Le Fort II osteotomy

The majority of cleft patients with maxillary deficiency will benefit from advancement of the maxilla at le Fort I level. However, a few cleft patients who have nasomaxillary deficiency may require a le Fort II osteotomy.

The midface is accessed by a coronal approach combined with maxillary buccal sulcus incisions.

Note: As an alternative some surgeons use a combination of paranasal and oral incisions and avoid the coronal approach.

The coronal approach is used with the following considerations:

Only the nasal bridge requires exposure, so lateral dissection of the coronal flap can be minimized (as illustrated)

• The dissection proceeds into the orbit behind the posterior lacrimal crest inferiorly to the orbital floor taking great care not to damage the naso-lacrimal ducts which are displaced anteriorly with the flap.
• The dissection in the orbital floor should then communicate with the subperiosteal dissection inferiorly from the oral approach.

The buccal sulcus approach is used with the following considerations:

• The intraoral dissection must communicate with the inferior aspect of the coronal approach in the nasomaxillary region.

An osteotomy cut is made across the nasal bridge above the lacrimal crests and angling slightly downwards. This cut should extend to a few mm behind the posterior lacrimal crest.

Care has to be taken that this cut is below the level of the cribriform plate in the anterior cranial fossa. This is best evaluated preoperatively by coronal CT.

The nasal osteotomy is extended inferiorly behind the posterior lacrimal crest down towards the orbital floor. The inferior aspect of this osteotomy should connect with the superior aspect of the osteotomy to be made from the oral approach and will be just medial to the infraorbital nerve. The periorbita is retracted during these osteotomies with flat malleable retractors to protect the orbital contents.

From the transoral approach a vertical osteotomy is made through the infraorbital rim medial to the infraorbital nerve, connecting with the previous osteotomy from above in the orbital floor.

Pearl: The distance between this vertical cut and the pyriform rim of the nose is narrow and produces a weak area that may fracture during mobilization. It is advisable to make the vertical cut as lateral as possible.

It is usually possible to do this solely with a combination of the coronal and transoral approaches. If difficulty is encountered in the region of the orbital floor, the approaches can be supplemented by a transconjunctival incision.

Inferior to the infraorbital nerve, the osteotomy is extended posteriorly to the pterygomaxillary junction as in a Le Fort I osteotomy.

All osteotomies are checked for completion with fine osteotomes.

The maxilla is separated from the pterygoid plates with a curved osteotome from the transoral approach.

The final osteotomy is made through the nasal septum from the nasal bridge towards the posterior nasal spine. To accomplish this, a 1 cm wide gently curved osteotome with the curvature pointing inferiorly is introduced through the nasal bridge osteotomy.

The surgeon directs the osteotome towards the back of the nasal septum and places a finger behind the soft palate at the posterior nasal spine. The osteotome must be directed towards the posterior nasal spine.

This completes the Le Fort II osteotomies.

The nasomaxillary complex is then mobilized with Rowe's disimpaction forceps taking great care to observe that all the osteotomy sites are opening.

Full mobilization is necessary to allow passive repositioning of the nasomaxillary complex.

Mobilization can be supplemented with the use of Tessier mobilizers inserted behind the maxillary tuberosities from the transoral approach.

Mandibular-maxillary fixation is performed to position the nasomaxillary complex to the desired relationship with the mandible. A prefabricated surgical splint/wafer may be used to facilitate this.

The maxillomandibular complex is now rotated around the condylar hinge until the planned position has been attained.

Click here for more details on mandibulo-maxillary fixation (MMF)

The nasomaxillary complex is stabilized with two miniplates across the nasal bridge, one on each side. This is supplemented by two additional miniplates placed across the zygomaticomaxillary buttresses.

After completion of osteosynthesis on both sides, the MMF is removed and the resulting occlusion is checked against the pre-planned position.

The splint may be fixed to the maxillary teeth with a few thin wires and left in place during the healing phase to allow for neuromuscular adaption and position control.

Bone grafting is carried out with cortico-cancellous bone blocks. The principal area for grafting is the nasal bridge, but grafts are also sometimes required within the orbit and on the lateral maxilla.

The graft over the nasal bridge can be contoured with a burr to provide the correct shape of the nasofrontal angle.

Pearl: It is sometimes necessary to reposition the medial canthal ligaments in order to reduce the intercanthal distance. This should be performed before the bone grafting procedure.

If MMF screws or Temporary Anchoring Devices (TADs) are used intraoperatively, they are removed at the end of surgery if not further needed for elastic traction. If a final splint was used, it may be fixed to the orthodontic devices (brackets) of the upper jaw to assure the planned occlusion and to serve as guidance for the neuromuscular adaption during functional training for about 2 weeks postoperatively.

To reduce swelling, the application of ice-packs or cooling devices during the early post-operative phase is advice. Intravenous steroids should also be continued for a short period postoperatively for the same purpose.

Antibiotic prophylaxis is continued for 1-5 days depending on the nature, complexity, and duration of the surgical procedure.

Especially in two-jaw surgery, the airway control is of major importance. An individual decision has to be taken if the patient can be extubated or should remain intubated until it is clear that safe airway can be established.

Early post-operative x-rays are obtained to verify correct segment position. Additional postoperative imaging is performed as needed.

Regular follow up examinations to monitor healing and the postoperative occlusion are required. If an occlusal problem is present in the early postoperative phase, the surgeon must determine its etiology. If the malocclusion is secondary to surgical edema or muscle detachment/disorders, training elastics may be beneficial. The elastics are only used for guidance, because active motion of the mandible is desirable. Patients should be instructed how to place and remove the elastics using a hand mirror. If the malocclusion is secondary to a bone problem due to inadequate fragment positioning, displaced or failed hardware, or condylar displacement during surgery, elastic training will be of no benefit. The patient must be rescheduled for revision surgery.

At each appointment, the surgeon must evaluate the patient's ability to perform adequate oral hygiene and wound care and should provide additional instructions if necessary.

Postoperatively, patients will have to follow three basic instructions:

1. Diet
In orthognathic surgery the internal fixation devices usually do not allow for full functional load. A soft diet should be used up to 6 weeks, starting with liquids for the first 3-4 days. Elastics can be removed during eating.

2. Oral hygiene
Patients with intraoral wounds must be instructed in appropriate oral hygiene procedures. The presence of orthodontic appliances, the splint, and elastics makes this a more difficult task. A small soft toothbrush with toothpaste should be used.Any elastics are usually removed for oral hygiene procedures. Additionally, antiseptic rinses can be used in the early postoperative period. An oral irrigator (eg, Waterpik) is a very useful tool to help . If a Waterpik is used, care should be taken not to direct the jet stream directly over intraoral incisions to prevent wound dehiscence in the early postoperative phase.

3. Functional training/physiotherapy
The patient is instructed how to perform functional training (opening and excursive exercises) as soon as possible. The progress should be monitored by the surgeon. If available and needed, a physiotherapist can support the functional rehabilitation. An undisturbed mouth opening of minimum 35 mm interincisal jaw opening should be attained by 4 weeks postoperatively.

In case of undisturbed healing, the postoperative orthodontic treatment can usually start 2 to 6 weeks after surgery depending on the case.