It is important to perform a bone grafting operation to insert bone into the alveolar cleft defect in order to:
Convert the maxilla into one bony structure
Provide bone into which the permanent maxillary canine tooth can erupt
Assist in the reconstruction of the nasal floor
To repair labial and palatal fistulae
Provide some support to the alar base
Enable orthodontic alignment of teeth
Provide a solid maxillary structure if later orthognathic surgery is required
In older patients, to provide a substructure for the insertion of dental implants or other prosthetic rehabilitation
Frequently the premaxilla in a bilateral cleft patient is misplaced and needs to be lined up with the lateral segments. This can usually be achieved by orthodontics. Occasionally the premaxilla will not move with orthodontics. In such cases a premaxillary osteotomy should be considered. This can be combined with palatal fistula repair and alveolar bone grafting.
Note: In the bilateral complete cleft lip and palate case, the bone of the premaxilla will be attached only to the inferior aspect of the nasal septum. Its blood supply comes from relatively narrow soft tissue and bony pedicles. Therefore, when osteotomizing the premaxilla, considerable care has to be exercised to preserve sufficient soft tissue pedicles..
Timing of alveolar bone grafting
The majority of cleft teams prefer to bone graft between the ages of 8 to 10 years to provide bone into which the permanent canine can erupt and to support adjacent teeth.
A small number of cleft units practice very early bone grafting in the first year or two of life. This is a controversial area as there is insufficient data on its effect on alveolar bone survival into adolescence or on maxillary growth.
Choice of graft material
There are many potential donor sites for alveolar bone grafting. The most commonly used site is the anterior iliac crest.
For details on how to harvest the cancellous bone from the anterior iliac crest, please click here.
Incomplete cleft patients
In the incomplete cleft and in patients with clefts of the lip and the alveolus alone, there is less likely to be a palatal fistula that needs to be repaired. In addition there is usually to some extent a bony palatal shelf. The alveolar bone grafting procedure is exactly the same as for the complete cleft patient but is usually easier.
Planning of premaxillary osteotomy
On a plaster model of the upper teeth, the premaxilla should be sectioned and moved to the desired position. A strong labial arch wire should be prepared so that the premaxilla can be stabilized in its planned position after osteotomy. Sometimes an acrylic wafer or stent is also helpful.
Temporary removal of orthodontic devices
The maxillary segments are stabilized with bands or brackets on the first molar and premaxillary teeth with lateral arms retaining the expanded lateral segments. The removable transpalatal arch has already been removed and the labial archwire is in situ but is removed temporarily at the start of surgery.
3. Premaxillary osteotomy
The labio-buccal alveolar soft tissues on the lateral and premaxillary segments are injected with local anaesthetic with vasoconstrictor for hemostasis.
The incision for the premaxillary osteotomy must not in any way compromise the blood supply to the premaxilla. A small vertical mucosal incision (approximately 1 cm in length) is made down to bone on the lateral aspect of the premaxillary mucoperiosteum adjacent to the alveolar cleft to which the premaxilla is to be moved.
Mucoperiosteum on the premaxilla is elevated just sufficiently for adequate exposure of the bony pedicle of the premaxilla.
A small osteotome (3 or 5 mm) is then used to divide the premaxilla from its bony attachment to the base of the nasal septum.
The premaxilla is then mobilized using digital pressure and moved into the preplanned position with the assistance of a stent or wafer if prepared.
Stabilization of the premaxilla
The premaxilla is then stabilized with the pre-formed rigid labial arch wire.
Note: When preforming a premaxillary osteotomy in combination with alveolar bone grafting the osteotomy access incision is incorporated into the surgical approach for the alveolar bone grafting.
4. Repair of palatal fistulae
Inspection of the oral site for fistulae
A cleft gag is inserted and the palate inspected for fistulae using a large lacrimal probe.
If there is no communication to the nose, it may not be necessary to carry out an anterior palate repair.
Any fistula communicating with the nose ideally requires a two layer closure.
Local anesthesia and disinfection
The anterior palate is injected with local anaesthetic with vasoconstrictor for hemostasis.
The nose is gently cleaned with cotton buds soaked in an antiseptic solution.
Palatal fistula repair
Note: This description is for the typical bilateral complete cleft case. Depending on the precise original cleft and the surgery carried out, there can be considerable variation in fistulae and the technique has to be modified accordingly.
