Le Fort Fractures: A Collective Review

Introduction

Originally described by Rene Le Fort in 1901, Le Fort fractures are specific facial bone fracture patterns that occur in the setting of blunt facial trauma (most commonly involving motor vehicle collision, assault, or falls) [1,2]. All Le Fort fracture types involve the pterygoid processes of the sphenoid bones and therefore, disrupt the intrinsic buttress system to the midface-however further differentiation of Le Fort types I, II, and III depends on involvement of the maxillary, nasal, and zygomatic bones [3-5]. Though mortality rates are low, these fractures seldom occur in isolation and are often associated with serious injuries of the head and neck [6]. Thus, the ability to quickly recognize and diagnose Le Fort fractures is crucial for proper management of blunt-force facial trauma.

Methods

A comprehensive search of the world’s literature was conducted through PubMed and Elton B. Stephens Co. (EBSCO) databases. Search terms included “facial injuries”, “Le Fort”, “facial”, “craniofacial”, and “intracranial” and the resultant articles were then categorized according to PRISMA guidelines. All studies in English were screened by title and abstract for relevance and sources discussing Le Fort fracture etiology, epidemiology, diagnosis, treatment, complications, and outcomes in adults were selected. Studies were excluded due to inadequate study size, inclusion of pediatric populations, or lack of relevance.  The selections were then further limited to those published between 1980 and 2016 resulting in a narrowed reference list of 51 articles (Figure 1).

Fig. 1. PRISMA-Based Approach.

Results

An initial literature search for the term “facial injuries” returned 5,854 results. Next, a literature search containing “facial injuries” and “Le Fort” returned 491 results. Finally, a literature search containing “facial injuries” and “Le Fort” and “facial or craniofacial or intracranial” was done, yielding 176 results. Of these studies, 46 met inclusion criteria and 5 supplemental articles were identified outside of the search process, totaling 51 studies (Figure 1).  The 51 sources consisted of one Level II study, thirty-six Level IV studies, and fourteen Level V articles (Tables 1 and 2). This review found Le Fort fracture types I, II, and III occurred in 16%, 19%, and 30% of facial trauma cases (Table 3) and the majority of these injuries were caused by high-velocity MVCs (Table 4).

Table 1. Levels of Evidence.

Table 2: Le Fort Fractures, 1980-2016, Level II and IV Evidence

Table 3. Le Fort Fracture Incidence

^aSome patients sustained different grade fractures on contralateral sides, thus the total percent of patients with Le Fort fractures is >100%
^bThese are the reported isolated Le Fort fractures, 10 patients had fractures involving multiple levels, including 4 LFIII fractures. Additional information was not available, so it was not included in analysis

Table 4. Le Fort Fracture Etiology and Concomitant Injuries, 1980-Present

Discussion

Background
Le Fort fractures constitute a subset of injuries that result in discontinuity of the midface, a structure comprised of the maxilla, inferiolateral orbital rims, sphenoids, ethmoids, and zygomas. Fracture to these bones may result in disruption of the facial buttresses, which provide strength and rigidity to the facial skeleton.  The facial skeleton contains four paired vertical buttresses: the lateral, medial, and posterior maxillary, and posterior vertical mandibular buttresses and four paired vertical buttresses: the upper maxillary, lower transverse maxillary, upper mandibular, and lower transverse mandibular buttresses [7] (Figure 2). Disruption of these rigid structures may produce the midface instability and potential facial deformity associated with Le Fort fractures.

Fig. 2. Vertical and Transverse Buttress Systems.

Le Fort I fractures are horizontal fractures of the anterior maxilla that occur above the palate and alveolus and extend through the lateral nasal wall and the pterygoid plates.  These fractures result in mobility of the tooth-bearing maxilla and hard palate from the midface and are associated with malocclusion and dental fractures [7] (Figure 3).

Fig. 3. Le Fort Fracture Patterns.

