Diagnosis and Management of Inner Lower Lip Laceration
An inner lower lip laceration is diagnosed by direct visual inspection of the oral cavity, and should be repaired using a transverse mucosal incision at the vermilion-vestibular mucosa junction with absorbable sutures, following appropriate anesthesia and wound preparation. 1, 2
Initial Assessment
The diagnosis is established through direct examination of the oral cavity to determine:
- Depth of injury: Assess whether the laceration involves only the mucosal surface or extends into deeper structures including the orbicularis oris muscle 1
- Location specificity: Determine if the laceration is confined to the inner mucosal surface or crosses the vermilion-cutaneous border 1, 2
- Wound tension: Evaluate tension at the wound edges, as this determines the appropriate closure method 1
Anesthesia and Wound Preparation
For pain control, apply topical LET (lidocaine, epinephrine, tetracaine) solution directly to the open wound for 20-30 minutes until wound edges appear blanched. 1 Use 3 mL for patients over 17 kg or 0.175 mL/kg for patients under 17 kg. 1 In pediatric patients, oral acetaminophen should be administered for systemic pain relief. 2
Clean the wound with warm saline using gauze or an oral sponge before repair. 2
Repair Technique
For lacerations confined to the inner mucosal surface, use a transverse mucosal incision to hide the scar at the junction of the vermilion and vestibular mucosa. 1, 2 Close with either interrupted or continuous non-locked 3-0 or 4-0 delayed absorbable sutures such as polyglactin or poliglecaprone. 3
For lacerations that traverse both mucosal and cutaneous tissues, a vertical incision approach may be required. 2 Tissue adhesives can be considered for low-tension wounds as an essentially painless closure option. 1
Post-Repair Care
Apply white soft paraffin ointment to the lips every 2-4 hours to protect and moisturize during the acute healing phase. 1, 2 However, avoid chronic use of petroleum-based products on lips, as they promote mucosal dehydration and create an occlusive environment that increases secondary infection risk. 1
Clean the mouth daily with warm saline mouthwashes to reduce bacterial load. 1, 2 Maintain oral hygiene with a soft toothbrush and mild fluoride toothpaste. 2
Prescribe acetaminophen or ibuprofen for routine pain control, reserving opiates only if needed. 1
Avoid irritants including spicy foods, hot foods and drinks, and citrus fruits, as these delay healing. 2, 4
Feeding and Hydration Considerations
For pediatric patients, ensure adequate hydration as painful lip injuries may cause children to resist drinking. 2 Offer soft, bland foods at room temperature during the healing period. 2
Follow-Up
Arrange early follow-up within two weeks to assess healing. 1
Critical Pitfalls to Avoid
- Do not use topical anesthetics excessively in children, as accidental ingestion can lead to systemic toxicity 2
- Ensure scars are placed along natural anatomic boundaries when possible to optimize cosmetic outcomes 1, 4
- Do not delay repair excessively, though evidence suggests wounds may be safely closed even 18 or more hours after injury depending on wound type 5