1. The infraorbital nerve

a) Is a terminal branch of the maxillary division of the trigeminal nerve
b) is a terminal branch of the maxillary branch of the facial nerve
c) Carries parasympathetic secret motor neurons to the lacrimal gland
d) Innervates the inferior part of the orbicularis oculi muscle.

2. The lateral pterygoid muscle

a) Is attached to the coronoid process and elevates the mandible.
b) Is attached to the condylar process and elevates the mandible.
c) Is attached to the coronoid process and protrudes the mandible.
d) Is attached to the condylar process and protrudes the mandible.

3. Which of the following statements is true of the temporomandibular joint?

a) It has an articular disc of hyaline cartilage
b) Its articular surfaces are covered by hyaline cartilage
c) Proprioceptive information is carried by the chorda tympani and deep temporal nerves
d) Proprioceptive information is carried by the masseteric and auriculotemporal nerves.

4. The major concentrations of proprioceptive receptors providing information about position of the TMJ are located in

a) The capsule and ligaments of the TMJ and the medial pterygoid muscle.
b) the capsule and ligaments of the TMJ and the lateral pterygoid muscle
c) The articular disc of the TMJ and the medial pterygoid muscle.
d) The articular disc of the TMJ and the lateral pterygoid muscle.

5. Which muscle is the most active during a right lateral excursion of the mandible?

a) Left lateral pterygoid muscle
b) Right lateral pterygoid muscle
c) Left medial pterygoid muscle
d) Right medial pterygoid muscle

6. When you examine a patient who has suffered an unfavourable fracture of the body of the mandible, you would expect the

a) anterior fragment to be displaced downwards by the action of the digastric muscle
b) Posterior fragment to be displaced anteriorly by the action of the lateral pterygoid muscle.
c) anterior fragment to be displaced backwards by action of the temporalis muscle
d) Posterior fragment to be displaced medially by action of the medial pterygoid muscle.

7. Double contrast phase contrast arthroscopy is used to study

a) Clicking of TMJ
b) Deviation of TMJ
c) Joint space
d) Disc

8. Dislocation is treated by forcing the mandible

a) Upwards and backwards
b) Upwards and forwards
c) Downwards and forwards
d) Downward and backward

9. Hydrocortisone acetate is injected in a painful arthritic TMJ to

a) Increase the blood supply
b) Lubricate the synovial joint
c) Anaesthetize the nerve supply
d) Decrease the inflammatory response

10. The joint which is histologically & morphologically best simulate the tmj

a) 5th costochondral graft
b) 3rd metatarsal graft
c) Sternoclavicular graft
d) None of the above

Answers

1. A

The infraorbital nerve is the terminal cutaneous sensory branch of maxillary division of the trigeminal and contains no motor or autonomic neurons. There is no maxillary division of the facial nerve but branches of this nerve supply the orbicularis oculi muscles; they also carry parasympathetic neurons to the lacrimal gland.

2. D

The lateral pterygoid muscle is attached to the pterygoid fovea on the anterior aspect of the condylar neck of the mandible and its principal action is protrusion of the mandible.

3. D

The articular surfaces of the TMJ are covered by fibrocartilage, and the disc comprises dense fibrous tissue.

4. D

The capsule and ligaments of all synovial joints contain large numbers of proprioceptive nerve endings. In the TMJ, proprioceptive information from the lateral pterygoid muscles also plays a significant role in monitoring joint position.

5. D

The lateral pterygoid muscles protrude the mandible whereas the medial pterygoids elevate it. Lateral excursion is the equivalent of a unilateral protrusion on the opposite side from the deviation; thus the left muscle is most active during as right excursion

6. A

The elevator muscles of the mandible would displace the posterior fragment upwards and the suprahyoid muscles would displace the anterior fragment downwards thus separating the bones at the fracture line.

7. C

8. D

9. D

A temporomandibular joint (TMJ) injection is the injection of a corticosteroid into the affected jaw joint. The injections help to reduce inflammation and pain in the temporomandibular joint associated with chewing, talking, or yawning. This procedure can also help those suffering from chronic jaw pain.

10. C

The Sternoclavicular joint and TMJ are similar morphologically and histologically as they are the only two synovial joints covered with fibrocartilage.