AUTHOR AND EDITOR INFORMATION

Section 1 of 11  

• Authors and Editors
• Introduction
• Indications
• Contraindications
• Workup
• Treatment
• Complications
• Outcome and Prognosis
• Future and Controversies
• Multimedia
• References

INTRODUCTION

Section 2 of 11  

• Authors and Editors
• Introduction
• Indications
• Contraindications
• Workup
• Treatment
• Complications
• Outcome and Prognosis
• Future and Controversies
• Multimedia
• References

History of the Procedure

The first description of mandible fractures was as early as 1650 BC, when an Egyptian papyrus described the examination, diagnosis, and treatment of mandible fractures. Many patients either were not treated properly or received no treatment and subsequently died.

Hippocrates was the first to describe reapproximation and immobilization through the use of circumdental wires and external bandaging to immobilize the fracture. The importance of establishing proper occlusion first was described in a textbook written in Salerno, Italy, in 1180. Maxillomandibular fixation first was mentioned in 1492, in an edition of the book Cyrugia printed in Lyons. Chopart and Desault used dental prosthetic devices to immobilize fracture segments.

Most fracture treatment involved some form of external bandage or wrap occasionally used in conjunction with a bridle wire throughout the 19th century.

Guglielmo Salicetti first accomplished the use of intermaxillary fixation. Orthodontic bands and arches were used for intermaxillary fixation. However, Gilmer reformed the treatment of fractures when he fixated full arch bars on both the mandible and the maxilla.

Buck and Kinlock described the use of wire ligature for the immobilization of mandible fractures in the middle of the 19th century. In 1888, Schede was the first to use a solid steel plate held by 4 screws for fixation.

For excellent patient education resources, visit eMedicine's Back, Ribs, Neck, and Head Center, Breaks, Fractures, and Dislocations Center, and Teeth and Mouth Center. Also, see eMedicine's patient education articles Broken Jaw and Broken or Knocked-out Teeth.

Frequency

United States

Olson and associates demonstrated that vehicular accidents caused 48% of fractures. In a retrospective study, Fridrich and associates demonstrated that altercations accounted for 47% of fractures and automobile accidents for 27%.

International

Thorn and colleagues reported that 156 jaw fractures (90%) in Greenland were due to interpersonal violence. Adekeye, in Nigeria, reported that 76% were related to vehicular accidents.

Etiology

The primary causes of mandible fractures are vehicular accidents and assaults. These vary according to the area in which the survey was taken and the socioeconomic and ethnic status of the community. Other significant causes are falls and sports injuries. In a large retrospective study of 2137 patients with mandibular fractures, Ellis et al reported that 43% were caused by vehicular accidents, 34% by assaults, 7% were work related, 7% occurred as the result of a fall, 4% occurred in sporting accidents, and the remainder had miscellaneous causes. Vaillant and Benoist described 14 cases of gunshot injuries to the mandible. Patients were aged 6-68 years. Two children were victims of accidents, and the adults were either suicide or assault victims.

Location of mandibular fractures

Most fractures occur in the body (29%), condyle (26%), and angle (25%) of the mandible. The symphyses account for 17% of mandibular fractures, whereas the ramus (4%) and coronoid process (1%) have a lower occurrence rate.

Fridrich and associates showed that when fractures due to automobile accidents were considered, the condylar region was the most common site. When motorcycle accidents were considered, the symphysis was affected most often. When assault was considered, the angle demonstrated the highest incidence of fracture.

Facial fractures associated with mandibular fractures

The only facial bone fractures were mandibular fractures in an average of 70% of the patients. Of the patients reported, 15% had another facial bone fracture along with the fractured mandible.

Number of fractures per mandible

The number of mandibular fractures per patient was 1.5-1.8. A mean of 53% of patients had unilateral fractures, 37% of the patients had 2 fractures, and 9% had 3 fractures.

Pathophysiology

Classification of mandibular fractures

• Simple or closed - Fracture that does not produce a wound open to the external environment, whether it be through the skin, mucosa, or periodontal membrane
• Compound or 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 (see Images 18-20)
• Greenstick - Fracture in which one cortex of the bone is broken and the other cortex is bent
• Pathologic - Fracture occurring from mild injury because of preexisting bone disease
• Multiple - Variety in which two or more lines of fracture on the same bone are not communicating with one another
• Impacted - Fracture in which one fragment is driven firmly into the other
• Atrophic - Fracture resulting from severe atrophy of the bone, as in edentulous mandibles
• Indirect - Fracture at a point distant from the site of injury
• Complicated or complex - Fracture in which considerable injury to the adjacent soft tissues or adjacent parts occurs; may be simple or compound

