Incision A (vestibular incision) can be used when there is no third molar present, or when there is an unerupted third molar that may or may not require removal.
Incision B is used when there is an erupted third molar that must be removed during surgery. Incision B allows the development of a buccal mucoperiosteal flap that can be advanced to cover the extraction socket.
4. Choice of implant
A suitably sized strut plate is chosen.
Open reduction and stable internal fixation in the dentate patient begin with fixation of the occlusion. Before placing the patient into MMF, the fracture should be exposed, and any extractions determined necessary performed. The bones should also be reduced before placing the patient into occlusion and securing the MMF.
6. Plate adaption
The strut plate is placed on the buccal surface of the mandible, spanning the fracture site.
Ideally, the superior row of screw holes are located above the inferior alveolar canal, and the lower row of screw holes are located below the inferior alveolar canal.
The plate is adapted to lie passively along the buccal cortex.
If locking screws are used, a perfect adaptation will not be required.
If conventional screws are used, accurate contouring is required to prevent loss of reduction during screw tightening.
The first screw hole that is drilled is the superior hole just posterior to the fracture line.
An appropriately sized drill is used to make a mono-cortical hole.
Insert a 6 mm screw but tighten it loosely.
The plate is adjusted to lay flush to the bone, and the first screw is tightened.
Insertion of the second screw
The second screw hole is drilled in the inferior hole just posterior to the fracture line.
Fully insert a 6 mm screw.
The remaining two posterior screws are then inserted.
Drag the plate/ramus anteriorly with a point of a periosteal elevator to close the fracture gap. Drill the superior hole just anterior to the fracture and insert the screw.
The remaining screws anterior to the fracture are then inserted.
One should then release the MMF and check the occlusion for accuracy before proceeding with closure.
X-ray shows the completed osteosynthesis.
8. Aftercare following ORIF of mandibular symphysis, body, angle, and ramus fractures
Use of jaw bra
If significant degloving of the soft tissues of the mandible has occurred, there may be a consideration for using a jaw bra or similar support dressing.
If arch bars or MMF screws are used intraoperatively, they are usually removed at the conclusion of surgery if proper fracture reduction and fixation have been achieved. Arch bars may be maintained postoperatively if functional therapy is required or if required as part of the fixation.
Postoperative x-rays are taken within the first days after surgery. In an uneventful course, follow-up x-rays are taken after 4–6 weeks.
The patient is examined approximately 1 week postoperatively and periodically thereafter to assess the stability of the occlusion and to check for infection of the surgical wound. During each visit, the surgeon must evaluate the patient's ability to perform adequate oral hygiene and wound care and provide additional instructions if necessary. Many patients need to be seen regularly for replacement of their intermaxillary elastics and to encourage range of motion in their TMJ in the later course of the treatment.
Follow-up appointments are at the discretion of the surgeon and depend on the stability of the occlusion on the first visit. If a malocclusion is noted and treatable with training elastics, weekly appointments are recommended.
The patient should be warned to continue routine follow up with their dentist. Fractures near the dental roots can often result in delayed loss of tooth viability, requiring periapical films and additional dental procedures.
If a malocclusion is detected, the surgeon must ascertain its etiology (with appropriate imaging technique). If the malocclusion is secondary to surgical edema or muscle splinting, training elastics may be beneficial. The lightest elastics as 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.
Basic postoperative instructions
Depending upon the stability of the internal fixation, the diet can vary between liquid and semi-liquid to “as tolerated”, at the discretion of the surgeon. Any elastics are removed during eating.
Patients having only 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. Chlorohexidine may cause staining of the teeth and should not be used longer than necessary. For larger debris, a 1:1 mixture of hydrogen peroxide (0.25%)/chlorhexidine (0.12%) can be used. The bubbling action of the hydrogen peroxide helps remove debris. A water flosser, providing a water jet, is a very useful tool to help remove debris from the wires. If a this is used, care should be taken not to direct the jet stream directly over intraoral incisions as this may lead to wound dehiscence.
Physiotherapy can be prescribed at the first visit and opening and excursive exercises begun as soon as possible. Goals should be set, and, typically, 40 mm of maximum interincisal jaw opening should be attained by 4 weeks postoperatively. If the patient cannot fully open his mouth, additional passive physical therapy may be required such as Therabite® or tongue-blade training.