and get the source of the irritation resolved.

Cheek chewing: chewing your cheeks in a bad habit. The risk of infection is low because of he protection from salava. However there are other and possibly more serious consequences of his habit. See a dentist about this.