ABPS Plastic Surgery Within the Head and Neck cheat sheet

Facial nerve branches (temporal, zygomatic, buccal, marginal mandibular, cervical) exit the stylomastoid foramen and traverse the parotid; the marginal mandibular branch runs near the inferior border of the mandible.

The external carotid artery gives off the superior thyroid, lingual, facial, occipital, and posterior auricular branches before bifurcating into the maxillary and superficial temporal arteries.

The trigeminal nerve (CN V) provides sensory innervation to the face via its ophthalmic (V1), maxillary (V2), and mandibular (V3) divisions; V3 also carries motor fibers to the muscles of mastication.

The facial artery crosses the mandible at the antegonial notch and ascends to the nasolabial fold, terminating as the angular artery; it anastomoses with the ophthalmic artery, a route for retrograde spread of infection.

Wound healing phases: hemostasis (immediate), inflammation (days 1–5), proliferation (days 5–21), and remodeling (weeks to months); facial skin heals faster than trunk skin due to rich vascularity.

Corticosteroids and chemotherapy impair wound healing by suppressing inflammation and fibroblast proliferation; vitamin C and zinc deficiency also delay collagen synthesis.

The scalp has five layers (skin, connective tissue, aponeurosis, loose areolar tissue, pericranium); the loose areolar layer is the plane of avulsion and danger space for infection.

Hypertrophic scars remain within the wound boundary and often improve with time; keloids extend beyond the original wound and have a high recurrence rate after excision alone.

Tension on facial wounds is minimized by aligning incisions with relaxed skin tension lines (RSTLs), which are perpendicular to the underlying mimetic muscle fibers.

Le Fort I fracture separates the maxilla from the pterygoid plates at the nasal floor; Le Fort II is pyramidal through the zygomaticomaxillary suture; Le Fort III is craniofacial disjunction through the frontozygomatic suture.

Zygomaticomaxillary complex (ZMC) fractures typically involve the zygomaticofrontal suture, zygomaticomaxillary buttress, zygomatic arch, and orbital floor; the infraorbital nerve is often injured.

Mandibular fractures are most common at the angle, followed by the body and condyle; bilateral condylar fractures can cause anterior open bite.

Orbital floor blowout fractures may entrap the inferior rectus muscle, causing restricted upward gaze and diplopia; urgent repair is indicated for entrapment or large defects (>50% of floor).

Naso-orbitoethmoid (NOE) fractures are classified by the status of the medial canthal tendon attachment; telecanthus indicates tendon avulsion or bony detachment.

Panfacial fractures are managed with a systematic sequence: reestablish mandibular arch, then maxillary position, then zygomatic and orbital reconstruction, and finally nasal projection.

Frontal sinus fractures with posterior table displacement or CSF leak may require cranialization or obliteration; anterior table fractures are often managed with open reduction and fixation.

Condylar fractures can be managed closed with maxillomandibular fixation or open reduction; indications for open include displacement into the middle cranial fossa, inability to obtain occlusion, and bilateral fractures with open bite.

Pediatric facial fractures have higher proportions of greenstick and minimally displaced fractures; resorbable plates may be used but can interfere with growth.

Craniosynostosis is premature fusion of one or more cranial sutures; scaphocephaly (sagittal) is most common, followed by trigonocephaly (metopic) and plagiocephaly (coronal).

Crouzon syndrome (FGFR2) features craniosynostosis, midface hypoplasia, proptosis, and normal extremities; Apert syndrome (FGFR2) adds syndactyly of hands and feet.

Pierre Robin sequence consists of micrognathia, glossoptosis, and cleft palate; airway obstruction may require prone positioning or mandibular distraction.

Treacher Collins syndrome (TCOF1) causes mandibulofacial dysostosis with downward-slanting palpebral fissures, malar hypoplasia, and microtia.

Fronto-orbital advancement is performed in infancy for craniosynostosis affecting the coronal sutures to relieve intracranial pressure and improve orbital position.

Distraction osteogenesis can lengthen the mandible or midface; latency phase 5–7 days, distraction rate 1 mm/day, consolidation 6–8 weeks.

Hemifacial microsomia (Goldenhar syndrome when associated with epibulbar dermoids and vertebral anomalies) arises from first and second pharyngeal arch defects.

Encephalocele is a neural tube defect with herniation of brain tissue through a skull defect; occipital encephaloceles are most common in Western populations, while frontoethmoidal are more common in Southeast Asia.