Le Fort II fractures are pyramidal in shape and involve the zygomaticomaxillary suture, nasofrontal suture, pterygoid process of the sphenoid, and the frontal sinus.  These fractures cause disruption of the medial, lateral, upper transverse, and posterior maxillary buttresses and produce discontinuity of the inferomedial orbital rims. Involvement of the orbit seen in such fractures may lead to the development of complications including extra-ocular muscle injury, orbital hematoma, globe rupture or impingement, and optic nerve damage. Furthermore, damage to the medial maxillary buttress has been associated with epistaxis, cerebral spinal fluid (CSF) rhinorrhea, lacrimal duct and sac injury, medial canthal tendon injury, and sinus drainage obstruction [4] (Figure 3).
Le Fort III fractures involve the nasal bones, medial, inferior, and lateral orbital walls, pterygoid processes, and zygomatic arches, which results in complete separation of the midface from the cranium. These fractures affect the medial maxillary, lateral maxillary, upper transverse maxillary, and posterior maxillary buttresses.  Similar to Le Fort II fractures, they can be associated with orbital complications and CSF rhinorrhea [3-5,8] (Figure 3).
Though these fractures are defined by the collection of bones involved, Patil et al. found that only 24% of Le Fort fractures followed the classically described fracture patterns [9]. In this study, a majority of midfacial fractures (56%) partially resembled classic Le Fort fracture patterns but were associated with additional mid-face fractures including naso-orbito-ethmoid, palatal, zygomaticomaxillary, or dento-alveolar fractures [8]. An additional 20% of facial fractures were comminuted and did not follow Le Fort fracture lines at all [9]. As a majority of these fractures were caused by MVCs, the high forces involved may be responsible for this deviation from the classically described fracture patterns. This deviation indicates the need for a revised classification system that includes unilateral, comminuted, pan-facial fractures, and associated skull base and mixed dentition fractures [8].
In 2008, Carinci et al., [8] proposed a classification system that uses seven designated Midface Regional Units (MRU): a single nasal unit, and two paired alveolar, paranasal, and zygomatic units.  Using this system, fractures are classified by the number of MRUs involved (Table 5). Le Fort I fractures are classified as F2 or F3 (two alveolar fractures), while Le Fort II and III fractures are categorized as F4.  Le Fort II fractures contain five MRUs (two alveolar, two paranasal, and one nasal fracture) and Le Fort III fractures contain all seven MRUs.  This classification system shows that there is a high correlation between the number of MRUs involved, the number of surgical interventions required, and the number of post-surgical complications developed [9].

Table 5. Midface Regional Unit Classification System

Etiology
Trauma velocity has been associated with the type and severity of Le Fort fractures. Low-velocity trauma mechanisms, defined as a fall from standing height or blunt assault, were responsible for 56% of Le Fort I fractures.  High-velocity trauma mechanisms, defined as falls from greater than one story or high-speed MVCs, were more closely associated with Le Fort II and III fractures. Higher grade Le Fort fractures were also associated with increased rates of concomitant head and neck injuries that most commonly involved skull fracture (40.7%), closed head injury (5.4%), and cervical spine injury (5.4 %.) [10,11].
MVCs, assault, and falls were the most common etiologies of facial fractures [2,6,8,12-22] (Table 4). In developing countries, MVCs represented a higher proportion of fractures compared to all other causes [14]. Facial trauma that occurred secondary to assault commonly resulted in isolated low-energy nasal, orbital or ZMC fractures, however Le Fort I, II, and III fractures were identified in 6%, 5%, 3% of cases [23,24]. Falls resulting in facial trauma had a 43.9% incidence of Le Fort fractures, occurred from an average height of 7.3 meters, and were associated with extremity, head, or chest injuries 9.8% of the time [25-27]. Sports-related facial trauma had a greater frequency of Le Fort fractures in high-speed sports such as mountain-biking and skiing [28]. Specifically, Maladière et al. found that there was an increased incidence of Le Fort fractures in mountain bikers when compared to cyclists (15.2% vs. 3.7%), likely due to the high velocity and dangerous terrain associated with mountain biking compared to cycling. Conversely, lower velocity maxillofacial fractures typically occurred in the setting of contact sports such as soccer and rugby [28].
Drug and alcohol use has been documented in 28-45% of traumas that result in facial fracture and has been associated with more severe Le Fort fracture types [6,10,14,26,28]. One study found that positive screens for drug or alcohol use were present in 13.6%, 18.1%, and 52.1% of Le Fort I, II, and III fractures [6]. Another study identified positive screens for drug and alcohol in 52% of severe and/or comminuted Le Fort III fracture patients compared to 32% in Le Fort I and II fracture patients [13].

