Anatomy of the Frontal Bone

Frontal Bone

Frontal Sinus

• Air-filled cavities located within the frontal bone
• Two separate sinus cavities, one on each side of the midline
• Functions:
  • Reduce weight of the skull
  • Warm and humidify inspired air
  • Add resonance to the voice
  • Provide mucous drainage

Supraorbital Ridge

• A bony prominence located above the orbit (eye socket)
• Forms the upper margin of the orbit
• Contains the supraorbital notch (or foramen), which transmits the supraorbital nerve and vessels

Glabella

• A smooth, flat area located between the supraorbital ridges
• The most anterior (frontal) point of the frontal bone
• Used as a landmark for measuring the size and shape of the skull

Cranial Sutures

• The frontal bone articulates with adjacent bones through cranial sutures:
  • Metopic suture: separates the two halves of the frontal bone
  • Coronal suture: separates the frontal bone from the parietal bones
  • Sphenofrontal suture: separates the frontal bone from the sphenoid bone

Foramens and Articulations

• Foramen cecum: a small opening located at the junction of the frontal and nasal bones
• Frontal notch: a notch located on the inferior surface of the frontal bone, which articulates with the nasal bone
• Zygomaticofrontal suture: separates the frontal bone from the zygomatic bone

Frontal Bone

Frontal Sinus

• Located within the frontal bone, two separate cavities on either side of the midline
• Functions include reducing skull weight, warming and humidifying inspired air, adding resonance to the voice, and providing mucous drainage

Supraorbital Ridge

• Bony prominence above the orbit (eye socket), forming the upper margin of the orbit
• Contains the supraorbital notch (or foramen), transmitting the supraorbital nerve and vessels

Glabella

• Smooth, flat area between the supraorbital ridges, most anterior point of the frontal bone
• Used as a landmark for measuring skull size and shape

Cranial Sutures

• Frontal bone articulates with adjacent bones through:
  • Metopic suture: separates the two halves of the frontal bone
  • Coronal suture: separates the frontal bone from the parietal bones
  • Sphenofrontal suture: separates the frontal bone from the sphenoid bone

Foramens and Articulations

• Foramen cecum: small opening at the junction of the frontal and nasal bones
• Frontal notch: inferior surface notch articulating with the nasal bone
• Zygomaticofrontal suture: separates the frontal bone from the zygomatic bone