1. Aphthous ulcers: These are the most common type of oral ulcers and are also known as canker sores. They are small, round or oval-shaped ulcers with a white or yellowish center and a red border. They can be painful and may occur on the inside of the lips, cheeks, or under the tongue.
2. Herpetic ulcers: These ulcers are caused by the herpes simplex virus (HSV) and are commonly known as cold sores or fever blisters. They are fluid-filled blisters that burst and form painful ulcers. Herpetic ulcers typically occur on the lips or around the mouth.
3. Traumatic ulcers: These ulcers are caused by physical injury or trauma to the oral tissues. They can result from accidental biting, burns, sharp objects, or dental procedures. Traumatic ulcers are usually shallow and heal within a week or two.
4. Erosive lichen planus ulcers: Lichen planus is a chronic inflammatory condition that can affect the skin, mucous membranes, and oral cavity. In the oral cavity, lichen planus can cause erosive ulcers characterized by white, lacy patches and painful sores. These ulcers can occur on the gums, tongue, or inner cheeks.
5. Behçet's disease ulcers: Behçet's disease is a rare autoimmune disorder that causes inflammation in various parts of the body, including the mouth. Oral ulcers associated with Behçet's disease are typically large, painful, and recurrent. They can occur on the lips, tongue, or inside the cheeks.