At the time of surgery, the decision is made whether to place one or two plates. This decision is based on fracture morphology, the amount of bone available to hold plates and screws, and on surgeon preference.
Ideally, two miniplates should be applied in a triangular fashion with one plate below the sigmoid notch and one plate along the posterior border.
Always choose the strongest possible osteosynthesis.
As an alternative way of achieving the same stability, a single heavier plate can be used where there is limited bone available for plating. This plate is placed along the long axis of the condylar process.
With plate and screw systems, micromovement of condylar fracture fragments is minimized. Correct application along with good fracture reduction will lead to primary bone healing and subsequent bone formation along the fracture surface.
Depending on the fracture location in the condylar region, one or two plates are used. In high condylar fractures, due to bony limitations, only one plate can be placed. In most cases, a mandibular plate 2.0 with two screws on each side of the fracture line is sufficient.
Adequate mechanical stability is gained by use of two adaptation plates or one stronger plate.
Plate and screw fixation used in condylar fractures allows immediate postoperative function.
In condylar fractures, muscle relaxation is crucial.
Several extraoral surgical approaches to the condylar region can involve the facial nerve. During the soft-tissue dissection, a nerve stimulator may be used to identify the facial nerve. Chemical muscle relaxation will interfere with the use of a nerve stimulator. However, once the bony fracture has been reached, muscle relaxation may help the surgeon reduce and stabilize the fracture.
Therefore, a sufficient dose of muscle relaxant is administered before the reduction maneuvers.
When treating condylar fractures, the surgeon may use arch bars or another form of mandibulomaxillary fixation (MMF). However, reduction and manipulation of the fracture may be best accomplished with the jaw open. At some point during the plate and screw fixation, the patient should be placed into occlusion. This may be accomplished by an assistant holding the patient into occlusion while the fracture is being plated. This minimizes the risk of postoperative malocclusion.
Additionally, many surgeons prefer the use of training elastics in the postoperative period.
The endoscopic technique is an alternative treatment technique for condylar fractures.
The two most important advantages of the endoscopic technique are the avoidance of face scars and minimizing the risk of facial nerve injury. The disadvantages are the necessity of endoscopic/special equipment and the specialized training and experience required for this surgical technique.
Following special considerations may need to be taken into account:
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The below aditional reading may be useful:
For this procedure the following approaches may be used:
If only one plate can be used, the surgeon should opt for a thicker plate and bicortical screws if possible.
The plate used can either be a mandible plate 2.0or preferably a small/medium locking plate 2.0. A DCP 2.0 can also be used (for its strength but not for its compression) as well as a large profile locking plate 2.0 because of their increased rigidity.
In each side of the fracture line, a minimum of two screws have to be inserted. Plates with or without a center space can be used.
The plate should be positioned in the center of the condylar region or close to the posterior border. The numbers indicate the order of screw insertion.
There are several options of plates that can be used with condylar fractures:
Thicker plates are usually best fixed with bicortical screws.
Lastly, mandible and locking plates 2.0 are preferred over compression plates by many surgeons.
In the following procedure, a combination of a 2-hole with a 4-hole mandible plate 2.0 is shown.
It is advantageous if the condylar fragment is already displaced laterally (lateral override). However, the most common displacement of the condylar fragment is medial, by pull of the lateral pterygoid muscle. If the fragment is displaced medially, the surgeon must manipulate it and convert it into a lateral override situation.
Then the plate can be applied and fixed with one screw to the condylar fragment while it is supported by the underlying mandibular ramus. Using the plate as a handle, the condylar fragment can be reduced anatomically.
Intraoperative image shows angulation and lateral displacement of the condylar fragment.
One plate
If the use of only one plate is possible, the plate should be centered over the long axis of the condylar process.
Two plates
If two plates are being used, the anterior plate is used to reduce and initially stabilize the condylar fragment. The second plate is placed parallel to the posterior border of the ramus.
Drill a hole in the midaxis of the condylar fragment through the plate hole closest to the fracture line using the 1.5 mm diameter drill. The use of the drill guide is recommended to avoid injuries in the soft tissues.
Place the plate and insert the screw manually without complete tightening. The aim of not tightening the screw completely is to be able to apply traction to the fragments later in the procedure.
Reduction of the fracture is done under direct vision by aligning the posterior border of the ramus.
Pull the mandible inferior and anterior in order to restore the posterior height of the ramus and achieve reduction.
The lower end of the plate prevents the medial displacement of the condylar fragment during reduction.
Clinical image shows the reduced fracture. The plate acts as stop during the reduction and prevents medial displacement of the condylar fragment.
In this clinical example a 5-hole locking plate without center space is used. The center hole is placed directly over the fracture line and left empty.
To keep the jaw open and aid fracture reduction, a bite block is placed in the molar region after placement of the first screw in the plate.
This results in posterior vertical distraction and rotation of the mandible.
