Download 12-Temporal & infratemporal fossa I

Dr. Ahmed Fathalla Ibrahim
TEMPORAL FOSSA
TEMPORAL FOSSA
INFRATEMPORAL FOSSA
TEMPORAL FOSSA
BOUNDARIES:
• Anterior: Zygomatic process of
frontal bone + zygomatic bone
• Superior & Posterior: Temporal
lines
• Inferior: Zygomatic arch
TEMPORAL FOSSA
CONTENTS:
1. Temporalis muscle
2. Deep temporal nerve & vessels
3. Superficial temporal vessels
4. Auriculotemporal nerve
INFRATEMPORAL FOSSA
BOUNDARIES:
• Superficial (lateral): Ramus of mandible
• Deep (medial): Lateral pterygoid plate
• Superior: Infratemporal surface of
greater wing of sphenoid
• Anterior: Tuberosity of maxilla
INFRATEMPORAL FOSSA
COMMUNICATIONS:
1. With temporal fossa: through a gap
deep to zygomatic arch
2. With cranial cavity: through foramen
ovale, foramen spinosum, foramen
lacerum
3. With orbit: through inferior orbital
fissure
4. With pterygopalatine fossa: through
pterygomaxillary fissure
INFRATEMPORAL FOSSA
CONTENTS:
1. Lateral & medial pterygoid muscles
2. Mandibular nerve & its branches
3. A part of maxillary nerve & 2 of its
branches
4. Otic ganglion
5. Chorda tympani
6. A part of maxillary artery & 2 of its
branches
7. Pterygoid plexus of veins
THE MANDIBLE
TEMPOROMANDIBULAR JOINT
TEMPOROMANDIBULAR JOINT
• TYPE: synovial, condylar variety
• ARTICULAR SURFACES:
1. Upper: mandibular fossa + articular
tubercle
2. Lower: head of mandible
• CAPSULE: attached to:
1. margins of mandibular fossa &
articular tubercle
2. Neck of mandible
TEMPOROMANDIBULAR JOINT
•
JOINT CAVITY: divided into upper & lower
parts by an articular disc
• ARTICULAR DISC: a plate of fibrocartilage
with a concavoconvex upper surface and a
concave lower surface
• LIGAMENTS
1. Lateral temporomandibular: from tubercle
on the root of zygoma to lateral surface of
neck of mandible
2. Sphenomandibular: from spine of sphenoid
to lingula of mandible
3. Stylomandibular
TEMPOROMANDIBULAR JOINT
•
•
•
•
1.
2.
3.
4.
NERVE SUPPLY: auriculotemporal
ARTERIAL SUPPLY: maxillary
MOVEMENTS: elevation, depression,
protrusion, retraction, chewing (side-toside) movements
RELATIONS
Anterior: mandibular notch, masseteric
nerve & vessels
Posterior: tympanic plate of temporal bone
Lateral: Parotid gland
Medial: auriculotemporal nerve, maxillary
artery
MUSCLES OF MASTICATION
1.
2.
3.
4.
•
•
•
•
•
TEMPORALIS
MASSETER
LATERAL PTERYGOID
MEDIAL PTERYGOID
They are derived from mesoderm of 1st
branchial arch
They originate from temporal or
infratemporal fossa
They are inserted into ramus of mandible
They are supplied, through their deep
surfaces by branches of mandibular nerve
They act on temporomandibular joint
MUSCLES OF MASTICATION
MUSCLES OF MASTICATION
TEMPORALIS
•
ORIGIN: floor of temporal fossa & deep
surface of temporal fasica
• INSERTION: the tendon passes deep to
zygomatic arch to be inserted to all
coronoid process (except its lateral surface)
• NERVE SUPPLY: 2 deep temporal nerves
from anterior division of mandibular nerve
• ACTION:
1. Elevation of mandible
2. Its posterior fibers retract the mandible
MASSETER
•
ORIGIN: lower border & inner surface of
zygomatic arch
• INSERTION: lateral surface of ramus of
mandible
• NERVE SUPPLY: from anterior division of
mandibular nerve
• ACTION:
1. Elevation of mandible
2. Protrusion of mandible (when muscles on
both sides act together)
3. Side-to-side movement (when muscles on
both sides act alternatively)
LATERAL PTERYGOID
•
1.
2.
•
•
•
1.
2.
3.
ORIGIN:
Upper head: infratemporal surface of greater wing
of sphenoid
Lower head: lateral surface of lateral pterygoid
plate
INSERTION: pterygoid fovea (in front of neck of
mandible) + capsule & articular disc of TMJ
NERVE SUPPLY: from anterior division of
mandibular nerve
ACTION:
Pulls the condylar process forward to depress the
mandible
Protrusion of mandible (when muscles on both
sides act together)
Side-to-side movement (when muscles on both
sides act alternatively)
MEDIAL PTERYGOID
•
1.
