Mandibular Fracture Management in the ED

Updated: Feb 08, 2022
  • Author: Thomas Widell, MD; Chief Editor: Trevor John Mills, MD, MPH  more...
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Practice Essentials

Facial fractures account for a comparatively small proportion of emergency department (ED) visits; of these injuries, the most common are nasal and mandibular fractures. Although the vast majority of nasal fractures can be managed without surgery, operative intervention for mandibular fractures is relatively common because of the complexity of the structure’s anatomy and function. [1]

The mandible is a mobile, ringlike bone that frequently fractures in more than one location; these fractures are at risk for wound contamination with oral flora, may be complicated by teeth in the fracture line, and, in some cases, can compromise the patient’s airway. [1]


Maxillofacial fractures are the result of blunt or penetrating trauma. 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. [2, 3, 4, 5, 6, 7, 8, 9]

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

Mandibular fractures are among the maxillofacial fractures most commonly observed in the ED; they are caused mainly by road accidents. Clinical features of mandibular fractures include malocclusion and loss of mandibular function. Panoramic radiography is usually limited to isolated lesions, whereas computed tomography is the tool of choice for all other facial traumatic events. No reference standard classification system for the different types of mandibular fractures has been defined. Therapeutic options include a conservative approach or surgical treatment based on the anatomic area and the severity of the fracture. [10]

Mandibular fractures usually occur at 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 the mandible often fractures between teeth and communicates with the oral cavity.

Mandibular fractures are uncommon in children younger than 6 years, likely because of the relative prominence of the forehead compared to the chin. When they do occur, they are often greenstick fractures. [1]

Indications of the presence of mandibular fracture include the following [11] :

  • Pain
  • Bite abnormality
  • Numbness
  • Bleeding
  • Swelling
  • Dyspnea
  • Crepitus
  • Restricted function

Diagnosis and treatment

Fractures of the mandible are often associated with other craniofacial, cervical, and systemic injuries and may destabilize the airway. Therefore, the approach to emergency treatment must be to secure the airway and provide hemostasis prior to fracture management. [11, 12, 13] Diagnosis of mandibular fracture is part of the secondary survey in ED care, although it should also be kept in mind when the airway is evaluated in the primary survey.

Do not focus on obvious deformity, thereby forgetting to perform a complete primary survey. Rapidly diagnose other life threats, and undertake appropriate resuscitation.

The best plain film for assessment of the mandible is a panoramic view (ie, Panorex), which shows the mandible in its entirety in a single view. If the panoramic view is not available or if the patient is unable to sit for the film, obtain routine mandible films, such as bilateral lateral oblique projections and Townes view. CT is the imaging modality of choice when a traumatic mandibular injury is assessed. 

Laboratory studies may be ordered for fractures of the mandible, such as drect laboratory studies toward workup of a trauma patient. If it is an isolated injury, laboratory studies may not be required. If fracture is an isolated injury and surgery is planned, obtain preoperative labs.

Isolated mandibular fracture from a blunt mechanism usually does not require intubation, but frequent suctioning is mandatory. Early intubation before swelling occurs makes airway control much easier, rather than waiting until a problem arises from obstruction. Before using paralytics in an intubation, carefully evaluate lo manage the airway with a bag and mask or a laryngeal airway. If unable to manage the airway, do not paralyze the patient. Fiberoptic guides or bronchoscopically guided intubation may be an option. If in doubt, prepare for a cricothyroidotomy before attempting to manage the airway with either sedation or paralytics.

Open fractures require antibiotics. Penicillin or one of the cephalosporins is the current drug of choice. Penicillin-allergic patients can be given clindamycin. [14]

Choosing appropriate surgical management can prevent complications such as malocclusion, pain, and revision procedures. Depending on type and location of fractures, various open and closed surgical reduction techniques can be utilized. [15]

The overall prognosis for patients who suffer mandible fractures is good, particularly in the absence of other associated injuries.

(See the image below.)

Anatomy of the mandible. Anatomy of the mandible.