Classification by anatomic region

• Symphysis - Fracture in the region of the central incisors that runs from the alveolar process through the inferior border of the mandible
• Parasymphyseal - Fractures occurring within the boundaries of vertical lines distal to the canine teeth (see Image 16)
• Body - From the distal symphysis to a line coinciding with the alveolar border of the masseter muscle (usually including the third molar) (see Image 28, Image 29)
• Angle - Triangular region bounded by the anterior border of the masseter muscle to the posterosuperior attachment of the masseter muscle (usually distal to the third molar) (see Image 30)
• Ramus - Bounded by the superior aspect of the angle to two lines forming an apex at the sigmoid notch (see Image 25, Image 31)
• Condylar process - Area of the condylar process superior to the ramus region (see Image 1)
• Coronoid process - Includes the coronoid process of the mandible superior to the ramus region
• Alveolar process - Region that normally contains teeth (see Image 11)

The effect of muscle action on the fracture fragments is important in classification of mandibular angle and body fractures. Angle fractures may be classified as (1) vertically favorable or unfavorable and (2) horizontally favorable or unfavorable. The muscles attached to the ramus (masseter, temporal, medial pterygoid) displace the proximal segment upward and medially when the fractures are vertically and horizontally unfavorable. Conversely, these same muscles tend to stabilize the bony fragments in horizontally and vertically favorable fractures. In bilateral fractures in the cuspid areas, the symphysis of the mandible is displaced inferiorly and posteriorly by the pull of the digastric, geniohyoid, and genioglossus muscles.

Condylar fractures are classified as extracapsular, subcondylar, or intracapsular. The lateral pterygoid tends to cause anterior and medial displacement of the condylar head. Five types of condylar fractures are described in order of increasing severity:

• Type I is a fracture of the neck of the condyle with relatively slight displacement of the head. The angle between the head and the axis of the ramus varies from 10-45°.
• Type II fractures produce an angle from 45-90°, resulting in tearing of the medial portion of the joint capsule.
• Type III fractures are those in which the fragments are not in contact, and the head is displaced medially and forward. The fragments are confined within the area of the glenoid fossa. The capsule is torn, and the head is outside the capsule.
• Type IV fractures of the condylar head articulate on or in a forward position with regard to the articular eminence.
• Type V fractures consist of vertical or oblique fractures through the head of the condyle.

Clinical

History

• A complete medical and psychiatric history is important for diagnosis and future treatment of mandible fractures.
• Thoroughly explore possible bleeding disorders, endocrine disorders, or bony and collagenous disorders prior to surgery.
• History of previous mandibular trauma can help prevent misdiagnoses.
• Any pretraumatic temporomandibular joint dysfunction needs to be documented in detail prior to treatment.
• The source, size, and direction of traumatic force are helpful in diagnosis.
• • Fractures sustained by a fist tend to have single, simple, or nondisplaced fractures whereas patients involved in motor vehicle accidents sustain compound comminuted fractures.
  • Localized trauma (eg, pipe, stick, hammer) tends to cause a single comminuted fracture since the force is concentrated in a small area.
  • Trauma distributed to a larger surface area may cause several fractures (eg, symphysis, condyle) secondary to distribution of the force throughout the mandible.
  • Direction of the force can help in making the diagnosis of concomitant fractures. Trauma directed to the chin often results in a symphyseal fracture with concomitant unilateral or bilateral condylar fractures.

Clinical examination

• Advanced trauma life support protocol
• • Note facial lacerations, swellings, and hematomas. A common site for a laceration is under the chin, and this should alert the clinician to the possibility of an associated subcondylar or symphysis fracture.
  • From behind the supine or seated patient, bimanually palpate the inferior border of the mandible from the symphysis to the angle on each side. Note areas of swelling, step deformity, or tenderness.
  • Note areas of paresthesia, dysesthesia, or anesthesia along the distribution of the inferior alveolar nerve. Numbness in this region is almost pathognomonic of a fracture distal to the mandibular foramen.
  • Standing in front of the patient, palpate the movement of the condyle through the external auditory meatus. Pain elicited through palpation of the preauricular region should alert the clinician to a possible condylar fracture.
  • Observe any deviation on opening of the mouth. Classically, deviation on opening is toward the side of the mandibular condyle fracture. Note any limited opening and trismus that may be a result of reflex muscle spasm, temporomandibular effusion, or mechanical obstruction to the coronoid process resulting from depression of the zygomatic bone or arch.
  • Changes in occlusion are highly suggestive of a mandibular fracture. A change in occlusion may be due to a displaced fracture, fractured teeth and alveolus, or injury to the temporomandibular joint.
  • Look for intraoral mucosal or gingival tears. Floor of the mouth ecchymosis may indicate a mandibular body or symphyseal fracture.
  • If a fracture site along the mandible is suggested, grasp the mandible on each side of the suspected site and gently manipulate it to assess mobility.

INDICATIONS

Section 3 of 11  

• Authors and Editors
• Introduction
• Indications
• Contraindications
• Workup
• Treatment
• Complications
• Outcome and Prognosis
• Future and Controversies
• Multimedia
• References

The indications for closed versus open reduction have changed dramatically over the last century. The ability to treat fractures with open reduction and rigid internal fixation (ORIF) has dramatically revolutionized the approach to mandibular fractures.

