Fracture-related plate dimensions (Greenberg and Prein 2002; Marchena and Johnson 2005; Stewart 2005a, b)

In facial reconstruction, depending on the traumatic impact and region, microand miniplate systems varying in dimension are applied. In the cranial compartment, micro-/miniplate systems of 1.3 or 1.5 mm are used; in the midfacial compartment, according to bone thickness, 2.0- or 1.5-mm miniplate systems are indicated in the region of the bone struts and 1.3-mm microplate systems in the orbital and naso-ethmoidal regions (Greenberg and Prein 2002).

Indications: Miniplate system, 1.5/2.0 mm

Application in

•Zygomatico-orbital fractures

•Maxillary fractures

•Zygomatico-maxillary fractures

•Zygomatico-frontal frontal

•Frontonasal fractures

•Zygomatic arch fractures

•Cranial fractures

Indications: Microplate systems, 1.0–1.3 mm

Fragments can be stabilized and fixed using these tiny plate-and-screw systems. However, one can only exceptionally succeed in neutralizing functional forces.

•Areas for application of 1.3-mm systems: Zygomatico-orbital, cranial-fronto-glabellar, NOE, zygomatic arch, periorbital region and nasal skeleton, NOE fractures, cranial fractures

•Areas for application of 1.0-mm systems:

Very fine osseous areas such as the maxillary sinus wall, infraorbital margin, nasal bone, alveolar process; anchoring naso-orbital-ethmoidal and small cranial fragments

et al. 1999; Booth et al. 2003; Ernst et al. 2004). The principle of stability requires that the osteosynthesis plate must be fixed to a stable, immobile midfacial structure with a minimum of two screws.

11.4.2.1  Surgical Approaches

The approach in central pyramidal fractures (Le Fort II, Wassmund II fractures) is carried out by a combination of an intraoral vestibular incision with an extraoral transconjunctival, subcilliary, infraorbital, or mediopalpebral approach. In selected cases, a median nasofrontal,verticalapproachmaybenecessary.Alternatively, a midfacial degloving through intraoral and intranasal incisions can be performed (Thumfart et al. 1998).

In centrolateral fractures (Le Fort III, Wassmund IV fractures), a combination of an intraoral, vestibular approach with a mediopalpebral and supraorbital or/ and lateral approach may be sufficient for exposure (Brisett and Hilger 2005). In case of extensive zygomatic bone dislocations or complex NOE fractures, the coronal incision is the approach of choice for fracture treatment (Perott 1991) (Fig. 11.4).

11.4.2  Fracture-Related Osteosynthesis

There are standardized principles concerning the osteosynthesis of anatomically correct repositioned skeletal structures. The osseous struts and trajectories define the areas for an elective, stable osteosynthesis according to their thickness (Champy et al. 1978, 1986; Klotch and Gilliand 1987; Prein et al. 1998; Härle

Fig.11.4  Anterior surgical approaches to the facial skeleton (mod. a. Prein et al. 1998, Prein and Lüscher 1998). CI coronal incision, GI glabellar incision, SCI subciliar incision, TCI transconjunctival incision, LBI lower blepharoplasty incision, LEI lower eyelid incision, UBI upper blepharoplasty incision

11.4.2.2  Lateral Midface Fractures

The amount of osteosynthesis required depends on the degree of dislocation and the extent of the fracture in the midfacial skeleton (Rowe 1985; Chuong and Kaban 1986; Jackson 1989; Zingg et al. 1991; Ellis, 1991; Prein et al. 1998; Gruss et al. 1999; Maniglia et al. 1999; Stewart 2005 b; Marchena and Johnson 2005).

•One-point plate fixation:

Fixation at the zygomatico-frontal suture for stabilization of nondislocated zygoma fractures. Osteosyn­­ thesis using supraorbito-lateral 2.0-mm miniplates (Prein et al. 1998; Markowitz and Manson 1998).

•Two-point plate fixation:

Fixation at the zygomatico-frontal suture and at the zygomatico-alveolar crest or infraorbital for stabilization of dislocated zygoma fractures with a rotational component. Osteosynthesis using supraorbito-lateral 2.0- or 1.5-mm miniplate and infraorbital 1.3-mm microplates (Prein et al. 1998; Markowitz and Manson 1998).

•Three-point plate fixation:

Lateral midface fractures with distinct dislocation but secured sagittal projection are stabilized using three-plate osteosynthesis at the zygomatico-frontal suture with 2.0-mm miniplates, infraorbital margin with 1.3-mm microplates and the zygomatico-alve- olar crest with 1.5- or 2.0-mm miniplates (Holmes and Matthews 1989; Prein et al. 1998; Markowitz and Manson 1998) (Fig. 11.5–11.7).

•Four-point plate fixation:

In cases of extensive comminution with the loss of sagittal projection, there is a selective necessity to expose and stabilize the zygomatic arch. Osteo­ synthesis is performed using 1.5-mm miniplates. Occasionally, depending on extent and localization of the fracture region, further additional osteosynthic stabilzation is necessary in the cranial, maxillary or/and facial region (Fig. 11.8–11.12).

•Concomitant orbital floor/orbital wall fractures

It is obligatory to expose, control, and reconstruct the orbital floor in cases of complex or dislocated

Fig.11.6  Reposition and fixation of a complex lateral midface fracture with significant displacement of the zygomatic bone into the maxillary sinus with three mini-plates: at the lateral

orbital wall, infraorbital rim and zygomatico-maxillar buttress. Emphysema in the orbit and pterygomandibular fossa

zygomatico-orbital fractures, particularly in the case of verifiable dislocated orbital floor fractures with or without functional deficits (Chen et al. 1992; Joos 1995; Brady et al. 2001; Stewart and Soparkar 2005).

