Dr Ahmed Fathalla Ibrahim TEMPORAL FOSSA TEMPORAL FOSSA
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
TEMPOROMANDIBULAR JOINT • • 1. 2. TYPE: synovial, condylar variety ARTICULAR SURFACES: Upper: mandibular fossa + articular tubercle Lower: head of mandible CAPSULE: attached to: margins of mandibular fossa & articular tubercle Neck of mandible
TEMPOROMANDIBULAR JOINT • • • 1. 2. 3. 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 Lateral temporomandibular: from tubercle on the root of zygoma to lateral surface of neck of mandible Sphenomandibular: from spine of sphenoid to lingula of mandible 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 1 st branchial arch They are inserted into ramus of mandible They are supplied, through their deep surfaces by branches of mandibular nerve They act on temporomandibular joint
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: 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 3 rd 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
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