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
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