Periosteal new bone formation in the jaws. A computed tomographic study.

OBJECTIVES

To investigate the diagnostic significance of a periosteal reaction (PR) in diseases of the jaws.

METHODS

The frequency of PR was investigated in 1142 patients who had undergone CT of the maxilla or mandible. The pattern of PR was categorized as either parallel, irregular, spicule or Codman's triangle. We examined the relationship of the pattern of PR to the specific disease categories of osteomyelitis, trauma, cysts, benign tumours and malignant tumors.

RESULTS

Seventy patients were found to have PR. It was found in 40% of cases with osteomyelitis and 15% of malignant tumors. The only benign lesion was an eosinophilic granuloma. There were no cysts. The frequency of PR was higher in younger patient and in those with sarcomas or bone metastases compared with those with carcinomas. Ninety-one percent of the patients with osteomyelitis showed single or multi-layered PR parallel to the cortical bone, while 61% of those with malignant tumors had a spicule pattern. With the exception of Codman's triangle, none of the PR patterns were specifically associated with any one disease category. When the PR pattern was combined with the pattern of cortical bone destruction, 90% of the patients with PR could be correctly assigned to one or other of the four disease categories of osteomyelitis, trauma, benign lesion or malignant tumor.

CONCLUSIONS

The pattern of PR on CT in combination with the pattern of the cortical destruction of the cortex is useful in differentiating osteomyelitis from malignant tumors.