Diagnosis
Diagnosis of Le Fort fractures is made through physical examination and utilization of imaging.  It is important to note that though physical examination findings such as raccoon eyes and midface mobility support the diagnosis of Le Fort fracture, they may not always be present and should not be overly relied on for diagnosis.  Additionally, providers should avoid assuming bilateral symmetry or terminating the diagnostic process after identification of a single Le Fort fracture, as these classic fracture patterns are not always followed when injury is associated with high-velocity traumas [29].
Several radiologic features should trigger further evaluation for Le Fort fractures. The most important feature is the presence of a pterygoid fracture, which is found in all Le Fort fractures types. Other signs that should prompt the provider to investigate further for signs of Le Fort fracture include fractures of the lateral nasal wall, inferior orbital rim, lateral orbital wall, and the zygomatic arch [4].
Paranasal sinus effusions may be a useful indicator to determine whether or not a Le Fort fracture is present. In patients with facial trauma secondary to MVCs, a clear sinus sign (CSS) was associated with a lack of fracture in 73%. Though the lack of paranasal sinus effusion does not rule out a midfacial fracture (sensitivity of 76.7%, specificity of 73.2%), Le Fort I, II, and III fractures were associated with paranasal sinus effusions in 100% of cases [25].
When visualizing Le Fort fractures, 2-D CT imaging is preferable to 3-D CT because it provides increased detail of fracture lines and associated soft tissue injuries [8]. However, 3-D CT is capable of identifying Le Fort fractures that are not obviously be seen on single 2-D cuts and may be helpful for surgical planning [10]. Multidetector CT (MDCT) is considered the imaging modality of choice because it produces high-resolution images and also allows for 3-D rendering.  This facilitates identification of small fracture lines and differentiation of soft tissue and bone injury [25].

