Anatomy of the Mandible

The Mandible

• Forms the lower jaw
• A single bone
• The largest and strongest bone of the face
• Horseshoe-shaped
• Composed of a horizontal body and two rami (plural of ramus)
• The only movable bone in the skull
• Articulates with the temporal bone via the temporomandibular joint (TMJ)
• Serves as an attachment point for mastication muscles

GDC Learning Outcomes

• Describe relevant dental, oral, craniofacial, and general anatomy
• Explain application to patient management

Intended Learning Outcomes

• Describe the key features of the mandible
• List the main parts of the mandible
• List the range of movement of the mandible

Key Parts of the Mandible

• Body: Horizontal portion, right and left halves fused in the midline forming a U-shaped bone
• Ramus: Ascending portions on each side of the body, topped by the condyle and coronoid process
• Coronoid Process: Sharp, beak-like, anterior process to the body
• Condyle: Roller-shaped process that articulates with the mandibular fossa of the temporal bone
• Neck: Bar of bone supporting the condyle
• Alveolar Process: Houses the teeth with facial (lateral) and lingual (medial) plates connected by bone septa

Articulations of the Mandible

• The temporal bone of the skull through a movable synovial joint, the temporomandibular joint.
• Mandibular teeth articulate with those of the maxillary teeth.

External Features

• External oblique ridge: A ridge of bone originating at the mental tubercle and sweeping upwards, becoming the sharp anterior border.
• Mental foramen: Located mid-inferior border/alveolar crest, transmitting the mental nerve
• Mental protuberance: A triangular elevation of bone (the chin)
• Mental tubercles: Small elevations on either side of the mental protuberance

Internal Features

• Digastric fossa: Small depressions on either side of midline, originating the anterior belly of the digastric muscle
• Mental spine (Genial tubercles): Up to 4 separate spines or a single fused spine. The upper aspect originates the genioglossus muscle, the lower aspect originates the geniohyoid muscle
• Mylohyoid ridge: Origin of the mylohyoid muscle (floor of anterior mouth).
• Submandibular fossa (SMF): Site of submandibular salivary gland
• Sublingual fossa (SLF): Site of sublingual salivary gland
• Mandibular (Inferior dental) foramen: Oblique opening at the ramus midpoint, passing inferior dental nerve and artery.
• Lingula: Lip of bone covering anterior edge.

Movement of the Mandible

(Specific details of movement are not provided in the materials.)

Useful Links

• Links to YouTube videos about the Maxilla, the Mandible, and other related bone systems are presented.