In order to align the posterior border, pull traction on most distal hole of the plate with a clamp.
The first plate to be applied will simplify the fracture. In this case the anterior plate is applied first.
Drill a hole in the proximal fragment with the 6 mm drill stop drill bit of 1.5 mm diameter. The use of the drill guide is recommended to avoid injuries in the soft tissues.
Place the plate and insert the screw manually without complete tightening. The aim of not tightening the screw completely is to be able to apply traction to the fragments later in the procedure.
Reduction of the fracture is done under direct vision by aligning the posterior border of the ramus.
Pull the mandible inferior and anterior in order to restore the posterior height of the ramus and achieve reduction.
The lower end of the plate prevents medial displacement of the condylar fragment during reduction.
To keep the jaw open and aid fracture reduction, a bite block is placed in the molar region after placement of the first screw in the anterior 2-hole plate
This results in posterior vertical distraction and rotation of the mandible.
In order to align the posterior border, pull traction on the small plate with a clamp (illustrated) or an angled hook.
Place the inferior screw of the plate while the patient is in occlusion.
Completely tighten both screws at this time.
Fill the remaining screw holes in the order shown in the illustration with additional screws and fully tighten them.
Completed osteosynthesis.
3-D CT reconstruction shows a one plate fixation using a large profile locking plate 2.0.
Case example.
Another case example.
Place the inferior screw of the anterior plate while the patient is in occlusion.
Completely tighten both screws at this time.
Check the proper alignment of the posterior border. If it is properly aligned, adapt the plate. Sometimes, a template can be beneficial if the lateral pole of the condylar head is approached. However, use of a template is not always possible due to the size of the surgical approach and fracture morphology.
In the condylar neck and subcondylar region, the plate does not require much bending. Bending is done using bending pliers.
Drill the first screw hole in the condylar fragment close to the posterior border. It is recommended to drill the first hole without the plate applied.
Apply the plate and insert the first screw but do not completely tighten it.
Place the plate parallel to the posterior border of the ramus.
Apply the second screw which is placed in the plate hole next to the fracture line and fully tighten it. Then fully tighten the first screw.
Fill the remaining screw holes with additional screws and fully tighten them.
Clinical image shows the completed osteosynthesis.
Option: plate without center space
As an option for the anterior plate, a 3-hole plate with empty center hole over the fracture is used.
X-ray of the completed osteosynthesis.
If MMF screws are used intraoperatively, they are usually removed at the conclusion of surgery. Arch bars may be maintained postoperatively for functional therapy.
Postoperative x-rays are taken within the first days after surgery.
It is imperative that the occlusal relationship and mandibular function be assessed early and on a regular basis. The patient is evaluated at 1 week to verify the occlusion and to assure adequate performance of functional rehabilitation exercises.
If a malocclusion is detected, the surgeon must ascertain its etiology (using the appropriate imaging technique). If the malocclusion is secondary to surgical edema or muscle splinting, training elastics will be beneficial. The lightest elastics possible are used for guidance, because active motion of the mandible is desirable. Patients should be shown how to place and remove the elastics using a hand mirror.
If the malocclusion is secondary to a bony problem due to inadequate reduction or hardware failure or displacement, elastic training will be of no benefit. The patient must return to the operating room for revision surgery.
The frequency of follow-up will largely be based on the findings of the 1 week appointment. Typically, if the patient is doing well at 1 week, they will not be seen for 2 more weeks. The necessity and frequency of future appointments will be based upon the findings from this appointment.
Postoperatively, patients will have to follow three basic instructions:
1. Diet:
The patient can eat whatever is comfortable. If solid foods cause pain, the patient will self-limit their diet to softer foods. There is no contraindication to taking solid foods from the standpoint of their fracture. Nevertheless, most surgeons recommend soft diet for a variable period of time.
2. Oral hygiene
Patients with extraoral approaches are not compromised in their routine oral hygiene measures and should continue with their daily schedule.
Patients with intraoral wounds must be instructed in appropriate oral hygiene procedures. The presence of the arch-bars and any elastics makes this a more difficult procedure than normal. A soft toothbrush (dipping in warm water makes it softer) should be used to clean the surfaces of the teeth and arch-bars. Any elastics are removed for oral hygiene procedures. Chlorhexidine oral rinses should be prescribed and used at least three times each day to help sanitize the mouth. For larger debris, a 1:1 mixture of hydrogen peroxide/chlorhexidine can be used. The bubbling action of the hydrogen peroxide helps remove debris. A Waterpik® is a very useful tool to help remove debris from the wires. If a Waterpik is used, care should be taken not to direct the jet stream directly over intraoral incisions as this may lead to wound dehiscence.
3. Physiotherapy
Patients are instructed in physical therapy maneuvers to restore mandibular excursions. This includes maximum jaw opening, right and left lateral excursions, and protrusive excursions of the mandible. They should perform these exercises several times a day.