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: Temporalis muscle Deep temporal nerve & vessels Superficial temporal vessels 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: With temporal fossa: through a gap deep to zygomatic arch With cranial cavity: through foramen ovale, foramen spinosum, foramen lacerum With orbit: through inferior orbital fissure With pterygopalatine fossa: through pterygomaxillary fissure
INFRATEMPORAL FOSSA CONTENTS: Lateral & medial pterygoid muscles Mandibular nerve & its branches A part of maxillary nerve & 2 of its branches Otic ganglion Chorda tympani A part of maxillary artery & 2 of its branches Pterygoid plexus of veins
THE MANDIBLE
TEMPOROMANDIBULAR JOINT
TEMPOROMANDIBULAR JOINT 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 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 NERVE SUPPLY: auriculotemporal ARTERIAL SUPPLY: maxillary MOVEMENTS: elevation, depression, protrusion, retraction, chewing (side-to- side) 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 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: Elevation of mandible 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: Elevation of mandible Protrusion of mandible (when muscles on both sides act together) Side-to-side movement (when muscles on both sides act alternatively)
LATERAL PTERYGOID 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 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 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