Mandibular fracture classification

The AO (working group for bone fusion) launched the first comprehensive classification system for craniomaxillofacial (CMF) fractures. The AO CMF classification system uses a hierarchical framework with 3 levels of growing complexity (levels 1, 2, and 3). Level 1 identifies the presence of fractures in 4 anatomic areas (mandible, midface, skull base, and cranial vault). Level 2 variables describe locations of fractures within those defined areas. Level 3 variables describe details of fracture morphology such as fragmentation, displacement, and dislocation. This multiplanar radiographic image–based AO CMF trauma classification system is constantly evolving and is receiving worldwide application. Validation of this system is mandatory, so reliable communication and data processing in clinical and research environments can be ensured. [16]

A validation study determined that the AO CMF classification system is reliable and accurate when used to classify mandibular fractures for most level 2 and 3 variables. At present, the AO CMF classification system for mandibular fractures is suitable in both clinical and research settings for level 2 variables. However, accuracy and reliability decrease for level 3 variables specifically pertaining to fractures and displacement of condylar process fractures. Further investigation into why these fractures are characterized unreliably will guide modifications of the system and future instructions for its usage. [16]



Because of its ringlike structure, multiple fractures are seen in more than 50% of cases of fracture of the mandible. [1]

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). [17]

Bones that require high impact to fracture include the following:

  • Supraorbital rim: 200 g

  • Symphysis of the mandible: 100 g

  • Frontal bone-glabella: 100 g

  • Angle of the mandible: 70 g

Bones that require only low impact to fracture include the following:

  • Zygoma: 50 g

  • Nasal bone: 30 g

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

Fractures of the mandible can be stable (favorable) or unstable (unfavorable), depending on how the fracture line courses in the bone. Muscles attached to the mandible continue to exert their forces. Mandibular fractures are favorable when muscles tend to draw fracture fragments together, and unfavorable when muscle forces displace fracture fragments. [1]  Elevators of the mandible include masseter, temporalis, and medial pterygoid; depressors and retractors include mylohyoid, geniohyoid, and anterior belly of the digastric muscle. The lateral pterygoid is the protrusor muscle of the mandible.

Direction of fracture determines whether it is stable or unstable. Fractures running from posterior downward to anterior (favorable) generally are stable because muscles pull the fragments together; these fractures can be treated with soft diet and arch wires if fragments are not aligned.

Depending on fracture locations, the patient can present with trismus, dental malocclusion, swelling, and external and intraoral tenderness. Damage to the inferior alveolar nerve may result in anesthesia to the lower lip and chin. Loose teeth and intraoral lacerations with or without bony step-offs may be present as well. [1]



The mandible is the third most frequently fractured bone of the face. Of these fractures, approximately 20-35% occur 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. [2]

One study placed the incidence of severe maxillofacial injury (fractures, lacerations) at 0.04-0.09% for motor vehicle crashes. The incidence of fractures due to motor vehicle injuries is higher in rural areas; altercation-related injuries are more frequent in inner cities. The incidence of other major injuries is as high as 50% with high-impact mandibular fractures, whereas it is 21% with low-impact fractures. The mortality rate for 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 as compared to patients with violence-related injuries. The incidence of associated cervical spine injuries ranges from 0.2-6%.

Dental injuries (DIs) are associated with facial fractures, particularly mandibular fractures. DIs are common and often multiple in pediatric mandibular fracture patients regardless of background factors. DIs often lead to tooth loss. Prompt replantation of an avulsed tooth, early detection of DIs, and prevention of tooth loss whenever possible are important to avoid permanent tooth defects. [18]  In the pediatric population, any fracture of the mandible may damage permanent teeth. Follow-up with an oral and maxillofacial surgeon or a pediatric dentist is indicated. [1]

The presence of lower wisdom teeth may increase risk of fracture of the angle of the mandible. Patients with a mandibular fracture who have wisdom teeth also have higher infection risk (16.6%) when compared to patients without wisdom teeth (9.5%). [1]

In a study of 1,565 patients with 2,195 mandibular fractures, 33 (2.1%) presented with bilateral mandibular angle fractures. The average age of the cohort was 25.2 ± 1.8 years (range, 18-48). Mechanisms of injury were assaults (30/33; 90.9%), motor vehicle collisions (2/33; 6%), and a fall (1/33; 3%). Twenty-seven patients (81.8%) had at least 1 mandibular third molar at the time of injury. Three patients (9.1%) had minor postoperative wound problems, with 1 occurrence (3.0%) of malocclusion. [19]

In another study, of 363 patients with mandibular fractures, systemic illness was noted in 10.5% of the cohort, and more than 80% had sustained injury as the result of assault. The mandible angle was the most common site of fracture (56%). Most patients (64%) had sustained multiple fractures, and when multiple sites were involved, the angle and the body were more commonly involved. [20]

Age and sex

The adult male-to-female ratio for mandibular fracture is 3:1. Suspect domestic violence or sexual assault in women, as this may coexist in 30% of cases. Male predominance is reduced to 3:2 among children. With non–motor-vehicle injury, the possibility of child abuse should be a concern.