Access to the orbital floor is normally achieved via a subcilliary, a medio-palpebral or a transconjunctival incision (Manson et al. 1987; Hammer 1995, 2001). In general, the same rules apply to treating orbital wall fractures (Jackson et al. 1986; Serletti and Manson 1992; Hammer and Prein 1998) (Fig. 11.13–11.15).

•Removal of the dislocated fragments and repositioning of the periorbita. In the case of medial orbital wall fractures, simultaneous treatment of the fractured ethmoid cells.

•Reconstruction of the orbital walls by repositioning the bony fragments; small gaps are covered with a patch. In extensive defects, reconstruction of the orbital walls with autogenous grafts or alloplastic membranes is necessary (Fukado et al. 1981).

•Transplant fixation in the orbital floor or medial/­ lateral orbital wall is carried out with microscrews or plates (Frodel 2002).

In complex orbital fractures, the stronger periorbital bone segments are first repositioned and stabilized by miniplate osteosynthesis before the fragile structures of the orbital walls are reconstructed (Stewart 2005 b; Marchena and Johnson 2005).

11.4.2.3  Central: Centrolateral Midface

Fractures

The following principles apply to central subcranial and centrolateral midface fractures (Schwenzer 1986; Prein et al 1998; Manson 1998; Marchena and Johnson 2005; Stewart 2005a, b):

Fig.11.7  Posterior displacement of the zygomatic bone, fracture of the anterior and lateral maxillary sinus walls, fracture of the zygomatic arch and outward displacement of the lateral

orbital wall. Reposition and fixation with three mini-plates at the lateral orbital wall, infraorbital rim and zygomatico-maxillar buttress

Fig.11.9  Reconstruction of a complex lateral orbito-zygomatic fracture with extrusion of the globe (a,b,d,e). Decompression of the orbit with reposition of the malrotated zygomatic bone and

osteosynthesis of the lateral orbital wall, the inferior orbital rim and anterior maxillary wall (c). The destroyed globe was removed and replaced with an epithesis (c, f)

Fig.11.10  Fragmentation of the zygomatic bone with flattening of the lateral midface and deconfiguration of the orbit. (a–d) Complex fracture of the lateral orbital wall and orbital floor (c). Application of multiple osteosynthesis plates (7) (e–h). PDS foil

implant to support the orbital floor and prevent soft tissue herniation into the fracture defects (f, g, h). Stabilization of the anterior maxillar walls and the volume of the sinus with a Foley catheter (f, g)

• Le Fort I fractures

Classically Le Fort I fractures are treated by osteosynthesis in the region of the anterior nasal aperture (apertura piriformis) and the zygomatico-alveolar buttress using four 2.0-mm miniplates (Stanley 1990).

Smaller bone fragments from the antral region are reintegrated and fixed with 1.3-mm miniplates. Additional sagittal maxillary fractures are stabilized with a transversal plate below the piriform aperture and occasionally by an additional transversal palatinal 1.5-mm miniplate (Sofferman et al. 1983; Manson et al. 1990; Gruss and Philipps 1992; Prein et al. 1998; Härle et al. 1999; Stewart 2005 a; Marchena and Johnson 2005).

Reconstruction of the anterior wall of the maxillary sinus is carried out by reintegrating the bony fragments or with bone grafts, but also by applying titanium meshes to avoid soft tissue collapse or invasion into the sinus (Kuttenberger and Hardt 2001; Marchena and Johnson 2005; Stewart 2005a, b).

• Le Fort II fractures/Wassmund II fractures

Le Fort II fractures are stabilized in the region of the naso-frontal suture, the zygomatico-alveolar buttress and the infraorbital margin. Following instrumental repositioning (ROWEforceps) and intermaxillary adjustment to the position of central occlusion, the Le Fort II complex is bilaterally fixed to the zygomatico-alveolar buttress with 1.5-mm miniplates and to the infraorbital region with 1.3-mm miniplates. A facultative fixation to the naso-frontal region using 1.5-mm miniplates may be necessary (four-point osteosynthesis) (Prein et al. 1998).

Remaining bony fragments are reintegrated using 1.5-mm or 1.3-mm minior microplates. Alternatively, the orbital floor may either be reconstructed with autogenous fragments, autogenous bone grafts, alloplastic membranes or titanium-mesh systems.

• Le Fort III fractures/Wassmund III and IV fractures

Due to its vertical pull, the masseter muscle occasionally causes extensive caudal dislocation. Osteosynthesis

Fig.11.13  Surgical reconstruction of the orbital floor (intraoperative views). (a) Herniation of orbital fat into the maxillary sinus. (b) Defect of the orbital floor after reposition of the fatty-

orbital tissue (arrow). (c) Reconstruction of the orbital floor using polyurethane foil (Neuropatch)

must, therefore, be able to withstand tensile forces, especially in the region of the zygomatico-frontal suture and naso-frontal suture.

Following manual or instrumental repositioning and intermaxillary fixation in a position of central occlusion, osteosynthesis is carried out bilaterally at the zygomatico-frontal suture using 2.0-mm miniplates and optionally at the naso-frontal suture with 1.5-mm miniplates (Prein et al 1998; Manson 1998).

• Le Fort III fractures and Wassmund II fractures

Combined Le Fort III/Wassmund II fractures are stabilized at the naso-frontal suture (1.5-mm miniplates), at the region of the infraorbital margin (1.3-mm microplates), the zygomatico-frontal suture (2.0-mm miniplates) and the zygomatico-alveolar buttress (1.5-mm miniplates) (Prein et al. 1998; Manson 1998).