Alveolar bone is the bone of the upper

Alveolar bone is the bone of the upper& lower jaw that surrounds & support the roots of the teeth. The existence of alv. Bone dependent on the presence of teeth. If the teeth extracted or not erupt , the alv. Bone doesn't develop.

Alveolar bone ( processes ) composed from 3 layers : a. Alveolar bone proper ( cribriform plate ) b. Cortical bone. c. Cancellous bone ( spongy bone ).

A. alveolar bone proper : Is the thin layer of bone that lines the socket to surround the root of the tooth. The alveolus is the bony socket , a cavity in the alv. Bone that houses the root of tooth. The alveolar bone proper has numerous holes, that allow blood vessels from cancellous bone to connect with the vessels of PDL space. The ends of PDL fibers are embeded in alv. Bone proper.

B. Cortical bone : Is a layer of compact bone that forms the hard, outside wall of mandible & maxilla. The buccal cortical bone is thin in incisors & premolar areas , and thicker in molar area. Doesn't appear on radiograph; only the cancellous bone & alv. Bone proper appear on radiograph. The alveolar crest is the most cortical portion of alveolar processes.

C. Cancellous bone ( spongy bone) Is a latticelike bone that fill the interior portion of alveolar processes.

D. Periosteum : Is a layer of soft C. T covering the outer surface of bone; it consists of an outer layer of collagenous tissue and inner layer of fine elastic tissue.