Midface Fractures

Klaus Louis Gerlach and Hans-Dieter Pape

Introduction

The aims of treatment of midface fractures are to reestablish midfacial height, width, depth, and projection together with the occlusion and the integrity of the nose and the orbit (Manson, 1986). These requirements can only be achieved by a stable osteosynthesis of the different fractured bones, using, for example, miniplates and microplates.

Technique

Access via intraoral, paraorbital, or bitemporal incisions allows the use of miniplates or microplates at all levels for the fixation of reduced maxillary fractures. Only some parts of the craniofacial skeleton constitute compact and solid bone: the cranium, especially at the level of the superior orbital rims, the zygomatic bone, the orbital margins, the nose and the supporting pillars of the maxillary skeleton including the zygomaticomaxillary buttresses, and the piriform aperture (Mariano, 1978). Evaluations of skulls showed that the bone thickness of these regions is strong enough for fixation of plates with screws 5–7 mm long (Ewers, 1977). Therefore, in these regions the application of standard miniplates is recommended. However, the role of miniplates in the midface has been superseded by different microplates developed during recent years. These are especially recommended for other anatomical structures whose lamellar structure has a thickness of only 1–1.5 mm. Generally, a microplate is used to span comminuted areas from solid bone to solid bone. First, the contoured plate has to be fixed at the solid bone parts, then the various comminuted fragments are repositioned and fixed against the plate with the aid of a small hook or an elevator. A hole is drilled through the plate into the fragment and a screw placed, thereby stabilizing the fragments to the plate. Examinations by computed tomography (CT) or magnetic resonance imaging (MRI) are often required preoperatively and postoperatively, especially in cases of combined injuries of the cranium and face. It is recommended, therefore, particularly in the midface, that osteosynthesis material made of titanium is used, to avoid distracting artifacts (Hoffmeister and Kreusch, 1991).

Fractures of the Zygoma

For the stable restitution of anatomical form, after repositioning fragments, the application of only one miniplate is recommended, preferably at the frontozygomatic process (Fig. 19.1). Alternatively, a plate at the zygomaticomaxillary buttress may be used. This “one point fixation” renders a solid stability to the cheek-bone, as demonstrated in large numbers of clinical follow-ups (e. g., Michelet, Deymes, and Dessus, 1973; Champy et al., 1977;Iatrou et al., 1991; Krause, Bremerich, and Kreidler, 1991;Zingg et al., 1991).

A further alternative, recommended by Pape (1997), is the use of one or two microplates at the zygomaticomaxillary buttress to stabilize the reduced zygoma.

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