The first article on bone mass quantification appeared in which decade?

• A. 1920s
• B. 1930s
• C. 1950s
• D. 1970s

Answer: (B)

The main concept here is when bone density began to be measured in a quantitative way rather than just described visually. The first article that quantified bone mass appeared in the 1930s, marking the shift from qualitative radiographic impressions to numeric estimates of bone density using early radiographic density measurements and calibration standards. This decade set the groundwork for later, more refined bone densitometry techniques, while earlier work in the 1920s was more about qualitative assessment and later decades built on these initial quantitative efforts.