Ameloblastoma
From Wikipedia, the free encyclopedia
Ameloblastoma is a rare, benign tumor of odontogenic epithelium (the cells that create the enamel, or outside portion, of the teeth during development) much more commonly appearing in the mandible than the maxilla. While these tumors are rarely malignant or metastatic (that is, they rarely spread to other parts of the body), and progress slowly, the resulting lesions can cause severe abnormalities of the face and jaw. Additionally, because abnormal cell growth easily infiltrates and destroys surrounding bony tissues, wide surgical excision is required to treat this disorder.
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[edit] Subtypes
There are three main clinical subtypes of ameloblastoma: unicystic, multicystic, peripheral. A fourth subtype, malignant, has been considered by some oncologic specialists, however, this form of the tumor is rare and may be simply a manifestation of one of the three main subtypes.
[edit] Clinical features
Ameloblastomas are often associated with the presence of unerupted teeth. Symptoms include painless swelling, facial deformity if severe enough, pain if the swelling impinges on other structures, loose teeth, ulcers, and periodontal (gum) disease. Ameloblastoma is tentatively diagnosed through X-ray examination and must be confirmed by histological examination (e.g., biopsy). Radiographically, it appears as a lucency in the bone of varying size and features--sometimes it is a single, well-demarcated lesion whereas it is often demonstrates a multiloculated "soap bubble" appearance. Resorption of roots of involved teeth can be seen in some cases, but is not unique to ameloblastoma. The disease is most often found in the posterior body and angle of the mandible, but can occur anywhere in either the maxilla or mandible.
Ameloblastoma is often associated with bony-impacted wisdom teeth--one of the many reasons dentists recommend having them extracted.
[edit] Treatment
Ameloblastomas are relatively resistant to chemotherapy or radiation therapy, thus, surgery is the most common treatment of this tumor. Because of the invasive nature of the growth, excision of normal tissue near the tumor margin is often required. Some have likened the disease to basal cell carcinoma (a skin cancer) in its tendency to spread to adjacent bony and sometimes soft tissues without metastasizing. While not a cancer that actually invades adjacent tissues, ameloblastoma is suspected to spread to adjacent areas of the jaw bone via marrow space. Thus, treatment of the disease is very much like surgical treatment of cancer. Wide margins that are clear of disease are required for a good prognosis. Often times, treatment requires excision of entire portions of the jaw. Recurrence is common.
