Le Fort fractures account for 10-20% of all facial fractures. They result from exposure to a considerable amount of force. Motor vehicle accidents are the predominant cause; other causes include assaults and falls. With seatbelt laws and the increased use of airbags by auto manufacturers, the overall incidence of midface fractures has decreased.
Globally, the epidemiologies of midface fractures are similar. Young males are the typical patients, with motor vehicle accidents and assaults being the most common overall causes of facial and midfacial trauma. Male patients with midface fractures outnumber female patients with midface fractures by 5 to 1. Typically, these fractures affect younger males.
The incidence of midface fractures is far lower in children than in adults, owing to anatomic differences and the overall elasticity of children’s tissues.1,2,3
In a study from United Arab Emirates, the average age of patients with facial fractures was 26.5 years.4The majority of patients (83%) were males. The most common cause was motor vehicle accidents (59%), followed by falls (21%). Of all the patients with facial fractures, 33% had isolated midface fractures, and 14% had a combination of midface fracture and mandibular fracture.
In a study from China, 78.6% of midface fractures occurred in males; motor vehicle accidents were the leading cause (33%), followed by assaults (25%).
In a study by Motamedi from Iran, 89% of maxillofacial trauma patients were male.5Motor vehicle accidents were the number one cause (31%), followed by assaults (10%). Le Fort II fractures were the most common (55%), followed by Le Fort I fractures (24%) and Le Fort III fractures (12%).
In a Turkish study on maxillofacial trauma by Aksoy et al, 83% of fractures occurred in males.6The most common causes of facial fracture were motor vehicle accidents (90%) and assaults (3%).
Because of the degree of force required to produce midface fractures, such injuries are often associated with a high incidence of serious intracranial and ophthalmologic injury. Le Fort fractures are often comminuted and are often associated with frontal or mandible fractures.
Because of the accompanying injuries to the entire body, the standard trauma protocol of ABCs must be strictly followed before any intervention. Often, the midface fracture is of less immediate concern because of the severity of intracranial injury and associated bodily injuries. Because about one half of midface fractures are associated with significant cerebral edema and a low Glasgow Coma Scale score (<5), and because such patients have a poor prognosis, it is important to understand the goals of the family and the other medical teams involved in the care of the trauma patient.
First of all, it is important to evaluate the airway early to rule out intraoral hemorrhage, edema, loose teeth, and posteroinferior displacement of the maxilla. Establishment of a safe airway is a priority; a tracheostomy may be needed if intubation proves to be impossible or unsafe for the patient.
Bleeding may complicate midface fractures. If the bleeding is severe enough, packing of the midface vessels and temporary reduction of the fracture may be necessary. Angiography may be necessary to locate arterial bleeding from the internal maxillary before embolization.
Obvious clinical signs of facial skeleton compromise include malocclusion, subcutaneous emphysema, abnormally mobile skeletal structures, and palpable step-offs. Crepitus may be a result of paranasal sinus air leaking into the soft tissues of the face. Palpable step-offs are seen especially with zygomatic fractures. Associated facial fractures must be evaluated and ruled out.
The patient’s visual status, before and after traumatic insult, is vital in the treatment algorithm of midface fracture. There is a high incidence of visual problems associated with midface fractures, including enophthalmos, diplopia, entrapment, and epiphora. Epiphora occurs in 4% of Le Fort II or III fractures.
CSF leakage is also seen, especially in Le Fort III fractures. Any persistent, clear rhinorrhea should be tested appropriately for CSF fluid leak. Patients may complain of paresthesias of the upper jaw because of damage to the superior alveolar nerve.
As with all facial fractures, it is important to assess malocclusion. Patients may present with trismus and mouth pain. Palatal fractures often include a lip laceration and/or lacerations of the gingival and palatal mucosa. Patients with a palatal fracture may have an anterior open-bite deformity.
Facial edema may obscure the facial examination, and step-offs may not be palpable. It is important to assess fracture mobility by palpating the anterior maxilla between the thumb and forefinger. Motion at the level of the anterior nasal spine without simultaneous motion is a sign of a Le Fort I fracture. Le Fort I fractures may be associated with gingival crepitation.
Le Fort II fractures result in motion of the nasal pyramid along the medial orbit rims. The patient may have midface flattening and elongation. Le Fort II fractures often are associated with infraorbital paresthesias.
In Le Fort III fractures, motion is seen at the zygomaticofrontal suture (craniofacial dysjunction). The patient may have anosmia resulting from fracture at the cribriform plate, as well as severe edema, or lengthening; this is known as a dish-face deformity. This is a result of the lack of sagittal projection from the face, causing it to lose its contours and look spherical.
