I have 2 slits in the corners of my mouth what are they and how can i treat them and preventing it from happening again and why do i have them?

Cheillosis: It is called angular cheilosis or cheillitis and is usually cause by iron deficiency, B-vitamin deficiency, dentures, excessive lip licking, diabetes, or immunosuppression. People with celiac disease can also get them. They are usually Candidal yeast infected or Staph or Strep bacterial. You can try lotrimin cream (clotrimazole) found over the counter twice daily.