Plastic And Reconstructive Surgery Flashcards
In using GAN for facial nerve reinnervation, what length of the GAN can be harvested?
Sural nerve?
Medial antebrachial cutaneous nerve?
10cm
70cm
20cm
How many epineural sutures in nerve-nerve anastomosis?
4, with 8-10mm of extra length for each anastamosis
Most common smile form dominated by action of zygomaticus major muscle. Corners of mouth move laterally and superiorly
Mona lisa smile
Smile type dominated by levator labii superioris muscle. Vertical elevation of the upper lip, lateral elevation of the upper mouth.
Canine smile.
Smile type with simultaneous elevation of the elevators and depressors of the lips and angles of the mouth.
Full denture smile/toothy smile
When to perform EMG prior to performing reanimation?
12 mos after
Most desired neural source for rejuvination of the paralyzed face?
Ipsilateral facial nerve
Single most important test to determine type of operative procedure to be performed?
EMG
Type of EMG pattern in reinnervation?
Polyphasic potentials
EMG pattern where normal denervated muscles exist?
Denervation or fibrillation potentials
EMG pattern when there is atrophy or congenital absence of muscle, provided there is proper electrode positioning.
Electrical silence.
Order of priority of reinnervation of nerve.
Buccal and zygomatic
Marginal mandibular
Temporal
Cervical
Pinna is composed of what type of cartilage?
Fibrocartilage
Bowl of the ear has 3 concavities?
Cavum concha
Cymba concha
Fossa triangularis
Sensory innervation if the ear?
CN 5 (auriculotemporal nerve)
CN 7
CN X (arnolds nerve)
C2 and c3
Cartilagenous protuberance at the helix?
Darwins tubercle
Otic placode arises at what week aog?
3rd
Six hillocks arise at how many weeks aog?
6weeks aog
Hillocks fuse at how many weeks?
12th week. Failure to do so will result in pre auricular sinuses.
Cartilage formation begins at how many weeks aog? (Ear)
7 weeks
Helix furls at how many weeks aog? Antihelix?
8-12 weeks, 12-16weeks
Normal auriculocephalic angle?
25-35 degrees
What auriculocephalic angle is considered abnormal?
> 40-45 degrees
Pinna is positioned how many mm from the scalp?
15-20mm
Otoplasty done at what age?
5-6
What age does ear attain 85% of adult size?
Fully adult size?
3 years old
5-6 years old
Another name for V-Y pushback palatoplasty?
Oxford method
What is Sutherland’s classification for nerve injury?
1st degree: reversible nerve block
2nd degree: Wallerian degeneration occurs but endoneurium stays intact and recovery is usually complete.
3rd degree: Endoneurium is destroyed but perineurium stays intact and recovery is incomplete.
4th degree: All is destroyed except for the epineurium; recovery is poor.
5th degree: Complete nerve transection; untreated recovery is not expected.
What is Hering’s Law?
Unilateral ptosis with contralateral lid retraction-if you cover the ptotic eye with a patch for 30-60 minutes, the retracted eye will settle into the normal position and the ptotic eye will reveal itself.
What are the 4 strategies in the correction of a deviated septum?
- Septum straightening
- Complete osteotomies, including intermediate osteotomies
- Long and wide spreader grafts for cartilaginous dorsal deviation
- Strategic camouflage
Average epidermal thickness.
0.1 mm
Melanocytes are derived from?
Neural crest cells.
Epidermis is derived from?
Ectoderm
Dermis is derived from?
Endoderm.
Contains ground substance with highly developed microcirculation?
Papillary dermis
Contains thick bundles of collagen and elastic fibers?
Reticular dermis
Classification of flaps? (4) (FARM)
Free microvascular flaps
Arterial cutaneous (axial) flaps
Random cutaneous
Myocutaneous and fasciocutaneous flaps
Vascular supply of random cutaneous flaps?
Subdermal plexus. Plane of dissection subcutaneous fat. Survival of flaps depend on perfusion pressure and not length to width ratio.
Blood supply of acial flaps?
Septocutaneous aa.
Needs microvascular anastamosis of artery and vein.
Free microvascular flaps.
Flap can tolerate ___of complete avascularity and survive.
13 hours
Pressure at which there is no longer enough intravascular pressur to maintain capillary blood flow.
Critical closing pressure.
Neovascularization, which begins 3-4days after flap transposition, occurs at what rate?
0.2mm/day
New capillaries join preexisting flap vessels.
Inosculation.
Is a vasodilator and inhibitor of platelet aggregation.
PGI 2.
Tissues tolerate short periods of ischemia fairly well but exhibit histologic injury after return of perfusion. May be due to free radicals or lactic acid.
Reperfusion injury.
Principal structural framework of extracellular matrix?
Collagen 1 and 2.
Increase in strain seen when a constant stress is applied to th skin.
Creep
Decrease in stress when skin is held under tension in constant strain.
Stress relaxation.
Force required to counteract the attachment between the dermis and the underlying tissue.
Shearing force
Reduction of shearing force and wound tension is decreased with undermining of up to?
4cm
Most common intrinsic factor affecting flap survival is?
Inadequate blood flow
Improves blood flow, conditions tissue to ischemia, closes AV shunts.
Delay
How many hours delay to be effective?
At least 24 hours.
Vasodilators to increase flap viability?
Phenoxybenzamine Phentolamine Lidocaine Isoflurane Verapamil Nitroglycerin (venous>arterial)
Leaching/hyperbaric oxygen improves what zone of viability?
Zone 1.
How long is the inflammatory phase?
2-5 days.
After ____ days, lymphocytes (-> Langerhans cells) become the dominating leukocyte subset.
14days
Nitric oxide greatest during?
Inflammatory phase.