February 2002

By James R. Roberts, MD

A 35-year-old man who was punched in the mouth during a bar fight presented four hours later with a laceration of the mucosa of the lower lip. Physical examination of mouth revealed minimal soft tissue swelling and no evidence of head injury, jaw fracture, or active bleeding. The patient's two upper front teeth were chipped, but no other injuries were apparent after further examination. Since the injury was not a cosmetic problem and intraoral lacerations usually heal quickly, and because suturing would increase the chance of infection, the emergency physician decided to leave the cut open. As it turned out, however, he had overlooked an important aspect of this case.

CLICK HERE FOR ANSWER

ANSWER

Lip lacerations caused by a punch in the mouth are commonly seen by emergency physicians. Most heal well without suturing and do not become infected if proper wound care is performed. Even relatively large intraoral lacerations need not be sutured. In this case, however, the astute clinician would surmise that the patient's chipped two upper front teeth were no doubt forced into his lower lip by the punch, causing the jagged lower lip laceration. Whenever a fall, punch, or other injury produces broken teeth and a lip laceration, the emergency physician must be certain that none of the tooth fragments is embedded in the wound; otherwise, infection is almost inevitable. In this case, three chips were buried in the patient's laceration.

Like glass buried in a deep laceration on an extremity, small or even surprisingly large tooth fragments may be very difficult to find in a swollen macerated lip laceration, and the search can be complicated when a patient is uncooperative or other injuries take precedence. Because the chance of infection associated with lip laceration is so low, usually much less than 10%, the presence of pus in a recent wound should be regarded as a sign of a foreign body until proved otherwise.

Emerg Med 34(2):61, 2002

Dr. Roberts is professor of emergency medicine at the Medical College of Pennsylvania and chairman of the department of emergency medicine at Mercy Catholic Medical Center in Philadelphia. He is also a member of the Emergency Medicine editorial board.