Midface fractures are usually not confused with other phenomena. The main concern is whether associated fractures are present. Examples include nasoethmoidal and orbitozygomatic fractures. These associated fractures are typically evident on examination or CT scanning A history of trauma to the face and proper suspicion of imaging results should lead to the proper diagnosis.7,8
Denture wearers typically have additional protection from midface fracture. However, when fractures do occur, unusual fracture patterns are common.
Lack of repair of the overlying soft tissue may result in descent and diastasis of the soft tissue of the face, leaving a flat or depressed area of the face.
Hypesthesia of the infraorbital nerve is a common complaint. The infraorbital nerve is entirely sensory. If a neuroma develops or if the patient’s pain becomes intolerable, resection of the nerve may be required
Malocclusion is a common complaint. Molar occlusion is based on the angle classification of the first maxillary molar in relationship with its corresponding mandibular molar. When malocclusion occurs, additional osteotomies or orthognathic work may be required.
Infection of the bone is always a concern. Any fracture with mucosal involvement of the nose, sinus, or mouth should be considered a compound fracture. These should be treated with the appropriate antibiotic coverage to prevent further complication.
Le Fort classification system
Rene Le Fort described the classic patterns of fracture in his 1901 work. Le Fort’s experiments consisted of dropping cadaver skulls from several stories or striking them with a wooden club. He found 3 distinct fracture patterns, which he termed the linea minoros resistentiae. Simply stated, in the Le Fort I fracture, the palate is separated from the maxilla; in the Le Fort II fracture, the maxilla separates from the face; and in the Le Fort III fracture, craniofacial dysjunction is present.
The Le Fort I fracture is a low transverse fracture that crosses the floor of the nose, pyriform aperture, canine fossa, and lateral wall from the maxilla, resulting in separation of the palate from the maxilla.
The Le Fort II fracture crosses the nasal bones on the ascending process of the maxilla and lacrimal bone and crosses the orbital rim. Only the Le Fort II fracture violates the orbital rim. Because of this proximity to the infraorbital foramen, type II fractures are associated with the highest incidence of infraorbital nerve hypesthesias. The Le Fort II fracture extends posteriorly to the pterygoid plates at the base of the skull. A Le Fort I fracture is characterized by a low septal fracture, whereas a Le Fort II fracture results in a high septal fracture.
Finally, the Le Fort III fracture traverses the frontal process of the maxilla, the lacrimal bone, the lamina papyracea, and the orbital floor. This fracture often involves the posterior plate of the ethmoid. Because of their location, Le Fort III fractures are associated with the highest rate of cerebrospinal fluid (CSF) leaks.9,10,11
Shortcomings of the Le Fort classification system
Despite its shortcomings, the Le Fort fracture classification system is still the most accepted method of classifying fractures and the location of osteotomies of the midface. However, recent studies have demonstrated that this classification system may be imprecise.
The Le Fort fracture system is deficient in addressing most midface fractures because most midface fractures do not follow the simple Le Fort pattern of fracture; rather, a combination of Le Fort fractures is usually encountered. In addition, most midface fractures have some degree of comminution and are complicated by fractures and displacement not addressed in the Le Fort system. These midface fractures include palate, medial maxillary arch, dentoalveolar, and anterior maxillary fractures.
Other classification systems
Sagittal fractures of the palate occur in as many as 25% of all patients with fractures of the midface. They are not classified in typical Le Fort fracture terminology. However, Rene Le Fort did describe traumatic injuries to the palate in his series of papers on maxillary fractures. Palatal fractures were classified by Hendrickson et al, who described 6 types of palatal fractures, including the following: I, anterior and posterolateral alveolar; II, sagittal; III, parasagittal; IV, para-alveolar; V, complex; and VI, transverse. Palatal fractures are associated with Le Fort I fractures 100% of the time and with either Le Fort II/III or mandible fractures 50% of the time.
There are many other classification systems for describing midface fractures. In the system of Donat et al, the face is divided into a matrix of vertical and horizontal beams, creating a lattice of 11 unilateral and 22 bilateral sites; this lattice is used to describe midface fractures.12According to their preliminary data in 87 patients with midface fractures, this scheme enabled accurate transcription and communication among physicians 98% of the time.
Another classification system is the Wassmund system. This system classifies fractures into grades I-V. A Wassmund I fracture is equivalent to a Le Fort II fracture. A Wassmund IV fracture is equivalent to a Le Fort III fracture. A Wassmund III fracture is characterized as a Le Fort III fracture without inclusion of the nasal bones.
Manson described a facial fracture classification system on the basis of CT findings.13He divided fractures into low- and high-impact fractures. His schema is described further in the CT scan section below.
