The introduction of gas into the soft tissues around the mouth can result in oral emphysema.
Causes of emphysema in the oral mucosa:
(1) infection with gas producing bacteria
(2) introduction of gas into local subcutaneous tissues, usually during a dental procedure
(2a) dental treatment with an air turbine dental drill
(2b) use of a high pressure air syringe
(3) dissection of gas from neck or thorax
(3a) pneumothorax after thoracic trauma
(3b) penetrating injury to the tracheobronchial tree
(3c) mechanical ventilation with positive pressure
(3d) gas insufflation of peritoneal cavity for laparoscopy
(3e) vigorous mask ventilation during anesthesia
Clinical findings:
(1) swelling
(2) palpable crepitus
(3) crackles heard when compression the tissue with a stethoscope
The distribution of the gas may be better appreciated on imaging studies.
The presence of local inflammation, fever and systemic responses suggests infection. This requires aggressive management to prevent serious complications.