Orofacial

• Bones that the parietal bone articulates with

  • Occipital
  • Frontal
  • Temporal
  • Sphenoid

  
• Parietal bone


  • Forms posterior roof of the skull
  • Protects the skull and brain
  • Sagittal suture joins each parietal bone

  
• Location of parietal bone


  Superior and posterior portion of the skull

  
• Bones that the temporal bone articulates with

  • Zygomatic
  • Parietal
  • Occipital
  • Sphenoid
  • Mandible

  
• Location of temporal bone

  Lateral walls of skull

  
• Temporal bone


  • Paired cranial bones that form lateral walls of the skull
  • Each temporal bone has 3 portions: Squamous, Tympanic, Petrous

  
• Parts of the temporal bone

  • Zygomatic process
  • Zygomatic arch
  • TMJ
  • Articular fossa
  • Articular eminence
  • Postglenoid process
  • External acoustic meatus
  • Petrotympanic fissure
  • Mastoid process
  • Mastoid notch
  • Styloid process
  • Stylomastoid foramen
  • Aperture of carotid canal
  • Jugular notch
  • Internal acoustic meatus

  
• Squamous portion of temporal bone


  • Large, flat, fan-shaped
  • Forms the zygomatic process of the temporal bone

  
• Other bones that form part of the zygomatic process

  
• Zygomatic process


  • Forms part of the zygomatic arch (cheekbones)
  • Forms cranial portion of the TMJ (Temporomandibular joint)
  • Inferior of zygomatic process is the articular fossa
  • Anterior to articular fossa is articular eminence and posterior to articular fossa is the postglenoid process
  • Articular fossa and articular eminence articulate with the mandible at the TMJ
• Tympanic portion of temporal bone

  • External acoustic meatus: mostly formed by tympanic portion; a short canal leading to tympanic cavity; located posterior to articular fossa
  • Petrotympanic fissure: a fissure that separates the tympanic portion from petrosal portion. This is where the chorda tympani nerve emerges.
• Petrous portion of temporal bone

  • Mastoid process: inferior of petrous portion, posterior to acoustic meatus, large roughened projection. Composed of air spaces (mastoid air cells) that communicate with the middle ear cavity. Site for attachment of large muscles of the neck like the SCM (sternocleidomastoid muscle).
  • Mastoid notch: medial to mastoid process.
  • Styloid process: inferior/medial to external acoustic meatus, long, pointed bony projection, tongue attachment, and pharyngeal muscles/ligaments.
  • Stylomastoid foramen: carries C7 (facial nerve).
  • Aperature of carotid canal: large, circular, transmits into the cranium the internal carotid artery and the carotid plexus of nerves.
  • Jugular notch: lateral portion of the jugular foramen

  
• The other bone that forms the medial portion of the jugular foramen

  
• Internal acoustic meatus


  • Intracranial, carries C8 (vestibulocochlear nerve) which stays inside the petrous portion and houses the inner ear and C7 (facial nerve) travels through the meatus and emerges at the styloidmastoid foramen.
• Bones that the sphenoid bone articulates with

  • Frontal
  • Parietal
  • Ethmoid
  • Temporal
  • Zygomatic
  • Maxillary
  • Palatine
  • Vomer
  • Occipital

  
• Location of sphenoid bone

  Midline bone, midsagittal section of the cranial bones

  
• Sphenoid bone


  • Connects cranial skeleton to facial skeleton
  • Made up of its body and its processes
  • Complex bone

  
• Foramina in the sphenoid bone

  • Superior orbital fissure
  • Foramen rotundum
  • Foramen ovale
  • Foramen spinosum
• Body of sphenoid bone

  • Middle portion
  • Anterior articulates with ethmoid bone
  • Posterior articulates with the basilar portion of occipital
  • Contains the paired sphenoid sinuses aka. Paranasal sinuses
• Processes of the sphenoid bone

  • Lesser wing process (anterior, base of the orbital APEX)
  • Greater wing process (posterolateral)
  • Pterygoid process (inferior to greater wing, muscles of mastication attachment. Is made up of 2 Plates, a Fossa and a HAMULUS)
• Greater wing of sphenoid bone

