Orthognathic correction of jaw deformity may require a period of inter-maxillary fixation (IMF) at operation or during the post-operative period. A splint has been designed which may be used for both fixation and localisation of the jaws and which employs a quick release mechanism designed for use during surgery. It may be used also by the patient when intermittent fixation is required post-operatively and by non-medical staff in the event of an emergency such as airway obstruction.