Characterization and Management of Mandibular Fractures

Key points

  • Proper treatment cannot be completed without an accurate diagnosis.

  • Whenever possible, occlusion should be used to guide reduction.

  • Anatomic reduction is the goal.

  • In complex fractures, maintain large segments of bone and obtain soft tissue coverage.

Introduction

The ongoing wars in Iraq and Afghanistan have provided the oral and maxillofacial surgeon unique challenges in reconstructing and restoring function to these soldiers with complex facial injuries. Indeed, injuries that were unsurvivable in previous conflicts are now commonplace because of early surgical intervention, body armor, and rapid evacuation. This article examines the history, etiology, diagnosis, classification, treatment, and complications of mandibular fractures, with emphasis on the challenges in treatment of facial injuries associated with blast and penetrating injuries common in Iraq and Afghanistan.

Introduction

The ongoing wars in Iraq and Afghanistan have provided the oral and maxillofacial surgeon unique challenges in reconstructing and restoring function to these soldiers with complex facial injuries. Indeed, injuries that were unsurvivable in previous conflicts are now commonplace because of early surgical intervention, body armor, and rapid evacuation. This article examines the history, etiology, diagnosis, classification, treatment, and complications of mandibular fractures, with emphasis on the challenges in treatment of facial injuries associated with blast and penetrating injuries common in Iraq and Afghanistan.

History

Archeological evidence shows humans have survived complex mandibular fractures long before they were documented in written history. The first writings appeared as early as 1650 bc , but it was Hippocrates who first developed the concept of reapproximation and immobilization in 400 bc . The development of our current practice has been slow, with the importance of occlusion first introduced in 1180. Certainly, until the late 19th century, fixation of fractures centered on monomaxillary wiring and external bandages.

Hippocrates said, “War is the only proper school for a surgeon.” Indeed, many major advances in treating maxillofacial injuries have arisen from conflicts.

The United States Civil War resulted in the next major technological advance in treating mandibular fractures—the use of interdental splints and intermaxillary fixation. Thomas Brian Gunning showed the importance of dentistry in treating these fractures by restoring occlusion with vulcanite splints.

During World War I, further advancement in treatment was pioneered by Kazanjian, who began wiring segments of bone together in combination with intermaxillary fixation. The external fixator, developed in 1936, was widely in use during World War II and continues to be useful in complex mandibular fractures. Internal fixation as we know it would be impossible without the development of safe antibiotics in the 1940s.

From the 1960s to the present, the focus in treatment of mandibular fractures has focused on internal fixation. Early treatment focused on large bulky plates placed through extra-oral incisions. Over time, technology has resulted in smaller plates placed through intraoral incisions, which are effective in many fractures. Current technology seems focused on resorbable plates composed of copolymers of D- and L-lactic acid. Titanium and biodegradable miniplates are now often used in place of larger reconstruction bars with good success.

Combat-related maxillofacial injuries are primarily caused by explosives. The mandible is most commonly injured, with open fractures 3 times more common than closed fractures. These injures are difficult to classify, and treating these often avulsive, penetrating, and burn injuries presents new challenges in our field ( Fig. 1 ).

Fig. 1
Distribution of combat-related craniomaxillofacial fractures in Operation Iraqi Freedom and Operation Enduring Freedom from October 2001 to December 2007.
( Adapted from Lew TA, Walker JA, Wenke JC, et al. Characterization of craniomaxillofacial battle injuries sustained by United States service members in the current conflicts of Iraq and Afghanistan. J Oral Maxillofac Surg 2010;68(1):3–7; with permission.)

The wars of Iraq and Afghanistan will continue to challenge our capabilities as oral and maxillofacial surgeons. These injuries often involve complex burns and devastating tissue loss. The care of these patients will usually require multiple surgeries and coordination with critical care, neurosurgery, plastic surgery, anesthesia, and frequently psychiatry, speech therapy, and prosthodontics. Advances in regenerative medicine, wound healing, and even composite tissue allografting may be the future of treatment in these demoralizing injuries.

