The flared mandible sign of the flail mandible.

A useful radiographic finding is described for the diagnosis of a flail mandible. The flail mandible removes forward support for the tongue, which may result in airway obstruction. Immediate radiographic diagnosis allows quick surgical correction of the fractured mandible and relief of the obstruction, decreasing the time during which an endotracheal or tracheostomy tube is needed to keep the airway open.