Management
Hospitalization was required for 84.5% of maxillofacial fracture patients [2]. The percentages of Le Fort I, II, and III fracture patients taken directly to the OR were 9.1%, 27.3%, and 26.1%, the average hospital length of stay for each patient was nine days, and each patient underwent an average of 1.7 operations [6].
Tracheostomy is an effective and safe way of securing airway management in the setting of severe facial trauma.  One study found that tracheostomy was required in 22.4% of all Le Fort fracture patients and 43.5% of Le Fort III fracture patients [11]. The need for tracheostomy has been associated with poorer outcomes as the mortality rate for patients that did not require tracheostomy was 0%, while the mortality rate for those requiring tracheostomy was 7.2% [30]. Tracheostomy can often be avoided through utilization of fiber optic intubation techniques.  Contraindications to endotracheal intubation include concomitant cervical spine injury or blast injuries affecting the face [31].  Retromolar intubation, orotracheal intubation secured in the retromolar space, allows for intraoperative mandibulomaxillary fixation and dental occlusion [26]. Submental intubation allows for unimpeded access of both the midface and the oral cavity [32]. Nasotracheal intubation in the setting of facial fracture is contraindicated as it can result in sinus infection, mediastinal emphysema, and most importantly, accidental intracranial intubation [26].
The goals for surgical management of Le Fort fractures include restoration of facial projection, height, and proper occlusion [4,31]. Preservation of midface structure is dependent on vertical buttress repair and restoration of midface aesthetics is achieved through repair of horizontal buttresses. Surgical repair traditionally follows the sequence of arch bar placement, fracture exposure, fracture reduction, malocclusion repair, plate fixation, and soft tissue repair [31]. This review found that Le Fort fractures required open reduction and internal fixation in 60% of cases, 30% of cases were managed conservatively, and the remaining 10% of cases required no treatment. Open fixation for Le Fort fractures at the zygomatic buttress, zygomaticomaxillary suture, and the frontozygomatic suture provides stable fixation and sufficient anatomic repositioning when indicated [22]. Le Fort fractures are frequently accompanied by fractures of the hard palate, dentoalveolar unit, and the mandible.  This creates another set of challenges when attempting repair, as normal occlusion must be restored before the upper midface can be anchored to the maxilla.  Furthermore, if there are concomitant zygomaticomaxillary complex, naso-orbito-ethmoid, or frontal sinus fractures, reconstruction of the frontal bar should be completed before resuspension of the midface takes place [4]. 
Upon review of the literature, most Le Fort I fractures were accessed surgically through a gingivo-buccal sulcus approach, while Le Fort II and III fractures often required additional subciliary or transconjunctival approaches [4]. A coronal approach offers wide exposure of the zygomatic arch in Le Fort II and III fractures, but can result in complications secondary to the dissection of neurovascular structures [22].
Minimally invasive surgical approaches provide an alternate method for surgical management of Le Fort fracture types II and III as they can be accessed via lateral eyebrow, intraoral vestibular, and subciliary approaches.  All 10 patients with Le Fort fractures treated by this approach in a 2010 study experienced effective aesthetic results-no complications were observed [33]. Endoscopic zygomatic arch repair allows for dissection of the deep temporal fascia to protect the facial nerves. An endoscopic approach is not indicated if concomitant fractures necessitate raising a coronal flap for repair [34]. Minimally invasive approaches require increased operative time, specific training, and specialized equipment, but the potential to conserve facial neurovasculature is worth considering when managing Le Fort fractures [34].  
Surgeon preference for the different plating systems varies, but generally 1.5-2.0 mm plates are adequate for fixation of the buttresses. Smaller plates may be used at the infraorbital rim, nasal root, frontozygomatic region, and zygomatic arch where less strength is needed and bone grafts may be used to bridge bony defects present in the buttresses. Management of fractures involving the hard palate has traditionally been accomplished with a palatal splint and arch bars, however Hendrickson states that rigid internal fixation may eliminate the need for palatal splinting and provide greater stability and accuracy for alignment [31,35].
Permanent rigid fixation has been implicated in cases of poor skeletal development. Up to 12% of titanium implants used for facial fractures require removal, generally due to palpable hardware, pain, plate or screw loosening or migration, infection, dehiscence, or thermal sensitivity. Biodegradable hardware is an alternative that provides sufficient stability to facilitate fracture healing, yet reabsorbs quickly enough to prevent a foreign body reaction.  An additional advantage of biodegradable hardware is that is does not require removal if it becomes loose [36].
Other less common surgical techniques, including screw-wire osteotraction, crewe halo and box frame techniques, and wire fixation, were noted in our review of the literature. Screw-wire osteotraction (SWOT) is traditionally used in treatment of lower facial fractures, however it has been successfully applied to Le Fort injuries [37]. Crewe halo frame and box frame techniques have also been utilized to allow for triple rigid fixation for Le Fort II or III fractures without the need for incisions [38]. Wire fixation is also a promising alternative in developing countries where hardware can be prohibitively expensive [11].
In a randomized controlled trial, there was no significant difference in rate of infection between patients treated with 24 hours of post-operative antibiotics and those treated with 5 days of post-operative antibiotics [39]. Post-operative infections were detected in 4% of all zygoma and Le Fort fracture patients, with an equal number of infections occurring in both the one-day and five-day groups. All Le Fort fracture infections were associated with Le Fort I fractures treated by open reduction internal fixation (ORIF) through an intraoral approach. Factors such as body mass index (BMI), implant type, presence of multiple fractures, and smoking history had no impact on the rates of post-operative infection [39].

