Bones of the Human Adult Skull
The human adult skull consists of 22 bones: 8 cranial bones and 14 facial bones. 1
Cranial Bones (8 bones)
The cranial vault, which protects the brain, comprises the following bones:
- Frontal bone (1) - Forms the forehead and anterior portion of the cranial vault 2, 3
- Parietal bones (2) - Paired bones forming the superior and lateral aspects of the cranium 3, 4
- Temporal bones (2) - Paired bones located at the sides and base of the skull, containing structures of the ear 2
- Occipital bone (1) - Forms the posterior and inferior portion of the cranium 2
- Sphenoid bone (1) - Butterfly-shaped bone at the skull base 2
- Ethmoid bone (1) - Located between the nasal cavity and cranium, contributing to the orbital walls 2
Facial Bones (14 bones)
The facial skeleton comprises:
- Maxillae (2) - Paired bones forming the upper jaw and central midface 2, 5
- Zygomatic bones (2) - Paired cheekbones 2
- Nasal bones (2) - Paired bones forming the bridge of the nose 5
- Lacrimal bones (2) - Small paired bones in the medial orbital wall 2
- Palatine bones (2) - Paired bones forming the posterior hard palate and lateral nasal wall 2
- Inferior nasal conchae (2) - Paired scroll-like bones within the nasal cavity 2
- Vomer (1) - Forms the inferior portion of the nasal septum 2
- Mandible (1) - The lower jaw, the only movable bone of the skull 6, 5
Structural Organization
The skull bones develop through intramembranous ossification and have dual embryonic origins from cranial neural crest cells and paraxial mesoderm 4. The calvarial bones (frontal and parietal) originate from the supraorbital arch region mesenchyme 4. The facial skeleton can be conceptualized as a series of horizontal and vertical buttresses that provide structural support 2.