# Soft Tissue Injuries of the Face

## Overview

Facial soft tissue injuries are common and range from simple lacerations to complex avulsions. The face has an excellent blood supply, providing superior healing potential and infection resistance. The principles of management are meticulous wound assessment, minimal debridement, layered closure, and preservation of specialized structures. Functional and aesthetic outcomes depend on early, careful management. Specialized structures at risk include the facial nerve, parotid duct, lacrimal system, lip vermillion, nasal cartilage, and eyelid structures.

## Wound Assessment

### History

The mechanism of injury (sharp, blunt, crush, avulsion, bite) and the time since injury are important. The golden period for primary closure of facial wounds extends up to 24 hours, which is longer than other body regions due to the face's excellent vascularity. Contamination (soil, saliva, foreign bodies), tetanus immunization status, allergies and medications (especially anticoagulants), and pre-existing conditions affecting healing (diabetes, immunosuppression) are all assessed.

### Examination

Wound characteristics including depth, length, tissue loss, and contamination are documented. Vital structures are assessed before local anesthesia when possible: facial nerve function (all five branches), parotid duct integrity (expressing saliva from Stensen duct), lacrimal system (evaluating for canalicular injury in medial canthal lacerations), extraocular muscles (in periorbital lacerations), and globe integrity (in periorbital wounds). Foreign bodies such as glass, gravel, and teeth fragments are sought (with radiograph if suspected). Associated fractures are identified by palpating underlying bone through the wound.

## Principles of Facial Wound Management

### Wound Preparation

Anesthesia is provided with local infiltration or regional nerve blocks before wound exploration. Copious normal saline irrigation (pulse lavage or syringe irrigation) at 100-250 mL per centimeter of wound length removes debris and reduces bacterial load. Debridement in the face should be conservative, preserving as much tissue as possible. Only clearly necrotic tissue is excised, and ragged edges are minimally trimmed for better approximation. Tissue should never be aggressively excised because the excellent facial blood supply allows survival of tissue that would be debrided elsewhere. Foreign body removal requires meticulous extraction of all particulate matter to prevent tattooing, using a scrub brush for embedded road debris and a needle tip for individual particles.

### Closure Principles

Layered closure is critical for facial wounds to prevent dead space and optimize cosmesis. Deep layers use absorbable sutures (polyglactin/Vicryl, poliglecaprone/Monocryl). Muscle reapproximation (orbicularis oculi, orbicularis oris) restores function. Skin closure uses fine non-absorbable sutures (6-0 nylon for the face, 5-0 for the scalp) or tissue adhesive for superficial wounds. Landmarks are aligned first: vermillion border, eyebrow, alar rim, helical rim, and hairline. A 1 mm mismatch at the vermillion border is noticeable, so it should be marked before injection of local anesthetic. Skin edges are everted to prevent depressed scars. Tension is minimized by undermining when necessary and using deep dermal sutures to close dead space and offload skin tension. Suture removal timing is 5 days for the face (to minimize suture marks), 7-10 days for the scalp, and 3-5 days for eyelids.

<image>Step-by-step illustration of layered facial laceration repair showing wound irrigation, conservative debridement, deep absorbable suture placement to close dead space and approximate muscle layers (orbicularis oris), precise alignment of the vermillion border with the first skin suture placed at this landmark, and final skin closure with everted edges using 6-0 nylon interrupted sutures</image>

## Management of Specific Structures

| Structure | Key Landmark/Concern | Repair Technique | Suture/Material | Critical Point |
|---|---|---|---|---|
| Lip | Vermillion border | Layered: mucosa, muscle, skin | 6-0 nylon (skin), 4-0 Vicryl (muscle) | 1 mm mismatch is noticeable |
| Eyelid | Gray line (mucocutaneous junction) | Tarsal plate + 3 margin sutures + skin | 5-0 Vicryl (tarsus), 6-0 nylon (skin) | Canalicular stent if medial |
| Parotid duct | Tragus-to-upper-lip line | Microsurgical anastomosis over stent | 8-0 to 9-0 nylon | Stent 2-4 weeks |
| Facial nerve | Lateral canthus-to-angle line | Epineural repair (proximal injuries) | 8-0 to 10-0 nylon | Repair within 72 hours |
| Ear | Cartilage exposure | Cartilage reapproximation + bolster | 5-0 Vicryl (cartilage) | Drain hematoma immediately |
| Nose | Septal hematoma | Layered closure; drain hematoma | Absorbable (cartilage), 6-0 nylon (skin) | Untreated hematoma = saddle nose |

