Augmentation and Preservation of the Alveolar Process and Alveolar Ridge of Bone

The alveolar process is the part of the maxilla and the mandible that house and support the alveoli of the teeth. It develops in conjunction with the development and eruption of the teeth, over the basal bone and coronal to it. The alveolar process consists of an outer layer of cortical bone, an inner cancellous bone, and a special layer alveolar bone proper which together with the root, cementum and the periodontal membrane constitutes the dental attachment apparatus. The attachment apparatus supports the tooth in the jaw, on the one hand, and distribute forces generated by the teeth to the alveolus and bone peripheral to it, on the other hand. The forces transferred to the jaw due to teeth activities, influence the structure, architecture, size and density of the cancellous bone trabeculae. Fig. 1a-c shows a cross section through dentate sites in the mandible at a level corresponding to the roots and through an edentulous site (d). In health, the bone lining the wall of the socket (alveolar bone proper) is continuous with the cortical bone at the lingual and buccal aspects of the alveolar process (Fig.1a-c,e) however, if the buccal plate of bone is extremely thin (Fig.1. a,c) the buccal cortical plate and the alveolar bone proper unite having no cancellous bone between them. The different structures of the alveolar process, i.e. cortical and cancellous bone, are constantly undergoing remodeling in response to functional forces acting on the teeth. Once teeth are lost, the attachment apparatus is destroyed, and the alveolar process, mainly the alveolar ridge, undergoes significant structural changes; these are referred to as "disuse atrophy" (Fig. 1a,c,f).