Facial nerve reanimation, Alopecia

Question 1

Describe the Norwood Classification of Male Pattern Baldness

Answer 1

Class I: Minimal to no recession

Class II: Small triangular areas of recession

Class III: Vertex hair loss (minimum grade to be considered balding)

Class IV: More severe frontotemporal recession (with vertex loss). Still a connected band of dense hair across the midline (thick bridge)

Class V: Progressing frontotemporal recession with vertex loss (thin hair bridge)

Class VI: High temporal hairline with loss of hair bridge

Class VII: Low temporal hairline

Kevan FP Page 80

Question 2

Describe the Ludwig Classification of Female Hair loss

Answer 2

Grade I: Minimal hair loss
Grade II: Moderate hair loss
Grade III: Severe, generalized thinning. Scalp easily visible.

Kevan FP Page 80

Question 3

List 8 functional deficits resulting from a distal (extracranial) facial nerve injury.

Answer 3

1. Incomplete eye closure
2. Oral incompetence
3. Decreased sensation to ear (posterior auricular branch)
4. Loss of brow elevation
5. Unilateral nasal obstruction
6. Upper lip ptosis
7. Loss of corneal reflex (efferent)
8. Articulation difficulties (orbicularis oris)

Question 4

What is the optimal timing for facial nerve repair?

Answer 4

A. If intraoperative or immediate complete FN paralysis post-trauma:
1. Immediate FN repair is ideal
2. Primary repair and grafting must be done within 72 hours (distal segments maintain stimulability and makes them easier to identify)
3. Ideal repair is a direct microanastomosis with no tension

B. If delayed onset:
1. Wait 1 year to observe for signs of recovery
2. Must do nerve repair within 3 years (motor end-plates begin to die after 3 years)

Within the temporal bone, thorough exposure of the site of injury is recommended, and surgical repair indicated when ≥ 50% of diameter is violated.

Question 5

List 4 options for facial reanimation

Answer 5

1. Primary anastomosis
2. Nerve Graft
3. Reinnervation Techniques
4. Dynamic Muscle Transfer

Question 6

Discuss nerve grafting for facial reanimation. What are the best choices?

Answer 6

1. Great auricular nerve if gap < 10cm
2. Sural nerve if gap > 10 cm
3. Medial antebrachial cutaneous nerve - ideal for total facial nerve reconstruction (has multiple branches)

Question 7

Discuss reinnervation techniques for facial reanimation. What are the best choices, and what are the advantages, disadvantages, and contraindications?

Answer 7

1. Hypoglossal nerve to facial nerve
   - Classic technique: CNXII is transected and a neurorhaphy is performed to the facial nerve stump
   - Jump graft: End-to-side between the hypoglossal nerve, and a donor cable graft (usually GAN). The donor graft is then sewn to the FN trunk
   - Advantages: Convenient location, dense population of motor axons, relative acceptability of hemi-tongue weakness
   - Disadvantages: Mass facial movement, variable tongue dysfunction
   - Contraindications: Patients that are likely to develop other neuropathies (e.g. NFII), patients with ipsilateral CNX deficits (may result in profound swallowing dysfunction
2. Spinal accessory to facial
3. Masseteric to facial
4. Cross face VII to VII grafting
   - Only donor source with the potential for mimetic function (e.g. involuntary blink, emotive smile)
5. trigeminal to masseter

Question 8

Describe dynamic muscle transfer for facial reanimation. What are the best choices?

Answer 8

• Free muscle transfer = Dynamic reconstruction
• Fascia lata suspension = Static reanimation

Regional Muscle Transfer:
- Temporalis (most common regional muscle transfer)
- Masseter (almost never used now due to contour defect and unfavourable vector of pull)
- Digastric

Free muscle transfer:
- Gracilis (most popular)
- Pectoralis minor
- Lattisimus Dorsi

• Free muscle transfer can either be reinnervated with an ipsilateral motor branch (e.g. masseter) in 1 stage, or with a cross-face-graft (2 stage).
• Single stage procedures have a higher success rate and greater excursion, but does not provide a spontaneous emotive smile
• 2 Stage approach:
• STAGE 1: Cross face nerve graft (usually sural) from contralateral facial nerve branches
• STAGE 2: 6-9 months later. Once there is appropriate reinnervation (assess with Tinel’s sign - tingling/pins needles over site), the Gracilis is attached to modiolus.

Question 9

Describe adjunctive approaches for facial reanimation for the upper face

Answer 9

Ptotic Brows
1. Brow lift

Upper lid
1. Eyelid weights (e.g. gold or platinum tarsal plate)
2. Eyelid spring placement
3. Tarsorrhaphy

Lower lid
1. Tarsal strip
2. Fascia lata sling (for weak lower lid)
3. Canthoplasty/canthopexy

Lacrimal function
1. Botox for Bogorad’s
2. Artificial tears for hypolacrimation

Question 10

Describe adjunctive approaches for facial reanimation for the mid face

Answer 10

Nose
1. Fascia lata sling for external nasal valve collapse
2. Alar batten grafting
3. Lateral crural extension grafts

Nasolabial fold
1. Suture suspension for flaccid paralysis
2. Botox for hypertonic paralysis

Oral Commissure
1. Static reanimation (Tensor fascia lata)
2. Dynamic reanimation:
a/ Regional muscle: temporalis, digastric, masseter
b/ Free muscle: Gracilis, pec minor, latissimus
- Can be one stage (ipsilateral) or two stage (with cross face nerve graft)

Options for static sling reconstruction:
Tensor fascia lata
Goretex
Alloderm
Dermis
Tendon (palmaris longus)
Silastic
Rubber

Question 11

Describe adjunctive approaches for facial reanimation for the lower face

Answer 11

1. Botox injection
2. Platysmectomy or botox injection for platysmal synkinesis

Question 12

What are the 3 basic smile shapes?