Concomitant Injuries
Patients with facial fractures should be evaluated for potential cervical spine and head injuries, especially when the injury has been sustained from a high velocity mechanism [40]. Le Fort fractures, specifically, have been associated with spinal fracture or dislocation (1.4%) and cervical cord injury (1%) [40]. Higher grade Le Fort fractures (types II and III) have been associated with a 2.88-fold and 2.54-fold increased risk of concomitant intracranial injuries, and of facial fracture patients requiring neurosurgical intervention, 70% had sustained Le Fort III fractures [10,11,21].
Ocular injuries including periorbital edema, subconjunctival ecchymosis, chemosis, diplopia, retrobulbar hemorrhage, optic nerve compression, traumatic mydriasis, and retinal detachment have been associated with 8.3% and 6.7% of Le Fort II and III fracture cases [41]. Of the ocular injuries associated with midface fractures, 4.5% required ophthalmologic surgical intervention for either lens dislocation or ruptured globe repair.  Retinal detachment leading to blindness was present in 0.84% of these patients [42]. Because of the potential for ocular injury, a thorough ocular examination is necessary when evaluating a patient with midface fractures [42].
Dental injuries are associated with Le Fort fractures at higher rates than when compared to all facial fractures (47.7% vs. 23.2%.) [43]. This is likely attributed to the fact that the zygomatic complex is the facial bone most susceptible to fracture, yet requires bigger insult (due to its location) for dental injury to be involved. Blunt facial trauma has been associated with internal carotid injuries in 1.2% of cases, and specifically internal carotid artery injuries were found in 6.9%, 5.6%, and 3.0% of Le Fort I, II, and III fracture patients [44]. The Eastern Association for the Surgery of Trauma (EAST) recommends screening for internal carotid injury in asymptomatic patients with significant blunt traumatic head injuries including Le Fort II and III fracture patients [44].

Outcomes
Mortality rates of facial trauma patients depend on the mechanism of injury, location and severity of injury, and presence of associated injuries.  Complex facial fractures, including Le Fort fractures, had a mortality rate of 11.6%, compared to 5.1% seen in simple midface fractures. Le Fort I, II, and III fractures had mortality rates of 0%, 4.5%, and 8.7%, respectively and Le Fort II fractures were associated with a 1.94-fold increased mortality risk when compared to simple facial fractures [21]. Le Fort fractures are associated with significant morbidity, including the development of visual problems (47%), diplopia (21%), epiphora (37%), difficulty with breathing (31%), and difficulty with mastication (40%) [13]. Patients with severe or comminuted Le Fort fractures have been reported to have higher levels of injury-related disability [13]. Fewer patients with a Le Fort III or comminuted fracture were able to return to work compared with those that had sustained Le Fort I or II (58% vs. 70%.) [13]. Satisfactory outcomes with regards to function and aesthetics were achieved in 89.1% of patients, while long term infection, temporary temporomandibular joint stiffness, or facial deformity were seen in 10.9% of patients [14]. 

Conclusion

Le Fort fractures are specific patterns of facial bone fractures that develop secondary to blunt facial trauma. While mortality rates due to Le Fort fractures themselves are low, these injuries rarely occur in isolation and are frequently associated with other severe injuries to the head and neck. The ability to quickly and accurately diagnose Le Fort fractures is crucial to the successful management of blunt facial trauma patients. Our review found that there is a lack of published data regarding Le Fort fracture management, especially reporting on the usage of minimally invasive surgical techniques and long term outcomes. Further research is needed to determine the optimal management plans for these patients.

Acknowledgments

The authors would like to thank the following residents and students for their help and assistance with this manuscript: S. Typher, E. Samlowski, E. Murray, and S. Holzmer.

Funding

External sources of funding were not used in either the preparation or submission of this manuscript.

Compliance with Ethical Standards

All authors state clearly that we have nothing to disclose regarding potential conflicts of interest. This collective review study did not directly involve Human Participants and/or Animals. As such, informed consent was not required. This article does not contain any studies with human participants or animals performed by any of the authors. External sources of funding were not used in either the preparation or submission of this manuscript.

Conflict of Interest: The authors declare no conflict of interest.