Degeneration of tooth roots caused by endocrine imbalance or excessive pressure of orthodontic appliances. Root resorption may be categorized as internal or external. Internal root resorption, sometimes called internal granuloma, is usually a result of pulpal trauma. Affected teeth demonstrate a radiolucent enlargement within the pulp canal on a dental radiograph. External root resorption has a variety of causes, including eruption pressure, localized infection, and forced orthodontic pressure. Radiographs demonstrate roots that appear to be sawed off or shortened.