8 Face, Scalp, CN V and VII Flashcards
Pt presents with severe scalp lacerations which were sutured. After 3 days, the wound is inflammed, swollen and painful. Between which layers is the infxn located?
Typically, infxns will be located in the loose CT (between the aponeurosis and periosteium) because of the ease with which infectious agents spread via the many veins located in the region. This is the danger zone of the scalp because infxns can be trasmitted into the skull via emissary veins.
Where is the location of the postganglionic PS neural cell bodies that directly innervate the parotid gland?
The otic ganglion lies on the mandibular division of the trigeminal nerve near the foramen ovale.
A woman feels a soft, thing ridge of tissue across the masseter muscle toward her upper lip. What structure is this?
The parotid duct (aka Stenson’s duct) crosses the masseter muscle transversely and extends to the oral cavity where it opens by the upper second molar.
The facial artery can be palpated in the groove anterior to the mandibular angle.
A patient has a type I LeFort fracture and comminuted fracture of the mandible and TMJ. The patient develops hyperacusis. Which muscle is most likely paralyzed?
The stapedius receives its innervation from the facial nerve and dampens the movement of the middle ear ossicles, thereby muting sound and preventing hyperacusis.
A patient injured her right greater petrosal nerve. What would be seen on examination?
The greater petrosal nerve carries PS fibers that are involved in the innervation of the lacrimal gland as well as the mucosal glands of the nose, palate and pharynx. Injury would result in decreased lacrimal secretion for the right eye.
Which nerve would a dentist need to anesthetize to treat tooth decay of the a mandibular molar teeth?
The inferior alveolar branch of the mandibular division of the trigeminal nerve provides sensory innervation to the mandibular teeth and would require anesthesia to abolish painful sensation.
A patient had facial paralysis postsurgery. There was accumulation of saliva in the vestibule of his oral cavity and dribble from the corner of his mouth. Which muscle was most likely paralyzed?
Normally, the tonus of the buccinator muscle prevents the accumulation of saliva and food in the oral vestibule.
Which artery supplies most of the blood to the tonsils?
The palatine tonsils are highly vascular and are primarily supplied by the tonsilar branch of the facial artery
A patient has pain between the lower eyelid and upper lip. To reach the trigeminal nerve, a needle would be inserted through which opening?
The infraorbital branch of the maxillary division of the trigeminal nerve exits the front of the skull below the orbit through the infraorbital foramen. A needle inserted into the infraorbital foramen and directed posterioly will pass through the foramen rotundum to reach the trigeminal ganglion and the beginning of the maxillary division of the trigeminal nerve.
Which layer of the scalp is regarded as the danger zone?
The loose, areolar CT is known as the danger zone because an infection can spread easily from this layer into the skull by means of emissary veins that pass into and through the bones of the skull.
Patient injured the inferior alveolar nerve at its origin. Which muscle would be paralyzed as a result?
Just before it passes into the mandible to supply the lower teeth and chin, the inferior alveolar nerve gives rise to the mylohyoid nerve, a motor nerve supplying the mylohyoid and anterior belly of the digastric.
An infant injured his facial nerve. What is the most common place for facial nerve injuries in an infant?
At the point where the facial nerve exits the stylomastoid foramen it is most susceptible to shearing forces. In infants, in whom the mastoid process has not yet developed, the facial nerve lies unprotected, just beneath the skin.
Which nerve is resposible for painful sensations from the region of the parotid gland?
The auriculotemporal nerve, a branch of the mandibular division of the trigeminal nerve (V3) leads into the parotid gland and its compression in mumps can be associated with severe pain.
Patient has nausea, vomiting and severe headaches. An MRI shows an acoustic neuroma. Which nerve is most likely compressed?
An acoustic neuroma (vestibular schwannoma or neurolemmoma) is a benign tumor of the vestibulocochlear nerve which causes compression of the facial nerve.
Extension of the neuroma into the right internal acoustic meatus can be seen in the MRI.
Examination of patient reveals lesion of the facial nerve proximal to the origin of the chorda tympani in the posterior wall of the tympanic cavity. Which function would remain intact?
The greater petrosal nerve is a branch of the facial nerve that ultimately supplies the lacrimal gland. This branch comes off the facial nerve at the geniculate ganglion proximal to the chorda tympani.
