Soft Tissue Trauma

Repair of soft tissue trauma to the lips requires careful attention to both function and esthetics. This article outlines basic lip anatomy, goals in managing lip injury, and appropriate workup and ultimate treatment of various types of trauma to the lips.

Key points

  • In-depth knowledge of lip anatomy will help a surgeon properly perform lip repair.

  • Proper lip repair is key for the return of lip form and function.

  • Correct alignment of the vermillion border is critical to an aesthetic repair.

  • Local tissue arrangements are always preferred over distant donor sites for lip repair.

Background: anatomy and function

The lips play a critical role in speech, nutritional intake, appearance, and sensation. Any injury and subsequent repair require consideration of these features and functions. The lips function as a muscular sphincter for the oral cavity, allowing for proper speech and swallowing without spillage of air or food from the oral cavity. ,

The upper and lower lips are composed of several layers (from inside out) ( Fig. 1 ) :

  • Mucosa

  • Submucosa

  • Muscle

  • Subcutaneous fat

  • Dermis

  • Epidermis

Fig. 1
Layers of the lip. Illustrations done by Dr Ashley Houle.

The upper and lower lips receive vascular supply from branches of the facial artery, the superior and inferior labial arteries ( Fig. 2 A, B), respectively. Sensory information from the lips is carried by the infraorbital nerve and the inferior alveolar nerve ( Fig. 3 ), which are branches of the trigeminal nerve. The facial nerve provides the motor innervation. ,

Fig. 2
( A ) Vascular supply to the upper and lower lips. ( B ) Clinical image of intact labial artery after lip injury.

Fig. 3
( A ) Through-and-through lip laceration with underlying mandible fracture. ( B ) Underlying mandibular fracture. The mental nerve can be visualized at the superior distal end of the mandibular hardware coursing to the laceration site.

Goals of management ,

  • Achieve 3-layered closure where indicated: mucosa, orbicularis oris, skin

  • Restore the orbicularis oris sphincter

  • Maintain the oral commissures when possible

  • Maintain oral competence

  • Maintain the size of the aperture (avoiding microstomia)

  • Optimize esthetic outcome: continuity of the vermillion border, align vermillion border, the wet/dry line, and white roll, maintain appearance of philtral column and cupid’s bow, symmetry, avoid distortion

  • Minimize complications: infection, hematoma, scar formation, nerve injury

Patient evaluation overview

A proper trauma workup must be performed to identify and manage any potentially life-threatening injuries in the primary survey. In the secondary survey, injury to the lips is addressed. A thorough history and physical examination should be performed to adequately assess the patient and avoid overlooking concurrent injuries. When indicated, appropriate imaging should be ordered and reviewed, particularly if there is concern of foreign body impaction in the soft tissues. Pertinent components to the history and physical examination of the patient specific to addressing soft tissue trauma to the lips are listed in later discussion. , ,

  • History

    • Mechanism

    • Associated symptoms

    • Age of wound

  • Physical examination

    • Location

    • Extent of injury: depth, length, involvement of the vermillion border, layers involved (through-and-through laceration)

    • Condition of wound: gross contamination, foreign body impaction, such as an embedded tooth or fragment, devitalized tissue, hemostasis

    • Associated injuries (including underlying facial bone fractures)

Surgical and interventional treatment options

Abrasion

An abrasion is a superficial wound typically caused by friction. They tend to be quite painful, as terminal endings of nerve fibers are often involved. Minimal bleeding is encountered from superficial capillaries. When abrasions are superficial, there is typically minimal scarring. Thorough cleansing of the wound bed is indicated. If the abrasion is deep or foreign material and debris are noted, local anesthesia may be used for more aggressive scrubbing with a surgical brush and a petrolatum-based gel. It is imperative to remove all foreign debris at the time of initial injury before epidermal healing occurs. Aftercare includes the use of a topical antibiotic ointment with or without an overlying loose bandage. Petrolatum dressing changes may be used daily to cleanse the grossly contaminated wound. Abrasions to the mucosal lip often heal with no treatment. Chlorhexidine rinse may be given when gross contamination is present.

Puncture/Bite Wounds

Puncture and bite wounds often appear superficially small. However, care must be taken to appropriately cleanse and debride the area, as they can penetrate deeply. Deep penetration allows inoculation and embedding of bacteria, particularly with feline bite wounds. Closure is typically not indicated, as this can contribute to the development of infection. Bites from pit bulls are unique in that they tear tissue, causing avulsion and the need for additional reconstruction.

Contusion

Tissue disruption with subcutaneous or submucosal hemorrhage manifests as a contusion (bruise) that typically does not involve a break in the surface tissues. The bleeding will tamponade when the hydrostatic pressure within the soft tissues equals the pressure within the blood vessels. Therefore, early intervention with ice and pressure dressing can aid in ceasing the bleed through vasoconstriction and pressure. Patients should be counseled regarding the ecchymosis expansion and progression of the contusion. Infection is unlikely, and there is no indication for antibiotic therapy.

Laceration

Management of lip lacerations requires careful reapproximation of the involved layers so as to not compromise form and function. Unlike surgical incisions, unfortunately one cannot control the design of a laceration. Understanding of the relaxed skin tension lines can help predict outcomes of closure ( Fig. 4 ). Lacerations that cross perpendicular to the resting skin tension lines tend to widen and form a less esthetic scar. Therefore, it is crucial to provide good dermal support during closure, leaving no tension on the skin sutures. Most lacerations can be closed primarily, with the exception being in the setting of gross infection. In this situation, the wound may be packed with regular dressing changes and closed by delayed primary closure.

Jul 5, 2021 | Posted by in Oral and Maxillofacial Surgery | Comments Off on Soft Tissue Trauma

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