Week 9.1 - TMJ and infratempora fossa Flashcards Preview

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Flashcards in Week 9.1 - TMJ and infratempora fossa Deck (27)
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1
Q

What is the TMJ?

A

-Articulation between the cranium and the mandible which facilitates jaw movement

2
Q

Name the main bony features of the TMJ

A
  • Mandible head
  • Articular tubercle
  • Mandibular fossa
3
Q

What type of joint is the TMJ?

A

-Synovial

4
Q

Describe the fibrocartilage of the TMJ

A

-Covers both articular surfaces and also there is a fibrocartilage disk which separates the joint into two cavities (superior and inferior)

5
Q

Why is the articular disk of the TMJ important?

A
  • Bones are poorly aligned so allows them to fit

- Adds stabilisation of the joint as it is thinner in the centre and thicker at the edges

6
Q

Describe the capsule of the TMJ

A

-Loose and thin to allow movement but this sacrifices stability

7
Q

What is the main ligament of the TMJ which stengthens? Where is it?

A

-Temperomandibular ligament
-From zygoma to ramus of mandible
(2 medial ligaments also stengthen)

8
Q

Name the accessory ligaments of the TMJ

A
  • Sphenomandibular

- Stylomandibular

9
Q

What is the function of the accessory ligaments of the TMJ?

A

-Prevent inferior dislocation

10
Q

What separates the parotid from the submandibular gland? Why is this relevant to TMJ?

A
  • Deep parotid fascia

- Stylomandibular ligament forms part of this

11
Q

When is the jaw least stable?

A

-When it is open

12
Q

Why does occlusion of the teeth aid stabilisation?

A

-Most force is transferred through the teeth

13
Q

What limits posterior displacement of the jaw?

A

-Posterior glenoid tubercle

14
Q

What limits anterior displacement of the mandible?

A

-Articular tubercle

15
Q

What two types of movements produce all movements of the jaw?

A

-Translation and rotation

16
Q

Which cavity of the TMJ produces which movement?

A
  • Superior produces translation

- Inferior produces rotation

17
Q

Describe the movements which open the mouth

A
  • Translation as the condyles are pulled forward by the lateral pterygoids
  • Rotation as the chin is pulled down by digastric
18
Q

Describe the movements which close the mouth

A
  • Retraction of the mandible by posterior fibres of temporalis
  • elevation of the mandible by temporalis, masseter and medial pterygoid
19
Q

What is bruxism?

A

-grinding of the teeth during sleep

20
Q

What is the infratemporal fossa?

A

-Irregular shaped cavity which lies below the middle cranial fossa, behind the maxilla and zygoma

21
Q

State the boundaries of the infratemporal fossa

A
  • lateral -> ramus of mandible
  • medial -> lateral pterygoid plate of sphenoid
  • Anterior -> posterior surface of maxilla
  • Posterior -> Carotid sheath
22
Q

Name the muscular contents of the infratemporal fossa

A
  • Temporalis
  • Medial pterygoid
  • Lateral pterygoid
23
Q

Which nerves run through the infratemporal fossa?

A
  • Otic ganglion
  • Chorda tympani
  • Mandibular nerve gives branches auriculotemporal, inferior alveolar, buccal and lingual
24
Q

What are the arterial contents of the infratemporal fossa?

A
  • Maxillary artery (ECA) travels through the fossa

- Middle meningeal artery branches off here (travels into the cranium by foramen spinosum)

25
Q

Describe the venous contents of the infratemporal fossa

A
  • Pterygoid plexus
  • Maxillary vein
  • Middle meningeal vein
26
Q

State the openings into the infratemporal fossa

A
  • Foramen ovale (CNV3)
  • Foramen spinosum (MMA)
  • Alveolar canal
27
Q

Why are nerve blocks of relevance to the infratemporal fossa?

A
  • Inferior alveolar nerve block used in dentistry

- Mandibular nerve block used to block inferior alveolar, buccal, lingual and auriculotemporal