Traditionally, closed reduction (CR) and ORIF with wire osteosynthesis have required an average of 6 weeks of immobilization mandibular fracture (IMF) for satisfactory healing. Difficulties associated with this extended period of immobilization include airway problems, poor nutrition, weight loss, poor hygiene, phonation difficulties, insomnia, social inconvenience, patient discomfort, work loss, and difficulty recovering normal range of jaw function.

In contrast, rigid and semirigid fixation of mandible fractures allow early mobilization and restoration of jaw function, airway control, improved nutritional status, improved speech, better oral hygiene, patient comfort, and an earlier return to the workplace.

The technique of rigid internal fixation was developed and popularized by AO/ASIF (Arbeitsgemeinshcaft fur Osteosynthesefragen/Association for the Study of Internal Fixation) in Europe in the 1970s. The basic principles of the AO, outlined by Spiessl, call for primary bone healing under conditions of absolute stability. Rigid internal fixation must neutralize all forces - tension, compression, torsion, and shearing - developed during functional loading of the mandible to allow for immediate function. This is accomplished by interfragmentary compression plates. Use an inferior border plate to counter compression forces and a superior border plate or arch bars to counter traction or tension forces at the superior border.

AO reconstruction plates also impacted the management of comminuted and infected mandibular fractures. Ellis reported a 7.5% infection rate in treatment of mandibular angle fractures with and AO reconstruction plate without IMF (see Image 9).

During the same time that Spiessl was expounding the AO doctrine, Champy et al in France was developing the concept of adaptive osteosynthesis. Champy advocated transoral placement of small, thin, malleable stainless steel miniplates with monocortical screws along an ideal osteosynthesis line of the mandible. Champy believed that compression plates were unnecessary due to masticatory forces that produce a natural strain of compression along the inferior border.

These two changes of AO rigid internal fixation and the Champy method of monocortical miniplates revolutionized the treatment approach to mandibular fractures. Many fractures previously treated with closed reduction or open reduction with wire osteosynthesis are now commonly treated with open reduction with plate and screw fixation. An example of this evolution is the treatment of comminuted mandibular fractures. These were thought to be treated best by closed reduction to minimize stripping of the periosteum of small bone fragments. Although this treatment modality is still used, rigid fixation now enables the clinician to avoid closed reduction with the use of reconstruction plates and good soft tissue coverage.

Indications for closed reduction

• Nondisplaced favorable fractures: Open reduction carries an increased risk of morbidity, thus use the simplest method to reduce and fixate the fracture.
• Grossly comminuted fractures: Generally, these are best treated by closed reduction to minimize stripping of the periosteum of small bone fragments.
• Severely atrophic edentulous mandibles: These have little cancellous bone remaining and minimal osteogenic potential for fracture healing. Closed reduction with the use of circummandibular wires offers a more conservative approach.
• Fractures in children involving the developing dentition: Such fractures are difficult to manage by open reduction because of the possibility of damage to the tooth buds or partially erupted teeth. A special concern in children is trauma to the mandibular condyle. The condyle is the growth center of the mandible, and trauma to this area can retard growth and cause facial asymmetry. Early mobilization (7-10 d of intermaxillary fixation) of the condyle is important. If open reduction is necessary because of severe displacement of the fracture, the use of resorbable fixation or wires along the most inferior border of the mandible may be indicated.
• Coronoid fractures: These fractures usually require no treatment unless impingement on the zygomatic arch is present.
• Treatment of condylar fractures: This is one of the most controversial topics in maxillofacial trauma. Indications for open reduction are discussed below. If condylar fractures do not fall within this criteria, they can be treated with closed reduction for a period of 2-3 weeks to allow for initial fibrous union of the fracture segments. If the condylar fracture is in association with another fracture of the mandible, treat the noncondylar fracture with ORIF, and treat the condylar fracture with closed reduction.

Indications for open reduction

• Displaced unfavorable fractures through the angle of the mandible: Often, the proximal segment is displaced superiorly and medially and requires an open technique for proper reduction.
• Condylar fractures: Although strong evidence supporting open reduction of condylar fractures is lacking, a specific group of individuals benefit from surgical intervention. The classic article by Zide and Kent lists absolute and relative indications for open reduction of the fractured mandibular condyle. Careful evaluation of each case on an individual basis is crucial.
• • Absolute indications
  • 1. Displacement of the condyle into the middle cranial fossa
    2. Inability to obtain adequate occlusion by closed techniques
    3. Lateral extracapsular dislocation of the condyle
  • Relative indications
  • 1. Bilateral condylar fractures in an edentulous patient when splints are unavailable or impossible because of severe ridge atrophy (see Image 9)
    2. Unilateral or bilateral condylar fractures when splinting is not recommended because of concomitant medical conditions or when physiotherapy is not possible
    3. Bilateral fractures associated with comminuted midfacial fractures
• Medically compromised patients: These patients may require open reduction. This group of patients includes those with decreased pulmonary function, GI disorders, severe seizure disorders, and patients with psychiatric or neurologic problems.
• Complex facial fractures: Such fractures can be reconstructed best after open reduction and fixation of the mandibular segments to provide a stable base for restoration.
• Other fractures: Consider open reduction with primary bone grafting in fractures of a severely atrophic edentulous mandible with severe displacement of the fracture segments or a nonunion after closed reduction of a severely atrophic edentulous mandible fracture.
• • Mandibular nonunions require open access for debridement and subsequent reduction.
  • Malunions after improper reduction often require osteotomies through open surgical approaches to correct mandibular discrepancies.

