Fractures of the zygomatic complex may result in secondary fractures of the frontal bone, sphenoid bone, maxillary region or temporal bone, and as a result include the skull base in the fracture.

3.2.6  Midface: Combined Fractures

As the intensity of the impact kinetic energy increases, varying combinations of diverse fracture types may occur, with partly irregular progressions in differing fracture levels and midface compartments (Riefkohl et al. 1985; Mc Mahon et al. 2003).

With increasing comminution, there is a greater probability that the frontofacial compartment (IV) is involved with an immanent participation of the frontal skull base, frontal sinus and the ethmoidal cells (Boeninghaus 1974; Bull et al. 1989; Denneke et al. 1992; Weerda and Siegert 1992; Wolfe and Baker 1993; Stoll 1993; Schroeder 1993; Weerda 1995).

Fracture course: complex combined fractures

Here we are dealing with profoundly severe comminuted fractures of the midface as a result of brute force, which fails to comply with all rules and whereby there is almost always a simultaneous subcranial/ intracranial trauma (Manson 1986, 1998). Besides open fractures, one finds impressions and asymmetries of the facial skeleton, there are often posttraumatic hyperteleorism and dural injuries with rhinoliquorrhea with additional frontobasal fractures (Rowe and Williams 1985; Habal and Aryan 1989).

3.2.7  Naso-Orbito-Ethmoidal Fractures

(NOE Fractures)

The interorbital skeleton is described as the NOE complex and is composed of a robust anterior section (nasal bone, frontal maxillary process) and a weaker dorsal

section [median skull base, ethmoidal cell system with crista galli, medial orbital walls (lacrimal bone-papy- raceous plate, nasal orifices and conchae)] (Holt and Holt 1985; Messerklinger and Naumann 1995; Ewers et al. 1995; Weerda 1995; Prein et al. 1998; Schwenzer and Ehrenfeld 2002).

NOE fractures are difficult to classify as a result of their immense variability. Splinter fractures with totally random dislocations of varying fragment size are typical following injury to the interorbital region.

On midface impact with a hard object, the depressed naso-ethmoidal complex simultaneously involves the ethmoidal labyrinth, orbital walls, skull base and orbital soft tissues, and, due to the enlargement of the intercanthal distance, results in a posttraumatic telecanthus (Paskert and Manson 1988; Mathog et al. 1995).

Normal and pathologic distances of the naso-orbital complex (Holt and Holt 1985)

Normal intercanthal distance 30 mm

Normal interpupillary distance 60 mm

Telecanthus 45 mm

Today the classification from Markowitz et al. (1991) is generally accepted. It differentiates between three fracture types, which may appear unior bilaterally­.

Classification of NOE fractures (Markowitz et al. 1991)

Type 1 a: En bloc – fracture with moderate dislo­ cation

Type 1 b: En bloc – fracture with extensive dislo­ cation

Type 2: Multifragmental NOE complex with preservation of the canthal ligament attachment to central fragment

Type 3: Multifragmental NOE complex with avulsion of the canthal ligament from the central fragment

The actual state of the central fragment is crucial, i.e., the region of bone bearing the medial ligamentous attachment of the lid (Hammer 1995; Hammer and Prein 1998).

One can differentiate between three types of injuries depending on the severity of the cantho-ligamental displacement (Mathog et al. 1995).

Fig. 3.11  Classification of the cantho-ligamental injuries in nasoorbitoethmoidal fractures (NOE - fractures) (mod. a. MATHOG et al 1995) NOE fractures may be classified as type I, II, or III according to the severity of the injury (a-c) Type1 – NOE - fracture with disruption of the medial canthal ligament and increase

in intercanthal­ distance without accompanying increase in interpupillary distance (posttraumatic telecanthus) (b-d) Type 2 – NOE - fracture with unilateral comminution and displacement of the medial orbital wall (central fragment) with adherent medial canthal ligament and accompanying increase in interpupillary distance