Temporal

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Temporal infratemporal fossae

• Temporal fossa extends above by the sup.temporal
  line and below by zygomatic arch.
• Infratemporal fossa lies beneath the base of
  the skull, between the pharynx (medially) ramus
  of mandible (laterally). or the
  space lying below the temporal fossa and behind
  the maxilla.

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Muscles of mastication 1-Temporalis

• It lies in the temporal fossa.
• Origin floor of temporal fossa temporal
  fascia.
• Insertion by a tendon into the coronoid process
  of the mandible.
• N.supply deep temporal nerves from the
  ant.division of mandibular N.
• Action anterior fibers --- elevate the
  mandible. posterior fibers---
  retract the mandible.

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Muscles of mastication

• 2-Masseter muscle
• Origin lower border inner surface of
  zygomatic arch.
• Insertion lateral (outer) surface of ramus of
  the mandible.
• N.supply masseteric N. from anterior division
  of mandibular N.
• Action raises the mandible.

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Muscles of Mastication attached to mandible
Medial Surface
Lateral Surface
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Contents of the temporal fossa

• 1-Temporalis muscle.
• 2-Temporal fascia---- covers temporalis
  muscle, attached above to sup.temporal line and
  below to upper border of zygomatic arch.
• 3-Deep temporal nerves from the ant. division
  of mandibular N., emerge from upper border of
  lateral pterygoid, enter the deep surface of
  temporalis .

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Contents of the temporal fossa
4-Auriculotemporal nerve arise from the
posterior division of mandibular N. It
emerges from upper border of parotid gland ,
It lies behind
superficial temporal artery TMJ,
in front of the auricle.
It supplies skin
of auricle , ext.auditory meatus and the scalpe
over the temporal region.
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Contents of the temporal fossa

• 5-Superficial temporal artery it is a terminal
  branch of ext.carotid artery.
• It Emerges from upper border of parotid gland,
  behind T.M.J.
• It crosses root of zygomatic arch in front of
  auriculo-temporal N. auricle ,here its
  pulsation can be easily felt.

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Contents of Infratemporal fossa

• Lateral medial pterygoid muscles
  (muscles of mastication)
• Branches of the mandibular N.
• Otic ganglion.
• Chorda tympani.
• Maxillary artery.
• Pterygoid venous plexus.

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Lateral pterygoid

• Origin upper head---- from the infratemporal
  surface of the greater wing of sphenoid. Lower
  head---- from the lateral surface of lateral
  pterygoid plate.
• Insertion neck of mandible (pterygoid fovea)
  articular disc of T.M.J.
• N.supply anterior division.of mandibular N.
• Action
  1-Pulls the neck of mandible
  forward with the articular disc to depress
  mandible during opening of mouth.
  2-Acting with
  medial pterygoid of the same side during movement
  of chewing. 3-Acting with
  medial pterygoid to protrude the mandible.

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Medial pterygoid

• Origin superficial head----- from the
  tuberosity of the maxilla. Deep head----- from
  the medial surface of the lateral pterygoid
  plate.
• Insertion angle of mandible (medial surface).
• N.supply main trunk of mandibular N.
• Action
  1-elevates the mandible. 2-Acting
  with lateral pterygoid during movement of chewing.

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Tempromandibular joint (TMJ)

• Articlation between the articular tubercle
  mandibular fossa of temporal bone, and the head
  of mandible (condyloid process).
• Type condyloid synovial joint.
• Capsule it surrounds the joint.
• Synovial membrane--- lines the capsule in upper
  lower cavities.

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Ligaments of Temperomandibular joint

• Lateral temporomandibular ligament lies on the
  lateral side of joint ,between the tubercle and
  lateral surface of the neck of mandible.
• Sphenomandibular ligament lies on the medial
  side of the joint ,it connects the spine of
  sphenoid to the lingula of mandibular foramen.
• Stylomandibular ligament behind medial .to the
  joint. it is a band of thickened deep cervical
  fascia, from apex of styloid process to
  angle of mandibule.

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Intracapsular articular disc

• It is a plate of fibro-cartilage, it divides the
  joint into upper lower cavities.
• It is attached in front to the tendon of lat.
  pterygoid , and by fibrous bands to head of
  mandible.
• Its upper surface is concavo-convex to fit the
  articular tubercle mandibular fossa , while
  its lower surface is
  concave to fit the head of mandible.

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N.supply-auriculotemporal masseteric branches
of mandibular N. Movements

• Depression of mandibule by lat.pterygoid,
  helped by digastric, geniohyoid mylohyoid
  muscles.
• Elevation by temporalis, masseter, and medial
  pterygoid.
• Protrusion by lateral medial pterygoids of
  both sides.
• Retraction by post.fibers of temporalis .
• Lateral chewing movement by lat. med.
  Pterygoids of both sides acting alternately.

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Relation of the Temporomandibular joint (TMJ)

• Anteriorly mandibular notch and masseteric N.
  artery (structures passing through mandibular
  notch).
• Posteriorly ext.auditory meatus, glenoid
  process of parotid gland., auriculotemporal N.,
  superficial temporal artery.
• Laterally parotid gland, fascia skin.
• Medially maxillary vessels.

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Clinical significance of the TMJ

• The great strength of the Lat.TM ligament
  prevents head of mandible from passing backward
  to cause fracture of the tympanic plate in case
  of severe blow on the chin.
  
  
• The articular disc
  
• may be partially detached
  causing noisy
  audible
  click, during movements
  of the
  joint.

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Dislocation of the TMJ

• Sometimes occurs when the mandible is depressed.
• In case of minor blow on chin or sudden
  contraction of lateral pterygoids as in yawning,
  leads to pull the head of mandible articular
  disc forward beyond the summit of tubercle.
• Reduction of disloction by pressing the thumbs
  downward on the lower molar teeth and pushing the
  jaw backward.

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