Root resorption is the breakdown and loss of the root structure of a tooth. This occurs when living body cells attack part of the tooth. Deciduous root resorption is a natural process which allows exfoliation of the primary teeth to make way for the secondary teeth. Root resorption frequently occurs because of a change in pressure on the surface of the tooth root. In deciduous teeth, this pressure is exerted by the erupting secondary teeth. Root resorption of secondary teeth can be caused by trauma, inflammation, aggressive tumors and growth, among other things. Severe root resorption can be difficult to treat and may require extraction of teeth, but cases can often be further examined with cone beam technology to determine the best course of treatment.