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, simple - ORIF

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Glossary

1 Principles top

Special considerations

Following special considerations may need to be taken into account:

Click on any subject for further detail.


Choice of implant

 

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.
  4. 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.

2 Reduction top

The fracture should be exposed and any extractions determined necessary be performed 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.


The fracture should be exposed and any extractions determined necessary be performed enlarge

Using forceps

Forceps can be used to manipulate the mandibular fragments into proper reduction (when using an extraoral approach).


The fracture should be exposed and any extractions determined necessary be performed enlarge

Maintaining the reduction

A bone clamp or a plate (illustrated here) can be placed above the area where the reconstruction plate is to be applied, to maintain reduction of the fragments during plate adaptation and screw placement. The temporary plate may be removed after the reconstruction plate has been applied.

3 Fixation top

Most commonly there will be one or two holes without screws located over the fracture 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 screws on each side of the fracture. The screws adjacent to the fracture should be at least 7 mm away from the fracture line. Most commonly there will be one or two holes without screws located over the fracture. There are advantages to using a locking reconstruction plate system.

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

Plate adaptation
The plate must be contoured to the lateral surface of the mandible flush with the inferior border 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 using 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 is applied anterior and one set posterior to the fracture.


The sequence of screw insertion is not important if the plate is securely clamped to the bone enlarge

Inserting screws

The sequence of screw insertion is not important if the plate is securely clamped to the bone. Drill guides should always be used to center the screw within the plate hole.
For step-by-step description follow this link.


Clinical image of the completed osteosynthesis enlarge

Completed osteosynthesis

Illustration shows the completed osteosynthesis.


Clinical image of the completed osteosynthesis enlarge

Clinical photograph of the completed osteosynthesis.


X-ray shows the completed osteosynthesis enlarge

X-ray of 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