Role of reduced enamel epithelium in root resorption

The precise mechanism of root resorption in human primary teeth is unclear. However, research has suggested that the enamel organ and dental follicle of the successive (permanent) teeth are important for this process. This review focuses on the mechanism of root resorption.

Impaction of the maxillary permanent canines is occasionally seen. Computer tomography studies have shown that these canines cause root resorption in 12.5% of the neighboring central and lateral incisors. In such cases, enlargement of the radiolucent areas around the canine crowns is frequently seen. These radiolucent areas include dental follicles and reduced enamel epithelium, which are composed of degraded ameloblasts and cells of the papillary layer. Root resorbing factors, expressed from the reduced enamel epithelium, are likely to induce the odontoclastic root resorption. Physiological root resorption of the primary teeth is generally milder than this pathological root resorption, but involvement of the reduced enamel epithelium of the permanent tooth can be also proposed.

This review highlights the role of the reduced enamel epithelium in root resorption under both pathological and physiological conditions.