Squamous cell carcinoma is the most common head and neck malignancy; risk factors include tobacco, alcohol, and HPV (especially oropharyngeal).

Nodal staging: N1 = single ipsilateral node ≤3 cm; N2a = single ipsilateral 3–6 cm; N2b = multiple ipsilateral ≤6 cm; N2c = bilateral/contralateral ≤6 cm; N3 = >6 cm.

The most common intraoral site for SCC is the lateral tongue, followed by the floor of mouth; lesions >4 mm depth or with perineural invasion have higher nodal risk.

Free flap reconstruction options: radial forearm (thin, pliable, good for oral lining), fibula (bone for mandible), anterolateral thigh (bulk), and rectus abdominis (large defects).

Selective neck dissection levels: I–III for oral cavity, II–IV for larynx/hypopharynx, and II–V for oropharynx with advanced nodal disease.

Postoperative radiation therapy is indicated for positive margins, extracapsular nodal extension, perineural invasion, lymphovascular invasion, or multiple positive nodes.

Parotid malignancies: mucoepidermoid carcinoma is most common; facial nerve preservation is attempted unless directly invaded; high-grade tumors require neck dissection and adjuvant radiation.

Sentinel lymph node biopsy is used for early oral cavity SCC (cN0) and cutaneous melanoma to stage the regional basin and guide neck management.

Osteoradionecrosis risk increases with radiation dose >60 Gy, poor dental hygiene, and tooth extraction after radiation; hyperbaric oxygen may be used adjunctively.

The SMAS (superficial musculoaponeurotic system) is a continuous fibrous network investing the facial mimetic muscles; SMAS plication or elevation provides durable facelift results.

The danger zone for filler injection in the glabella and nasolabial fold includes the supratrochlear and dorsal nasal arteries; hyaluronidase is the antidote for hyaluronic acid fillers.

Rhinoplasty: the Keystone area is the junction of the upper lateral cartilages and nasal bones; over-resection of the dorsum can cause inverted-V deformity.

Blepharoplasty: the orbital septum is opened to access fat pads; the lacrimal gland must be identified and not resected; lateral canthal tendon laxity may require canthopexy.

Cervicofacial rhytidectomy: the marginal mandibular nerve is at risk in the sub-SMAS plane; the great auricular nerve is at risk posterior to the sternocleidomastoid.

Otoplasty: Mustardé sutures and conchal setback treat prominent ears; avoid overcorrection that causes a telephone ear deformity.

Chemical peels: superficial (glycolic, salicylic) affects epidermis; medium (TCA 35%) reaches papillary dermis; deep (phenol) reaches reticular dermis and carries higher risk of hypopigmentation and scarring.

Laser resurfacing: ablative (CO2, erbium) removes epidermis and heats dermis; fractional devices create microthermal zones to reduce downtime and complications.

Basal cell carcinoma is the most common cutaneous malignancy; subtypes include nodular, superficial, morpheaform, and basosquamous; morpheaform has higher recurrence and requires wider margins.

Squamous cell carcinoma of the skin: risk factors include UV exposure, immunosuppression, and chronic wounds; high-risk features include depth >2 mm, perineural invasion, and poor differentiation.

Melanoma: Breslow thickness is the strongest prognostic factor; sentinel lymph node biopsy is recommended for thickness ≥1 mm or ≥0.8 mm with ulceration.

Mohs micrographic surgery is indicated for recurrent, ill-defined, or cosmetically sensitive facial tumors; it offers highest cure rates with tissue conservation.

Excision margins: basal cell carcinoma low-risk 4 mm; squamous cell carcinoma low-risk 4–6 mm; melanoma in situ 5 mm, invasive melanoma 1–2 cm depending on thickness.

Sebaceous carcinoma occurs most often on the eyelid and can be misdiagnosed as chalazion; Muir-Torre syndrome association warrants genetic evaluation.

Dermatofibrosarcoma protuberans (DFSP) is a locally aggressive spindle cell tumor with tentacle-like extensions; wide local excision or Mohs with margins is required.

Cutaneous angiosarcoma of the scalp presents as a bruise-like patch and has a poor prognosis; treatment is wide excision with adjuvant radiation.

House-Brackmann scale grades facial nerve function from I (normal) to VI (total paralysis); grade III is moderate dysfunction with noticeable but not disfiguring asymmetry.

Bell's palsy is idiopathic facial nerve paralysis; corticosteroids within 72 hours improve recovery; antiviral agents may be added in severe cases.