CONTRAINDICATIONS

Section 4 of 11  

• Authors and Editors
• Introduction
• Indications
• Contraindications
• Workup
• Treatment
• Complications
• Outcome and Prognosis
• Future and Controversies
• Multimedia
• References

Contraindications to closed reduction:

• Patients with poorly controlled seizure history
• Patients with compromised pulmonary function (ie, moderate-to-severe asthma, chronic obstructive pulmonary disease)
• Patients with psychiatric or neurologic problems
• Patients with eating or GI disorders

These patients benefit from ORIF.

WORKUP

Section 5 of 11  

• Authors and Editors
• Introduction
• Indications
• Contraindications
• Workup
• Treatment
• Complications
• Outcome and Prognosis
• Future and Controversies
• Multimedia
• References

Imaging Studies

• The following types of radiographs are helpful in diagnosis of mandibular fractures:
• • Panoramic radiograph (see Image 4, Image 5, Image 8)
  • Lateral oblique radiographs
  • Posteroanterior (PA) mandibular view
  • Reverse Towne view
  • Mandibular occlusal view
  • Periapical radiographs
  • Temporomandibular joint views including tomography
  • CT scan (see Image 9, Image 10)
• Initial screening of patients is most effective with a panoramic radiograph, since it shows the entire mandible including the condyles.
• Standard mandibular series should consist of at least a panoramic radiograph, a PA view, and a reverse Towne view.
• Since an accurate panoramic radiograph requires that the patient is able to stand upright and without any motion, achieving good quality films with severely traumatized patients may be difficult. Traditional lateral oblique views of the mandible can be used when obtaining a panoramic radiograph is not possible.
• The reverse Towne view is the plain film of choice for excluding condylar and subcondylar fractures. Transcranial temporomandibular radiographs also may be helpful in detecting condylar fractures and anterior displacement of the condylar head. If visualization of the condylar head is difficult with plain films, obtain a CT scan. Although high cost and radiation exposure limit its use, CT scan is ideal for intracapsular and high neck condylar fractures.
• Occlusal views are helpful for accurate assessment of symphyseal fractures.
• Obtain periapical radiographs of the teeth on either side of a fracture to assess root fractures.

Diagnostic Procedures

• For cases where the preinjury occlusion is difficult to determine, particularly in partially dentate and edentulous patients, the use of study models is very helpful. Model surgery on the study models can be performed and acrylic splints fabricated to the new arch form. These splints may include a lingual, palatal, or labial splint that will be secured in place during surgery. The splints may be secured with the use of circummandibular wires for the mandible or with circumzygomatic or piriform wires for the maxilla. A maxillary splint also may be secured with palatal screws.
• For fully edentulous patients, dentures can be secured to the maxilla and mandible and used for splints. If dentures are not available, impressions are taken of the jaws, and acrylic baseplates are processed and used as dentures. These are known as Gunning splints. An arch bar also can be processed into the dentures, or holes can be placed into the flange of the denture for intermaxillary wires. Prosthetic incisor teeth can be removed for existing dentures, and space can be made in the acrylic to allow food intake.

TREATMENT

Section 6 of 11  

• Authors and Editors
• Introduction
• Indications
• Contraindications
• Workup
• Treatment
• Complications
• Outcome and Prognosis
• Future and Controversies
• Multimedia
• References

Surgical Therapy

Closed Reduction of Dentate Patients

Erich arch bars

• Initially, use a bar of sufficient length to accommodate the maxillary and mandibular arches from first molar to contralateral first molar.
• Next, use 24-gauge stainless steel circumdental wires at the first bicuspid positions, one on each side of the arch to secure the arch bar.
• At this point, tightly place circumdental wires along the greater segment of the fracture. The greater segment is the fracture segment; that is the most tooth-bearing segment.
• Loosely place circumdental wires along the lesser segment of the fracture. The lesser segment is the fracture segment that bears the least amount of teeth.
• Then tightly place circumdental wires along the opposing arch.
• Place the patient into his or her preinjury occlusion. With the patient held into occlusion, tighten the looser segment circumdental wires. This prevents arch bar placement from interfering with proper occlusion.
• Place interarch 25-gauge stainless steel box wires along the molar/premolar region and the premolar/canine region bilaterally (see Image 32).
• Placement of arch bars can be difficult when dentition is poor, the fracture is unstable and comminuted, and dentoalveolar fractures are present.

