Maxillary fractures comprise 6–28 % of all facial fractures. Most of them occur in 20–40-year-old men; half of those acquire the trauma while intoxicated with alcohol [1–5]. Motor vehicle accidents, assaults, and falls are the major reasons for maxillary fractures [1, 3, 6, 7]. The percentage of maxillary fractures and the involvement of orbital bones secondary to motor vehicle accidents has significantly risen over the past several decades from 10 % in the 1950s to 50 % in the 1990s [8]. Furthermore, maxillary fractures affect the zygomatic bone in 80 % of patients [9]. The anterior visual pathway is affected to some extent in 90 % of patients, while severe damage such as globe rupture or optic neuropathy is observed in 12–20 % of cases [1, 10].

Finally, 30–40 % of patients have multiple traumas combined with brain injury and limb fractures [2, 6, 11–13].

The classification of non-gunshot maxillary fractures was proposed by French surgeon René Le Fort in 1901 [14]. Three main types of maxillary fractures have been described in experimental studies using cadaver skulls. The formation of a certain type of fracture depends on the degree, direction, and the point to which the vector force of the trauma is exerted.

Le Fort I fractures (also known as horizontal, floating, or Guérin’s fractures) are formed when the vector force of the trauma moves downward and affects the maxillary alveolar process. The fracture line extends from the nasal septum toward the edges of the piriform aperture, runs posteriorly in the horizontal direction over the apex of the teeth above the level of the bottom of the maxillary sinus, crosses the zygomaticoalveolar crest, and passes through the tuber maxillae and the lower third of the pterygoid process of sphenoidal bone (Fig. 7.2a, b). Sometimes the fracture line stops near the sockets of the second or third molar teeth. It is accompanied by transverse fracture of the nasal septum. The floor of the nasal cavity and maxillary sinus is detached and their mucous membranes are inevitably damaged. This fracture type occurs in 14–24 % of patients [15, 16]; in 9 % of these cases, the fracture is unilateral and nondisplaced [17]. Le Fort I fractures do not affect the orbit.

Le Fort II (pyramidal) fractures are the most common type (55–64 %) of maxillary fractures. They result from a blow to the lower or mid-maxilla. Two variations are possible depending on the angle of trauma.

A direct blow results in a typical pyramidal fracture with or without injury to the hard palate. The fracture line crosses the nasofrontal suture and descends along the medial orbital wall (the lacrimal bone) and the orbital floor to reach the inferior orbital fissure where it turns forward. It crosses the infraorbital rim along the infraorbital foramen or in close proximity to it, extends along the anterior wall of the maxillary sinus above the zygomatic bone, and crosses the pterygomaxillary fissure to reach the pterygoid process of the sphenoidal bone. The nasal septum can be involved in bilateral fractures. The cribriform plate of the ethmoidal bone and the frontal sinus are damaged in more severe cases, and the pattern of the naso-orbito-ethmoidal fracture is formed (Fig. 7.2c, d). Thus, the maxillary and nasal bones are detached from the zygomatic and neurocranial bones in Le Fort II fractures (complete detachment of the maxilla and nasal bones).

A side blow gives rise to a unilateral zygomatico-orbital fracture combined with Le Fort I and/or II fractures [17].

Le Fort III fracture (also known as transverse fractures or craniofacial disjunction) results from a blow to the nasal dorsum or the upper third of the maxilla. The fracture line starts near the nasofrontal or frontomaxillary suture and extends posteriorly along the medial orbital wall through the lacrimal groove and the ethmoidal bone. Located posteriorly, the appreciably thick sphenoid bone usually (but not always) prevents the extension of the fracture line into the optic canal. Hence, the fracture turns toward the infraorbital fissure and extends posterolaterally through the lateral orbital wall, the frontozygomatic suture, and the zygomatic arch. It subsequently runs posteriorly and downward along the greater wing of the sphenoidal bone to reach the upper section of the pterygoid process and the body of the sphenoidal bone. In the nasal cavity, the fracture line runs through the base of the perpendicular plate of the ethmoidal bone and the vomer and between the pterygoid processes of the sphenoidal bone to its body (Fig. 7.2e, f). Thus, the facial bones are detached from the neurocranial bones in this type of fracture. Le Fort III fractures are observed in 8–12 % of patients with maxillary fractures [15, 16].

Although the practical significance of the Le Fort classification is obvious, one should bear in mind that it is not perfectly comprehensive. The reason is that the energy of the trauma sustained in motor vehicle accidents is much higher than that used by R. Le Fort in his experiments. In most cases, contemporary maxillary fractures are a combination of various Le Fort fractures (either I–II or II–III) (Fig. 7.6d) [18, 19]. The fracture lines frequently diverge from the trajectories described above to form unilateral (hemi-Le Fort) fractures, mixed fractures, and other atypical varieties of fractures [20]. Finally, extremely high-energy maxillary fractures can be combined with injuries to the mandible and cranial vault, thus forming panfacial fractures.

Furthermore, the Le Fort classification does not describe the two rather common types of maxillary injuries. The first type is a small isolated fracture that usually localizes near the alveolar process of the anterior wall of the maxillary sinus or the nasomaxillary suture. This type of injury is caused by a strong local impact of an object (e.g., a hammer) (Fig. 7.6e, f). The rate of these fractures is as high as 9–10 % [16]. The second type comprises fractures resulting from an impact directed upward and damaging the horizontal “reinforcing ribs” of the face: the alveolar process, the infraorbital rim, and the zygomatic arc.

The usefulness of plain X-rays is limited because of the shielding effect of swollen soft tissues and overlapping projections of numerous midfacial bones [32]. Nevertheless, frontal and lateral radiography of the skull and targeted examination of the zygomatic bone are still used for screening.

X-rays of accessory nasal sinuses shed light on the condition of zygomatic arches, nasal bones, the anterior and lateral walls of the maxillary sinus, and the orbital rims. Radiography provides appreciably clear imaging of all maxillary buttresses. Lateral radiography of the skull allows one to evaluate the sagittal dimensions of the midface and the integrity of the anterior and posterior walls of the frontal sinus. Hemosinus, facial edema, and emphysema also have certain diagnostic values. Evaluation of the condition of the cervical spine makes it possible to rule out its injury (e.g., a whiplash fracture). However, CT scanning is an indispensable method for analyzing multiple fractures, evaluating the concomitant injuries to the cartilages and soft tissues, and revealing injuries involving the optic canal and remains the main diagnostic tool (Fig. 7.6).