,The fact that bundle bone gradually may disappear following tooth removal is in agreement with findings from experiments in dogs (Cardaropoli et al. 2003; Araujo & Lindhe 2005) who studied socket healing during a 4- to 6-month period. In the early phase of healing, periodontal ligament fibers as well as bundle bone occurred in the lateral walls of the socket. During the process of modeling and remodeling, however, the bundle bone disappeared and was eventually replaced with bone marrow. It is suggested that the loss of function and disappearance of the periodontal ligament fibers and the bundle bone following tooth extraction may play a crucial role for the resorption and diminution of the residual ridge. This assumption is in agreement with Sennerby et al. (1988) who stated that the loss of ridge dimension “could be described as a resorptive atrophy, a fundamental and physiologic reaction to loss of function and inactivity.”