Technical Note Trauma Use of a custom designed external fixator system to treat ballistic injuries to the mandible A. J. Gibbons, N. Mackenzie, R. S. Breederveld: Use of a custom designed external fixator system to treat ballistic injuries to the mandible. Int. J. Oral Maxillofac. Surg. 2011; 40: 103–105. Crown Copyright # 2010 Published by Elsevier Ltd on behalf of International Association of Oral and Maxillofacial Surgeons. All rights reserved. A. J. Gibbons, N. Mackenzie, R. S. Breederveld Peterborough Military District Hospital Unit, Peterborough, UK Abstract. The authors describe a custom designed mandibular external fixator II system that can be used to treat complex, comminuted fractures. The system is adjustable and lightweight, quick, robust, simple to apply, and allows mouth opening during healing, It is well suited to use in the modern war surgery environment. The authors present a case of successful treatment of a ballistic fracture of the mandible using this device. Accepted for publication 3 August 2010 Available online 16 September 2010 In 21st century conflicts, the use of body armour and improvised explosive devices have changed injury patterns. The inci- dence of maxillofacial injuries has risen to 21% 6 to 30% 5 of combat casualties. Frac- tures of the mandible are seen frequently as the lower face is often unprotected. Ballistic high-energy exchange trauma to the mandible results in complex and comminuted mandibular fractures with penetrating, perforating, or avulsive hard and soft tissue injuries 4 . External fixators have proved a popular method of treating ballistic injuries to the mandible 2 , but traditional external fixators have significant disadvantages. Systems incorporating an acrylic bar with metal pins require extra materials and equip- ment, and are not quickly applied; once in place, they cannot be adjusted 3 . The use of fixators designed to treat wrist fractures, although quick and simple to apply, are bulky to wear and the bar shapes and pins are not customised for the mandible. In contrast, the mandibular external fixator II (MEF II) system (Synthes Medical Ltd, Welwyn Garden City, AL7 1LG, UK) has titanium bars that are shaped to conform to the contours of the mandible. This allows the main bar to stand just 1 cm from the skin surface over the mandible so the whole system is less obtrusive. As the bar is closer to the bone than in other systems, it gives more stability at the fracture sites. Unlike conventional exter- nal fixators 3 , special titanium pins have the correct length of screw head for the parasymphyseal, body and ramus regions of the mandible. The novel combination clamps to connect the fixator bar, pins and any additional connecting titanium rods are of a snap-on design. They can connect two rods in any orientation and are easier to use than previous mandibular external fixator clamp designs. The system is adjustable and lightweight. The authors present a case of a gunshot wound of the mandible treated successfully using the MEF II system. Case report A 25-year-old soldier was shot in the face, at distance, by a high velocity round. The bullet entered his left cheek and lodged beneath the skin of his neck in the left occipital area. Computed tomography (CT) scans showed the position of the bullet, and fractures of his mandible at the left parasymphysis and complex com- minuted fractures at the left angle and ramus (Fig. 1). He had a stable fracture of the lateral mass of his first cervical vertebra and mild weakness of the man- dibular division of his facial nerve from the gunshot injury. Contrast CT showed no vascular damage. There was palpable mobility of the fractured ramus parts and the patient could not occlude his teeth Int. J. Oral Maxillofac. Surg. 2011; 40: 103–105 doi:10.1016/j.ijom.2010.08.001, available online at http://www.sciencedirect.com 0901-5027/010103 + 03 $36.00/0 Crown Copyright # 2010 Published by Elsevier Ltd on behalf of International Association of Oral and Maxillofacial Surgeons. All rights reserved.