Mandibular Fracture Management in the ED

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]

Because maxillofacial fractures are the result of trauma, primary survey and attention to airway, breathing, and circulation take priority.[7, 28, 29]  

Causes of fracture of the mandible include motor vehicle accidents, as an occupant or as a pedestrian struck by a vehicle; violence, by being struck with fists, feet, or objects, including bullets in penetrating injuries; and falls, either from a height or in a case of syncope.

Focus the primary evaluation on patency of the airway, control of the cervical spine, breathing and circulatory impairment, and loss of consciousness, if the patient is experiencing neurologic impairment.

Once life threats have been addressed, obtain a thorough (AMPLE) history:

• Allergies

• Medications

• Past medical history

• Last meal

• Events leading to injury

Next, ask the patient specific questions regarding the facial injury, such as these:

• Do you have epistaxis or clear fluid running from the nares or ears?

• Did you lose consciousness? If so, for how long?

• Have you had any visual problems, such as double or blurred vision?

• Have you had any hearing problems, such as decreased hearing or tinnitus?

• Do you have any malocclusion (crooked teeth or a poor bite)? Can you bite down without pain?

• Does moving your jaw cause pain or spasm?

• When the jaw moves, does this produce a grinding sound?

• Do you have areas of numbness or tingling on your face?

• (For women) Was your injury caused by a partner? Do you feel threatened by anyone?

• (For children) Ask questions to determine whether child abuse is an issue.

Complete examination of the face is necessary because multiple injuries can easily occur.[17] Portions of the examination specific to the mandible are marked with an asterisk (*).

• Inspect face for asymmetry, performed while looking down from the head of the bed.

• Inspect open wounds for foreign bodies, and palpate for bony injury.

• Palpate bony structures of the supraorbital ridge and the frontal bone for step-off fracture.

• Thoroughly examine eyes for injury, abnormal ocular movements, and visual acuity.[30]

• Inspect nares for telecanthus and widening of the nasal bridge, then palpate for tenderness and crepitus.

• Inspect nasal septum for septal hematoma and clear rhinorrhea, which may suggest cerebrospinal fluid (CSF) leak.

• Palpate zygoma along its arch, as well as along its articulations with the frontal bone, temporal bone, and maxillae.

• Check facial stability by grasping the teeth and hard palate and gently pushing back and forth and up and down, while feeling for movement or instability of the midface.[17]

• *Test teeth for stability and inspect for bleeding at the gumline—a sign of fracture through the alveolar bone.

• *Check teeth for malocclusion and step-off.

• *Palpate mandible for tenderness, swelling, and step-off along its symphysis, body, angle, and coronoid process anterior to the ear canal.

• *Check for localized edema or ecchymosis in the floor of the mouth.

• Evaluate distributions of the supraorbital, infraorbital, *inferior alveolar, and *mental nerves for anesthesia.

• *If teeth are missing, account for them to ensure that they have not been aspirated.

• *Inspect the area just anterior to the meatus of the ear for ecchymosis, and palpate for tenderness. This is the condyle of the mandible and is the site of often-missed fracture. Plain radiographs are not good for visualizing the condyle; maintain a high level of suspicion if the physical exam is suggestive.

• *Mandibular fracture is suggested by inability to open the mouth, trismus, malocclusion of the teeth, or palpable step-offs of bone along symphysis, angles, or body. Gingival bleeding at the base of a tooth suggests fracture, especially if the teeth are malaligned. Edema or ecchymosis may be present in the floor of the mouth. Neurologic findings may include hypesthesia in the distribution of inferior alveolar or mental nerves.

Radiographs

X-ray projections typically have been used to detect a mandibular fracture but are limited to anteroposterior (AP), lateral, and oblique views in an unstable trauma patient. These views are inadequate to detail the level of fracture displacement, and they show poor detail in the condylar region.[23]

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. The panoramic view is not always available, as it requires a special radiographic machine. If the panoramic view is not available, or if the patient is unable to sit for the film, obtain routine mandible films.

Routine views include bilateral lateral oblique projections (to look at the angle, the body, and, to a lesser extent, the symphysis) and Townes view (to look at the condyles).

The submental view can be helpful in evaluating the symphysis.

Obtain chest films for patients with unaccounted for missing teeth to rule out aspiration.

