Monday 18 March 2013
Penetrating or blunt trauma most commonly involves the parotid gland. The submandibular and sublingual glands are afforded some protection by the mandible.
Penetrating facial trauma may involve the parotid duct and/or facial nerve, and a thorough assessment of facial nerve function should be performed in any case of facial trauma. If the injury occurs posterior to the anterior border of the masseter muscle, parotid duct injury may be suspected, and exploration of the wound should be performed to evaluate this possibility. If ductal injury has occurred, identification of the proximal and distal segments with primary reanastomosis is the ideal therapy. Reanastomosis is performed over a polyurethane catheter which may be removed when adequate healing has occurred. Closure of salivary gland parenchyma may usually be managed conservatively with interrupted sutures for the parenchyma and fascia. A salivary fistula may be a complication, but this usually heals with repeated aspirations and application of a pressure dressing. If this is not the case, gland excision may be necessary.
The wounds of penetrating facial injuries must be assessed for disruptions of the facial nerve. If injury has occurred posterior to a vertical line from the lateral canthus to the mental foramen, an attempt is made to identify proximal and distal nerve segments with subsequent primary reanastomosis. If injury has occurred anterior to this line, recovery will usually take place even in the event that obvious dysfunction is present at the time of injury.
Blunt trauma may result in the formation of a hematoma. This requires adequate drainage to prevent its subsequent organization, fibrosis, and possible cosmetic deformity.