![](https://www.endotext.org/wp-content/uploads/2018/01/etx-bone-ch2-fig4.png)
Figure 4. Peak Bone Mass. Schematic representation in relative units of normal skeletal development, demonstrating changes in bone resorption and formation. The crossover of formation/resorption occurs during the fourth decade. In osteoporosis, there is an accelerated loss of bone because of increased resorption and decreased formation. (see Acknowledgements).