### Lip Lacerations

The vermillion border is aligned by marking the white roll/vermillion junction with a skin marker before injecting local anesthetic. The first suture is placed precisely at the vermillion border because even 1 mm mismatch is conspicuous. Full-thickness lip lacerations are closed in layers: mucosa (4-0 or 5-0 chromic gut or Vicryl), orbicularis oris muscle (4-0 or 5-0 Vicryl, which is critical for sphincter function), and skin (6-0 nylon). For tissue loss less than 25% of the lip, primary closure with advancement is performed; greater than 25% may require local flap reconstruction (Abbe flap, Karapandzic flap, or Estlander flap).

### Eyelid Lacerations

Lid margin lacerations require precise repair to prevent notching. The gray line (mucocutaneous junction) is aligned as the first reference point. Tarsal plate repair (5-0 or 6-0 Vicryl) provides structural support. Three key margin sutures are placed at the gray line, lash line, and meibomian gland orifice line, followed by skin closure. Ophthalmology consultation is obtained for complex lid injuries. If ptosis is present, levator palpebrae involvement should be suspected and requires repair. Canalicular lacerations of the medial lower or upper lid injure the lacrimal drainage system and require canalicular stenting (Crawford tubes or monocanalicular stent). The silicone stent is left in place for 3-6 months. Failure to repair leads to chronic epiphora.

### Parotid Duct Injury

Parotid duct injury should be suspected when a laceration lies in the mid-cheek area along a line from the tragus to the midpoint of the upper lip (the course of Stensen duct). Diagnosis involves cannulating the duct intraorally and irrigating with saline to observe for egress from the wound. Repair involves primary microsurgical anastomosis over a stent (IV catheter or silicone tubing placed through the duct), with the stent maintained for 2-4 weeks using 8-0 or 9-0 nylon for ductal repair. If the duct is unrepairable, it is ligated (the parotid gland undergoes atrophy) or a controlled fistula into the oral cavity is created. Failure to address the injury results in sialocele or cutaneous salivary fistula.

### Facial Nerve Injury

The location of injury determines management. Proximal to a line from the lateral canthus to the mandibular angle, repair is required because nerves will not spontaneously recover. Distal (anterior) to this line, extensive branching and cross-innervation allows spontaneous recovery, and observation is usually appropriate. Repair technique involves primary epineural repair with microsurgical technique (8-0 to 10-0 nylon under magnification). Repair should occur within 72 hours when possible, as nerve stimulation can locate distal stumps during this period. After 72 hours, Wallerian degeneration prevents electrical stimulation of the distal stump, and the nerve must be traced anatomically. If a gap greater than 2 cm exists, an interposition nerve graft (great auricular nerve or sural nerve) is used.

### Auricular Lacerations

Auricular cartilage exposure carries risk of chondritis and cauliflower ear deformity. All cartilage should be preserved, with debridement only of clearly necrotic tissue. Cartilage is reapproximated with absorbable sutures (5-0 clear nylon or Vicryl), and perichondrium and skin are closed meticulously. A bolster dressing (cotton bolster or dental roll sutured through-and-through) compresses dead space and prevents hematoma. For avulsions, replantation is attempted if the segment is available (fenestrating cartilage to allow vascular ingrowth). Auricular hematomas are drained immediately with a bolster applied to prevent cauliflower ear.

