Thickness of the hard palate : A new criterion for the diagnosis of osteoporosis?

Background: We were looking for an osteoporosis screening in computed tomography (CT) exams, simple and without additional examinations. We hypothesized that the criterion of "decreasing cortical thickness", may have an influence on the hard palate. Therefore, we investigated whether thickness of the hard palate (HPT) may serve as an indicator of osteoporosis for patients imaged for other reasons.

Methods: Patients with dual-energy x-ray absorptiometry (DXA) and CT were identified by a radiology information system (RIS)-based, full-text search. Measurement of thickness of hard palate done in existing CT image by radiologist and dentist and compared with available findings and DXA measurements.

Results: We identified a "test group": 57 patients with DXA and CT available out of 449 patient population and we selected further 70 patients without bone diseases as "control groups". The measurements showed that HPT correlated with age and bone density. The mean HPT was 2.4 mm in normal, 0.9 mm in osteopenia, 0.8 mm in osteoporosis and 5.3 mm in osteopetrosis case. No bone "healthy" patient fell below 1 mm. The relationship between bone density and HPT has not been described previously. HPT was highest in the bone-healthy group and decreased with age, osteopenia, and osteoporosis. Osteopetrosis, as a disease with increased bone density showed an increase in HPT.

Conclusions: HPT correlates with bone disease. We propose a new criterion for assessment on CT and digital volume tomography (DVT) or cone beam computed tomography (CBCT). A threshold of 1.0 mm when applying a simple measurement of HPT on Head CT or DVT may serve as an indicator for potential osteopenia or osteoporosis as incidental finding without extra imaging further diagnosis and treatment leading to early notice of Osteoporosis.