2.
•
•
•
1.
2.
3.
ORIGIN:
Superficial head: tuberosity of maxilla
Deep head: medial surface of lateral pterygoid
plate
INSERTION: medial surface of ramus & angle of
mandible
NERVE SUPPLY: from trunk of mandibular nerve
ACTION:
Elevation of mandible
Protrusion of mandible (when muscles on both
sides act together)
Side-to-side movement (when muscles on both
sides act alternatively)
ALL MUSCLES OF
MASTICATION
Elevate mandible EXCEPT
• Lateral pterygoid
Protrude mandible EXCEPT
• Temporalis
Are supplied by anterior division of
mandibular nerve EXCEPT
• Medial pterygoid
MANDIBULAR NERVE
INFRATEMPORAL FOSSA
MANDIBULAR NERVE
• COMPOSITION:
• Formed of 2 roots: motor &
sensory
• ORIGIN:
• Sensory root: peripheral processes
of cells of trigeminal ganglion in
the middle cranial fossa
• Motor root: axons of cells of motor
nucleus of trigeminal nerve in pons
MANDIBULAR NERVE
• COURSE:
• Both roots emerge separately
through foramen ovale to
infratemporal fossa
• The 2 roots unite, below foramen
ovale
• The nerve soon divides into a
small anterior & a large posterior
division
MANDIBULAR NERVE
•
1.
2.
3.
RELATIONS:
Superficial: lateral pterygoid
Deep: otic ganglion
Posterior: middle meningeal artery
BRANCHES FROM TRUNK
OF MANDIBULAR NERVE
• One motor: Nerve to medial
pterygoid: supplies medial
pterygoid & gives off 2 branches
that pass through otic ganglion
(without relay) & supply tensor
palati & tensor tympani muscles
• One sensory: meningeal branch
(nervus spinosus) passing through
foramen spinosum to supply
meninges of middle cranial fossa
BRANCHES FROM ANTERIOR
DIVISION OF MANDIBULAR NERVE
Four branches
Three motor:
• Masseteric nerve: emerges through upper
border of lateral pterygoid & turns along
mandibular notch to reach masseter
• Deep temporal nerves: emerge through
upper border of lateral pterygoid
• Nerve to lateral pterygoid
One sensory:
• Buccal nerve: emerges between the 2 heads
of lateral pterygoid, supplies skin & mucous
membrane overlying buccinator
BRANCHES FROM POSTERIOR
DIVISION OF MANDIBULAR NERVE
Four branches
Three sensory:
Auriculotemporal nerve:
• Arises by 2 roots encircling middle
meningeal artery
• Runs backward, deep to neck of
mandible
• Gives sensory branches to skin of
auricle, temple, TMJ & parotid gland
• Carries postganglionic
parasympathetic secretomotor fibers
from otic ganglion to parotid gland
BRANCHES FROM POSTERIOR
DIVISION OF MANDIBULAR NERVE
Lingual nerve:
• Emerges through lower border of lateral
pterygoid then superficial to medial
pterygoid
• Joins chorda tympani
• Runs just below 3rd molar tooth (dangerous
position because it is only covered by
muscous membrane)
• Runs superficial to hyoglossus & is
connected to submandibular ganglion by 2
roots
• Carries general sensations from anterior 2/3
of tongue
BRANCHES FROM POSTERIOR
DIVISION OF MANDIBULAR NERVE
Inferior alveolar nerve:
• Emerges through lower border of
lateral pterygoid then superficial to
medial pterygoid, behind lingual nerve
• Passes through mandibular foramen &
canal to supply lower teeth
• Emerges through mental foramen as
mental nerve supplying skin of lower
lip & chin
BRANCHES FROM POSTERIOR
DIVISION OF MANDIBULAR NERVE
One motor:
Mylohyoid nerve:
• A branch of inferior alveolar nerve just
above mandibular foramen
• Passes in mylohyoid groove of
mandible
• Supplies mylohyoid & anterior belly of
digastric muscles
RELATIONS OF LATERAL
PTERYGOID
RELATIONS OF LATERAL
PTERYGOID
• Superficial: temporalis, masseter, ramus of
mandible, maxillary artery, buccal nerve
• Deep: medial pterygoid, mandibular nerve,
middle meningeal artery, otic ganglion
• Emerging through its upper border: deep
temporal & masseteric nerves
• Emerging through its lower border: lingual &
inferior alveolar nerves + maxillary artery
• Emerging between its 2 heads: buccal nerve,
maxillary artery