Classification of Craniofacial Fractures

Craniofacial traumatology comprises:

•Combined fractures of the visceraland neuro­ cranium

•Posttraumatic craniofacial defects and deformations

Fractures of the craniofacial skeleton comprise variable fractures of the anterior skull base, the frontoglabellar region, the orbit and the maxillary complex (Weerda 1995) (Fig. 3.1).

Fractures affecting the skull base are the most common form of neurocranial injuries, particularly in midface fractures type Le Fort II and III, respectively Wassmund III and IV (Hausamen and Schmidseder 1975; Machtens 1987; Manson 1986, 1998; Joss et al. 2001).

The neurocranial involvement ranges from facultative skull base fractures in subcranial midface fractures to extensive craniofacial skull fractures with obligatory frontobasal and frontofacial poly-fragmentation in combination with duraand intracranial soft tissue injuries (Manson 1986; Weerda 1995).

The following trauma compartments (midface fracture levels according to Le Fort and Wassmund) with frontobasal involvement are differentiated:

•Subcranial midface fractures – fontobasal fractures Fracture levels: II/III/I + II + III/II + III

•Craniofacial fractures – frontobasal fractures Fracture levels: II + VI/III + IV/II + III + IV

•Frontofacial fractures – frontobasal fractures Fracture level: IV (Fig. 3.2)

Fig. 3.1  Fractures of the craniofacial skeleton consist of variable fractures of the anterior skull base, the frontoglabellar region, the orbit and the maxillary complex (mod.a. Weerda 1995)

3.1  Frontobasal: Frontofacial Fractures

Fractures of the frontofacial level (fracture level IV) include skull base fractures in the region of the anterior cranial fossa with involvement of the neighboring aerated sinuses and fractures of the frontal and glabella structures, frequently including the orbital roof.

These fractures most often occur in the frontal region, including the anterior and/or posterior wall of the frontal sinus. As combined fractures, frontofacial fractures involve the anterior and middle third of the ethmoid (naso-ethmoidal fracture) or the midface (Raveh et al. 1988).

Fig. 3.2  Subdivisions of the midfacial skeleton into three compartments: central (I-II), lateral (III) and frontofacial (IV) (mod.

a.Hardt et al 1990)

•Specific pathogenetic danger exists in frontobasal and cranio-cerebral injuries when the subbasal paranasal sinuses are involved in the course of the fracture, providing an interconnection between the intracranial space and the paranasal sinuses, so increasing the risk of an ascending infection.

the posterior wall of the frontal sinus as well as the ethmoid roof combined with dura lacerations and brain injuries (Probst 1971; Boeninghaus 1974; Schwab 1995; Weerda 1995).

3.1.1.2  Type 2

Localized mid-frontobasal fracture resulting from circumscribed violence applied to the fronto-naso-basal region:

Localized depressed fracture or bony comminution in the frontal sinus/ethmoid region primarily in the region of the cribriform plate, the crista galli, the posterior ethmoid and the roof of the sphenoid with dural injuries (Probst 1971; Boeninghaus 1974; Schwab 1995; Weerda 1995).

3.1.1.3  Type 3

Low frontobasal fracture with subcranial midface avulsion resulting from violent force acting on the midface:

Midface avulsion from the skull base in the context of midface fractures, particularly in Le Fort II, Le Fort III, Wassmund IV and Wassmund III levels, whereupon depending on the applied force, extensive particles of the frontal base may be shattered and dislocated (Probst 1971; Boeninghaus 1974; Schwab 1995; Weerda 1995; Ernst et al. 2004).

3.1.1  Anatomical Classification:

Skull Base Fractures

Escher introduced a classification for frontobasal fractures according to the fracture site, the extent of the fracture and according to the direction of the traumatic force acting. He defined four different types of frontobasal fractures: high, middle, low, and lateral fractures — types 1–4, respectively (Escher 1969, 1971, 1973).

3.1.1.1  Type 1

3.1.1.4  Type 4

Latero-orbital frontobasal fracture from forces acting on the orbito-temporal region with fracture of the frontal sinus and dislocation of latero-frontal parts of the orbital roof (Probst 1971; Boeninghaus 1974; Weerda 1995; Schwab 1995).

3.1.2  Topographic Classification:

Skull Base Fractures

Extensive high frontobasal fracture resulting from a direct craniofrontal impact to the upper frontal bone radiating into the paranasal sinuses:

Extended frontobasal comminuted fractures with disintegration of the frontal bone and participation of

For therapeutic purposes, the modern classification of frontobasal fractures relates to the frontobasal topographic diagnosis, which correspondingly classifies the individual regions of the paranasal sinuses as follows (Oberascher 1993; Schroeder 1993):