Ameloblastoma

Overview

Ameloblastoma is a rare, noncancerous (benign) tumor that develops most often in the jaw near the molars. Ameloblastoma begins in the cells that form the protective enamel lining on your teeth.

The most common type of ameloblastoma is aggressive, forming a large tumor and growing into the jawbone. Treatment may include surgery and radiation. In some cases, reconstruction may be necessary to restore your teeth, jaw and facial appearance. Some types of ameloblastoma are less aggressive.

Though ameloblastoma is most often diagnosed in adults in their 30s through 60s, ameloblastoma can occur in children and young adults.

Symptoms

Ameloblastoma often causes no symptoms, but signs and symptoms may include pain and a lump or swelling in the jaw.

If left untreated, the tumor can grow very large, distorting the shape of the lower face and jaw and shifting teeth out of position.

When to see a doctor

Talk to your dentist or health care provider if you have jaw swelling or pain or any other concerns with your oral health.

Causes

Ameloblastoma begins in the cells that form the protective enamel lining on your teeth. Rarely, it may start in gum tissue. The exact cause of the tumor is unclear, but several genetic changes (mutations) may be involved in the development of ameloblastoma. These changes may impact the location of the tumor, the type of cells involved and how fast the tumor grows.

Ameloblastomas are generally classified by type, but they can also be classified by cell type. The four main types include:

• Conventional ameloblastoma. This is the most common type and grows aggressively, usually in the lower jawbone, and approximately 10% recur after treatment.
• Unicystic ameloblastoma. This type is less aggressive, but typically occurs at a younger age. The tumor is often in the back of the lower jawbone at the molars. Recurrence is possible after treatment.
• Peripheral ameloblastoma. This type is rare and affects the gums and oral tissue in the upper or lower jaw. The tumor has a low risk of recurrence after treatment.
• Metastasizing ameloblastoma. This type is very rare and is defined by tumor cells that occur away from the primary site in the jaw.

Complications

Rarely, ameloblastoma can become cancerous (malignant). Very rarely, ameloblastoma cells can spread to other areas of the body (metastasize), such as the lymph nodes in the neck and lungs.

Ameloblastoma may recur after treatment.