Features of the Mandible
Skull - Anterior View
Key functions of the skull:
- Protects the brain and associated sensory organs,
- Provides attachment sites for the facial and neck muscles.
- 8 Cranial bones that enclose the brain
- 14 Facial bones that protect entryway to nasal and oral cavities, and provide muscle attachment sites.
The unpaired bones:
Frontal
- Forms the forehead and superior rim of eye orbits.
- Supraorbital margin is the bony ridge framing the orbit superiorly
- Supraorbital notch/foramen provides passageway for neurovascular structures.
- Contributes to the posterior and inferior surface and base of the skull.
- A bat-shaped bone that spans the width of the skull.
- An irregularly shaped bone that lies deep within the skull.
- Contributes superior and middle nasal conchae.
The paired bones:
Parietal
- Comprise the superior and lateral aspects of the skull.
- Comprise the inferior portion of the lateral skull.
The facial bones include:
The unpaired bones:
Vomer
- Contributes to the nasal septum.
- The bone of the lower jaw.
- Alveolar margin houses lower teeth.
- Mental foramen for neurovascular structures.
The paired:
Zygomatic
- Form the inferior margins of the orbits and the lateral cheekbones.
- Contribute to the medial walls of the orbits.
- Comprise the bridge of the nose.
- Lie within the nasal cavity.
- Contribute a small portion to the medial orbit wall (but chiefly contribute to the hard palate of the oral cavity).
- Fuse at the midline of the face to form the medial and inferior orbit walls, cheeks, and upper jaw.
- Infraorbital foramen for neurovascular structures.
- Alveolar margin is the border of the maxilla where the upper teeth are housed.
Spaces within the eye orbit:
- The superior orbital fissure is a wide space within the sphenoid (specifically, between the greater and lesser wings).
- The inferior orbital fissure is the space between the sphenoid, zygomatic, and maxillary bones.
- The optic foramen is the opening to the optic canal, through which the optic nerve (cranial nerve II) passes.