Transcript DENTAL GROSS ANATOMY CASE 3 INFRATEMPORAL FOSSA

DENTAL GROSS ANATOMY
CASE 3
INFRATEMPORAL FOSSA &
TEMPOROMANDIBULAR JOINT
HISTORY
Sherry Goldsmith was involved in a two-car collision and suffered severe facial
injuries.
EXAMINATION
In the ER she was found to have the following injuries:
1. The ramus of the mandible was shattered on the left side and displaced
medially into the infratemporal fossa.
2. The condyloid and coronoid processes were broken off on the left side.
3. The TMJ was driven medially breaking off the spine of the sphenoid.
4. A sliver of the windshield passed deeply into the infratemporal fossa,
reaching beyond the level of the infratemporal crest.
5. A large hematoma was found within the fossa shrouding the other contents.
After debridement of the wounds, an MRI was performed to determine the
total amount of the injuries.
POSTOPERATIVE OUTCOME
After a lengthy hospitalization and numerous surgeries, Ms. Goldsmith
was found to have the following neural and neuromuscular disorders:
1. Ipsilateral loss of taste sensations on the anterior part of the tongue.
2. Ipsilateral loss of general sensations on the anterior part of the tongue.
3. When the patient opens her jaw, the mandible deviates toward the side
of the injury.
4. Ipsilateral cutaneous anesthesia involving a strip of skin extending from
the lower lip and proceeding anterior to the ear and superior to the scalp.
5. Ipsilateral anesthesia of the lingual gingiva (mandibular region), floor of
the mouth and mandibular teeth.
6. There was a reduction of the volume of saliva.
1. What are the bony boundaries
of the infratemporal fossa?
BOUNDARIES OF THE INFRATEMPORAL FOSSA
Ramus of mandible
(lateral wall)
BOUNDARIES OF THE INFRATEMPORAL FOSSA
Temporal fossa
Infratemporal crest of
greater wing of sphenoid
Infratemporal surface of
greater wing of sphenoid
(roof)
Styloid process
(posterior wall)
Lateral pterygoid plate
(medial wall)
Infratemporal surface of maxilla
(anterior wall)
2. Name the six, usually expected,
contents of the infratemporal fossa.
1. Muscles of mastication
(except masseter)
2. Pterygoid plexus of veins
3. 1st and 2nd parts of maxillary a.
(mandibular and pterygoid parts)
4. Mandibular division of V (V3)
5. Otic ganglion
6. Chorda tympani n.
CONTENTS OF INFRATEMPORAL FOSSA
Mandibular n. (V3)
Lateral pterygoid m.
Chorda tympani n.
Medial pterygoid m.
CONTENTS OF INFRATEMPORAL FOSSA (MEDIAL VIEW)
V3
Otic ganglion
Chorda tympani n.
Maxillary a.
Medial pterygoid m.
CONTENTS OF INFRATEMPORAL FOSSA
Pterygoid plexus
Maxillary vv.
Superficial temporal v.
Retromandibular v.
3. Discuss the specific attachments
and actions of the muscles of
mastication.
Temporalis fascia
Temporalis m.
Zygomatic arch
Deep part
(masseter m.)
Superficial part
(masseter m.)
Temporalis m.
Insertion of temporalis m.
into coronoid process and
anterior border of ramus
of mandible
Insertion of masseter m.
into lateral surface of
ramus of mandible
Articular disc of TMJ
Superior and inferior heads
of lateral pterygoid m.
Superficial and deep heads
of medial pterygoid m.
Pterygoid fovea
of neck of mandble
Angle of mandible
4. Explain the peculiar deviation
of the intact mandible.
Lateral pterygoid plate
V3 injured
on this side
Lateral pterygoid m.
Medial pterygoid m.
Deviation of mandible
to paralyzed side
5. Name the foramen through which the
mandibular division of the trigeminal
nerve (V3) passes into the infratemporal
fossa.
In which boundary of the infratemporal
fossa is this foramen located?
Does V3 supply any muscles other than
the muscles of mastication?
Foramen ovale (V3)
in roof of infratemporal fossa
V3 SUPPLIES ALL MUSCLES DERIVED FROM
PHARYNGEAL ARCH 1
Temporalis
Masseter
Mylohyoid &
ant. belly of digastric
NOT SHOWN
Tensor palati &
tensor tympani
NOT SHOWN
Medial & lateral
ptergoids
Anterior division (V3) (mostly motor)
Posterior division (V3) (mostly sensory)
Temporalis fascia
and m.
