Executive Editor: Marcelo Figari, Gregorio Sánchez Aniceto General Editor: Daniel Buchbinder

Authors: Ricardo Cienfuegos, Carl-Peter Cornelius, Edward Ellis III, George Kushner

Mandible - Angle and ramus, complex - ORIF

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Glossary

1 Principles top

Load-bearing fixation

Comminuted fractures must have load-bearing fixation applied across the area of comminution. The bone fragments within the area of comminution will provide no buttressing to help stabilize the fracture. A reconstruction plate with at least three and preferably four screws on each side of the comminuted area is the only mechanism by which load-bearing fixation can be provided.

Click here for a detailed discussion of load-bearing versus load-sharing fixation.


Choice of implant

Locking versus nonlocking plates
There are several advantages to a locking plate/screw system:

  1. Conventional plate/screw systems require precise adaptation of the plate to the underlying bone. Without this intimate contact, tightening of the screws will draw the bone segments toward the plate, resulting in alterations in the position of the osseous segments and the occlusal relationship. Locking plate/screw systems offer certain advantages over other plates in this regard; the most significant being that it becomes unnecessary for the plate to intimately contact the underlying bone in all areas. As the screws are tightened, they "lock" to the plate, thus stabilizing the segments without the need to compress the bone to the plate. This makes it impossible for the screw insertion to alter the reduction.
  2. Another potential advantage in locking plate/screw systems is that they do not disrupt the underlying cortical bone perfusion as much as conventional plates, which compress the undersurface of the plate to the cortical bone.
  3. A third advantage to the use of locking plate/screw systems is that the screws are unlikely to loosen from the plate. This means that even if a screw is inserted into a fracture gap, loosening of the screw will not occur. Similarly, if a bone graft is screwed to the plate, a locking head screw will not loosen during the phase of graft incorporation and healing. The possible advantage to this property of a locking plate/screw system is a decreased incidence of inflammatory complications due to loosening of the hardware.
    Locking plate/screw systems have been shown to provide more stable fixation than conventional nonlocking plate/screw systems.

Click here for a description of locking plate principles versus conventional plating.


Special considerations

Following special considerations may need to be taken into account:

Click on any subject for further detail.

2 Reduction top

The bones should be reduced prior to placing the patient into occlusion enlarge

MMF

Open reduction and stable internal fixation in the dentate patient begins with fixation of the occlusion. Prior to placing the patient into MMF, the fracture should be exposed and any extractions determined necessary be performed. The bones should also be reduced prior to placing the patient into occlusion and securing the MMF.

Click here for further details on methods for applying MMF.


Forceps can be used to manipulate the mandibular fragments into proper reduction enlarge

Manipulating fragments

Once the fracture has been exposed, forceps can be used to manipulate the mandibular fragments into proper reduction.

3 Fixation top

Temporary/initial fixation of mandibular fragments enlarge

Pearl: simplifying the fracture

Temporary/initial fixation of mandibular fragments can be accomplished by using small plates and screws applied in locations that will not interfere with the reconstruction plate.

The small plate(s) may be left in placed or may be removed after the placement of the reconstruction plate.


The plate must be long enough so that there can be a minimum of three or preferably four screws on each stable fragment enlarge

Plate selection

For load-bearing fixation, a reconstruction plate 2.4 should be used. The plate must be long enough so that there can be a minimum of three or preferably four screws on each stable fragment. Preangled reconstruction plates may be necessary to provide an adequate number of screw holes. There are advantages to using a locking reconstruction plate system.
Click here for a description of locking plate principles versus conventional plating.


The plate must be long enough so that there can be a minimum of three or preferably four screws on each stable fragment enlarge

Plate adaptation

The plate must be contoured to the lateral surface of the mandible, flush with the inferior and posterior borders to avoid injuring the inferior alveolar nerve.
Click here to see a step-by-step description of plate bending using locking reconstruction plate.


Insert the properly contoured plate onto the lateral surface of the mandible enlarge

Securing the plate to the bone with bone clamps

Insert the properly contoured plate onto the lateral surface of the mandible and hold it there using ball pointed reduction forceps. Ideally, one set of forceps would be applied anterior and one set posterior to the area of comminution.


The sequence of screw insertion is not important enlarge

Inserting screws

The sequence of screw insertion is not important if the plate is securely clamped to the bone. Threaded drill guides should always be used to center the screw within the plate hole.
Click here for a step-by-step description.

Large fragments (like the triangular one in this photograph) can be secured to the plate to hold them in position.


Illustration of the completed osteosynthesis enlarge

Completed osteosynthesis

Illustration of the completed osteosynthesis.


X-ray shows the completed osteosynthesis. enlarge

X-ray shows the completed osteosynthesis.


Final check

One should then release the MMF and check the occlusion for accuracy before proceeding with closure.

v1.0 2008-12-01