Postmenopausal changes of cervical vertebral bone mineral density

Objectives: Osteoporosis is the most popular bone disease, which rapidly increases in women in menopause. Bone mineral density (BMD) of spine has been widely used to detect the risk of bone fracture due to osteoporosis. Measurement of BMD at thoracic or lumbar spine using a medical computed tomography (CT) is considered as the standard of diagnosis for osteoporosis. On the other hand, clinical cone beam computerized tomography (CBCT) used in dental clinics can also scan cervical spine of the patients. Thus, objective of the current study was to examine whether dental patients’ CBCT images of the cervical vertebrates (C2 and C3) can identify sex and age dependent BMD changes.
Methods: After IRB approval, total of 149 CBCT images were retrospectively obtained from 93 female and 56 male patients (10 to 69 years of age). Bone voxels in CBCT images were segmented from non-bone voxels. C2 and C3 vertebral bodies were digitally isolated by removing lateral and posterior processes at 10 voxels from either side of the vertebral end plate. Non-bone voxels outside of the C2 and C3 were removed using a segmentation algorithm. Gray level, which is proportional to BMD, was averaged in the vertebral bodies. Multivariate analysis with Tuckey-Kramer post hoc test was performed for the comparison of gray levels between the age groups of male and female patients.
Results: The C2 and C3 gray levels of females who are older than 60 years of age were significantly lower than those of younger age (p<0.015). The gray level values were not significantly different between the age groups of men and women younger than 60 years of age (p>0.076).
Conclusions: Most women in the U.S. reach menopause in their 50s or within the 10 years of ranges over or under the 50s. The current findings indicate that CBCT is likely to be used to assess the changes of BMD due to postmenopausal osteoporosis.