Anatomy and natural history
The maxilla has 4 processes: zygomatic, frontal, palatine, and alveolar. The maxillary sinus is housed within the maxilla and varies in size, depending on the degree of pneumatization.
The midface can be thought of as a grid of horizontal and vertical buttresses that provide support for the face. The 3 paired vertical buttresses of the midface are the nasomaxillary, zygomaticomaxillary, and pterygomaxillary structures. The nasomaxillary buttress is formed by the lower maxilla, the frontal process of the maxilla, the lacrimal bone, and the nasal process of the frontal bone. The zygomaticomaxillary buttress is formed from the lateral portion of the maxilla, zygoma, and lateral portion of the frontal bone. The final buttress extends along the pterygoid plates to the skull base. The lone unpaired, vertical support mechanism is the nasal septum/ethmoid complex.
The horizontal buttresses are composed of the alveolus, the hard palate, the inferior orbital rim, and the frontal bar. Horizontal buttresses have coronal and sagittal components. The sagittal buttresses are vital for facial projection. The midface is relatively deficient in sagittal buttresses. The skull base is at a 45° angle relative to the occlusal plane of the maxilla and may act as an axial buttress as well.
Nahum revealed that low forces may create a fracture in the midface. This is partly the result of the presence of the large, air-filled sinus cavities. Therefore, the midface acts as a shock absorber. The midface is relatively resistant to vertically oriented forces (anteroposterior [AP] direction). The lateral forces may fracture the obliquely directed force vectors.
The fractures may be of significant functional and aesthetic importance. Functional problems may lead to disorders of occlusion, nasal obstruction, and trigeminal-nerve sensation. Aesthetic losses include decreased midface height, facial width, facial projection, and malar eminence. These losses may lead to a dish-face deformity.14
All patients with midface fractures are given antibiotics, because these fractures are considered open or compound. Violation of the paranasal sinus or alveolus and open soft tissue wounds are inevitable sequelae of midface fractures. Antibiotics have been shown to decrease the incidence of infection after midface fractures.
Typically, the earlier the repair of a midface fracture, the better the surgical result. This creates a dilemma for the midface reconstructive surgeon in that most patients with a midface fracture also have serious bodily injury. On the other hand, early repair prevents soft tissue scarring and memory from insetting, as well as fibrous malunion between the bony fragments.
A long surgical procedure in a terminal patient is not desirable for the patient, the patient’s family, or the surgeon. Also, an additional procedure in a patient who is in unstable condition may not be in the patient’s best interests. Piotrowski and Brandt have elucidated some parameters for reconstructive surgeons to allow for safe early repair. If the intracranial pressure is less than 15 mm Hg, midface repair—early, intermediate, or late—does not negatively affect the patient’s recovery.
The radiologist and the reconstructive surgeon must communicate about the specific location of the fracture. Exposure is crucial in repair of the midface fracture. Generally speaking, a Le Fort I fracture is approached from a sublabial exposure; a Le Fort II fracture is approached with a combination of sublabial and periorbital exposure; and a Le Fort III fracture requires a combination of sublabial and bicoronal fracture for adequate exposure.
The surgical approaches to fractures of the midface have changed radically in the past 20 years. The technology has now evolved to allow for miniplate fixation to the midface instead of bulky external hardware. Complex internal wiring was the standard of care 10 years ago, but because of poor cosmetic results and extended periods of IMF, newer technologies have replaced it. Miniplate technology involves the placement of strong titanium plates to bridge the fractured areas. The principle is similar to that of bridge making: Stable areas are fixed to unstable areas until the overall stability of the area has been secured. If large deficiencies are present, bone grafting may be necessary.
For fractures involving large, displaced segments, the displaced segment may need to be pulled forward with a hook or index finger. If the fracture is impacted into adjacent bone and is immobile, a Rowe forceps may be useful. Nondisplaced midface fractures require little intervention. Usually, a short period of IMF is all that is needed. With any displacement, an open approach is typically required. A variety of midface fractures may be addressed effectively with a closed technique. Patients with nondisplaced, noncomminuted fractures are ideal candidates for a closed approach.15,16,17,18,19,20
Repair in pediatric patients is a controversial area. Midface fractures are relatively rare in children because of their flexible skeleton, underdeveloped sinuses, unerupted dentition, and proportionally large frontal bone and mandible. Unerupted dentition results in several challenges for the surgeon.
The use of rigid fixation remains debatable. Animal experiments have shown that rigid fixation can lead to growth abnormalities. Some additional concerns are that an injury to the eyes or brain may happen due to slow movement of the plates. The counter-argument is that not treating the bony injury can lead to significant permanent deformities.