DENTAL GROSS ANATOMY: Answers to Sample Questions

Weeks of October 8,15, 2007

Two muscles which retract the mandible are the:
- A. Deep portion of the masseter and anterior temporal muscles
- B. Deep portion of the masseter and posterior temporal fibers
- C. Superficial masseter and posterior temporal fibers
- D. Superficial masseter and anterior temporal fibers
- E. Superficial masseter and middle temporal fibers
The meniscus attaches to the capsule in the TMJ:
- A. Only anteriorly
- B. Only posteriorly
- C. Only laterally
- D. Anteriorly and posteriorly
- E. Medially and laterally
At rest, the condyle is positioned:
- A. On the anterior slope of the articular eminence
- B. On the posterior slope of the articular eminence
- C. On the most superior aspect of the mandibular fossa
- D. On the posterior wall of the mandibular fossa
- E. None are correct
Emissary veins:
- A. Connect the dural venous sinuses with each other
- B. Are valveless and may conduct blood in either direction
- C. Do not pass through the foramen cecum
- D. Are associated only with the superior sagittal sinus
- E. Are an important drainage of the meninges
The tentorium cerebelli:
- A. Lies between the cerebellum and the frontal lobes of the brain
- B. Attaches to the lesser wing of the sphenoid
- C. Splits to enclose the transverse sinuses
- D. Has no free margins
- E. Attaches laterally to the squamous portion of the temporal bones

IDENTIFICATIONS

Nasal bones
Temporal bone (zygomatic process)
Mastoid air cell

The masseteric nerve passes through the mandibular notch. It is motor (efferent fibers) to the masseteric muscle and also has afferent fibers from the TMJ and the muscle. Cell bodies of the motor fibers are in the motor nucleus of the trigeminal nerve, located in the brain (pons). Cell bodies of the sensory fibers are in the trigeminal (semilunar) ganglion located on the petrous portion of the temporal bone in the middle cranial fossa.

CLINICAL CASE
If the bullet severely damages the lateral pterygoid muscle, protrusion of the mandible would be impaired and there would be an inability to move the jaw laterally to the the side opposite that of the injury. Difficulty opening and closing the mouth would also be expected. Often bullet fragments are not removed surgically unless function of the lateral pterygoid is impaired.