The mandible is an unpaired U-shaped bone of the skull. It belongs to the bones of the viscerocranium and is the largest bone in the group.

The mandible is the only movable cranial bone. It articulates with both temporal bones on each side of the external cranial base, forming the temporomandibular joints.

The mandible forms the lower jaw and shapes the contour of the inferior aspect of the face. Also, the mandible serves as an attachment site for many muscles involved in mastication and facial expression, as well as it houses the lower teeth and, therefore, has a crucial role in mastication. Overall, the mandible plays an essential role in biting, chewing, and speaking.

The mandible is composed of two parts:

Body
Ramus (paired)

The mandibular body is the horizontal portion that supports the lower teeth, while the mandibular ramus is the paired vertical part that connects the body to the skull. Both parts unite nearly at a right angle.

The site at which the ramus unites with the body is called the angle of the mandible (gonial angle). It can vary depending on the sex, age, and ethnicity. However, it usually varies between 110 and 130 degrees and is larger in men.

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Lower jaw anatomy (mandible)