Bridle wire

• Bridle wire is used for temporary stabilization of a fractured segment. This provides some patient comfort by minimizing mobility of the fracture segments.
• Manually reduce the segments with the use of local anesthesia.
• Loop two teeth (if available) with 24-gauge wire anterior and posterior to the fracture segment. The closest stable teeth can be used if the adjacent dentition is poor or missing.
• Tighten the wire in a clockwise fashion while manually reducing the segments (see Images 35-38).

Ivy loops

• Ivy loops are used for intermaxillary fixation when full dentition is present in good condition and the fracture is displaced minimally.
• Construct a loop in the middle of a 24-gauge wire.
• Pass the loose ends of the wire interproximal to two stable teeth.
• Loop the wire ends around the mesial and distal sides of the teeth.
• Pass the distal wire under or through the loop and then tighten it to the mesial wire in an apical direction.
• Accomplish the same procedure on the opposite arch directly opposing the first wire.
• The loops need to be short enough to allow for an interarch wire to be tightened.
• Pass a 25-gauge interarch wire through the two opposing loops and tighten it in a clockwise fashion.
• At least one ivy loop on each side is necessary.

A variety of wiring techniques (eg, Essig wire, continuous-loop [Stout] wiring) besides those mentioned above has been used for closed reduction and intermaxillary fixation.

Closed Reduction of Partially Edentulous Patients

If a patient is partially dentate, the existing partial denture can be used for intermaxillary fixation. The partial dentures can be secured to either jaw using circummandibular or circumzygomatic wiring techniques. If the patient has no existing partial denture, acrylic blocks also can be fabricated with an incorporated arch bar and secured with circummandibular or circumzygomatic wires.

Closed Reduction of Edentulous Patients

• If dentures are available, they can be secured with circummandibular wires, circumzygomatic wires, or palatal screws.
• Dentures also can be fabricated with incorporated arch bars as well as a space in the anterior for feeding (Gunning splint). They are secured in the same fashion with circummandibular wires, circumzygomatic wires, or palatal screws.
• Biphasic pin fixation (external pin fixation or Joe Hall Morris appliance) also is used for edentulous patients. Its indications for use are as follows:
• 1. In edentulous patients with a discontinuity defect because of either severe trauma or resection
  2. In severely comminuted fractures
  3. When intermaxillary or rigid fixation cannot be used
• Biphasic pin fixation using two pins on both the proximal and distal fragments: Use a transbuccal trocar approach to place two bicortical screws on either side of the fracture. Secure a series of locking plates and bars to the 4 or more pins and then construct a self-curing acrylic secondary splint.

Open Reduction

Wire osteosynthesis

This is rarely used for definitive fixation since the advent of rigid fixation. However, it may be useful for help in alignment of fractured segments prior to rigid fixation.

• This can be placed either by an intraoral or extraoral route. The wire should be a prestretched soft stainless steel.
• A straight wire can be used across the fracture site. This is placed so the direction of pull of the wire is perpendicular to the fracture site. This can be placed as a monocortical or bicortical wire.
• A figure-of-8 wire can provide increased strength at the superior and inferior borders compared to the straight wire.

Intraoral approach

• Advantages over the extraoral approach are that it is quicker to perform, results in no extraoral scar and no damage to the facial nerve, and can be performed under local anesthesia.
• Complication rates and infection rates appear to be similar between the intraoral and extraoral approaches when large numbers of patients are studied.
• Symphysis and parasymphysis fractures can be accessed through a genioplasty-type incision. Identification of the mental neurovascular bundle is important to preserve its integrity.
• Body, angle, and ramus fractures can be accessed through a vestibular incision that may extend onto the external oblique ridge as high as the mandibular occlusal plane. Extending the incision higher predisposes the buccal fat pad to prolapsing onto the surgical field. The entire surface of the ramus and the subcondylar region can be exposed by stripping the buccinator and temporal tendon with a notched ramus retractor and periosteal elevator. Bauer retractors placed in the sigmoid and antegonial notch can help in gaining access to the subcondylar and ramus regions.

Submandibular approach

• The submandibular approach often is referred to as the Risdon approach since he first described it in 1934.
• Make the skin incision approximately 2 cm below the angle of the mandible in a natural skin crease.
• Dissect the subcutaneous fat and superficial cervical fasciae to reach the platysma muscle.
• Sharply dissect the platysma to reach the superficial layer of the deep cervical fascia. The marginal mandibular nerve runs just deep to this layer.
• Carry dissection to bone through the deep cervical fascia with the aid of a nerve stimulator. Carry the dissection down to the level of the pterygomasseteric sling.
• Sharply divide the sling to expose the bone (see Images 21-23, Image 40, Image 41).