Cervical spine radiographs may be indicated for patients with severe facial injuries, or for patients with a consistent mechanism and neck pain.[6]

CT, US, and MRI

For selected patients with nondiagnostic radiographs in whom mandibular fracture is strongly suspected, computed tomography (CT) may be necessary to diagnose condylar fracture. CT scan of the brain should be considered to rule out intracranial injury.[3, 4, 5]

CT is the imaging modality of choice when a traumatic mandibular injury is assessed. Multidetector-row CT reduces motion blur and therefore produces accurate coronal and sagittal reconstructions with 100% sensitivity in detecting a fracture. Furthermore, reconstructive 3-dimensional CT images gained from planar views allow better understanding of the spatial relationship of the fracture to other anatomic landmarks, ensuring better appreciation of the severity and classification of a mandibular fracture and enhancing operative planning.[23]

Multidetector-row CT is used to determine the most appropriate treatment, management, fixation method, and surgical approach; to assess the adequacy of reduction; and to evaluate potential complications in the postoperative period.[31]

Ultrasonography (US) is another useful modality for detecting a mandibular fracture when the patient is too unstable to be transferred to a CT scanner. Sensitivity, however, is less in comparison to a CT series of images, and limited detail on the fracture pattern is revealed.[23]

Magnetic resonance imaging (MRI) can be used to assess soft tissue injury of the temporomandibular joint, such as hematoma, as well as complications of trauma.[11]  However, this is unlikely to be a matter of priority when a trauma patient is first assessed.[23]

Airway, breathing, and circulation are the first priority. Hold the airway open by jaw thrust or airway adjuncts, including endotracheal intubation.

Treat hypoventilation with intubation and bag ventilation. Nasotracheal intubation is considered a relative contraindication with severe maxillofacial trauma because of concern for intracranial placement of endotracheal tubes.

Suction usually is needed to keep the airway free of blood and debris.

Place the patient on a backboard with a collar if cervical spine injury is a possibility.

Control actively bleeding wounds by applying direct pressure with a bandage.

Airway, breathing, and circulation (primary survey)

Frequently assess the airway. 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. This is usually a clinical decision based on the projected course.

Before using paralytics in an intubation, carefully evaluate ability to 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.

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

Secondary survey

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.

If the patient has no airway compromise, place a Barton bandage by wrapping a gauze roll over the crown of the head and around the jaw to provide support. Wrap a second gauze roll around the forehead and the back of the head to hold the first bandage in place.

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

The following procedure takes a fair amount of time and usually is performed by an ear, nose, and throat (ENT) or dental consultant:

• Use the Erich arch bar to hold fractures that are stable by placing the arch bar around the base of the teeth and bending the ends around the posterior molar.
• Next, wire each tooth to the bar by wrapping a 26-gauge steel wire around the base of the tooth and then around the arch wire and twisting it tightly. If maxillary teeth are to be used as a splint, they are wired in the same manner.
• Then, use elastic bands to tie the 2 arch wires together. Remember, the patient's mouth is now banded shut. Do not perform this procedure if the patient is at risk of vomiting or has problems with the airway.

Consultations

Provide care for the patient with multiple injuries in collaboration with a surgeon who has experience in trauma care.

Definitive treatment of mandibular fractures is performed by an oral-maxillofacial surgeon or an ENT specialist.

The incidence of posttraumatic stress disorder is high among patients with facial injuries; consultation with a psychiatrist should be considered.[8, 32]

Complications

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]

Airway compromise is a life-threatening complication in maxillofacial fracture. However, the occurrence of airway compromise following mandibular fracture was little known. Maxillofacial fractures that occurred from 2017 to 2020 were investigated retrospectively. A total of 154 patients with maxillofacial fractures were identified; mandibular fractures accounted for 93% of maxillofacial fractures. Of these, 3 cases (1.9%) required airway management at the time of initial treatment.[33]

Complications include the following:

• Loss of airway

• Aspiration of avulsed teeth

• Infection

• Nonunion

• Malnutrition and weight loss if teeth are banded together

• Injury to inferior alveolar or, more distally, mental nerve

• Posttraumatic stress disorder[32]

Place the patient on a diet of soft or pureed food.

Instruct the patient to return if any signs of infection are noted.

Use medications such as NSAIDs, acetaminophen, or a short course of narcotics for pain control.

Liquid preparations of medications are preferable.

If arch wires are in place, instruct the patient on release of interwire bands and provide the proper tools. Inability to release the bands can be fatal if the patient vomits or has an airway problem.

Fractures of the body of the mandible running from anterior to posterior in a downward direction (unfavorable) usually are displaced and can be stabilized with wire bar fixation of upper and lower teeth. Unstable fractures may require open reduction internal fixation if they are not reduced by wire fixation, or if they are markedly unstable.

An edentulous mandible usually is unfavorable because the patient has no teeth to stabilize the fracture. A stable nondisplaced fracture in an edentulous patient may be splinted with his or her denture, and the patient restricted to a diet of soft food. An unstable fracture usually requires internal fixation to maintain reduction.

All open fractures and unstable fractures require admission. Depending on the institution, some patients with stable fractures that require arch band fixation are treated and released from the ED; others are treated on an inpatient basis.

Use of seat belts and airbags can reduce the incidence of facial injuries in motor vehicle crashes.

Use of a helmet with facial guards can reduce injury in motorcycle accidents and in accidents in sports such as skiing, snowboarding, hockey, and football.

