Ameloblastomas are similar to other jaw tumors in that they are most often discovered on a routine dental x-ray with no symptoms. Since these are somewhat slow growing, they usually don't cause pain. These tumors can grow quite large before they are detected because they are hidden in the bone under the gums. Some tumors are first discovered by patients if they notice swelling under the gums or around the face.
A panoramic (panorex) xray is often one of the first x-rays used to get an overall view of the jaws. Many surgeons will also use a cone beam CT scan which is available in most oral surgeon's offices these days. This allows viewing of the bones, teeth, and tumor 3-dimensionally to get a better appreciation of the extent of the tumor and other characteristics. After viewing these images, the surgeon can develop a "differential diagnosis" which is a list of possible tumors/cysts.
A biopsy is the next step to determine what type of tumor or cyst we are dealing with, which will ultimately determine the treatment. There are several dozen different cysts and tumors that can occur in the jaw and many are treated differently.
Many surgeons will also use a cone beam CT scan which is available in most oral surgeon's offices these days.