Lamina dura is bundle bone that lies adjacent to the periodontal ligament, lining the tooth socket. The lamina dura surrounds the tooth socket and provides the attachment surface with which the Sharpey's fibers of the periodontal ligament perforate. On an x-ray a lamina dura will appear as a radiopaque line surrounding the tooth root. An intact lamina dura is seen as a sign of healthy periodontium. Lamina dura, along with the periodontal ligament, plays an important role in bone remodeling and thus in orthodontic tooth movement. The part of the alveolar bone that lines the socket is a thin layer of dense cortical bone called the lamina dura. The bone that underlies the lamina dura is cancellous bone,Under the lamina dura is the less bright cancellous bone. trabeculii is the tiny spicules of bone crisscrossing the cancellous bone that make it look spongy. These trabeculii separate the cancellous bone into tiny compartments which contain the blood producing marrow.
Alveolar bone