👉 Tenontitis is a bacterial infection that occurs in the mouth, particularly on the tongue and palate. It is caused by the bacterium Streptococcus pyogenes, which can also cause infections of other areas of the body such as the lungs. Symptoms of tenontitis include redness, swelling, pain, and tenderness in the area around the gum line. Treatment usually involves antibiotics to help fight off the bacteria that cause the infection.