When airway control is needed, rapid-sequence induction is often the preferred method. Rapid-sequence induction utilizes medications to induce unconsciousness and muscle paralysis to facilitate intubation. A cricothyroidotomy kit should be kept at the bedside in case problems arise.

Use of medication, including NSAIDs, narcotics, and local anesthetics, is appropriate for pain control.

Patients with open fractures, which account for the majority of cases, should be given IV antibiotics.[14] Current choices include penicillin or a cephalosporin. For penicillin-allergic patients, clindamycin is a good alternative. If the patient has an open wound, administer tetanus toxoid if the patient is not current.

Class Summary

These agents are used most commonly for relief of mild to moderately severe pain. Effects of NSAIDs in treatment of pain tend to be patient specific, yet ibuprofen is usually the drug of choice (DOC) for initial therapy. Other options include flurbiprofen, ketoprofen, and naproxen.

Ibuprofen (Ibuprin, Advil, Motrin)

Usual DOC for treatment of mild to moderately severe pain, if no contraindications. Inhibits inflammatory reactions and pain, probably by decreasing activity of enzyme cyclooxygenase, which inhibits prostaglandin synthesis.

Ketoprofen (Oruvail, Orudis, Actron)

For relief of mild to moderately severe pain and inflammation.

Administer small dosages initially to patients with small bodies, to older persons, and to those with renal or liver disease.

Doses higher than 75 mg do not increase therapeutic effects. Administer high doses with caution, and closely observe the patient for response.

Naproxen (Anaprox, Naprelan, Naprosyn)

Used for relief of mild to moderately severe pain. Inhibits inflammatory reactions and pain by decreasing activity of enzyme cyclooxygenase, which decreases prostaglandin synthesis.

Flurbiprofen (Ansaid)

Provides analgesic, antipyretic, and anti-inflammatory effects. May inhibit cyclooxygenase enzyme, decreasing prostaglandin biosynthesis.

Class Summary

Pain control is essential for quality patient care. It ensures patient comfort, promotes pulmonary toilet, and aids physical therapy regimens. Many analgesics have sedating properties that benefit patients who have sustained fractures.

Acetaminophen (Tylenol, Panadol, aspirin-free Anacin)

DOC for treatment of pain in patients with documented hypersensitivity to aspirin or NSAIDs and in those with upper GI disease or taking oral anticoagulants.

Acetaminophen and codeine (Tylenol #3)

Drug combination indicated for treatment of mild to moderately severe pain.

Hydrocodone bitartrate and acetaminophen (Vicodin ES)

Drug combination indicated for relief of moderately severe to severe pain.

Oxycodone and acetaminophen (Percocet)

Drug combination indicated for relief of moderately severe to severe pain. DOC for aspirin-hypersensitive patients.

Morphine sulfate (Duramorph, Astramorph, MS Contin)

DOC for narcotic analgesia because of its reliable and predictable effects, safety, and ease of reversibility with naloxone. Administered IV, may be dosed in a number of ways, and commonly titrated until desired effect is obtained.

Class Summary

Prophylaxis is given to patients with open fractures. Therapy must cover all likely pathogens in the context of the clinical setting.

Penicillin G (Pfizerpen)

Interferes with synthesis of cell wall mucopeptide during active replication, resulting in bactericidal activity against susceptible microorganisms.

Ceftriaxone (Rocephin)

Third-generation cephalosporin that has broad-spectrum activity against gram-negative organisms, lower efficacy against gram-positive organisms, and higher efficacy against resistant organisms. By binding to one or more penicillin-binding proteins, arrests bacterial cell wall synthesis and inhibits bacterial growth.

Clindamycin (Cleocin)

Lincosamide useful as treatment against serious skin and soft tissue infections caused by most staphylococcal strains. Also effective against aerobic and anaerobic streptococci, except enterococci. Inhibits bacterial protein synthesis by inhibiting peptide chain initiation at the bacterial ribosome, where it preferentially binds to the 50S ribosomal subunit, inhibiting bacterial replication.

Class Summary

This agent is used for tetanus immunization. Booster injection is recommended for previously immunized individuals to prevent this potentially lethal syndrome.

Tetanus toxoid adsorbed or fluid

Used to induce active immunity against tetanus in selected patients. Tetanus and diphtheria toxoids given as the immunizing DOC for most adults and children >7 years of age. Booster doses needed to maintain tetanus immunity throughout life.

Pregnant patients should receive only tetanus toxoid, not diphtheria antigen-containing product.

In children and adults, may be administered into deltoid or mid-lateral thigh muscles. In infants, preferred site of administration is mid-thigh laterally.

Class Summary

Patients who may not have been immunized against Clostridium tetani products should receive tetanus immune globulin.

Tetanus immune globulin (TIG)

Used for passive immunization of any patient with a wound that may be contaminated with tetanus spores.