Transcript Anatomical variation of filum terminale fusion and dural

Temporal and Infratemporal Fossae
and Temporomandibular Joint
R. Shane Tubbs, MS, PA-C, PhD
Temporal Fossa
Temporal Fossa
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Ovoid area:
supramastoid crest,
superior temporal
line, zygomatic arch
Floor: frontal, parietal,
sphenoid, temporal,
zygomatic bones
Roof: temporalis
fascia
Infratemporal Fossa
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“an irregular space inferior and deep to the
zygomatic arch and posterior to the
maxilla” RT Woodburne
Infratemporal Fossa Boundaries
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Medial: lateral pterygoid plate
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Lateral: ramus of the mandible
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Superior: > wing of sphenoid (ovale, spinosum)
and infratemporal crest
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Inferior: alveolar process maxillary bone
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Anterior: maxilla
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Posterior: temporal bone (e.g. styloid process)
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Communicates with pterygopalatine fossa
medially via pterygomaxillary fissure
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Communicates with orbit via inferior orbital
fissure
Primary Contents
Parotid gland (glenoid process)
 Muscles of mastication
 Maxillary artery
 Pterygoid venous plexus
 Mandibular nerve
 Sphenomandibular ligament
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Muscles of Mastication
Pterygoid Muscles
MOM Function
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Temporalis: elevation, retraction
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Masseter: elevation, protrusion (superficial
fibers)
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Medial Pterygoid: elevation
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Lateral Pterygoid: protrusion
Maxillary Artery
Maxillary Artery
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1st part (mandibular)- branches enter
foramina/canals e.g. EAM, petrotympanic
fissure
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2nd part (pterygoid)-muscular branches
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3rd part (pterygopalatine)-pterygopalatine
fossa branches
1st part
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Deep auricular
Anterior tympanic
Middle meningeal
Accessory meningeal
Inferior alveolar
2nd part
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Masseteric
Anterior deep
temporal
Posterior deep
temporal
Pterygoid
Buccal
3rd part
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Posterior superior
alveolar
Infraorbital
Descending palatine
Artery of pterygoid
canal
Pharyngeal
Sphenopalatine
Pterygoid Venous Plexus
Mandibular Nerve
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Anterior Division: motor less the (long)
buccal nerve
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Posterior Division: sensory less the nerve
to mylohyoid
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Trunk: Nerve to medial pterygoid (tensors)
and nervus spinosus
Temporomandibular Joint
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Modified hinge (hinge/gliding) joint
(synovial)
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Lined with Fibro vs. hyaline cartilage
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Articular disc (biconcave)
Spheno (petrotympanic) mandibular ligament:
remnant of Meckel’s cartilage
Stylomandibular ligament: parotid
fascia derivative
TMJ
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Medial dislocation prevented by spine of
the sphenoid
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Posterior dislocation prevented by
tympanic plate and styloid process
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Dislocation generally anterior to the
articular tubercle
TMJ
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Suprameniscal
compartment: protrusion
(45-60o)/retraction
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Inframeniscal
compartment:
elevation/depression