Th 172404

Case #2

March 1, 2005
A 27-year-old male visited a dental office for a routine check-up and prophy. Examination revealed a bony mass near the inferior border of the mandible.

A 27-year-old male visited a dental office for a routine check-up and prophy. Examination revealed a bony mass near the inferior border of the mandible.


The patient denied any history of signs or symptoms associated with the bony mass. The patient appeared to be in a general good state of health, with no significant medical history. The patient’s dental history included regular dental examinations and routine dental treatment. At the time of the dental appointment, the patient was not taking medications of any kind.


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The patient’s vital signs were all found to be within normal limits. Examination of the head and neck region revealed no enlarged or palpable lymph nodes. Examination of the oral tissues revealed a localized, bony hard mass near the inferior border of the mandible. The mass measured approximately 1.0 cm x 1.0 cm. Further revealed no other lesions present.

After a thorough clinical examination, a radiograph was ordered and exposed. Examination of the radiograph revealed a large, well-defined radiopacity extending from the inferior border of the mandible (see radiograph).

Clinical diagnosis

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

• ossifying fibroma
• cementifying fibroma
• torus
• osteoma
• complex odontoma


• osteoma


The osteoma is a benign tumor that consists of mature, compact or cancellous bone. The cause of the osteoma is uncertain. The osteoma may occur in the mandible, maxilla, bones of the face and skull, or in long bones. Osteomas of the jaws are relatively uncommon.

Clinical features

The osteoma is seen in teens and adults, particularly in the second to fifth decades of life. Males are affected more frequently than females. The osteoma usually occurs as a solitary lesion. The presence of multiple osteomas may be seen with Gardner’s syndrome. Gardner’s syndrome is characterized by intestinal polyps, multiple osteomas, cysts and tumors of the skin, odontomas, and supernumerary teeth.

The mandible is involved more frequently than the maxilla; the most common location for the osteoma is the mandibular angle. The osteoma is an asymptomatic, slow-growing, and bony hard lesion. Pain is seldom a feature. Asymmetry may be noted as the lesion enlarges.

Radiographic features

The osteoma appears as a dense, well-defined radiopacity. The size of the osteoma is variable. The osteoma cannot be diagnosed from its radiographic appearance alone. All lesions identified on a dental radiograph must be documented in the patient record and described in terms of appearance, location, and size.

In order to establish a definitive diagnosis, a biopsy is necessary.


Histologically, the osteoma exhibits either dense, compact bone or coarse cancellous bone. Lesions that may be considered in the differential diagnosis for the osteoma include the exostosis and the complex odontoma.


The osteoma should be surgically removed. Following surgical removal, the osteoma does not recur.

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