Firearm Injury Analysis

Firearm injuries to the maxillofacial region can cause severe morbidity and mortality. These injuries vary in significance from trivial to life threatening, and are some of the more difficult injuries treated by multidisciplinary trauma teams (Fig. 1). Multiple critical structures are in close proximity in the maxillofacial region; therefore, damage can occur to multiple organ systems. Additionally, soft- and hard-tissue damage can be extensive, often requiring multiple interventions with limited functional and cosmetic results1.
The severity of maxillofacial firearm injuries depends on the degree and direction of force in the facial region, the force resistance offered by the facial structures, the point of application of force, the shape and size of the projectile and its kinetic energy at impact, which depends on the distance it traveled2,3. The formula for determining kinetic energy is KE = mv2, where KE is kinetic energy, m is mass of the projectile, and v is velocity.
Based on this formula, the velocity of a projectile has traditionally been considered far more important than its mass in determining its wounding power. Indeed, guns are often classified according to velocity as
low-velocity (< 350 m/s), medium-velocity (350–600 m/s), or high-velocity (> 600 m/s). Considering a typically sized projectile, a velocity of approximately 50 m/s is required to penetrate skin, and a velocity of approximately 65 m/s will fracture bone4.
High-velocity bullets have high kinetic energy at impact creating a transient cavitation space with a small entrance wound and a larger exit wound.
This type of perforating injury is usually avulsive and causes considerable damage to soft and hard tissues, with massive comminution of the facial skeleton. Concomitant injuries often include secondary distant fractures, caused by propagation of the shock wave, and avascular necrosis, caused by damage to the intimal lining of blood vessels. Low-velocity missile injuries are completely different, because these projectiles possess only about one-third of the kinetic energy of high-velocity projectiles. Such missiles generally cause penetrating injuries, which lead to multiple fractures and skin lacerations and rarely cause tissue
avulsion5-9.
The primary emergency treatment of ballistic injuries to the face should be carried out in accordance with the Advanced Trauma Life Support (ATLS) recommendations, with airway management and control of bleeding10. However, there is no consensus on management of these cases after initial stabilization; multiple opinions exist concerning the timing, sequence and techniques of surgical treatment. We present the experience-based protocol we use in the treatment of maxillofacial firearm injuries at our medical center in a simple and clear way.