# Facial Soft Tissue Trauma and Laceration Repair

## Introduction
The face is the most commonly injured body region in trauma; lacerations, avulsions, and soft tissue injuries require meticulous repair to optimize functional and aesthetic outcomes. Rich vascular supply of the face promotes wound healing and allows aggressive wound management (delayed primary closure up to 24 hours, minimal debridement). Systematic evaluation must exclude underlying fractures, ductal injuries, and nerve injuries before wound closure. Principles: anatomic alignment of landmarks, layered closure, tension-free repair, and respect for aesthetic subunits.

## Facial Anatomy Relevant to Trauma

### Aesthetic Subunits
Face divided into aesthetic subunits and regions: forehead, temples, periorbital, nose, cheeks, perioral, chin. Scars along **relaxed skin tension lines (RSTLs)** heal with superior cosmetic results. Repair should align wound edges with RSTLs whenever possible.

### Critical Structures at Risk
**Facial nerve**: exits stylomastoid foramen; five branches (temporal, zygomatic, buccal, marginal mandibular, cervical). Temporal branch: crosses zygomatic arch 1.5 cm anterior to the tragus; injury causes brow ptosis. Marginal mandibular branch: courses 1-2 cm below the mandible; injury causes lower lip asymmetry. Lacerations posterior to a vertical line from the lateral canthus should raise suspicion for facial nerve branch injury.

**Parotid duct (Stensen's duct)**: runs along a line from the tragus to the midpoint of the upper lip; crosses the masseter; penetrating injuries in this zone require duct evaluation. Test: cannulate the duct intraorally at the papilla opposite the second upper molar; irrigate with saline to check for extravasation. **Lacrimal system**: medial canthal lacerations may involve canaliculi; canalicular injury requires repair over silicone stents. **Trigeminal nerve branches**: supraorbital, infraorbital, and mental nerves exit through their respective foramina; all lie along a vertical line through the mid-pupil.

### Vascular Supply
**Facial artery**: primary blood supply to the face; courses along the anterior border of the masseter. **Superficial temporal artery**: supplies the temple and forehead. Rich anastomotic network allows survival of large flaps on narrow pedicles. Profuse bleeding from facial lacerations is common but rarely life-threatening; managed with direct pressure and ligation.

## Initial Evaluation and Management

### Primary Survey
Facial injuries are rarely immediately life-threatening but can compromise the airway. Assess for: airway obstruction (blood, edema, foreign bodies, mandible fractures), massive hemorrhage (internal maxillary artery injury), cervical spine injury. Control hemorrhage with direct pressure; avoid blind clamping (risk of nerve injury).

### Secondary Survey
Systematic examination of all facial structures. Test facial nerve function in all five distributions before administering local anesthetic. Assess parotid duct integrity for any laceration over the masseter. Check for lacrimal system injury in medial canthal wounds.

Evaluate for underlying fractures: palpate bony prominences, assess dental occlusion, check for step-offs. Ophthalmologic examination: visual acuity, pupillary response, extraocular movements, globe integrity. Document all injuries with photographs before and after repair.

### Wound Preparation
Copious irrigation: normal saline or tap water, minimum 150-250 mL per cm of wound length. High-pressure irrigation (using 30-60 mL syringe with 18-gauge needle or splash guard) reduces infection risk. Conservative debridement: remove only clearly nonviable tissue; preserve as much tissue as possible due to excellent facial blood supply. **Do NOT debride specialized structures**: eyelid margin, lip vermilion, nasal alar rim, ear cartilage.

Remove foreign bodies (glass, gravel, dirt) meticulously; retained debris causes traumatic tattooing. Shave hair only if absolutely necessary for wound visualization; **never shave eyebrows** (may not regrow, and loss eliminates an important landmark for alignment).

<image>Anatomical illustration of the face showing critical structures at risk during facial soft tissue trauma repair. The illustration shows a frontal view of the face with the skin partially transparent to reveal underlying structures. The five branches of the facial nerve are shown as yellow lines radiating from the stylomastoid foramen: the temporal branch crossing the zygomatic arch, zygomatic branches running toward the eye, buccal branches crossing the cheek, the marginal mandibular branch coursing below the mandible, and the cervical branch descending to the neck. The parotid duct is shown as a blue line running from the parotid gland across the masseter to its intraoral papilla opposite the second upper molar. A vertical dashed red line from the lateral canthus divides the face, indicating that nerve injuries lateral to this line may not recover spontaneously. The supraorbital, infraorbital, and mental foramina are marked along a vertical line through the mid-pupil. The facial artery is shown ascending along the anterior border of the masseter.</image>

## Laceration Repair Principles

### Anesthesia
Local anesthesia with lidocaine 1% with 1:100,000 epinephrine (safe on the face including nose and ears). Regional nerve blocks provide superior analgesia with less tissue distortion: supraorbital/supratrochlear (forehead), infraorbital (midface), mental (lower lip and chin). Allow 7-10 minutes for epinephrine effect before repair.

### General Principles of Closure
**Align anatomic landmarks first**: vermilion border, eyebrow, nasal alar rim, helical rim, hairline. Even 1 mm of malalignment at the vermilion border is noticeable; mark the border with a surgical pen before injecting anesthetic. **Layered closure**: deep dermal sutures (absorbable, 4-0 or 5-0 Vicryl/Monocryl) to close dead space and reduce skin tension; skin sutures (6-0 nylon or fast-absorbing gut) for precise epidermal approximation. Evert wound edges with each suture to prevent depressed scar formation. Minimize suture marks: remove facial sutures at 5-7 days (earlier than body sutures).

