Mandible Fracture 

Updated: Oct 22, 2016
Author: Thomas Widell, MD; Chief Editor: Trevor John Mills, MD, MPH 

Overview

Background

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.[1, 2, 3, 4, 5, 6, 7, 8]

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 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.

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.[9, 10, 11]

Indications of the presence of mandibular fracture include the following[9] :

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

See the image below.

Anatomy of the mandible. Anatomy of the mandible.

Pathophysiology

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).[12]

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

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.

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. Elevators of the mandible are the masseter, temporalis, and medial pterygoid, while depressors and retractors are the mylohyoid, geniohyoid, and anterior belly of the digastric. Lateral pterygoid is the protrusor 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 and can be treated with soft diet and arch wires if fragments are not aligned.

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

Epidemiology

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.[1]

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. 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. The incidence of associated cervical spine injuries ranges from 0.2-6%.

In one 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 to 48 yr). The mechanisms of injury were assaults (30 of 33, 90.9%), motor vehicle collisions (2 of 33, 6%), and a fall (1 of 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 incident (3.0%) of malocclusion.[13]

In a study of 363 patients with mandibular fractures, systemic illness was noted in 10.5% of the cohort, and more than 80% of the subjects had sustained their injury because of assault. The mandible angle was the most common site of fracture (56%). Most (64%) of the patients had sustained multiple fractures, and when multiple sites were involved, the angle and body were more commonly involved.[14]

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

In a retrospective review of pediatric patients (age, ≤18 yr) with mandibular fractures treated at the Mayo Clinic, 122 patients were identified with 216 mandibular fractures. The 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.[15]

According to another study of mandible fractures in pediatric patients (≤18 yr), younger patients (≤12 yr) and female patients tended to have condyle fractures caused more commonly by falls, while older patients (13-18 yr) and male patients tended to have angle fractures caused by assault.[16]

In a study of facial fractures in the elderly (>64 yr) compared with those in younger patients, elderly patients tended to experience less severe facial fractures and were more likely to have experienced injury from a fall. Compared to younger patients, the older patients sustained a higher incidence of maxillary, nasal, and orbital floor fractures and a lower incidence of mandible fractures.[17]

 

Patient Education

Instruct patient on how to release Erich arch wire if he or she has problems with airway.

Place patient on a diet of soft or pureed food.

For patient education resources, see the Breaks, Fractures, and Dislocations Center and Teeth and Mouth Center, as well as Broken Jaw.

Patients should be informed of the high risk of posttraumatic stress disorder and be referred to a psychiatrist should symptoms occur.[18]

 

Presentation

History

Because maxillofacial fractures are the result of trauma, primary survey and attention to airway, breathing, and circulation takes priority.[19, 6, 20]

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

Once life threats are addressed, obtain a thorough (AMPLE) history.

  • Allergies

  • Medications

  • Past medical history

  • Last meal

  • Events leading to injury

Next, ask specific questions regarding the facial injury.

  • Does patient have epistaxis or clear fluid running from nares or ears?

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

  • Has patient had any visual problems, such as double or blurred vision?

  • Has patient had any hearing problems, such as decreased hearing or tinnitus?

  • Does patient have any malocclusion, and is patient able to bite down without pain?

  • Does moving the jaw cause pain or spasm?

  • When the jaw moves, is a grinding sound produced?

  • Does the patient have areas of numbness or tingling on the face?

  • In women, ask if the injury was from a partner or if they feel threatened by anyone.

  • In children, ask questions to determine if child abuse is an issue.

Physical

Complete examination of the face is necessary because multiple injuries can easily occur.[12] Portions of the examination specific to the mandible are marked with an asterisk (*).

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

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

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

  • Thoroughly examine eyes for injury, abnormal ocular movements, and visual acuity.[21]

  • Inspect nares for telecanthus and widening of 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 teeth and hard palate and gently pushing back and forth then up and down, feeling for movement or instability of midface.[12]

  • *Test teeth for stability and inspect for bleeding at 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 they have not been aspirated.

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

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

Causes

Causes of fracture of the mandible include the following:

  • Motor vehicle accidents, as occupant or as pedestrian stuck by the vehicle.

  • Violence, by being struck with fists, feet, or objects, including bullets in penetrating injuries.

  • In falls, either from a height or in cases of syncope.

