In determining juvenile ages at the time of death the ribs that meet the sternum at the midline, can determine an approximate age range. Sternal ribs show macroscopic changes, joint surface deterioration, and bony erosion. Changes expected to be seen will build up ridges becoming longer and more jagged. In some cases, cartilage build-up into a bony structure can be long. This stabilizes the rib but also creates more brittle structures.