Inferior maxillary

Inferior Maxillary or the Mandible is the largest and strongest bone of the human face. It forms the lower jaw and holds the lower teeth in place. The mandible sits beneath the maxilla. It is the only movable bone of the skull (discounting the ossicles of the middle ear).

Anatomy

The mandible consists of a horizontal body and two perpendicular portions known as the rami. The body is curved, and its exterior surface gives attachment to the platysma muscle. The rami are quadrilateral in shape, and each has two surfaces, four borders, and two processes.

Body

The body of the mandible is curved, and the front part gives structure to the chin. It has two surfaces and two borders. From the inside, the mandible appears concave. Near the lower part of the symphysis is a pair of laterally placed spines, termed the mental spines, which give origin to the genioglossus and geniohyoid muscles.

Ramus

The ramus of the human mandible has four sides, two surfaces, four borders, and two processes. On the outside, the ramus is flat and marked by oblique ridges at its lower part. On the inside at the center is the mandibular foramen, for the entrance of the inferior alveolar vessels and nerve. The lower border is thick, straight, and continuous with the lower border of the body of the mandible.

Function

The mandible plays a vital role in many common tasks, including chewing, speech, and facial expression.

Clinical significance

Diseases of the jaw can affect the mandible, including fractures, dislocations, cancer, and infections such as osteomyelitis. In addition, there are several developmental disorders that can affect the mandible, including Pierre Robin syndrome and Treacher Collins syndrome.

See also

• Maxilla
• Human skull
• Temporomandibular joint
• Mandibular nerve
• Mandibular fracture