What is the ratio of bone mineral content to projected bone area measured in g/cm^2?

• A. Bone mineral content (BMC)
• B. Bone mineral density (BMD)
• C. Bone densitometry
• D. Osteoblasts

Answer: (B)

Bone mineral density is defined as the amount of mineral per unit area, so when you take bone mineral content (in grams) and divide by the projected bone area (in cm^2), you obtain a density value expressed as g/cm^2. This ratio directly reflects how densely mineral is packed in a given area of bone, which is exactly what BMD measures. Bone mineral content alone would be grams and not a ratio, while bone densitometry refers to the measurement technique rather than a specific ratio, and osteoblasts are the bone-forming cells, not a density metric. Therefore, the ratio in g/cm^2 corresponds to bone mineral density.