Skull and Its Landmarks - Part B

Skull and its Landmarks - Part B, Part 1 of 4

• The skull is divided into two sections: the neurocranium and the viscerocranium.
• The neurocranium consists of 8 cranial bones.
• The viscerocranium consists of 14 facial bones.
• Specific facial bones include:
  • Vomer (1 bone)
  • Nasal bones (2 bones)
  • Conchae (2 bones, also known as turbinate bones)
  • Maxilla (2 bones)
  • Mandible (1 bone)
  • Palatine bones (2 bones)
  • Zygomatic bones (2 bones)
  • Lacrimal bones (2 bones)
• The aim of this session is to cover the facial skeleton and link it with other sessions on the mandible, muscles of mastication, and facial expression.
• The content aims to help clinicians understand the features of the skull and their impact.
• Learning outcomes include identifying the 14 bones of the facial skeleton, detailing the palatine bones and orbit bones, labeling skull diagrams, describing intracranial fossae, and discussing the hyoid bone.

Bone Descriptions

• Nasal Bones: Two slender, oblong bones that form the bridge of the nose. Their size varies between individuals. They articulate with the frontal, other nasal, maxilla, and ethmoid.
• Inferior Nasal Conchae: Located within the nasal cavity, increasing the surface area for inspired air contact with cavity walls. Articulate with the ethmoid, maxilla, lacrimal, and palatine bones.
• Vomer Bone: A thin, singular bone running vertically within the nasal cavity, separating the left and right nasal chambers. Articulates with the maxilla, ethmoid, and palatine bones.
• Lacrimal Bones: The smallest facial bones, forming part of the medial wall of the orbit. Involved in tear drainage from the eye, which are important for the eye's functions. Articulates with the frontal, ethmoid, maxilla, and inferior nasal concha.
• Maxilla Bones: Forming the upper jaw, these bones house the teeth, parts of the nose, and portions of the eye sockets. Articulates with zygomatic, frontal, and palatine bones.
• Zygomatic Bones: Forming the cheekbones, they are diamond-shaped and contribute to mastication (chewing). Important attachment point for the masseter muscles. Articulates with the sphenoid, maxilla, frontal, and temporal bones.
• Mandible Bone: The largest facial bone, constituting the lower jaw and housing the lower teeth. The mandible is composed of the body and ramus and articulates with the temporal bone to form the temporomandibular joint.
• Palatine Bones: Located at the back of the nasal cavity, these bones help form the nasal cavity, eye socket, and hard palate. Articulates with the sphenoid, ethmoid, maxilla, inferior nasal concha, and opposite palatine bone. Foramina are present to transmit nerves and blood vessels (greater and lesser palatine). Each palatine bone has a horizontal and perpendicular plate.

Functions of the Facial Skeleton

• Protects the brain.
• Holds the sense organs (smell, sight, taste).
• Provides a framework for the soft tissues of the face (eating, expression, breathing, speech).
• Gives the face its shape.