A 48-year-old female visited a dentist for evaluation of a swelling to the lower jaw. Radiographic

A 48-year-old female visited a dentist for evaluation of a swelling to the lower jaw. Radiographic examination revealed a large multiocular lesion of the mandible.

A 48-year-old female visited a dentist for evaluation of a swelling to the lower jaw. Radiographic examination revealed a large multiocular lesion of the mandible.

Joen Iannucci Haring, DDS, MS

History

The patient did not have any pain associated with the swelling of the lower jaw and denied any history of trauma to the region. The patient appeared to be in good general health, with no significant medical history. The patient`s dental history included irregular dental examinations and sporadic dental treatment. At the time of the dental appointment, the patient was not taking any medication.

Examinations

The patient`s vital signs were found to be within normal limits. Examination of the head and neck region revealed no enlarged or palpable lymph nodes. Examination of the oral soft tissues revealed no unusual findings. Buccal bony expansion was noted in the mandibular anterior region.

A panoramic radiograph revealed a large, well-defined multilocular radiolucency extending from the right lateral incisor to the left canine mandible. Root divergence of teeth #22 and #23 was also evident on the panoramic film (see radiograph).

Clinical diagnosis

Based on the clinical and radiographic examination available, which one of the following is the most likely diagnosis?

* ameloblastoma

* odontogenic keratocyst

* ameloblastic fibroma

* central giant cell granuloma

* odontogenic myxoma

Diagnosis

ameloblastoma

Discussion

The ameloblastoma is a benign odontogenic tumor of epithelial origin. It evolves from elements that are normally involved in the formation of teeth. The actual histogenesis of this lesion is uncertain. The ameloblastoma is a common odontogenic tumor.s

Clinical features

The ameloblastoma is most often seen in adults ages 20 to 60; the average age at diagnosis is 33. There is no race or sex predilection. This lesion is most often found in the posterior region of the jaw; the mandible is affected far more frequently than the maxilla. 75 percent of all cases are identified in the posterior mandible and ramus areas. The ameloblastoma is a slow-growing, solitary lesion. Pain is usually not a feature. Bony expansion occurs as the lesion increases in size. The small, nonexpansile lesions are often discovered during routine radiographic examination.

The ameloblastoma is not a malignant lesion; however, if left untreated, it can become very large. This lesion has rapid growth potential, and may reach grotesque and disfiguring proportions.

Radiographic features

The ameloblastoma may appear as a unilocular or multilocular radiolucent lesion with well-defined and sclerotic borders. The classic radiographic appearance is that of a large, multilocular radiolucency that resembles soap bubbles. Other radiographic features include bony expansion, displacement of teeth, and root divergence. The size is variable and ranges from a very few centimeters in diameter to lesions that involve the entire jaw. The ameloblastoma cannot be diagnosed from its radiographic appearance alone; a biopsy is necessary to establish a diagnosis.

Diagnosis and treatment

Histologic examination of the lesion is necessary to make a definitive diagnosis. Other lesions that may be considered in the differential diagnosis for the ameloblastoma include the odontogenic keratocyst, central giant cell granuloma, and odontogenic myxoma.

The ameloblastoma is a tumor and must be treated. Surgical removal of the lesion is the treatment of choice. Treatment options include enucleation and curettage, block resection, and hemisection. The location, size, and histologic appearance of the lesion dictates the type of surgery.

The ameloblastoma has the highest recurrence rate of all odontogenic tumors. There appears to be a substantial risk for recurrence following surgical removal; approximately 55 to 90 percent recur after curettage and 15 percent recur after marginal or block resections. Yearly radiographic follow-up is necessary for at least five post-operative years. The importance of such follow-up must be stressed to the patient.

Joen Iannucci Haring, DDS, MS, is an associate professor of clinical dentistry, Section of Primary Care, The Ohio State University College of Dentistry.

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