Posterior and
anterior deep temporal nn.
Foramen ovale
Masseteric n.
Lateral pterygoid n.
and m.
Auriculotemporal n.
Chorda tympani n.
Buccal n.
(sensory)
Lingual n.
Inferior alveolar n. (cut)
Mylohyoid n.
(motor)
Mylohyoid m. (cut)
Inferior alveolar n. (cut)
Digastric m. (anterior belly)
Motor root
Sensory root
Mandibular n. (V3)
Tensor (veli) palatini m. and n.
Tensor tympani m. and n.
Medial pterygoid m. and n.
6. Explain the cutaneous loss
demonstrated by the patient.
V3
Mental n.
Buccal n.
Auriculotemporal n.
7. Explain the loss of taste on the
anterior part of the tongue.
Geniculate ganglion (of VII)
(sensory neurons)
Chorda tympani n.
(br. of VII) supplies
taste buds on
anterior 2/3 of tongue
8. Explain the decreased volume
of saliva.
V3
Otic ganglion
Lesser petrosal n.
Auriculotemporal n.
IX
Inferior salivatory nucleus
Parotid gland
Tympanic plexus
Tympanic n.
Presynaptic parasympathetic fibers
Postsynaptic parasympathetic fibers
Lingual n.
Chorda tympani n.
VII
Superior salivatory nucleus
Submandibular ganglion
Sublingual and submandibular glands
Presynaptic parasympathetic fibers
Postsynaptic parasympatheti fibers
9. a. Identify the branch of the maxillary
artery which enters the middle cranial
fossa. From what part of the maxillary a.
does it arise?
b. Discuss the pathway by which this
artery enters the middle cranial fossa.
Lateral pterygoid a. and m.
Anterior and posterior deep temporal aa.
Masseteric a.
Middle meningeal a.
Maxillary a.
Infraorbital a.
Posterior superior alveolar a.
Buccal a.
Medial pterygoid a. and m.
MAXILLARY A.
BRANCHES OF 1ST (MANDIBULAR) PART
BRANCHES OF 2ND (PTERYGOID) PART
BRANCHES OF 3RD (PTERYGOPALATINE) PART
Inferior alveolar a.
Middle meningeal a.
(entering foramen spinosum)
Auriculotemporal n.
9. c. What does this artery supply?
d. Name the condition which results from
tearing this artery within the cranial
cavity. What will be the consequence if
this injury is not repaired immediately?
Calvaria
Dura mater
Middle meningeal a.
(Does not supply the brain)
10. Through what fissure does the maxillary
artery extend medially out of the
infratemporal fossa?
Pterygomaxillary fissure
(conducts maxillary a. into pterygopalatine fossa)
11. a. What type of joint is the TMJ?
Be specific.
b. What structure lies inside the TMJ
and what kinds of movement occur
in each part of the joint?
TMJ IS A MODIFIED HINGE TYPE OF SYNOVIAL JOINT
Lower joint compartment (hinge action)
Upper joint compartment (gliding action)
Articular disc (avascular fibrous tissue)
Articular tubercle
Joint capsule
12. Describe the movements of the head
of the mandible when the mouth is
opened widely.
JAW CLOSED
JAW WIDELY OPENED
MOVEMENTS OCCURRING AT TMJ
13. Name the parts of the mandibular
fossa and their boundaries.
Articular tubercle
Mandibular fossa
(articular part formed
by squamous temporal)
Postglenoid tubercle
Mandibular fossa
(nonarticular part formed
by tympanic temporal)
14. What bony structure offers resistance to
medial displacement of the head of the
mandible?
Middle cranial fossa
Articular disc
Spine of sphenoid
15. Discuss the intrinsic and extrinsic
ligaments of the TMJ and the specific
function of the lateral thickening of the
fibrous capsule.
16. Name the arterial supply and nerve
supply of the TMJ.
Joint capsule
Lateral (temporomandibular) ligament
Styloid process
Stylomandibular ligament
.
Auriculotemporal n.
Maxillary a.
Inferior alveolar n.
Lingual n.
Sphenomandibular ligament
INTRINSIC LIGAMENT
EXTRINSIC LIGAMENTS
Mylohyoid a. and n.
17. Explain
(a) the movement resulting in the most
common displacement of the TMJ
(b) the “clicking” sound produced by
chronic dislocation of this joint.
DISLOCATION OF TMJ