Wisdom teeth are types of molars found in the very back of your mouth. These teeth usually appear in late teens or early twenties but may become impacted (fail to erupt) due to lack of room in the jaw or angle of entry. When a wisdom tooth is impacted, it may need to be removed. If it is not removed, you may develop gum tenderness, swelling, or even severe pain. Impacted wisdom teeth that are partially or fully erupted tend to be quite difficult to clean and are susceptible to tooth decay, recurring infections, and even gum disease.