Facial nerve anatomy: the nerve exits the stylomastoid foramen, divides at the pes anserinus into temporofacial and cervicofacial trunks, then into five branches.

Topographic diagnosis: forehead sparing suggests central (upper motor neuron) lesion; involvement of all branches suggests peripheral (lower motor neuron) lesion.

Facial nerve repair options: primary neurorrhaphy, interposition nerve graft (great auricular or sural), and nerve transfer (hypoglossal-facial, masseteric-facial).

Synkinesis after facial nerve recovery results from aberrant regeneration; treatment includes botulinum toxin injections and facial physical therapy.

Trigeminal neuralgia causes lancinating facial pain in V2/V3 distribution; first-line treatment is carbamazepine; microvascular decompression is definitive for refractory cases.

Spinal accessory nerve injury during neck dissection causes shoulder drop and winging; the nerve is located in the posterior triangle and is at risk in level V dissection.

Cleft lip results from failure of fusion of the medial nasal and maxillary processes; cleft palate from failure of fusion of the palatal shelves.

Timing of repair: cleft lip at 3–6 months (rule of 10s: weight >10 lb, hemoglobin >10 g/dL, age >10 weeks); cleft palate at 9–12 months before speech development.

The Millard rotation-advancement technique is commonly used for unilateral cleft lip repair; bilateral repairs may use Mulliken or Manchester techniques.

Palatoplasty techniques include von Langenbeck (bipedicled flaps) and Furlow double-opposing Z-plasty for soft palate lengthening.

Cleft palate repair may cause midface retrusion due to scarring; secondary alveolar bone grafting is performed at 6–9 years (mixed dentition) to support tooth eruption.

Velopharyngeal insufficiency after cleft palate repair causes hypernasal speech; evaluation includes nasopharyngoscopy and videofluoroscopy; treatment may be pharyngeal flap or sphincter pharyngoplasty.

Van der Woude syndrome is an autosomal dominant condition with lower lip pits and cleft lip/palate, linked to IRF6 mutations.

22q11.2 deletion syndrome (DiGeorge) features cleft palate, cardiac defects, hypocalcemia, and immunodeficiency; velopharyngeal insufficiency is common.

Malignant hyperthermia is triggered by volatile anesthetics and succinylcholine; treatment is dantrolene 2.5 mg/kg IV and supportive cooling.

Difficult airway predictors include Mallampati class III/IV, thyromental distance <6 cm, limited mouth opening, and cervical spine immobility.

Venous thromboembolism prophylaxis: Caprini risk assessment; mechanical prophylaxis for low risk, chemoprophylaxis with low-molecular-weight heparin for high-risk plastic surgery patients.

Local anesthetic maximum doses: lidocaine 4.5 mg/kg without epinephrine, 7 mg/kg with epinephrine; bupivacaine 2.5 mg/kg without epinephrine, 3 mg/kg with epinephrine.

Surgical site infection prevention: administer antibiotics within 60 minutes before incision, maintain normothermia, and avoid shaving the surgical site.

Perioperative beta-blockade should not be started on the day of surgery solely for perioperative risk reduction; continue chronic beta-blockers.

Postoperative nausea and vomiting prophylaxis: use multimodal approach with ondansetron, dexamethasone, and droperidol for high-risk patients.

Fire safety in the operating room: minimize oxidizer-rich environments, avoid alcohol-based prep pooling, and use a holster for electrocautery.

Informed consent requires disclosure of diagnosis, nature of procedure, risks, benefits, alternatives, and consequences of no treatment; the patient must have decision-making capacity.

Confidentiality is protected by HIPAA; exceptions include suspected abuse, public health reporting, and imminent threat to self or others.

Conflict of interest must be disclosed to patients and in research; financial relationships with device or pharmaceutical companies should be transparent.

Minors: consent from parent or guardian is generally required; emancipated minors may consent; emergency treatment may proceed without consent under the doctrine of implied consent.

Professional boundaries: avoid treating family members or close friends when possible; romantic relationships with patients are prohibited.

Research ethics: institutional review board (IRB) approval, informed consent, and equipoise are required for human subjects research; vulnerable populations need additional protections.

Medical errors should be disclosed to patients in a timely and honest manner; apology laws vary by state but generally protect expressions of sympathy.

Advertising and social media: maintain patient privacy, avoid misleading claims, and comply with state medical board regulations.