rotation of the maxilla round a vertical axis can be seen. Dorsal dislocation(s) as a result of traction of the pharyngeal muscles occurs rarely. However, it bears a high risk of airway obliteration. Only in atypical fracture patterns with disruption of the pterygoid process of the sphenoid can the pharyngeal muscular tract dislocate the fractured maxilla dorso-caudally.

Le Fort II fractures are caused by a blunt force that hits the middle part of the midface on a large impact surface. As the pterygoid process of the sphenoid is shorn off the skull base, the muscular pull of the medial pterygoid muscle can dislocate the midface dorsocaudally.

Le Fort III fractures are caused by blunt forces that hit the upper part of the midface on a large impact surface. As described above, a dorso-caudal dislocation of the fractured midface block is possible.

As the typical fracture line in Le Fort III fractures follows the plane of the skull base, additional fractures of the skull base may occur. Central and centrolateral fractures of the midface are often associated with fractures of the NOE complex (Gruss 1986; Probst and Tomaschett 1990; Kessler and Hardt 1998). NOE fractures are frequently combined with injuries to the skull base.

4.3.5  Position of the Skull

The damaging impact results from the energy affecting the object and the size of the object hitting the midface, but it also depends on the position of the head at the moment of impact.

4.3.5.1  Proclination

If the traumatic force hits the upper midface region in a proclined position of the head, the absorption by bony structures may prevent extended interorbital and skull base injuries, provided that the force is light to moderate (degree 1–2).

If the force is greater (degree 3), extended fractures of the NOE complex and of the glabellar, frontal, or supraorbital region are to be expected; these trauma patterns are due to a limited absorption zone frequently associated with skull base injuries (Rowe and Williams 1985).

4.3.5.2  Reclination

Considerable forces (degree 2) acting on the midface region in a reclined position of the head with the mouth open will lead to Le Fort II fractures. Extreme forces (degree 3) will result in Le Fort I or II fractures. Sagittal maxillary fractures with disruption of the median palatine suture can be expected.

If the force is primarily directed at the chin region, a mandibular fracture will occur with the risk of a bilateral condylar fracture. Subsequently the forces are absorbed by the midface complex leading to Le Fort I, II, and III fractures (Rowe and Williams 1985).

References

Boenninghaus HG (1974). Traumatologie der Rhinobasis und endokranielle Komplikationen. In: HH Naumann (ed), Kopfund Halschirurgie (vol II/2). Thieme: Stuttgart.

Bowerman JE (1985). Fractures of the middle third of the facial skeleton. In: NL Rowe, JL Williams (eds), Maxillofacial injuries (vol I). Churchill Livingstone: Edinburgh, pp 363–435.

Crow RW (1991). Diagnosis and management of sports-related injuries to the face. Dent Clin North Am 35, 4: 719–732.

Dutton GN, Al Qurainy I (1991). Ophthalmic consequences of maxillofacial injuries. In: RJ Fonseca, RV Walker (eds), Oral and maxillofacial trauma (vol 1). Saunders: Philadelphia.

Endo B (1966). Experimental studies of the mechanical significance of the form of the human facial skeleton. J Fac Sci Univ Tokyo 3: 5.

Ernst A, Herzog M, Saidl RO (2004). Traumatologie des Kopf- Hals-Bereiches. Thieme: Stuttgart.

Gassner R, Hackl W, Tuli F, Fink Z, Waldhart E (1999). Differ­ ential profile of facial injuries among mountainbikers and bicyclists. J Trauma 47, 1: 50–54.

Gruss JS (1986). Complex nasoethmoid-orbital and midfacial fractures: Role of craniofacial surgical techniques and immediate bone grafting. Ann Plast Surg 17, 5: 377–390.

Hardt N, Gottsauner A, Sgier F (1994). Results of various reconstructive procedures in defects of the fronto-facial area. Fortschr Kiefer Gesichtschir 39: 47–50.

Haskell R (1985). Applied surgical anatomy. In: NL Rowe, JL Williams (eds), Maxillofacial injuries (vol I). Churchill Livingstone: Edinburgh, pp 1–43.

Hill CM, Crosher RF, Carroll MJ, Mason DA (1984). Facial frac- tures-the results of a prospective four-year-study. J Maxillofac Surg 12, 6: 267–270.

Hill IR (1982). The mechanism of facial injury. Forensic Sci Int 20, 2: 109–116.

