norma lateralis

• Bones involved in Norma Lateralis

  • Temporal Bone
  • Parietal Bone
  • Occipital Bone
  • Frontal Bone
  • Zygomatic Bone
  • Maxilla
  • Mandible
  • Nasal Bone
  • Sphenoid Bone
  • Lacrimal Bone

  
• Cerebral Portion


  Located above the zygomatic arch
• Facial Portion


  Located below the zygomatic arch

  
• Characteristic features of Cerebral Portion

  • Temporal Lines
  • Supramastoid Crest
  • Temporal Fossa
  • Zygomatico-temporal foramen
  • Zygomatic arch
  • Infratemporal line/crest
  • Infratemporal fossa
  • Suprameatal triangle
  • Pterion
  • Asterion

  
• Characteristic features of Facial Portion

  • Zygomatic arch
  • Articular tubercle
  • External acoustic meatus
  • Mandibular fossa
  • Styloid process
  • Mastoid process
  • Mastoid foramen
  • Gonion
  • Pterygo-maxillary fissure
  • Pterygo-palatine fossa
  • Spheno-palatine foramen

  
• Parts of the Temporal Bone

  • Squamous part
  • Mastoid part
  • Tympanic part
  • Petrous part

  
• Fossae in Norma Lateralis

  • Temporal Fossa
  • Infratemporal Fossa
  • Pterygopalatine Fossa

  
• Temporomandibular Joint (TMJ)


  A complex articulation of the movable mandible and the base of the skull

  
• Articulation areas of TMJ

  • Between maxillary and mandibular teeth (interjaw dental occlusion)
  • Between the mandibular condyle and the mandibular fossa of the temporal bone

  
• Bones involved in TMJ

  • Condylar process or mandibular condyle
  • Mandibular fossa of the temporal bone
  • Articular eminence of the temporal bone

  
• Components of TMJ

  • Articular or Fibrous Capsule
  • Temporo-mandibular (lateral) Ligament
  • Articular Disc
  • Joint Cavities
• Articular or Fibrous Capsule


  Encloses the joint surfaces like a sleeve that runs from the temporal bone superiorly, to the condyle of the mandible inferiorly

  
• Temporo-mandibular (Lateral) Ligament


  A lateral thickening of the joint capsule that prevents posterior and inferior displacement of the condyle but allows limited anterior movements
• Articular Disc


  A biconcave disc that provides reciprocal articular surfaces between its inferior surface and the condyle, and its superior surface and the mandibular fossa and eminence
• Zones of the Articular Disc

  • Posterior thickening
  • Anterior thickening
  • Intermediate zone
• Joint Cavity


  The disc effectively divides the joint cavity into two distinct upper and lower compartments that allow two types of joint movements
• Accessory Ligaments of TMJ

  • Sphenomandibular ligament
  • Stylomandibular ligament
• Synovial Membrane


  A layer of synovium lines the inner aspects of the joint capsule and secretes synovial fluids for lubrication and nourishment
• Layers of Synovial Membrane

  • Intimal cellular layer
  • Vascular subintimal layer
• Nerve Supply of TMJ

  • Branches of the temporalis N.
  • Branches of the auriculotemporal N.
  • Branches of the masseteric N.
• Blood Supply of TMJ

  • Superficial temporal artery
  • Muscular branches of the maxillary artery
• Muscles Acting on the TMJ

  • Masseter
  • Temporalis
  • Medial Pterygoid
  • Lateral Pterygoid