Retromandibular approach

• Hinds and Girotti first described this approach in 1967.
• Make the incision approximately 0.5 cm below the lobe of the ear and continue it inferiorly 3-3.5 cm. Place it just behind the posterior border of the mandible; it may extend below the level of the mandibular angle.
• Carry the dissection through the scant platysma, superficial musculoaponeurotic layer (SMAS), and parotid capsule (see Image 2).
• The marginal mandibular branch and the cervical branch of the facial nerve may be encountered.
• The retromandibular vein runs vertically in this region and commonly is exposed. This vein rarely requires ligation unless it has been transected inadvertently.
• Carry out sharp incision through the pterygomasseteric sling.
• Strip the muscle off the lateral surface of the mandible superiorly, which gives access to the ramus and subcondylar region of the mandible (see Image 3).

Preauricular approach

• This approach is excellent for exposure to the temporomandibular joint.
• Make the incision sharply in the preauricular folds, approximately 2.5-3.5 cm in length as described by Thoma (1945) and Rowe (1972).
• Take care not to extend the incision inferiorly, since it may encounter the facial nerve as it enters the posterior border of the parotid gland.
• Carry the incision and dissection along the perichondrium of the tragal cartilage. Some surgeons advocate making the incision through the tragus.
• The temporal fascia is encountered along the superior portion of the incision. Take care to be sure one is deep to the superficial temporal fascia or the temporoparietal fascia.
• Make an incision through the superficial (outer) layer of the temporalis fascia beginning from the root of the zygomatic arch just in front of the tragus anterosuperiorly toward the upper corner of the retracted flap.
• Insert the sharp end of a periosteal elevator in the fascial incision, deep to the superficial layer of temporalis fascia, and sweep it back and forth.
• Once the periosteal elevator dissection is approximately 1 cm below the arch, sharply release the intervening tissue posteriorly along the plane of the initial incision.
• Retract the entire flap anteriorly, exposing the joint capsule. Fracture location dictates whether the capsule is opened.

Intraoperative Details

Concomitant dentoalveolar injuries should be evaluated and treated concurrently with treatment of mandibular fractures. Teeth in the line of fracture should be evaluated and if necessary, extracted. Whether teeth in the line of mandibular fractures are associated with increased morbidity is a controversial subject. Neal, Wagner, and Alpert reported that there was no statistical difference whether teeth in the line of fracture were removed or retained when examining 257 fractures with teeth in the line of fracture (molars, premolars, anteriors). Amaratunga looked at 191 patients with 226 fractures and used the following criteria for removal of teeth in the line of fracture:

• Excessive mobility
• Root exposure due to distraction of the fracture
• Tooth fracture with pulp exposure
• Caries with pulp exposure

Fractures were treated with mobilization mandibular fracture (MMF) for 4 weeks or open reduction. He found that 13.7% of teeth removed in the line of fracture had complications and that 16.1% of teeth retained in the line of fracture had complications. He concluded that there was no significant difference between the number of complications in the teeth removed and teeth retained groups, which indicates that noninfected teeth in the line of fracture can be preserved when antibiotics are used. After a review of the literature, Shetty and Freymiller made the following recommendations concerning teeth in the line of mandibular fracture:

• Intact teeth in the fracture line should be left if they show no evidence of severe loosening or inflammatory change.
• Impacted molars, especially full bony impactions, should be left in place to provide a larger repositioning surface. Exceptions are partially erupted molars with pericoronitis or those associated with a follicular cyst (see Image 33, Image 34).
• Teeth that prevent reduction of fractures should be removed.
• Teeth with crown fractures may be retained provided emergency endodontics is performed.
• Teeth with fractured roots must be removed (see Image 30, Image 31).
• Teeth with exposed root apices tend to develop pulpal or perio complications.
• Teeth that appear nonvital at time of injury should be treated conservatively due to potential for recovery.
• Perform primary extraction when there is extensive periodontal damage.
• Timing of the fracture is important; less complications occur when reduction and adequate fixation is instituted as soon as possible.

COMPLICATIONS

Section 7 of 11  

• Authors and Editors
• Introduction
• Indications
• Contraindications
• Workup
• Treatment
• Complications
• Outcome and Prognosis
• Future and Controversies
• Multimedia
• References

Delayed union and nonunion

• Delayed union and nonunion occur in approximately 3% of fractures.
• Delayed union is a temporary condition in which adequate reduction and immobilization eventually produce bony union.
• Nonunion indicates a lack of bony healing between the segments that persists indefinitely without evidence of bone healing unless surgical treatment is undertaken to repair the fracture.
• Nonunion is characterized by pain and abnormal mobility following treatment.
• Radiographs demonstrate no evidence of healing and in later stages show rounding off of the bone ends.
• The most likely cause for delayed union and nonunion is poor reduction and immobilization.
• Infection is often an underlying cause. Carefully assess teeth in the line of fractures for possible extraction or they may be a nidus for infection.
• Decreased blood supply can lead to a delay in healing. Excessive stripping of the periosteum, especially in comminuted and edentulous fractures, can lead to delayed healing.
• Alcoholics have been shown to have an increased incidence of delayed union and nonunion. These patients usually are at increased likelihood to sustain a mandibular fracture. Whether metabolic and vitamin deficiencies, poor compliance with intermaxillary fixation, poor bone quality, impaired local blood supply, or most likely a combination of the above reasons is the cause for an increased incidence of nonunion and delayed union is unknown.