### Nasal Lacerations

External nasal lacerations are closed in layers (mucosa, cartilage, skin). Exposed cartilage is repaired with absorbable sutures. Full-thickness injuries require mucosal lining closure to prevent scarring and stenosis. Septal hematoma requires urgent drainage (bilateral incisions) and packing -- untreated septal hematoma leads to cartilage necrosis and saddle nose deformity. Avulsed tissue is reattached when possible, though the nose has marginal blood supply compared to other facial areas.

<image>Clinical photographs demonstrating the key specialized facial wound repairs: vermillion border alignment in a lip laceration with the first suture placed at the white roll, three-layer eyelid margin repair with gray line suture placement, and parotid duct repair over a stent with microsurgical anastomosis of the severed duct ends</image>

## Animal and Human Bite Wounds

### Dog Bites

Dog bites are the most common animal bite to the face, especially in children, and often involve crush and avulsion injury. Management includes copious irrigation, minimal debridement, and primary closure, which is recommended for facial bites contrary to the general teaching of leaving bites open. The excellent facial blood supply provides infection resistance, and delayed closure leads to poor aesthetic outcome. Antibiotics (amoxicillin-clavulanate, which covers Pasteurella, streptococci, and anaerobes), rabies prophylaxis if indicated, and tetanus prophylaxis are provided.

### Cat Bites

Cat bites produce deep puncture wounds with a higher infection rate than dog bites. Pasteurella multocida is the primary pathogen. Management includes irrigation, antibiotics (amoxicillin-clavulanate), close observation, and primary closure of facial cat bites if tissue permits.

### Human Bites

Human bites carry high infection risk (Eikenella corrodens, anaerobes, streptococci). Copious irrigation and antibiotics (amoxicillin-clavulanate) are provided. Clean facial human bites are closed primarily, while delayed closure is considered if heavily contaminated. Bloodborne pathogen exposure assessment (hepatitis B, hepatitis C, HIV) is performed.

## Avulsion Injuries and Tissue Loss

Replantation of amputated segments (nose, ear, lip) is attempted whenever possible. The avulsed part is cooled in saline-moistened gauze on ice (not placed directly on ice). Microsurgical replantation is used for larger segments, and composite grafting for small segments (less than 1.5 cm). Flap reconstruction is used for tissue loss beyond primary closure, including local flaps (rotation, advancement, transposition), regional flaps (forehead flap for nasal reconstruction, cervicofacial flaps), and free tissue transfer for massive defects. Staged reconstruction is acceptable when definitive reconstruction cannot be performed acutely.

## Clinical Pearls

The face heals beautifully, so debridement should be conservative; tissue that looks questionable will often survive. Facial nerve function, parotid duct integrity, and lacrimal system status should always be assessed and documented before injection of local anesthetic. The vermillion border is the most unforgiving landmark -- it should be marked before injecting anesthetic, and the first suture should be placed here. Primary closure of facial dog bites is safe and produces better aesthetic outcomes than delayed closure. Septal hematoma is a surgical emergency, and missed diagnosis leads to septal necrosis, abscess, and permanent saddle nose deformity. Canalicular injury should be suspected in any laceration of the medial lower eyelid, and the system should be stented at the time of repair. Foreign body tattooing is permanent, so particulate matter must be scrubbed out of the wound aggressively at the initial visit. Muscle layers should be closed carefully because failure to repair the orbicularis oris or orbicularis oculi leads to functional deficits. Early scar management (silicone gel sheeting, sun protection, massage) beginning at 2-4 weeks can significantly improve long-term scar appearance.

## References
- Hollander JE, et al. Laceration management. Ann Emerg Med. 1999.
- Janis JE, et al. Facial soft tissue trauma. In: Facial Trauma Surgery. Elsevier. 2020.
- Chen HH, et al. Primary repair of dog bite injuries to the face. J Emerg Med. 2013.
- Talan DA, et al. Clinical presentation and bacteriologic analysis of infected human bites. Clin Infect Dis. 2003.
- Holt GR. Concepts of soft tissue trauma repair. Otolaryngol Clin North Am. 1990.
- Pereira MD, et al. Reconstruction of facial soft tissue defects. J Craniomaxillofac Surg. 2015.