When the root structure of a tooth undergoes a breakdown or destruction, it causes a person to lose a tooth. This occurs when the body's own cells start attacking a part of the tooth. When the entire root is damaged, it is called tooth resorption. There are two types of resorption processes that take place; internal and external. There are more cases of the latter compared to the former. What is Tooth Resorption? Tooth resorption is also called root resorption. It occurs due to the differentiation of the macrophages into osteoclasts. If this happens close to the root surface, it causes resorption of the cementum and the underlying bone surrounding the tooth. Cementum is the structure that covers the roots of teeth. It tends to resist resorption better than the bone as it is harder in nature. Depending on the area where the tooth resorption takes place, it is categorized as external and internal resorption. Root resorption is very common in children. It serves as a natural process to dissolve the primary teeth and make way for adult teeth. What is External Resorption? It is when the cells on the outer side of the tooth that is enamel or cementum start attacking the cells in the inner tooth. This condition is usually severe and may require extraction. In case of internal root absorption, the destruction occurs due to the internal make up of the roots. The cells attack the tooth and wear away its lining. It begins at the top of the root canal and starts spreading. When this destruction enters the cavity of the pulp chamber of the tooth crown, the patient is advised to undergo a root canal therapy. Causes The causes generally involve a trauma or injury that leads to loss of root surface. These include an injury that causes damage of the cementum. This leads to localized inflammation and an area of absorption. It can even occur due to a pressure from orthodontic materials or another nearby tooth. Impacted wisdom teeth can place pressure on the nearby teeth leading to resorption. An infection or inflammation due to bacterial infections can also cause the cells to destroy the tooth. If a person suffers from a violent trauma that results in the tooth breaking into little parts, the body will try to dissolve the tooth. Thus, leading to tooth resorption. When the tooth suffers from a trauma, it will lead to formation of osteoclasts. These are cells that can destroy the bone tissue. The osteoclasts tend to attach themselves to the surface of the root. They begin to dissolve the outer layer of the root and it continues till it reaches the inner root. This causes destruction of the blood vessels and nerve tissues. Thus, in the end the crown of the tooth becomes unstable and loose. In some cases, the space between the dissolved root tissues is filled in with bone. This bone undergoes a process called ankylosis. This helps in attaching the bone formed to the tooth. If this occurs, it will start converting the surrounding tissues into bone. Thus, leading to more severe dental complications. Treatment When one develops the dental condition causing external resorption, the best way to treat it is extraction. This is because, if not controlled sooner, it could spread to surrounding teeth. Once the tooth is removed, one can place a dental implant and replace the lost tooth. When one develops external resorption, they should get the affected tooth removed. An injury, trauma or chronic inflammation usually leads to this condition. However, in many cases it occurs due to idiopathic reasons. Speak to your dentist about the best line of treatment for your affected tooth and get treated sooner.