D

The apical foramen is not static; lifetime changes in cementum deposition or resorption can either narrow or widen it. Histologic studies have documented age-related widening in many teeth (e.g., mean foramen width increasing with age) [Stein, 1990, PMID 2304750], whereas other long-term observations show secondary osteocementum deposition that partly obliterates and narrows the foramen [Hiatt, 1982, PMID 6755336]. Thus, depending on which process predominates, the foramen’s size may increase or decrease with age.