Infection

• In some studies, particularly those without antibiotics, infection may occur in more than 50% of patients.
• Systemic factors include alcoholism, immunocompromised patients, and lack of antibiotic coverage (see Image 42).
• Local factors include poor reduction and fixation, fractured teeth in the line of fracture, and comminuted fractures.
• Most infections are mixed in nature, with alpha-hemolytic streptococci and Bacteroides organisms found most commonly.
• When infection is present it must be managed with debridement of sequestra, drainage, and antibiotic therapy. Apply rigid internal fixation with or without intermaxillary fixation across the fracture site. If a gap is present between the bone ends, a bone graft may be necessary (see Images 42-45, Image 13).

Malunion

• Malunion is defined as improper alignment of the healed bony segments. Not all malunions are clinically significant.
• When a dentate portion is involved in the malunion, a malocclusion can result.
• These malocclusions may be treated with orthodontics or osteotomies after complete bony union

Ankylosis

• Ankylosis is a rare complication of mandibular fractures.
• It is most likely to occur in children and is associated with intracapsular fractures and immobilization of the mandible.
• It is believed to occur secondary to intra-articular hemorrhage, leading to abnormal fibrosis and ultimately ankylosis.
• Ankylosis may result in disturbed growth and underdevelopment of the affected side in children. The use of only short periods of intermaxillary fixation in children can help reduce the occurrence of this complication.

Nerve injury

• The inferior alveolar nerve and its branches are the most commonly injured nerves. The prominent sign of inferior alveolar nerve deficit is numbness or other sensory changes in the lower lip and chin.
• Damage to the marginal mandibular branch of the facial nerve is rare. More commonly, nerve damage caused by trauma in the region of the condyle, ramus, and angle of the mandible and by lacerations along its course is seen.
• Most of the sensory and motor functions of these nerves improve and return to normal with time.

OUTCOME AND PROGNOSIS

Section 8 of 11  

• Authors and Editors
• Introduction
• Indications
• Contraindications
• Workup
• Treatment
• Complications
• Outcome and Prognosis
• Future and Controversies
• Multimedia
• References

• A higher prognosis is achieved with removal of grossly carious and periodontally involved teeth.
• Treatment should occur as soon as possible. Prolonged delay in treatment contributes to infection.
• Immobilization of the fracture segments is perhaps the most important aspect in avoiding delayed union, nonunion, and infection.
• Little difference seems to exist between the infection rates of intraoral and extraoral open reduction procedures.
• Alcohol abuse plays a major role in the etiology of mandibular fractures. It results in a higher rate of complications either secondary to noncompliance or as a result of metabolic dysfunction.

FUTURE AND CONTROVERSIES

Section 9 of 11  

• Authors and Editors
• Introduction
• Indications
• Contraindications
• Workup
• Treatment
• Complications
• Outcome and Prognosis
• Future and Controversies
• Multimedia
• References

The advent of resorbable plates and screws opens a new arena for the treatment of mandible fractures in the pediatric population.

More controlled prospective studies on the use of resorbable plates are necessary prior to their use for pediatric and adult patients with mandible fractures.

Rigid fixation techniques have evolved from larger, thicker plates to smaller, low-profile plates while maintaining adequate fixation.

MULTIMEDIA

Section 10 of 11  

• Authors and Editors
• Introduction
• Indications
• Contraindications
• Workup
• Treatment
• Complications
• Outcome and Prognosis
• Future and Controversies
• Multimedia
• References

