Your mouth is a complex structure that includes your gums, tongue, lips, palate, and the inside of your cheeks. Your teeth, which are essential for chewing and smiling, are made up of a visible crown and a root filled with nerves. There are four types of adult teeth: molars, premolars, canines, and incisors. Common mouth problems include canker sores, which are painful ulcers inside the mouth, and cold sores, which are contagious blisters on the lips caused by the herpes virus. Tooth decay occurs when sugars in food create acids that destroy enamel, leading to cavities. Gum disease, such as gingivitis and periodontitis, can cause tooth loss and is linked to other health issues like heart disease. Thrush is a yeast infection in the mouth that causes white patches on the tongue and gums. Tongue fissures are deep cracks that can trap food particles, while geographic tongue causes red, swollen areas that change frequently. Good oral hygiene, including brushing, flossing, and regular dental checkups, is essential for preventing these problems.