Collagen resorption by periodontal ligament fibroblasts at the hard tissue-ligament interfaces of the mouse periodontium.

Electron microscopic examination of the periodontal ligament of the mouse molar at the ligament-cementum and ligament-bone interfaces revealed fibroblasts apparently engaged in the severing and phagocytosis of ligament collagen fibrils originally anchored to bone or cementum as "Sharpey's fibers".