The Case of the Post-Extraction Bone Lesion

Case History

This 28-year old Caucasian male was referred to a general dental office for diagnosis and emergency treatment for pain in the mandibular right second molar area. The mandibular right third molar had recently been extracted and the patient was experiencing continued pain in this area. The patient’s chief complaint was “it hurts when I chew something hard or tough like steak.” All soft and hard tissue conditions were within normal limits with the exception of slight sensitivity to percussion of the mandibular right second molar. This tooth was non-vital to pulp testing with cold and electricity, and all other teeth tested with normal vitality. A periapical radiograph was taken and appeared as follows:

periapical radiograph showing bone lesion

The furcation area of the second molar clearly shows a fracture/perforation with massive obturation material (gutta percha) and sealer exuded more than half way to the apex.

The patient was referred to an oral surgeon’s office for extraction of the second molar.

After several months of healing time, the patient was appointed for an initial examination and treatment plan that included the following radiographs in the full mouth series:

radiograph 1
radiograph 2

The patient returned for a routine six-month dental health visit (which was approximately 9 months after the extraction of the mandibular right second molar) without any complaints and presented with the elements of this case challenge. He was immediately referred to an oral surgeon for an excisional biopsy.

Soft Tissue Examination

The alveolar ridge in the area of the extracted second molar was slightly bluish with a translucent appearance. The soft tissue had slight expansion bucco-lingually as did the bony cortical plates. There was an absence of fluctuance and no evidence of any exudate. The image below was taken of the alveolar ridge in the area of the extracted second molar.

Pulp Vitality Tests

All teeth tested normal to electric pulp testing and cold tests using “Endo-Ice” on a cotton applicator.

Supplemental Periapical Radiograph

The periapical radiograph below was ordered after the bitewing radiograph on the left was examined and a clinical examination was performed. The large radiolucent lesion distal to the first molar appears to have wispy internal septa and osseous expansion.

supplemental radiograph 1
supplemental radiograph 2

Excerpts from the Pathology Report

Clinical Surgical Findings: A 6.0 X 3.0 X 2.0 CM radiolucent, multilocular lesion of the right mandible.

The submitted specimen is in two containers labeled A and B. Specimen A comprises multiple, irregular, tan, soft tissue fragments 3.0 X 2.0 X 1.0 cm in aggregation. One of the fragments is cross sectioned revealing solid, brown, gray cut surfaces. Specimen B comprises multiple, irregular, brownish gray soft tissue fragments 3.0 X 2.0 X 0.8 cm in aggregation.

Microscopic Evaluation: Both specimens evaluated in this accession comprises similar morphologic variations. All portions of this specimen are essentially identical.

They reveal a cellular reactive-type response featuring fibroblastic, fibrous histiocytic, and benign giant cells. The giant cells are frequently multinucleated and occasionally smaller epitheliod or binucleated transition forms are observed. The fibroblastic type stroma features tightly-packed, plump, spindle-shaped, or rounded nuclei. These are frequently vesicular and associated with scattered mitotic activity. Hyperchomatism or atypia of stromal nuclei is not observed. The stroma contains large numbers of capillaries and extravasated red blood cells. Fragments of the specimen reveal a peripheral margin of cancellous bone suggesting specimen displacement or replacement of medullary connective tissues by this reactive-type proliferation.

Evaluation of the mitotic activity of the specimen reveal as many as 10 MF per 10 HPF of stromal cells. Additional preparations of this accession are ordered to date to further evaluate cytological details and especially the apparently increased rate of mitotic activity. Mitotic activity is not greater in multiple, additional preparations of the specimens.