Media file 1:  Right mandibular condylar fracture.
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Media file 2:  Retromandibular approach to right mandibular condylar fracture.
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Media file 3:  Intraoperative view. Fixation of right mandibular condyle fracture.
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Media file 4:  Mandibular fracture. Postoperative pantomogram.
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Media file 5:  Mandibular fracture. Close-up view of postoperative pantomogram.
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Media file 6:  Mandibular fracture. Intraoperative view. Reconstruction plate used to span continuity defect of right mandibular body.
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Media file 7:  Mandibular fracture. Autologous bone harvested from the patient's anterior iliac crest placed into defect.
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Media file 8:  Mandibular fracture. Postoperative pantomogram.
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Media file 9:  Mandibular fracture. Coronal CT scan demonstrating bilateral high condylar fractures.
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Media file 10:  Mandibular fracture. Postoperative coronal image demonstrating open reduction internal fixation of the left condylar fracture to restore posterior vertical height.
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Media file 11:  Mandibular sagittal symphysis fracture and dentoalveolar fracture.
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Media file 12:  Mandibular fracture treated with lag screw fixation and debridement of dentoalveolar segment.
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Media file 13:  Mandibular fracture. Patient lost to follow-up at local county jail presents with infected nonunion of mandibular symphysis.
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Media file 14:  Mandibular fracture. Infection treated with incision and drainage and intravenous antibiotics. Hardware was removed and site debrided. Postoperative posteroanterior cephalometric view demonstrating reconstruction plate in place.
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Media file 15:  Mandibular fracture. Lateral view.
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Media file 16:  Right mandibular parasymphysis fracture.
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Media file 17:  Mandibular fracture treated with 4-hole positional plate and maxillomandibular fixation.
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Media file 18:  Comminuted mandibular fracture.
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Media file 19:  Axial CT scan demonstrating multiple fractures of the mandible.
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Media file 20:  Axial CT scan demonstrating severe displacement.
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Media file 21:  Mandibular fracture. Intraoperative view demonstrating fixation of mandibular segments.
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Media file 22:  Mandibular fracture. Left lateral view.
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Media file 23:  Mandibular fracture. Right lateral view.
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Media file 24:  Mandibular fracture. Axial CT scan demonstrating status post fixation.
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Media file 25:  Right mandibular ramus and left mandibular parasymphysis fractures.
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Media file 26:  Mandibular fracture. Pantomogram status post fixation.
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Media file 27:  Mandibular fracture. Postoperative posteroanterior cephalometric view.
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Media file 28:  Right sagittal mandibular body fracture and left parasymphysis fracture.
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Media file 29:  Mandibular fracture. The right side was treated with 3 positional screws to engage buccal and lingual cortices of sagittal fracture. The right side is rigidly fixated with a 6-hole plate.
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Media file 30:  Right mandibular body fracture. Left mandibular angle fracture going through tooth #17.
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Media file 31:  Right mandibular body and left mandibular angle fractures status post fixation. Tooth #17 was extracted.
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Media file 32:  Mandibular fracture. Interarch elastics may be used for maxillomandibular fixation. They also may be used loosely for guidance during postoperative care.
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Media file 33:  Left mandibular angle fracture involving tooth #17. Right mandibular body fracture.
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Media file 34:  Tooth #17 was extracted. A superior border plate was placed at the left mandibular angle. An inferior border plate was placed for the right mandibular body fracture.
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Media file 35:  Mandibular fracture. Patient presents with occlusal step off between right mandibular central and lateral incisors.
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Media file 36:  Mandibular fracture. View of occlusal step off.
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Media file 37:  Mandibular fracture. Bridle wire used to decrease mobility and provide patient comfort.
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Media file 38:  Mandibular fracture. Barton bandage used to decrease fracture mobility and provide patient comfort until definitive treatment.
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Media file 39:  Left mandibular body fracture.
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Media file 40:  Mandibular fracture. Open reduction rigid internal fixation of left mandibular body fracture.
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Media file 41:  Mandibular fracture. Postoperative radiograph demonstrating reduction and fixation.
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Media file 42:  Mandibular fracture. Patient with poorly controlled type 1 diabetes with left open, complete, moderately displaced mandibular angle fracture between teeth #17 and #18.
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Media file 43:  Mandibular fracture. Treated initially with a superior border plate and an inferior border plate as well as extraction of tooth #17.
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Media file 44:  Mandibular fracture. Patient returns with infected nonunion of left mandibular angle and loose hardware. The superior border plate was removed. Tooth #18 was extracted. The patient was treated with intravenous and oral antibiotics.
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Media file 45:  Mandibular fracture. Rigid fixation with an 8-hole plate. Two holes in the center are used to span the fracture site.
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REFERENCES

Section 11 of 11

• Authors and Editors
• Introduction
• Indications
• Contraindications
• Workup
• Treatment
• Complications
• Outcome and Prognosis
• Future and Controversies
• Multimedia
• References

• Adekeye EO. The pattern of fractures of the facial skeleton in Kaduna, Nigeria. A survey of 1,447 cases. Oral Surg Oral Med Oral Pathol. Jun 1980;49(6):491-5. [Medline].
• Adell R, Eriksson B, Nylen O, Ridell A. Delayed healing of fractures of the mandibular body. Int J Oral Maxillofac Surg. Feb 1987;16(1):15-24. [Medline].
• Baker S, Betts NJ. Mandibular angle fractures. Oral and Maxillofacial Surgery Knowledge Update. 1998;2:25.
• Barton JR. A systemic bandage for fractures of the lower jaw. Am Med Recorder Phila. 1819;2:153.
• Chuong R, Donoff RB, Guralnick WC. A retrospective analysis of 327 mandibular fractures. J Oral Maxillofac Surg. May 1983;41(5):305-9. [Medline].
• Ellis E 3rd, Moos KF, el-Attar A. Ten years of mandibular fractures: an analysis of 2,137 cases. Oral Surg Oral Med Oral Pathol. Feb 1985;59(2):120-9.