Etiology of mandibular fractures

Early analysis of data by Zachar and Lew (Zachar MR, Labella C, Kittle CP, et al. Characterization of mandible fractures incurred from battle injuries in Iraq and Afghanistan from 2001-2010. Submitted to J Oral Maxillofac Surg) shows that the current system of facial injury classification is inadequate. The current coding system is insufficient in reporting the amount of tissue loss, burns, and atypical fracture patterns found in war injuries. A better system of reporting these injuries may improve care and decrease the number of procedures for these patients.

Mandible fractures are among the most frequently encountered types of facial injury in developed and undeveloped countries. The cause is usually by violent crime (assault) or motor vehicle accidents. Classification varies but minimally should include number of fractures, relationship to external environment, presence of teeth, and location ( Figs. 2–5 ).

Fig. 2
Complex facial injury with avulsive tissue loss. Many combat injuries result in burns, significant tissue loss, and exposed bone.

Fig. 3
Avulsive injury caused by explosive. Note loss of commisure, upper and lower lip defects, and burn eschar.

Fig. 4
Three-dimensional CT of patient in Fig. 2 . Note avulsion of large segment of mandibular body.

Fig. 5
Three-dimensional CT of patient in Fig. 3 . Note extensive comminution typical with explosive injury to the face.

When comparing battle injuries in Afghanistan and Iraq with civilian trauma, fractures involving the mandibular body and angle are significantly higher in the battle-injured population ( Fig. 6 ). This is because of the nature of blast injury forces compared with those of blunt trauma (Zachar MR, Labella C, Kittle CP, et al. Characterization of mandible fractures incurred from battle injuries in Iraq and Afghanistan from 2001–2010. Submitted to J Oral Maxillofac Surg).

Fig. 6
Comparison of mandibular trauma of combat-related injuries ( blue ) with those in a civilian trauma center ( red ).

Fracture classification by anatomic region

  • Midline—fracture between central incisors

  • Parasymphyseal—fractures occurring within the area of the symphysis

  • Symphysis—bounded by vertical lines distal to the canine teeth

  • Body—from the distal symphysis to a line coinciding with the alveolar border of the masseter muscle

  • Angle—triangular region bounded by the anterior border of the masseter muscle to the posterosuperior attachment of the masseter muscle

  • Ramus—bounded by the superior aspect of the angle to 2 lines forming an apex at the sigmoid notch

  • Condylar process—area of the condylar process superior to the ramus region

  • Coronoid process—includes the coronoid process of the mandible superior to the ramus region

  • Alveolar process—the region that would normally contain teeth ( Fig. 7 )

    Fig. 7
    Anatomy of the mandible: Fractures are named according to the portion of the mandible through which they pass. From medial to lateral: symphyseal, parasymphyseal, body, angle, ramus, subcondylar, condylar, coranoid process above angle/ramus.
    ( From Follmar KE, Baccarani A, Das RR, et al. A clinically applicable reporting system for the diagnosis of facial fractures. Int J Oral Maxillofac Surg 2007;36(7):593–600; with permission.)

Common descriptive terms of fractures

  • Simple (Closed)—fracture without wound open to external environment

  • Compound (open)—fracture in which an external wound, involving skin, mucosa, or periodontal membrane, communicates with the break in the bone

  • Comminuted—fracture in which the bone is splintered or crushed

  • Greenstick—fracture in which only one cortex of the bone is fractured

  • Pathologic—fracture occurring due to presence of disease

  • Multiple—2 or more lines of fracture on the same bone not communicating with each other

  • Impacted—a fracture in which one fragment is firmly driven into another

  • Atrophic—fracture resulting from atrophied bone

  • Indirect—a fracture at a point distant from the site of injury

  • Complicated (complex)—fracture with considerable injury to the adjacent soft tissue or adjacent parts, may be simple or compound

Shetty and colleagues recognize the lack of objectivity and standardization with our current methods of characterizing mandibular fractures. They have developed the UCLA Mandible Injury Severity Score to numerically classify the severity of injury and guide treatment. Unfortunately, this analysis eliminated complex injuries like gunshot wounds, so its use for characterizing battle injuries would be limited.

Fractures involving the condyle should be considered separately. Multiple classification systems have been proposed, but generally they are classified as intracapsular, extracapsular, or subcondylar. Degree of displacement and comminution will generally dictate treatment.

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Jan 23, 2017 | Posted by in Oral and Maxillofacial Surgery | Comments Off on Characterization and Management of Mandibular Fractures
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