text: help me? sores in my mouth? i have a sore in my mouth (on the inside of my gum. is that normal? and when i move my toung a certian way i have a sore spot on it. what could it be? there are a number of things that could cause a mouth sore such as bacteria, virus, fungal infection, tooth abcess, sharp edge from a a broken tooth or filling could be some of the culprit. if the sore has lasted more than a week after your dentist check it. meanwhile avoid things that irritate it like acidic food (orange juice, lemon juice).also check out american dental association link below for photos of some of the more common mouth sores. http://www.ada.org/public/topics/mouth_sores.asp http://www.nwsmilespecialist.com