Answer 12

1. Zygomaticus smile (2/3 of patients)
   - Zygomaticus major and buccinator have strongest action
2. Canine Smile (30% of patients)
   - Zygomaticus major and levator labii superioris codominate
3. Full denture smile (2% of population)
   - Equal activation of lip elevators and depressors

kevan FP Page 78

Question 13

List the components of the pilosebaceous unit

Answer 13

“HAS”

H = Hair follicle (follicular matrix + hair shaft)
A = Arrector Pili muscle
S = Sebaceous gland

Question 14

Discuss hair growth physiology. What influences hair growth? What are the 4 stages of hair development?

Answer 14

• Around 100000 hairs in the human scalp
• Androgens regular and influence growth
• At puberty, androgens increase the size of follicles in the beard, chest, and extremities
• As you age, they have the opposite effect and decrease the size of scalp follicles

4 stages of hair growth development:
1. Anagen (growth phase)
- 90% of hair cells at any time
- Lasts 3-4 years
2. Catagen (involution)
- 1% of hair cells at any time
- Involutionary period (where cellular proliferation stops)
- Lasts ~2 weeks
3. Telogen (rest phase)
- 10% of hair cells at any time
- Dormant period lasts 3-4 months
4. Exogen (shedding)
- Proteolytic enzymes secreted during telogen cause hair cells to shed

Question 15

Discuss 10 causes of alopecia. What is the most common?

Answer 15

1. Androgenetic Alopecia (male pattern baldness) - most common cause of hair loss in both men AND women
2. Autoimmune disease (alopecia areata, discoid SLE)
3. Thyroid disorders
4. Burns
5. Chemotherapy
6. Dermatologic disorders (psoriasis, bacterial folliculitis)
7. Neoplasms
8. Radiation
9. Traction
10. Psychological (trichotillomania, stress)

Question 16

What is the difference between scarring vs. non-scarring alopecia?

Answer 16

In non-scarring alopecia, hair follicles are preserved with potential for hair regrowth.

In scarring alopecia, the hair follicle is irreversibly destroyed due to destruction of stem cells in the bulge area of the outer root sheath, and replaced by fibrous scar tissue, leading to permanent hair loss.

Question 17

Describe two types of non-scarring alopecias. What is their cause, how are they diagnosed, and how can they be treated?

Answer 17

1. Alopecia Areata: Autoimmune form of hair loss where T-cells mistakenly attack hair follicle. Can be further described as:
   - Alopecia Areata: one or more localized areas of hair loss
   - Alopecia Totalis: complete loss of scalp hair
   - Alopecia Universalis: total loss of body hair
   - Alopecia Incognito: widespread but diffuse hair loss
   Dx: Biopsy scalp
   Tx: High potency topical steroids
2. Telogen Effluvium
   - Diffuse hair shedding process where a large number of hairs shift to dormant period –> telogen
   - Response to major physiologic stress (crash dieting, childbirth, severe mental stress, chronic illness, etc.)
   - Results in rapid diffuse hair loss 3-4 months after stressor event
   Tx: usually self-limiting, no tx required

Question 18

What is the main type of scarring alopecia?

Answer 18

Cicatricial Alopecia
- Results in permanent hair loss due to inflammatory destruction of the pilosebaceous unit
- Hair transplants risky due to waxing and waning of inflammatory infiltrate

Question 19

What are 6 management options for alopecia? 2 med 4 surg

Answer 19

Medical Management
1. Finasteride (5-alpha reductase inhibitor. Reduces conversion of testosterone to DHT)
2. Minoxidil (Rogaine - opens potassium channels, vasodilator. Historically had been used for HTN, unclear why it helps hair growth. Best medical treatment option in women. Higher % concentrations in women can cause facial hair growth however. Usually leave at 2% solution. Refer to endocrinologist if Female pattern baldness)

Surgical Management
1. Hair grafting
- Donor dominance = transplanted hair will have features of donor site
- Multiple methods. More recently, follicular unit extraction is more population
2. Scalp reduction
- Excise areas of non-hair-bearing scalp
- Dependent on scalp laxity
- Seldom performed nowadays
- Useful in Norwood Class IV-VI
3. Tissue Expansion
- Tissue expander under scalp
- After expansion, perform a scalp reduction
- Useful where there is a large bald area and little scalp laxity
4. Scalp flaps
- Juri flap: rarely performed today (temporoparietal occipital flap). Pedicled transposition flap based on the superficial temporal artery . Flap is transposed to address the frontal hairline (only addresses frontal hairline).

Kevan FP Page 82

https://jamanetwork.com/journals/jamaotolaryngology/article-abstract/607895

Question 20

What does SPF mean?

Answer 20

SPF = Sun protection factor

SPF 15 = 1/15 of the burning radiation will reach the skin

Question 21

List 10 complications of hair restoration surgery

Answer 21

1. Hematoma
2. AV fistula
3. Hypertrophic/keloid scar
4. Poor hairline design
5. Telogen
6. Necrosis (e.g. scalp advancement)
7. Dehiscence (e.g. scalp advancement)
8. Poor preoperative planning (e.g. donut deformity)
9. Scarring
10. Cysts