  • Flattened, Lateral
  • Divided into 2 smaller surfaces: TEMPORAL and INFRATEMPORAL surfaces divided by the INFRATEMPORAL CREST
  • SPINE: sharp, pointed area, posterior corner of each greater wing
• Bones that the ethmoid bone articulates with

  • Frontal
  • Sphenoid
  • Lacrimal
  • Maxillary
  • Adjoins the vomer (Inf. Post. Border)

  
• Location of ethmoid bone

  Midline, midsagittal plane

  
• Ethmoid bone


  • Aids to connect cranial to facial skeleton
  • Cannot be seen on various views like sphenoid
  • 2 Unpaired Plates: Perpendicular Plate and Cribriform Plate
  • Perpendicular plate seen in nasal cavity and aids the vomer and nasal septal cartilage in forming the nasal septum
  • Cribriform plate inside cranial cavity, superior part of bone is perforated by foramina to allow the passage of C1 olfactory nerves for smell
  • Ethmoidal sinuses (ethmoid air cells): variable number of small cavities in the lateral mass of the ethmoid
  • Crista galli: continuation of the perpendicular plate into cranium, attachment for layers covering the brain
  • Lateral portion of the ethmoid bone forms: Superior nasal conchae, Middle nasal conchae, and Orbital plates
• Facial bones are also called?


  viscerocranium

  
• Facial bones


  • Vomer (1)
  • Mandible (1)
  • Lacrimal (2)
  • Nasal (2)
  • Inferior nasal conchae (2)
  • Zygomatic (2)
  • Maxillary (2)
  • Palatine (2)

  
• Facial bones


  • Form the facial features and the base of dentition
  • Shared by 2 or more soft tissues. For example, the frontal bone forms the forehead and areas around the eyes.
  • An abnormality in one facial bone can involve more than one soft tissue area.

  
• Bones that the vomer articulates with

  • Ethmoid
  • Nasal cartilage
  • Palatine
  • Maxillae
  • Sphenoid

  
• Vomer


  • Single, midline
  • Forms posterior part of the nasal septum
  • Posteroinferior is free of articulations
  • Has no muscle attachments
• Bones that the lacrimal bone articulates with

  • Ethmoid
  • Frontal
  • Maxillary

  
• Lacrimal bone


  • Irregular thin plates
  • From small portion of the anterior/medial wall of the orbit
  • Smallest and most fragile
  • Nasolacrimal duct: at the junction of the lacrimal and maxillary bones
  • Lacrimal fluid (tears) from lacrimal gland drain through duct into inferior nasal meatus
• Bones that the nasal bone articulates with

  • With each other at midline superior to the piriform aperture
  • Frontal superiorly
  • Maxillae laterally

  
• Nasal bone


  • Paired
  • Forms bridge of the nose
• Bones that the inferior nasal conchae articulates with

  • Ethmoid
  • Lacrimal
  • Palatine
  • Maxillary
• Inferior nasal conchae


  • Separate facial bone that projects from maxillae
  • Forms portion of lateral walls of nasal cavity
  • Each inferior conchae is fragile, spongy curved like a scroll
  • Projects into nasal cavity to increase surface area, increases amount of mucus membranes and olfactory nerve (C1) endings exposed to inhale odors
  • No muscle attachment
• Bones that the zygomatic bone articulates with


  • Frontal
  • Temporal
  • Sphenoid
  • Maxillary

  
• Zygomatic bone


  • Forms cheekbone or malar surface
  • Diamond shaped
• Zygomatic bone


  • Composed of 3 processes: Frontal Process, Temporal Process, Maxillary Process

  
• Bones that the palatine bone articulates with


  • With each other
  • Maxillae
  • Sphenoid

  
• Palatine bone


  • Not strictly facial bones
  • 2 Plates both contribute to lip of bone of the orbital apex. Horizontal Plate- form posterior portion of hard palate, Vertical Plate- form portion of lateral wall of nasal cavity