Mandible Fracture in Emergency Medicine 

Hippocrates described an array of facial injuries as long ago as 400 BCE. In 1823, von Graeffe described the use of an elastic tube placed in the nares to maintain an open airway. During the early 20th century, Sir Harold Gilles, father of plastic surgery, taught army personnel about breathing problems in patients with facial injuries. He recommended positioning them supine to maintain an airway. Frenchman René Le Fort studied cadavers in 1901 and described 3 basic types of facial fractures. Endotracheal anesthesia and radiography, developed during the First World War, led to a better understanding and treatment of facial fractures. During the Second World War, a multidisciplinary approach to treatment of facial fractures continued to improve outcomes of severely injured soldiers. Advent of CT-guided reconstruction, along with new surgical techniques, has improved the final appearance of patients with bony injuries immensely.

Maxillofacial fractures are the result of blunt or penetrating trauma.^{[1, 2, 3, 4, 5, 6]} Most are blunt injuries caused by vehicular crashes, altercations, sporting-related trauma, occupational injuries, and falls. Penetrating injuries are mainly the result of gunshot wounds, stabbings, and explosions.

Shape and velocity of the striking object are the main factors that determine the type of maxillofacial injury (ie, soft tissue alone vs bony).

The amount of force needed to fracture different bones of the face has been studied, and these bones have been divided into those that require high impact to fracture (greater than 50 times the force of gravity [g]) and those that require only low impact to fracture (less than 50 g).^[7]

High impact is as follows:

• Supraorbital rim - 200 g
• Symphysis of the mandible - 100 g
• Frontal-glabella - 100 g
• Angle of mandible - 70 g

Low impact is as follows:

• Zygoma - 50 g
• Nasal bone - 30 g

Mandibular fractures usually occur in 2 or more locations because of the bone's U shape and articulations at the temporomandibular joints. Fractures also may occur at a site apart from the site of direct trauma. A large percentage of mandibular fractures are open, as they often fracture between teeth and communicate with the oral cavity.

Different mechanisms are associated with varying locations. Fractures from automobile crashes most frequently occur at the condyle and symphysis, those from motorcycle accidents at the symphysis and alveolus, and those from altercations mostly at the condyles, angles, and body.

For more information, see Medscape's Trauma Resource Center.

Frequency

United States

The mandible is the third most fractured bone of the face. Of these fractures, approximately 20-35% are at the condyle and ramus, 20-30% at the angle, 15-30% at the body, 8-20% at the symphysis, and 1-5% at the alveolar ridge.

One study placed the incidence of severe maxillofacial injury (fractures, lacerations) at 0.04-0.09% for motor vehicle crashes. Incidence of fractures due to motor vehicle injuries is higher in rural areas; altercation-related injuries are more frequent in inner cities.

Mortality/Morbidity

• Incidence of other major injuries is as high as 50% in high-impact mandibular fractures, whereas it is 21% in low-impact fractures. Mortality rate in high-impact fractures is as high as 12%, yet death rarely results directly from maxillofacial injury.
• Patients who are involved in motor vehicle crashes are more likely to have additional injuries than patients with violence-related injuries.
• Incidence of associated cervical spine injuries ranges from 0.2-6%.

Sex

Adult male-to-female ratio is 3:1. Suspect domestic violence or sexual assault in women as this may coexist in 30% of cases.

Age

Male predominance is reduced to 3:2 in children. In nonmotor vehicle injury, the possibility of child abuse should be a concern.