Hoffman HT, Krause CJ (1991). Traumatic injuries to the frontal sinus. In: RJ Fonseca, RV Walker (eds), Oral and maxillofacial trauma (vol I). Saunders: Philadelphia, pp 576–599.

Kessel FK, Guttmann L, Maurer G (1971). Neurotraumatologie mit Einschluss der Grenzgebiete (vol I). Urban und Schwarzenberg: München.

Kessler P, Hardt N (1998). Ergebnisse der transkranialen und sub kranialen Versorgung von Frakturen des nasoethmoidoorbitalen Systems bei komplexen Mittelgesichtsfrakturen. Mund Kiefer Gesichts Chir 2: 202–208.

Kretschmer H (1978). Neurotraumatologie. Thieme: Stuttgart. Lädrach K, Raveh J, Iizuka T (1999). Reconstruction of the mid-

face and fronto-orbital region following tumor resection and trauma. In: AJ Maniglia, FJ Stucker, DW Stepnick (eds), Surgical reconstruction of the face and the anterior skull base (1st edn). Saunders: Philadelphia, pp 113–140.

Mathog RH (1992). Atlas of craniofacial trauma. Saunders: Philadelphia.

Mathog RH, Arden RL, Marks SC (1995). Trauma of the nose and paranasal sinuses. Thieme: Stuttgart.

Nahum IS (1975). The biomechanics of maxillofacial trauma. Clin Plast Surg 2, 1: 59–64.

Panzoni E, Clauser C, Giorgi B (1983). Maxillofacial fractures in sports: Clinico-statistical study of 107 cases. Riv Ital Stomatol 52, 12: 955–960.

Probst C (1971). Frontobasale Verletzungen – Pathogenetische, diagnostische und therapeutische Probleme aus neurochirurgischer Sicht. Huber: Bern.

Probst C (1986). Neurosurgical aspects of frontobasal injuries with cerebrospinal fluid fistulas: Experience with 205 operated patients. Akt Traumatol 16, 2: 43–49.

Probst C, Tomaschett C (1990). The neurosurgical treatment of traumatic frontobasal spinal fluid fistulas (1982–1986). Akt Traumatol 20, 5: 217–225.

Rohrbach JM, Steuhl KP, Knorr M, Kirchhof B (2000). Ophthalmologische Traumatologie. Schattauer: Stuttgart.

Rowe NL, Williams JL (eds) (1985). Maxillofacial injuries (vol I). Churchill Livingstone: Edinburgh.

Spangenberg P, Scherer R, Stolke D (1997). Posttraumatische cerebrospinale rhinorrhoe. Anästhesiol Intensivmed Notfallmed Schmerzther 32, 2: 105–108.

Theissing J (ed) (1996). HNO – Operationslehre (3rd edn). Thieme: Stuttgart.

5.1  Epidemiology

Traffic accidents are still the main cause of skull bone and skull base fractures. According to the literature, 40–70% of the casualties in traffic accidents suffer from multiple fractures in the visceroand neuro-­cranium (Kalsbeck et al. 1980; Crossman et al. 2003).

Sport accidents and accidents in leisure time follow, with 19%; the number of casualties in this group is increasing strongly (Probst 1971, 1986; Prokop 1980; Panzonietal.1983;Hilletal.1984;ProbstandTomaschett 1990; Spangenberg et al. 1997; Gassner et al. 1999).

Skiing, biking and horse riding are the main activities with a high accident risk for cranio-maxillofacial injuries (Haeusler 1975; Crow 1991).

In 41% of our own patients, traffic accidents were the main cause of craniofacial trauma. Amongst them, 18% were due to car accidents, 17% due to bike accidents and 6% due to motorbike accidents. Falling during domestic activities caused approximately 23% of

the craniofacial injuries. Alcohol plays an important role in domestic accidents.

Sport activities were the cause in 18% of the craniofacial injuries. Ten percent of the craniofacial injuries were acquired at work. In 8%, violence was the cause, whereas 6% of the craniofacial injuries were related to suicide attempts using firearms and shotguns (Neidhardt 2002) (Fig. 5.1).

Statistical analysis of craniofacial fractures in our patients (Neidhardt 2002)

In conclusion, statistically in about 90% of the cases traffic and sporting accidents, as well as falling and work-related accidents, are responsible for serious and often multiple fractures in the frontofacial and frontobasal part of the visceral and neural cranium.