Facial Bones Anatomy Notes

Facial Bones

The facial bones are those of the skull that do not form the braincase. They primarily constitute the face and do not protect the brain.

Mandible

  • The mandible is the lower jawbone that houses the lower teeth.
  • Coronoid Process: A process on the mandible serving as a muscle attachment site, enabling movement of the mandible (e.g., talking, chewing).
  • Mandibular Condyle: A rounded structure on the mandible that articulates with the temporal bone, forming the temporomandibular joint.
  • Mandibular Fossa: Depression on the temporal bone that receives the mandibular condyle.
  • Temporomandibular Joint (TMJ): A synovial (movable) joint formed by the mandibular fossa of the temporal bone and the mandibular condyle.

Maxilla

  • The maxilla consists of two bones that form the upper jaw and hold the upper teeth.
  • Maxilla is singular, while maxillae refers to both.
  • A suture between the maxillae underlies the upper lip; failure to properly fuse during fetal development results in a cleft palate.
  • The maxilla contributes to:
    • The floor of the orbit.
    • The lateral walls of the nasal cavity.
    • The hard palate (roof of the mouth).

Palatine Bones

  • Located in the posterior portion of the roof of the mouth (hard palate).
  • Work with the maxillae to form the hard palate.

Lacrimal Bone

  • Located on the medial side of each orbit, near the tear duct.
  • "Lacrimal" pertains to tears or crying.

Vomer

  • Found in the nasal cavity.
  • Helps form the nasal septum (the wall dividing the nasal cavity).
  • The nasal septum is mainly cartilage, along with the vomer and a portion of the ethmoid bone.

Inferior Nasal Conchae

  • Located on the lateral walls of the nasal cavity.
  • "Inferior" denotes their lower position; "conchae" refers to their shell-like shape.
  • Increase surface area within the nasal cavity.
  • Function:
    • Slow down inhaled air.
    • Promote air turbulence for better filtration, warming, and moistening.

Zygomatic Bones

  • Form the cheekbones.
  • Zygomatic Arch: A bony bridge where the zygomatic bone articulates with the temporal bone.
  • Serve as crucial muscle attachment sites.

Nasal Bones

  • A pair of elongated, rectangular bones composing the bridge of the nose.

Bones of the Orbit

The orbit is formed by seven bones, but focus is given to six easily identifiable ones:

  1. Frontal Bone: Forms the roof of the orbit.
  2. Sphenoid Bone: Located in the posterior part of the orbit.
  3. Zygomatic Bone: Primarily forms the lateral wall of the orbit.
  4. Maxilla: Primarily forms the floor (base) of the orbit.
  5. Lacrimal Bone: Located on the medial wall, near the tear duct.
  6. Ethmoid Bone: Found on the medial wall of the orbit.

Hyoid Bone

  • Unique as it doesn't articulate with any other bone in the body.
  • Referred to as the "floating bone."
  • Location: Neck, atop the larynx (voice box).
  • Function: Serves as an anchor point for muscles in the neck and throat.