Radiographic Anatomy of Skull and Face

Skull Radiography - Head Shots 101

• Standard views: PA, Lateral, Townes (AP axial), Waters (occipito-mental), Submentovertex (SMV).
• PA view: Frontal bone, ethmoid/frontal sinuses, nasal fossae, orbits.
• Lateral view: Sella turcica, sphenoid sinus, mastoids, cranial vault shape.
• Townes view: Occipital bone, petrous pyramids, dorsum sellae.
• Waters view: Facial bones, maxillary sinuses, orbits, zygomatic arches.

  ⭐ Waters view is best for maxillary sinuses and facial bones.

• SMV view: Skull base, sphenoid/ethmoid sinuses, foramina ovale/spinosum.
• Digital radiography preferred for ↑ image quality & ↓ radiation.
• Indications: Trauma, sinusitis, foreign bodies, some craniofacial anomalies.

Mnemonic: 📌 Patients Love To Watch Sunsets (PA, Lateral, Townes, Waters, SMV).

Cranial Vault - Brain's Bone Box

• Forms protective bony casing for the brain (calvaria & cranial base).
• Bones (8):
  • Frontal (1), Parietal (2), Temporal (2), Occipital (1), Sphenoid (1), Ethmoid (1).
  • 📌 Mnemonic (Cranial Bones): "PEST OF" (Parietal, Ethmoid, Sphenoid, Temporal, Occipital, Frontal).
• Sutures (fibrous joints):
  • Coronal: Frontal & Parietal.
  • Sagittal: Between Parietals.
  • Lambdoid: Parietals & Occipital.
  • Squamous: Parietal & Temporal.
• Key Junctions/Landmarks:
  • Bregma: Coronal + Sagittal.
  • Lambda: Sagittal + Lambdoid.
  • Pterion: Junction of Frontal, Parietal, Temporal, Sphenoid.

    ⭐ Pterion: Weakest part of skull. Overlies anterior division of middle meningeal artery. Fracture → Epidural hematoma.

  • Asterion: Lambdoid + Occipitomastoid + Parietomastoid.
• Fontanelles (infants): Membranous gaps.
  • Anterior: Diamond; closes 18-24 months.
  • Posterior: Triangular; closes 2-3 months.

Facial Skeleton & Sinuses - Face Value Views

Key views for facial bones & Paranasal Sinuses (PNS):

• Waters' View (Occipitomental):
  • For: Maxillary sinuses, orbital floors, zygomatic arches.
  • Petrous ridges below maxillary sinuses.
  • 📌 "Water falls down" (petrous ridges down).
• Caldwell's View (Occipitofrontal):
  • Tube tilt: 15-20° caudal.
  • For: Frontal & ethmoid sinuses, superior orbital fissure.
  • Petrous ridges in lower 1/3 of orbits.
• Lateral View:
  • For: Sphenoid sinus, sella, mastoids, facial profile. Sinuses superimposed.
• Submentovertical (SMV) / Basal View:
  • For: Skull base, sphenoid/ethmoid sinuses, zygomatic arches ("jug-handle").
  • ⚠️ High eye radiation.

⭐ Blowout fracture of the orbit most commonly involves the orbital floor (thinnest wall), potentially trapping the inferior rectus muscle, causing diplopia on upward gaze.

Mandible & Skull Base - Jaw & Foundation

• Mandible: Largest facial bone.

  • Parts: Body, Ramus (Condylar & Coronoid processes), Angle.
  • Foramina: Mandibular (Inf. Alveolar N./vessels), Mental (Mental N./vessels).

• Temporomandibular Joint (TMJ):

  • Synovial joint: Mandibular condyle & Temporal bone (fossa, tubercle).
  • Movements: Elevation, depression, protrusion, retraction, lateral.

• Skull Base Foramina & Contents:

  Foramen	Key Structures Transmitted
  Optic Canal	CN II, Ophthalmic A.
  Sup. Orbital Fissure	CN III, IV, V1, VI, Ophthalmic V.
  Foramen Rotundum	CN V2 (Maxillary N.)
  Foramen Ovale	Otic Ganglion, CN V3, Acc. Meningeal A., Lesser Petrosal N., Emissary V. 📌 OVALE
  Foramen Spinosum	Middle Meningeal A. & V.
  Jugular Foramen	CN IX, X, XI, IJV

⭐ The Optic Canal, located in the lesser wing of the sphenoid, transmits the optic nerve (CN II) and ophthalmic artery.

High‑Yield Points - ⚡ Biggest Takeaways

• Waters view: Best for maxillary sinuses, zygomatic arches, and orbital floor.
• Caldwell view: Ideal for frontal sinuses, ethmoid sinuses, and superior orbital fissures.
• Towne's view: Visualizes occipital bone, petrous pyramids, and dorsum sellae.
• Submentovertex (SMV) view: Key for skull base foramina (e.g., ovale, spinosum) and sphenoid sinuses.
• Lateral view: Shows sella turcica, sphenoid sinus, and mastoid air cells.
• Foramen ovale: Transmits the mandibular nerve (V3) and accessory meningeal artery.
• Foramen spinosum: Transmits the middle meningeal artery and nervus spinosus.