L15. Head and Neck 2

Question 1

Give the name of the round head of the TMJ and where it sits.

Answer 1

The chondyle is the head of the TMJ.

It sits in the mandibular fossa.

Question 2

Name the disk which snaps down when the jaw opens and recoils when the jaw is closed.

Answer 2

Articular disk

Question 3

Name the only muscle which depresses the mandible and contracts when the jaw is opened.

Answer 3

Lateral pterygoid muscle

Question 4

Name the 2 parts which make up the jaw.

Answer 4

Body

Ramus

Question 5

Name the lower, flatter part of the jaw (jawline)

Answer 5

Body

Question 6

Name 3 features found in the body of the jaw.

Answer 6

1. Mental foramen (hole below lower canines for the mental nerve)
2. Mylohyoid line (seen on lingual aspect below 3rd molar as a groove in the bone)
3. Mental spine (line of bone extending backwards under the tongue from teeth)

Question 7

Name 3 features of the ramus.

Answer 7

1. Coronoid process - at the opposite side to the condyle
2. Condylar process - the head forming the TMJ
3. Mandibular foramen - On lingual aspect below 3rd molar for nerves to enter the jaw.

Question 8

Where do the ramus and body meet?

Answer 8

At the angle of the mandible

Question 9

Name the nerve which runs inside the mandibular foramen on the lingual aspect.

Answer 9

Inferior alveolar nerve

Question 10

What type of joint is the TMJ? What does this mean?

Answer 10

TMJ is a synovial joint meaning it doesn’t just move up and down.

Question 11

What is the TMJ’s articular surface covered by?

Answer 11

Hyaline cartilage

Question 12

Name the feature which sits in the ramus and contracts to only allow the jaw to open so far.

Answer 12

Sphenomandibular ligament

Question 13

Name the feature which runs down the outside the ramus and limits the opening of the mouth.

Answer 13

Stylomandibular ligament

Question 14

Which ligament lies in front of the condyle and is stronger than the shenomandibular and stylomandibular ligaments?

Answer 14

Lateral ligament

Question 15

When is the TMJ most stable?

Answer 15

When the teeth are occluded as the condyle is securely in the articular fossa.

Question 16

Which type of jaw dislocation is most common? What should you do?

Answer 16

Forward dislocation.

Don’t pop it back into place as this can damage nerves.

Question 17

Which artery supplies the superficial temporal region (skull surface) and maxillary branches?

Answer 17

External carotid artery

Question 18

Name the 5 muscles of mastication.

Answer 18

1. Masseter (vertical in cheeks)
2. Buccinator (horizontal)
3. Temporalis
4. Medial pterygoid (angle of mandible to eye)
5. lateral pterygoid (horizontal filling jaw arch)

Question 19

Name the muscles of mastication which closes the mouth.

Answer 19

Masseter
Temporalis
Medial Pterygoid

Question 20

Name the muscle with a deep part (small) and a superficial part (larger)

Answer 20

Masseter

Question 21

Which muscle of mastication is classed as a facial muscle?

Answer 21

Buccinator

Question 22

What function does the medial pterygoid have?

Answer 22

Elevates and protrudes the mandible

Question 23

What function does the lateral pterygoid muscle have?

Answer 23

Depresses and protrudes the mandible

Question 24

Answer the following:
Medial pterygoid (opens/closes)
Lateral pterygoid  (opens/closes)
Masseter  (opens/closes)
Temporalis  (opens/closes)

Answer 24

Medial pterygoid - closes
Lateral pterygoid - opens
Masseter - closes
Temporalis - closes