SPECIAL FEATURES
OF BONES:

Ethmoid
Hyoid
Mandible
Maxilla
Occipital
Palatine
Sphenoid
Temporal
Zygomatic

Total Facial Skeleton = 14 Total Cranial Skeleton = 8

SPECIAL FEATURES OF BONES:

Ethmoid Bone:

• Consists of 4 parts: Horizontal Cribriform Plate; Two Lateral Masses (Labyrinths); Perpendicular Plate
  
• Ethmoidal Labyrinths consist of Air Cells and Superior and Middle Nasal Conchae, and Uncinate Process (one on each side)
  
• Crista Galli, for the attachment of FaIx Cerebri

Hyoid: Made of 5 parts -Body, 2 Greater and 2 Lesser Cornua

Mandible:

• Body, Rami, Condyloid Process, Coronoid Process, Mental Symphysis, Mental Foramen, Alveolar Process
• Largest Facial Bone

Maxillary Bones:

• Maxillae are Second Largest Facial Bone
  
• Each Bone consists of Body and Four Processes (Zygomatic, Frontal, Alveolar, and Palatine)
  
• Infraorbital Foramen
  
• Nasal Notch and Anterior Nasal Spine
  
• Maxillary Tuberosity (Articulates with Palatine Bone)
  
• Maxillary Sinus (Antrum)
  
• Palatine Process articulates with its fellow from the opposite side to form most (three-fourths) of the Hard Palate.
  
• Incisive Foramen (Nasopal.N.Ant.brs.descending palat.a & v)

Nasal Bones:

• Each Bone has Two Surfaces, and Four Margins
  
• Frontonasal Suture [site of Congenital Cysts; Nasal Dermal Sinus and Cyst, & Extranasal (Glabella) Cephaloceles]
  
• Frontomaxillary Sutures and Frontonasal Suture uniting the arches over the Nose (Glabella)
  
• Nasomaxillary Suture
  
• Medial Margin articulates with the fellow from the opposite side (Dorsum of Nose)
  
• Inferior Margin articulates with Lateral Cartilage of Nose

Occipital Bone:

• Consists of a Squamous, Basilar, and Two Lateral (Condylar) Portions
  
• Has large Aperture (Foramen Magnum)
  
• Basilar Portion (Basiocciput) makes a Synchodrosis with Basilar portion of Sphenoid (Basisphenoid) and together form the Clivus.
  
• Slope from Dorsum SelIae to the Foramen Magnun is known as the Clivus
  
• Lateral parts contain on their undersurfaces the Occipital Condyles which articulate with Superior Facets of Atlas (Atlantooccipital Joint)
  
• The Base of each Condyle presents Anteriorly the Hypoglossal Canal(l2th C. Nerve) Condylar Canal (Transmit Emissay Vein)

Palatine Bones:

• Very small bone and extremely complex
  
• Located at the back of Hard Palate and Nasal Cavity
  
• Contributes to the formation of 3 Cavities (Nasal, Roof of Mouth, and Orbit)
  
• Horizontal and Vertical portions
  
• Articulates with Six Bones; its Fellow, Sphenoid, Ethmoid, Maxilla, Inferior
  Concha, and Vomer

• Located at the base of skull, Anterior to basilar part of Occipital Bone and back of the Ethmoid Bone.
  
• Composed of Body, Two Greater and Two Lesser Wings, and Pterygoid Processes (Medial and Lateral)
  
• Greater Wing contains Foramina Ovale, Rotundum, and Spinosum
  
• Lesser Wing contains Optic Canal
  
• Sella Turcica (Turkish Saddle)
  
• Tuberculum SeIIae (Rounded projection in front of the Saddle)
  
• Tuberculum SeIIae is posterior wall of Chiasmatic Groove
  
• Dorsum SelIae (Larger projection behind the Saddle)
  
• Anterior, Middle, and Posterior Clinoids
  
• Superior Orbital Fissure
  
• Sphenoid Sinuses

• Each consists of 5 parts
  
• Squamous including its Zygomatic Process
  
• Tympanic Bone (External Auditory Canal)
  
• Mastoid (Mastoid Air Cells)
  
• Petrous Bone, containing Otic Labyrinth and Internal Auditory Canal (IAC)
  
• Styloid Process
  
• Middle Ear Ossicles (Malleus, Incus, and Stapes)
  
• Inner Ear (Otic Labyrinth), Cochlear and Vestibular Labyrinth
  
• Carotid Canal (Internal Carotid Artery)
  
• Jugular Fossa (Int Jugular vein, 9th, 10th, & 1 1th Cranial Nerves)
  
• Facial Nerve Canal (Fallopian canal)
  
• Stylomastoid Foramen Petrotympanic Fissure
• Tympanomastoid Fissure
  
• Groove for Greater Superficial Petrosal Nerve
  
• Groove for Superior Petrosal Vein
  
• Labyrinthine Windows (Round and Oval)
  
• Otic Labyrinth (Cochlea, Vestibule, and 3 Semicircular Canals)
  
• Glenoid Fossa (TM Joint)
  
• Meckle's Cave, a shallow fossa at the apex of petrous bone, for the Trigeminal Ganglion (Gasserian Ganglion).

Zygomatic (Malar) Bones:

• Body and Two Processes (Frontal and Temporal)
  
• Zygomaticofacial Foramen connects by means of a canal through the bone to the Zygomaticoorbital Foramen

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