Males are twice as likely to experience parotid duct injury as females, and the mean age of individuals with parotid duct injury is approximately 30 years.
History
Important aspects of history of the wound include the circumstances surrounding the injury, precipitating cause, exact mechanism and site of injury, time of occurrence, and treatment initiated prior to presentation.Other important aspects of the history include tobacco, alcohol, or drug use; tetanus immune status; and co-morbid conditions that may place the patient at a higher risk for infection such as diabetes mellitus and immunosuppression.
Physical Examination
An internal fistula constitutes no consequences and requires no treatment. However, an external fistula connected with large ducts causes extreme discomfort every time the patient has a meal, smells or even thinks of food, due to excessive outpouring of saliva on the cheek causing skin excoriation (Figure 1). A sialogram will determine whether the fistula is ductal or glandular.
Figure 1.
Left external parotid fistula with out-pouring of saliva
A thorough clinical examination is necessary for proper evaluation of the overall state of health, co-morbidities, nutritional status, and mental status of the patient. Important signs or symptoms related to the wound include pain, fever, edema, discharge, and/or odor. Important aspects of wound assessment include location, shape, size, type (blunt or penetrating), depth, drainage (quality, character, odor), presence of a foreign body (e.g. glass, tooth fragments), loss of tissue, tenderness, asymmetry, surrounding skin (erythema, edema, crepitus), and status of the facial nerve.
An injury classification system that divides the parotid duct into 3 regions has been devised for parotid duct injuries as follows:
Site A: Posterior to the masseter muscle or intra-glandular (glandular).
Site B: Overlying the masseter muscle (masseteric).
Site C: Anterior to masseter muscle (pre-masseteric).