Face and Scalp

Question 1

why do facial lacerations tend to gape?

Answer 1

b/c face has no distinct deep fascia and the subQ b/w the cutaneous attachments of facial muscles is loose

Question 2

does a partially detached scalp have good chance to heal if replaced?

Answer 2

reasonable chance if one of the vessels supplying the scalp is intact

Question 3

what is the scalp proper and what is its clinical significance?

Answer 3

the first three layers of scalp - clinically considered one layer b/c they remain together when scalp flap is made

Question 4

does loss of scalp produce necrosis of calvarial bones? why or why not?

Answer 4

no - calvaria supplied by middle meningeal arteries, not by arteries of scalp

Question 5

why do superficial scalp wounds usually not gape?

Answer 5

epicranial aponeurosis

Question 6

why do deep scalp wounds gape widely?

Answer 6

laceration of epicranial aponeurosis leads to pulling in opposite directions by both the frontal and occipital muscle bodies

Question 7

what is the danger area of the scalp?

Answer 7

the loose CT layer b/c pus or blood spreads easily in it and can pass through emissary veins and reach intracranially

Question 8

why can a scalp infection not pass to neck?

Answer 8

b/c occipital bellies or occipitofrontalis muscle attach to the occipital bone and mastoid parts of temporal bones

Question 9

why can a scalp infection not pass laterally beyond zygomatic arches?

Answer 9

b/c epicranial aponeurosis is continuous w/ temporal fascia that attaches to these arches

Question 10

why can a scalp infection spread to the eyelid or root of nose?

Answer 10

b/c occipitofrontalis inserts into skin and subQ and does not attach to bone

Question 11

what is peri-orbital ecchymosis?

Answer 11

black eye

Question 12

what is ecchymosis?

Answer 12

purple patches - from extravasation of blood into subQ and skin of eyelids and surrounding areas

Question 13

what are sebaceous cysts?

Answer 13

cysts of ducts of sebaceous glands in skin (can move with scalp)

Question 14

what is cephalhematoma?

Answer 14

blood trapped in the pericranium/calvaria, usually over one parietal bone - benign

Question 15

what results w/ chronic mouth breathers?

Answer 15

dental malocclusion (improper bite)

Question 16

function of anti-snoring devices

Answer 16

attach to nose to flare the nostrils and maintain a more patent air passageway

Question 17

what does paralysis of orbicularis oculi cause?

Answer 17

-inferior eyelid everts (falls away from eye) -> lacrimal fluid not spread over cornea -> dehydration, not enough lubrication or flushing of cornea surface -> vulnerable to ulceration

Question 18

what does paralysis of orbicularis oris or buccinator cause?

Answer 18

food accumulates in oral vestibule during chewing

Question 19

where is an infraorbital nerve block done?

Answer 19

in region of infraorbital foramen, by elevating the upper lip and passing the needle through the junction of the oral mucosa and gingiva as the superior aspect of the oral vestibule

Question 20

mental nerve block

Answer 20

injection of anesthetic into the mental foramen blocks the mental nerve that supplies the skin and mucous membrane of lower lip from mental foramen to midline, including skin of chin

Question 21

buccal nerve block

Answer 21

injection of anesthetic into mucosa covering retromolar fossa to anesthetize skin and mucous membrane of cheek

Question 22

where is the retromolar fossa?

Answer 22

triangular depression posterior to the 3rd mandibular molar tooth b/w the anterior border of ramus and temporal crest

Question 23

what is trigeminal neuralgia/tic douloureux?

Answer 23

• sensory disorder of sensory root of CN V
• middle aged and old people
• sudden attacks of excruciating, lightening like jabs of facial pain (paroxysm)
• pain may be so intense a person winces (tic)
• demyelination of axons in sensory root

Question 24

what is paroxysm?

Answer 24

sudden sharp pain

Question 25

which nerve is most commonly involved in tic douloureux?

Answer 25

V2 then V3 then V1

Question 26

what initiates the paroxysms of tic douloureux?

Answer 26

touching a trigger zone, frequently around tip of nose or cheek

Question 27

what most often causes tic douloureux?

Answer 27

pressure of a small aberrant artery

Question 28

treatments for tic douloureux?

Answer 28

• surgery
• infraorbital nerve block
• radiofrequency selective ablation of parts of trigeminal ganglion
• rhizotomy
• tractotomy (sectioning spinal tract)

Question 29

lesions of trigeminal nerve cause widespread anesthesia involving:

Answer 29

• corresponding anterior half of scalp
• face, except for an area around the angel of the mandible, cornea, and conjunctiva
• mucous membranes of nose, mouth, and anterior tongue

-also get paralysis of muscles of mastication

Question 30

herpes zoster infection of trigeminal ganglion

Answer 30

• may produce a lesion in the cranial ganglia
• eruption of groups of vesicles following the course of the affected nerve (ophthalmic herpes zoster)
• often get corneal ulceration and scarring

Question 31

how do you test sensory function of CN V?

Answer 31

pt closes eyes, responds when types or touch are felt - one for each branch of V

Question 32

lesions of facial nerve prior to origin of greater petrosal n. vs. after origin of greater petrosal n.

Answer 32

before: loss of motor, taste, autonomic fxn
after but before chorda tympani: same but lacrimal secretion not affected
after both: loss of motor fxn only

Question 33

most common nontraumatic cause of facial paralysis

Answer 33

inflammation of the facial nerve near the stylomastoid foramen, often from viral infection

Question 34

what are some other causes of facial paralysis?

Answer 34

• fracture of temporal bone
• idiopathic
• following exposure to cold
• complication of surgery
• dental manipulation
• vaccination
• pregnancy
• HIV infection
• Lyme disease
• infections of middle ear (otitis media)

Question 35

what does a lesion of the zygomatic branch of CN VII cause?

Answer 35

paralysis, including loss of tonus of orbicularis oculi in inferior eyelid

Question 36

what does lesion of buccal branch of CN VII cause?

Answer 36

paralysis of buccinator and superior portion of orbicularis oris and upper lip muscles

Question 37

what does lesion of the marginal mandibular branch of CN VII cause?

Answer 37

paralysis of inferior portion of orbicularis oris and lower lip muscles

Question 38

where do you compress facial artery to stop bleeding from one of its branches?

Answer 38

on both sides b/c of numerous anastamoses b/w facial artery and other arteries of face

Question 39

describe bleeding and healing of facial wounds in feneral

Answer 39

bleed freely and heal quickly

Question 40

where can you feel temporal pulse?

Answer 40

where superficial temporal artery crosses zygomatic process just anterior to auricle

Question 41

where can you feel facial pulse?

Answer 41

as facial artery crosses inferior border of mandible immediately anterior to masseter muscle

Question 42

if you have stenosis of internal carotid artery, how can the intracranial structures receive blood?

Answer 42

from connection of facial artery to the dorsal nasal branch of ophthalmic artery

Question 43

what are the most common type of head injury requiring surgical care?

Answer 43

scalp lacerations- bleed profusely b/c arteries do not retract following lacerated due to dense CT layer of scalp holding them open

Question 44

squamous cell carcinoma of lip: where does it occur, what causes it, where does it spread?

Answer 44

• usually involves lower lip
• overexposure to sun, chronic irritaiton from pipe smoking
• spreads to submental lymph nodes if on central part of lower lip, floor of mouth, and apex of tongue
• spreads to submandibular nodes if on lateral parts of lower lip