Mandible

The mandible (from Latin mandibula, "jawbone") or inferior maxillary bone forms the lower jaw and holds the lower teeth in place.

Components

The mandible consists of:

• a curved, horizontal portion, the body. (See body of mandible).
• two perpendicular portions, the rami, which unite with the ends of the body nearly at right angles. (See ramus mandibulae)
• Alveolar process, the tooth bearing area of the mandible (upper part of the body of the mandible)
• Condyle, superior (upper) and posterior projection from the ramus, which makes the temporomandibular joint with the temporal bone
• Coronoid process, superior and anterior projection from the ramus. This provides attachment to the temporalis muscle

Foramens

• Mandibular foramen, paired, in the inner (medial) aspect of the mandible, superior to the mandibular angle in the middle of the ramus.
• Mental foramen, paired, lateral to the mental protuberance on the body of mandible.

Nerves

Inferior alveolar nerve, branch of the mandibular division of Trigeminal (V) nerve, enters the mandibular foramen and runs forward in the mandibular canal, supplying sensation to the teeth. At the mental foramen the nerve divides into two terminal branches: incisive and mental nerves. The incisive nerve runs forward in the mandible and supplies the anterior teeth. The mental nerve exits the mental foramen and supplies sensation to the lower lip.

Articulations

The mandible articulates with the two temporal bones at the temporomandibular joints

Pathologies

One fifth of facial injuries involveves mandibular fracture. Mandibular fractures are often accompanied by a 'twin fracture' on the contralateral (opposite) side.

The mandible may be dislocated anteriorly (to the front) and inferiorly (downwards) but very rarely posteriorly (backwards).

See also

• Bone terminology
• Terms for anatomical location
• Changes produced in the mandible by age
• Ossification of the mandible
• Oral and maxillofacial surgery

Additional images

References

External links

• – "Oral Cavity: Bones"
• Diagram at uni-mainz.de