Vestibular incisions The vestibular incision can be used for standard fracture fixation techniques or in conjunction with endoscopically assisted surgical techniques.
The ramus and condyle region can be exposed via an intraoral approach by extending the standard vestibular incision in a superior direction up the ascending ramus. The incision can be altered depending on the area of the ramus/condylar process that needs exposure and treatment.
Oral contamination is not a contraindication for an intraoral incision.
Restricted access and contamination In complex fractures including comminuted and avulsive fractures that require the placement of load-bearing reconstruction plates, a transfacial/extraoral approach can provide better access to treat the injury.
Sensory buccal nerve The sensory buccal nerve crosses the upper anterior rim of the mandibular ascending ramus in the region of the coronoid notch. It is usually below the mucosa running above the temporalis muscle fibers. When the posterior vestibular incision is carried sharply along the bony rim, the buccal nerve is at risk of transsection resulting in numbness in the buccal mucosal region. Therefore, to protect the nerve, the posterior incision is to be extended bluntly as soon as the lower coronoid notch is reached.
This photograph shows the sensory buccal nerve.
Buccinator muscle The lateral mucogingival vestibular incision transsects the lower attachment of the buccinator muscle. Stripping the mucoperiosteal flap laterally dislocates the lower border of the muscle. To reattach the muscle, the sutures for wound closure in the lateral vestibular should not only be superficial. The suture should catch all layers (mucosa and muscle) as a safeguard for muscle reattachment.
Reminder: The buccinator muscle belongs to the mimic muscle system and has a unique functional structure allowing for a movement comparable to a peristaltic motion. The deep fibers run in parallel bundles from the modiolus to the pterygomandibular raphe at the level of the occlusal plane (intercalar region) and account for the buccinator mechanism building up a ridge towards the occlusal plane. Its detachment can result in an impaired bolus transport out of the buccal space which is troublesome for the patient. The buccinator is innervated by the motor buccal branch of the facial nerve.
2. Vestibular incision
Unless contraindicated, infiltrate the area with a local anesthetic containing a vasoconstrictor.
Make an incision through the mucosa in the vestibule approximately 5 mm away from the attached gingiva (in the mucogingival junction), extending up the external oblique ridge.
3. Exposure of fracture
The lateral surface of the ramus and condylar process is exposed in a subperiosteal plane to visualize the fracture. Right-angled retractors and fiberoptic lighting would facilitate this procedure. The fracture must be reduced adequately before fixation is applied. The fixation can be done either by transbuccal or right-angled instrumentation.
The surgeon has the option of treating the fracture through the intraoral approach under direct vision or may opt for endoscopic assistance.
The image shows a clinical example of the transbuccal trocar instrumentation to reduce and fix a fracture of the condylar process.
4. Option: using an endoscope
Creation of optical cavity The incision is very similar to the standard incision used to approach the ramus and condyle unit. Surgeon preference for a smaller incision is acceptable.
A specific instrumentation is recommended in order to facilitate the endoscopically assisted condylar fracture treatment. Create the optical cavity for the endoscope by elevating the periosteum of the ascending ramus towards the condylar region. Stop the dissection once you have reached the fracture line. Dissection beyond the fracture line will be completed after introduction of the endoscope.
Insertion of the optical retractor After assembly of the optical retractor to its handle, insert and place it around the posterior border of the ramus.
Insertion of the endoscope Insert the endoscope through the optical retractor up to the fracture line.
Dissect over the condylar fragment Using the periosteal elevator dissect under endoscopic visualization over the condylar fragment. Care should be taken near the inferior border of the capsule so as not to violate the joint space.
Intraoperative endoscopic view.
Pitfall: dissection under the proximal fragment It is a common mistake to dissect under the medial side of the proximal fragment with the periosteal elevator if there is a lateral override of the condylar fracture fragment.
In order to avoid this, the surgeon needs to carefully assess the fracture on the preoperative x-ray or CT scan and visualize the fracture directly with the endoscope.
Pearl: condylar fracture fragment initially in medial displacement If the condylar fracture fragment is initially medially displaced, the surgeon must bring the fragment into a lateral position in order to complete the dissection for the osteosynthesis. This may be a highly demanding procedure.
5. Wound closure
Closure of the intraoral incision After thoroughly irrigating the wound and checking for hemostasis the incision is closed using interrupted or running resorbable sutures.
Surgical dressing An elastic pressure dressing covering the ramus/condylar process region helps support the soft tissues and prevent hematoma formation.