### Specific Wound Types

#### Simple Lacerations
Irrigate, align landmarks, layered closure. Consider tissue adhesive (2-octyl cyanoacrylate) for superficial, tension-free wounds in children.

#### Stellate and Irregular Lacerations
Do not convert to elliptical excision unless tissue is clearly nonviable. Trim irregularities minimally; close in layers. Irregularly closed wounds often heal better than expected due to facial vascularity.

#### Avulsion Injuries
Replant avulsed tissue whenever possible; even partially attached flaps with narrow pedicles survive due to facial vascularity. Completely avulsed tissue: replant as composite graft for ear and nasal tip (high take rate). Large avulsions may require local flap reconstruction or staged repair.

#### Tissue Loss
Primary closure with local tissue rearrangement if possible. Temporary coverage with moist dressings if extensive; delayed reconstruction with flaps. Healing by secondary intention may be appropriate in concavities (medial canthus, temple, nasal alar crease).

### Region-Specific Considerations

#### Lip Lacerations
Align the **vermilion-cutaneous junction (white roll)** as the first suture. Through-and-through lacerations: close in three layers (mucosa, orbicularis oris muscle, skin). Mucosal layer with absorbable sutures (4-0 chromic or Vicryl). Close orbicularis oris with 4-0 absorbable sutures to restore sphincter function.

#### Eyelid Lacerations
Full-thickness eyelid lacerations require three-layer closure: conjunctiva, tarsal plate, skin-orbicularis. **Marginal lacerations**: align the gray line precisely; use 6-0 silk marginal sutures. Canalicular injury: repair over silicone stents (Crawford or Mini-Monoka); refer to oculoplastic surgery if unsure. **Do NOT use epinephrine** near the globe (theoretical vasoconstriction concern, though debated).

#### Ear Lacerations
Preserve all cartilage; close perichondrium over exposed cartilage to prevent chondritis. Through-and-through: close anterior skin, cartilage with absorbable sutures, posterior skin. Bolster dressing to prevent auricular hematoma (which causes cauliflower ear deformity). Exposed cartilage without perichondrium: local flap coverage; avoid secondary intention healing.

<image>Step-by-step illustration of lip laceration repair demonstrating vermilion border alignment. Panel A shows a full-thickness lower lip laceration extending through the vermilion border with the wound edges separated and the malaligned vermilion-cutaneous junction visible. A marking pen dot is placed on each side of the vermilion border to ensure precise alignment. Panel B shows the first suture placed precisely at the vermilion-cutaneous junction (white roll) aligning the two marking pen dots. Panel C shows the layered closure from deep to superficial: the mucosal layer closed with absorbable sutures on the inner surface, the orbicularis oris muscle reapproximated with buried absorbable sutures in the middle layer, and the skin closed with fine interrupted nylon sutures on the outer surface. Panel D shows the completed repair with precise alignment of the vermilion border, no step-off visible, and everted skin edges.</image>

## Adjunctive Management
**Tetanus prophylaxis**: update if not current. **Antibiotics**: not routinely indicated for simple facial lacerations; indicated for bite wounds (human and animal), heavily contaminated wounds, through-and-through oral wounds, and immunocompromised patients. Amoxicillin-clavulanate for bite wounds. **Bite wounds**: human bites (most infection-prone) and dog bites; irrigate copiously; primary closure is safe on the face (unlike other body regions) due to vascularity; cat bites have highest infection rate.

**Scar management**: sun protection for 12 months, silicone gel/sheeting starting at 2-4 weeks, scar revision considered after 12 months if needed.

## Complications
**Infection**: 1-2% for facial lacerations (low due to vascularity); higher for bite wounds and contaminated wounds. **Traumatic tattooing**: retained foreign material (asphalt, dirt, gunpowder) permanently discolors skin; requires early aggressive scrubbing or dermabrasion within 24-48 hours. **Scar widening**: from excessive wound tension or premature suture removal. **Nerve injury**: facial nerve branches; those distal to the lateral canthus may recover spontaneously; proximal injuries require microsurgical repair. **Duct injury**: missed parotid duct injuries lead to sialocele or salivary fistula.

## Key Clinical Pearls
Always test facial nerve function before administering local anesthetic; lacerations posterior to a vertical line from the lateral canthus require specific nerve branch evaluation and may need microsurgical repair. The vermilion-cutaneous junction is the most critical landmark in lip repair; even 1 mm of malalignment produces a noticeable deformity; mark it before injecting anesthetic. Never shave eyebrows; they serve as essential alignment landmarks and may not regrow. The rich vascular supply of the face allows aggressive tissue preservation; replant avulsed segments as composite grafts and close wounds up to 24 hours after injury with low infection rates. Retained foreign bodies (gravel, glass, asphalt) cause permanent traumatic tattooing and must be removed within 24-48 hours; if missed, dermabrasion can be attempted but results are inferior to primary removal.

## References
- Hollander JE, Singer AJ, Valentine S, Henry MC. Wound registry: development and validation. Ann Emerg Med. 1995;25(5):675-685.
- Holt GR, Holt JE. Incidence of eye injuries in facial fractures: an analysis of 727 cases. Otolaryngol Head Neck Surg. 1983;91(3):276-279.
- Talan DA, Citron DM, Abrahamian FM, et al. Bacteriologic analysis of infected dog and cat bites. N Engl J Med. 1999;340(2):85-92.
- Zide MF, Kent JN. Indications for open reduction of mandibular condyle fractures. J Oral Maxillofac Surg. 1983;41(2):89-98.