In a retrospective review of pediatric patients (≤18 yr) with mandibular fractures treated at the Mayo Clinic, 122 patients were identified with 216 mandibular fractures. Prevalent mechanisms of injury were motor vehicle accidents (N = 52 [43%]), sports injuries (N = 24 [20%]), and assault (N = 13 [11%]). The most common fracture sites were subcondylar, parasymphyseal, angle, and body. [21]

According to another study of mandibular fractures in pediatric patients (≤18 yr), younger patients (≤12 yr) and female patients tended to have condylar fractures caused more commonly by falls; older patients (13-18 yr) and male patients tended to have angle fractures caused by assault. [22]

Fracture of the mandible is a common trauma presentation among young males and represents one of the most frequently encountered fractures within the viscerocranium. Historically, assault was the dominant contributing factor, but now, due to the increased number of motor vehicles used per capita, motor vehicle accidents are the primary cause. [23]

In a retrospective study of patients younger than 20 years of age with a recent mandibular fracture, the diagnosis of mandibular fracture was missed at first contact in 27 of 182 patients (14.8%). Fracture was missed significantly more often in patients younger than 13 years than in older patients (33.3% vs 8.8%; P< 0.001). The only significant symptom or clinical finding that was associated with missed fractures was skin wound of the jaw (P=0.009). There was no association between missed fracture and sex or mechanism of injury. Mandibular fractures in children are often missed at the first healthcare contact. Careful examination is necessary in pediatric mandibular injuries, particularly in the youngest age groups. Consultation between pediatric trauma units and maxillofacial surgeons should be smoooth. [24]

Recurrent fractures of the mandible are rare. A retrospective study in Australia that included 127 patients with 148 recurrent mandibular fractures found that most patients were male (85.8%) (P< 0.001); 62.8% were unmarried (P< 0.001); and 72.4% were indigenous (P< 0.001). Alcohol was involved in 79.1% of cases (P< 0.001), and assault was the most common mechanism of injury (84.5%) (P< 0.001). The angle of the mandible was the most common site of fracture (P< 0.001), and recurrent fractures were more likely to occur at sites different from a previous fracture site (P< 0.001). Smoking, alcohol abuse, and diabetes were strongly associated with recurrent fractures (all P< 0.001). Most cases were managed with open reduction internal fixation. In conclusion, recurrent fractures of the mandible frequently involved the angle of the mandible and occurred at different sites. Incidence was more common among the unmarried, male, and indigenous population; smoking, alcohol abuse, and diabetes were found to be significant risk factors. [25]

In a study of facial fractures in the elderly (>64 yr) compared to younger patients, elderly patients tended to experience fewer severe facial fractures and were more likely to experience injury from a fall. Compared to younger patients, older patients sustained a higher incidence of maxillary, nasal, and orbital floor fractures and a lower incidence of mandibular fractures. [26]




The overall prognosis for patients who suffer mandibular fractures is good, particularly in the absence of other associated injuries. Although the perioperative complication rate for patients who undergo open reduction internal fixation is fairly high because of the complexity of the repair (~20%), long-term results are good, with only 7% of patients reporting long-term complications, such as abscess, malunion/nonunion, and hardware exposure. [1]  

A study undertaken to evaluate the prognosis of teeth in the mandibular fracture line analyzed the relationship between degree of displacement of fracture fragments and relationship of the fracture line to the periodontium, as well as the condition of the teeth at first postoperative year. Researchers concluded that a preventive approach should be taken for teeth in the mandibular fracture line. Retained teeth in the fracture line should be monitored clinically and radiographically for at least 1 year, and unnecessary endodontic treatments should be avoided. [27]

Smoking and alcohol use, the latter of which frequently contributes to the original cause of the mandibular fracture, are associated with a higher rate of complications; patient age, sex, and type of injury do not appear correlated with outcomes. [1]