[Subcutaneous emphysema in the head and neck region].

Subcutaneous emphysema is a relatively harmless finding which is pathognomonic for a mid-facial fracture in most cases. Increasing pressure will cause air to expand beyond the tissues. It is often caused by blowing one's nose, but can also result from intubation in cases of more severe trauma. Crepitus can be heard or felt subcutaneously upon palpitation. Two cases of patients presenting at an oral and maxillofacial unit with extensive emphysema in the head and neck region illustrate both a common and an unusual cause.