Skill Checkup: Complex Lip Laceration

Richard H. Sinert, DO


October 11, 2019

Lip lacerations are commonly seen in emergency departments and are among the most common oral-maxillofacial injuries. Careful repair is necessary to minimize infection while ensuring the best cosmetic results and patient satisfaction. The approach in repair depends largely on location and type of injury.


  • Unlike the cosmetically important external facial lacerations that are almost always closed primarily, some small intraoral lacerations may be left open and will heal well without repair.

  • Small puncture lacerations through the lip may not require complete closure; the external portion may be repaired while the intraoral portion is allowed to heal without sutures.

  • Indications for external repair are the same as with any other facial laceration.

Indications for intraoral closure are as follows:

  • Mucosal laceration that creates a flap that interferes with chewing

  • Mucosal laceration that is large enough to trap food particles

  • Wounds longer than 2 cm


Lips are well innervated and very sensitive to pain. They can be difficult to anesthetize locally. In addition, local infiltration of anesthesia into external lip wounds often causes swelling and distortion of original landmarks.

Performing regional nerve blocks when possible can lead to optimal cosmetic and anesthetic results. To anesthetize the lower lip, perform a mental nerve block; for the upper lip, perform an infraorbital nerve block (see the images below).

Figure 1.

Areas of regional nerve blocks for the lips.

Figure 2.

Technique for extraoral infraorbital nerve block.

Figure 3.

Intraoral approach for infraorbital nerve block.

Pre-anesthetizing the mucosal area with a topical anesthetic 3 minutes prior to infiltrative injection is recommended.

For intraoral wounds, nerve blocks may not always be as effective. In these cases, consider further local anesthesia.

Supine patient positioning is preferred. Ensure that the height of the bed is appropriate and that optimal lighting is available for visualization.

Once the patient is anesthetized, inspect the wound carefully. Gentle probing may be required to visualize through-and-through lacerations (see the image below).

Figure 4.

Further inspection of the anesthetized wound reveals a through-and-through laceration.

Check for concurrent chipped, missing, or mobile teeth. Tooth fragments may be lodged inside the wound and may serve as a nidus of infection if not removed.

Intraoral wounds are prone to considerable contamination; therefore, thorough irrigation is necessary.

Through-and-through lip wounds are closed in subsequent layers.

For wounds in the deep soft-tissue layer, use 4-0 or 5-0 absorbable sutures such as Vicryl to anchor the fibrous tissue just underneath the anterior and posterior skin surfaces. In deep but not through-and-through lacerations, deep sutures can be placed using a simple interrupted technique that leaves the knot buried deep within the laceration. See the image below.

Figure 5.

Extraoral approach to close the deep layer.

If the vermilion border is involved, approximate it with the first suture placed on facial skin. Use 6-0 suture material. The approximation of the vermilion-cutaneous junction is the most crucial step in the closure of lip lacerations that involve the vermilion border. Misalignment of even 1 mm may cause a noticeable step-off when the wound has healed. See the image below.

Figure 6.

Placement of the first suture through the vermilion border.

In young children, consider using all absorbable sutures for repair of these lacerations. Eliminating the need for suture removal may result in decreased emotional and physical trauma, and studies show no discernable difference in cosmetic outcome. This is also an excellent option in adults. Fast-absorbing sutures are recommended.

Intraoral skin may be closed either before or after the facial skin. Approximate the buccal wet mucosa with simple interrupted absorbable sutures (4-0 or 5-0); absorbable sutures fall out or absorb and do not require removal. However, do not use fast-absorbing sutures on mucosal surfaces. Secure each stitch with four or more knots to ensure that the stitches are not untied by the tongue. These sutures can be continued onto the wet and dry vermilion surface of the lip. Silk is best avoided in the mouth, as it can irritate mucosal tissues. Any small intraoral flaps may be excised. See the image below.

Figure 7.

Closure of an intraoral skin laceration.

For wounds that involve the facial skin, using 6-0 sutures, approximate the skin with simple interrupted sutures. This suture material can be continued onto the lip. Absorbable sutures are often preferred on the dry vermilion surface. See the image below.

Figure 8.

Complete closure of the facial skin.


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