The human skull contains 22 bones and is divided into two distinct sections; the cranium, which houses the brain, and the facial structure. The bones that make up the jaw, included in the facial structure, are important to allow for the basic functions of eating and communicating.
There are two types of bones found in the jaw. Basal bone forms the basic structure for both the mandible and maxilla. The facial muscles also attach to the basal bone.
The alveolar bone, also called the alveolar process, is the specialized bone that is formed at the same time as the teeth. The alveolar process forms the bony part of the maxilla and mandible where the teeth are rooted. The alveolar bone is important for retaining teeth. This type of bone is susceptible to disease or trauma, which can cause it to breakdown resulting in loss of teeth.
The mandible, the bone of the lower jaw, is the largest and strongest bone in the skull. This horseshoe-shaped bone is unique as it is the only bone of the skull that is able to move. This bone has two borders, the inferior and superior and two surfaces, the internal and external.
The mandible consists of two main parts. The body of it, scientifically called the corpus mandibulae, is the horizontal curved portion that holds the lower teeth. The rami, of which there are two, are the perpendicular sections. The right and left rami each meet the body forming nearly right angles. The mandible meets the temporal bones on either side of the head creating the joints that allow for the movement.
The upper jaw bone, known as the maxilla, is actually two bones fused together to form the major portion of the center of the face and the place where the other facial bones connect. The maxilla anchors the upper teeth and is also where many of the muscles in the face are connected.
The maxilla bone creates the boundaries for three facial cavities; the roof of the mouth, the floor of the orbit which is what holds the eyeball and the floor and walls of the nasal cavity. Each of the two maxilla bones are shaped like a pyramid and each contains a cavity known as the sinus cavity. This cavity falls on each side of the nose.