 

DDx

 

Workup

Laboratory Studies

Laboratory studies for fracture of the mandible include the following:

  • Direct laboratory studies toward workup of a trauma patient. If this is an isolated injury, laboratory studies may not be required.

  • If fracture is an isolated injury, obtain preoperative labs if surgery is planned.

Imaging Studies

Radiographs

Best plain film to assess the mandible is a panorama view (ie, Panorex), which shows the mandible in its entirety in a single view. Panoramic view is not always available, as it requires a special radiographic machine. If panorama view is not available or patient is unable to sit for film, obtain routine mandible films.

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

Submental view can be helpful in evaluating the symphysis.

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

Cervical spine radiographs may be indicated with severe facial injuries or in patients with a consistent mechanism and neck pain.[5]

Computed tomography

In selected patients with nondiagnostic radiographs in whom mandibular fracture is strongly suspected, CT scan may be necessary to diagnose condylar fracture. Also, CT scan of the brain should be considered to rule out intracranial injury.[2, 3, 4]

Multidetector CT is used to determine the most appropriate treatment management, fixation method, and surgical approach; to assess the adequacy of the reduction; and to evaluate the potential complications in the postoperative period.[22]

Magnetic resonance imaging

MRI is helpful in evaluating soft tissue injury, such as hematomas and complications of trauma.[9]

 

 

Treatment

Prehospital Care

Airway, breathing, and circulation are the first priority. Hold 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 airway free of blood and debris.

Place 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.

Emergency Department Care

Airway, breathing, and circulation

Frequently assess airway. Isolated mandible 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 projected course.

Before using paralytics in an intubation, carefully evaluate the ability to manage the airway with a bag and mask or laryngeal airway. If unable to manage the airway, do not paralyze the patient. Fiber optic guides or bronchoscopic-guided intubation may be an option. If in doubt, prepare for a cricothyrotomy before attempting 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 of ED care, though it should be kept in mind when evaluating the airway in the primary survey.

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

Open fractures require antibiotics. Penicillin or one of the cephalosporins are current DOC. Penicillin-allergic patients can be given clindamycin.[23]

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

Erich arch bar can be used to hold fractures that are stable by placing arch bar around the base of the teeth and bending ends around the posterior molar. Next, wire each tooth to the bar by wrapping a 26-gauge steel wire around base of tooth and then around arch wire and twisting it tight. 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, patient's mouth is now banded shut. Do not perform this procedure if the patient has a risk of vomiting or has problems with the airway.

Consultations

Provide care for the multiple-injured patient in conjunction 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 in patients with facial injuries, and consultation with a psychiatrist should be considered.[7, 18]

Medical Care

Place patient on a diet of soft or pureed food.

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

Medications such as NSAIDs, acetaminophen, and a short course of narcotics can be used for pain control.

Liquid preparations of medications are preferable.

If arch wires are in place, instruct patient on release of interwire bands and give proper tools. Inability to release 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 and 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 institution, some patients with stable fractures that require arch band fixation are treated and released from ED, while others are treated on an inpatient basis.

Complications

Complication 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[18]

Prevention

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

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

 

Medication

Medication Summary

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

Medication for pain control is appropriate, including NSAIDs, narcotics, and local anesthetics.

Patients with open fractures, which are the majority, should be given IV antibiotics.[23] Current choices are penicillin or a cephalosporin. In penicillin-allergic patients, clindamycin is a good alternative. If the patient has an open wound, administer tetanus toxoid if the patient is not current.

Nonsteroidal anti-inflammatory drugs (NSAIDs)

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 DOC for initial therapy. Other options include flurbiprofen, ketoprofen, and naproxen.

Ibuprofen (Ibuprin, Advil, Motrin)

Usually 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, older persons, and those with renal or liver disease.

Doses higher than 75 mg do not increase therapeutic effects. Administer high doses with caution and closely observe 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)

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

Analgesics

Class Summary

Pain control is essential to 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 or 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 is titrated until desired effect obtained.

Antibiotics

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

Tetanus toxoid

Class Summary

This agent is used for tetanus immunization. Booster injection in previously immunized individuals is recommended 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 are immunizing DOC for most adults and children >7 y. Necessary to administer booster doses to maintain tetanus immunity throughout life.

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

In children and adults, may administer into deltoid or midlateral thigh muscles. In infants, preferred site of administration is midthigh laterally.

Immunoglobulins

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.