Ameloblastoma

Ameloblastoma is a rare, slow-growing tumor that develops in your jaw. Ameloblastomas grow from the same type of cell that forms your tooth enamel. About 80% of the time, it develops in your lower jaw in the space behind your back teeth (molars).

Ameloblastomas are benign (noncancerous). But ameloblastomas aren’t benign in the way most people may think of the word, as in harmless. They can grow big enough to change the structure of your jaw or damage your teeth. They can also recur (return) after treatment.

Early treatment and careful monitoring after treatment can prevent an ameloblastoma from damaging your jaw.

Types of ameloblastoma

At first glance through a microscope, all ameloblastoma cells look like tiny honeycombs or soap bubbles. Healthcare providers study the cells closely to classify ameloblastomas into types, including:

• Conventional ameloblastoma. Conventional ameloblastomas represent 85% of all ameloblastomas. These tumors grow more quickly than the other types and are likely to spread from your jaw to other nearby areas of your mouth.
• Unicystic ameloblastoma. These tumors are less likely to spread beyond your jaw than conventional ameloblastomas.
• Peripheral (extraosseous) ameloblastoma. Researchers believe these tumors likely spread to your jaw from your lower gum or soft tissue in your mouth. They grow more slowly than conventional and unicystic ameloblastoma.

Although extremely rare, ameloblastoma can be (or become) malignant. Types include:

• Metastasizing ameloblastoma. These tumors look like benign ameloblastoma beneath a microscope. In reality, they’re a form of metastatic cancer. Metastatic cancer spreads from a tumor to other parts of your body. A provider may not know that an ameloblastoma is metastatic until they find that the cancer has spread to your lungs, brain or skin.
• Ameloblastic carcinoma. These tumors may start as cancer. Or they may start off as benign ameloblastomas and then become malignant.

How common is ameloblastoma?

Ameloblastomas are one of the most common benign jaw tumors, but they’re still rare overall. Studies estimate that every year, only 1 in 1 million people is diagnosed with ameloblastoma. And only 2% of those people have malignant ameloblastoma.

Anyone can develop ameloblastoma, but the condition is more common in people from ages 30 to 60. Diagnoses are more common in Africa and Asia.