Lip lacerations

1. INTRODUCTION

• Facial lacerations hold more significant cosmetic considerations
  • Require careful attention to detail
  • Even 1mm difference in vermillion border can cause obvious cosmetic defect
• Longer window for closure
  • Skin in the face has more abundant blood supply compared to other areas of the body
  • Up to 24 hours for facial lacerations
• Consider consult for:
  • Complex lacerations
  • Significant tissue loss (e.g. >20-25% of middle of lip)
  • Dental injury
  • Facial nerve injury
• Associated injuries
  • Dental, intraoral, facial bones, intracranial

2. ANATOMY

• External surface, 3 distinct regions:
  • Skin
    • Including philtrum architecture which must be maintained for cosmesis
  • Vermillion border**
    • Vermillion border is most cosmetically important junction, where the skin meets the red portion of the lip
  • Oral mucosa (the red mucosa), divided into:
    • Dry mucosa: external lip surface which feels dry to touch
    • Wet mucosa: the wet surface which lies against teeth

• Muscle
  • Orbicular oris muscle surrounds mouth and is responsible for retaining saliva, producing bilabial sounds in speech and providing important facial expressions
• Innervation
  • Important consideration if using regional nerve blocks
  • Upper lip: infra-orbital nerve
  • Lower lip: mental nerve
  • Both are branches of the trigeminal nerve
• Arteries
  • Rich blood supply from labial arteries

3. CLASSIFICATION

• 1. Mucosal lacerations
• 2. Partial thickness lacerations that cross the vermillion border
• 3. Full thickness lacerations
  • Requires muscular layer to be closed in multiple layers

4. PRESENTATION

• External as well as intraoral examination very important to assess complete injury
• Examine:
  • Location
  • Depth
  • Extension
  • Presence of tissue avulsion
  • Emphasis on if laceration crosses vermillion border
• Intra-oral:
  • Depth of injury
  • Missing, impacted, or fracture teeth
  • Exposed bone of the maxilla or mandible

5. ANESTHESIA

• Strongly consider regional nerve blocks as local infiltration can distort soft tissue and obscure borders
• Upper lip: infra-orbital nerve block
  • For ipsilateral upper lip
  • Also includes lateral nose, lower eyelid and medial cheek
• Lower lip: mental nerve block
  • For ipsilateral lower lip
  • Also includes skin down to the angle of the mandible
• In children, may also require procedural sedation:
  • Important for both pain control and anxiolysis
  • Options include ketamine IV, or midazolam IN or fentanyl IN
  • Especially consider if repair will take >30 min, extensive or complex, or child is not able to hold still without significant physical restraints
  • Have additional hands as holders

6. PREPARATION

• Irrigation
  • Irrigation necessary for contaminated wounds
  • However, balance risk as high pressure can dissect through soft tissues
  • Previous 1998 study showed no difference in rates of infection or cosmetic outcomes in the no irrigation group for clean facial and scalp wounds
• Exploration
  • Explore for tooth fragments or missing teeth as will serve as nidus for infection
  • If uncertain, obtain x-rays to visualize small tooth fragments
• Suture choice
  • Controversial; significant debate
  • Absorbable sutures for mucosal lacerations
  • For skin, debate about whether absorbable vs. non-absorbable better
    • If using absorbable for skin, ensure it is rapidly dissolving
    • Argument that absorbable more convenient and less complications with suture removal. However, not as strong and thus higher risk for dehiscence.
    • Non-absorbable classically known to have less inflammatory response, thus less scarring and risk of infection
    • Recent small reported no significant difference in long term cosmetic outcomes nor risk of infection with absorbable vs. non-absorbable
  • Consider absorbable for external sutures if:
    • Child, where suture removal may be difficulty
    • Risk of loss in follow-up (e.g. if patient will not return for suture removal)
  • Size
    • 5-0 or 6-0 for facial skin lacerations to decrease scarring
    • 4-0 or 5-0 for mucosal repairs
• Gauze
  • Often helpful to place gauze pad between gums and lip to collect blood or other fluids

7. LACERATION REPAIR

• General concepts
  • Place sutures a little closer together than usual due to cosmetic concerns
  • Place 1-2mm from skin edge and 3mm apart to achieve better tissue approximation
  • Ideally, edges should be somewhat everted, but not so tight to pucker the skin
  • On mucosa and skin, tie at least 4-5 knots in sutures to prevent sutures from coming undone

• Intraoral mucosal
  • Isolated intraoral mucosal injuries may not need to be sutured, especially if <1cm
  • Use small bites as will minimize bunching of mucosa when suture knot is tied
  • Avoid catching underlying muscle while suturing
  • Caution regarding wet-dry mucosal border as this also needs to be appropriately align
• Partial thickness involving vermillion
  • First, use surgical marking pen to mark edges of the vermillion border
  • Place 1st stitch with intent of aligning vermillion border
    • Can be helpful to place sutures just above and below 1mm above and below the vermillion border to avoid bunching at the level of the vermillion border
  • If stitch does not seem well-placed, remove it and try again
  • Place remaining sutures in the lip skin (5-0 or 6-0) and lip mucosa (4-0 or 5-0), with care to evert skin edges

• Full thickness
  • Close in layers
  • Start with the deep mucosal layer with a rapidly absorbable sutures (4-0 or 5-0)
  • Irrigate from outside
  • Then approximate orbicularis oris muscle with simple interrupted, horizontal mattress, or figure-of-eight suture (4-0 or 5-0 absorbable)
  • Deeper sutures will decrease wound tension and decrease risk of wound dehiscence
  • If significant bleeding, can try injecting lidocaine with epinephrine.
    • But if bleeding is from cut artery, may need to place simple or figure-of-eight suture at the site of bleeding
  • Then close skin with simple interrupted sutures (5-0 or 6-0)