An incision is made in the marginal oral mucosa around the fistula as shown. The mucoperiosteum is elevated for a couple of mm sufficient to allow the edges to be approximated as a nasal layer.
Two palatal flaps are outlined as shown. Because of the shape and the size of the fistula, it is usually necessary for these flaps to be advanced anteriorly as well as moved medially. This can only be achieved if the flaps are mobilized well and freed as much as possible posteriorly.
The palatal flaps are raised subperiosteally. Over the palatal cleft the oral mucoperiosteal flaps are sharply divided from the nasal mucosa.
The subperiosteal dissection of the palatal flaps is extended posteriorly on either side of the greater palatine arteries. The flaps are then partially divided posteriorly with careful protection of the greater palatine arteries. This allows the flaps to be advanced sufficiently to cover the anterior fistula without tension.
The margins of the fistulae are then sutured to each other to create a nasal layer.
The flaps are then sutured anteriorly both to each other, to the premaxillary mucoperiosteum and to the surrounding anterior palatal tissues over the nasal repair and the fistula.
Although the palatal flaps can be sutured to premaxilla at this time, the final anterior palatal sutures are only placed after the bone grafting has been carried out. The labio buccal flaps are actually sutured to the anterior palatal flaps.
5. Repair of the alveolar cleft defect
The incision made for the premaxillary osteotomy is then extended for the alveolar bone grafting procedure.
The incisions are extended laterally on the lateral segments in the gingival margin around the necks of the teeth as far posteriorly as the anterior part of the permanent first molar teeth. Those incisions are then extended upwards and backwards into the buccal sulcus and brought forwards by about 5 mm to give the appearance of a hockey stick.
On the contralateral side a medially placed vertical elliptical incision is made around the labial fistula as medial as possible close to the premaxilla. On the medial side of the cleft, over the premaxilla no gingival incision is made and the mucoperiosteum should not be raised. This is in order not to compromise the blood supply to the premaxilla.
Raising of the flaps
The two lateral mucoperiosteal flaps are then raised to expose the alveolar cleft and floor of nose. It is especially important to separate the oral from the nasal mucosa. This separation is done with a scalpel.
When the flaps have been raised, remaining in the alveolar cleft is scar tissue and nasal mucosa attached to the palate.
Excision of tissue in the alveolar cleft
The scar tissue and excess nasal mucosa within the alveolar clefts is excised.
Pearl: Sometimes there has been an attempt at bony bridging across the alveolar cleft. Such bone is usually quite thin and serves little function. However, it does limit access to the alveolar cleft. It is usually best to remove such bony bridges in order to proceed as described.
Repair of the nasal floor
The nasal floor mucosa is repaired with resorbable sutures at as high a level as possible, which is at the level of what would be a normal nasal floor.
When the scar tissue and excess nasal mucosa within the alveolar cleft have been excised, sometimes the nasal mucosa is intact and at approximately the correct height. Clearly, nasal floor repair is not necessary in such a situation.
Pitfall: If too much nasal mucosa is excised it can be difficult to repair the nasal floor. On the other hand, if the nasal floor is too low, it must be mobilized superiorly or excess nasal mucosa excised and repaired to create space for the bone graft.
Pearl: Occasionally the inferior turbinate above the alveolar cleft defect is large and prevents repair of the nasal floor at the correct level. In such a case, a partial inferior turbinectomy (mainly of soft tissue) should be carried out prior to the repair of the nasal floor.
Pearl: If the surgeon is not confident that he or she has a good nasal floor repair, the repair should be covered with a small piece of an absorbable membrane as a barrier.
Pearl: If there is a complete alveolar defect with no anterior bony palatal shelf, it helps to insert a finger behind the anterior palate to provide posterior support while packing the bone.
Pearl: It helps to insert a fairly large piece of bone first, which will not find its way into the nose.
Closure of labial oral tissues
It is extremely important that the closure of the oral layer over the bone graft is completely free from tension. This requires the mobilization of the lateral flaps so that they can be easily stretched over the bone graft areas. This is achieved by dividing the periosteum horizontally with a scalpel on the inner and superior aspect of the lateral segment mucoperiosteal flaps.
The lateral segment mucoperiosteal flaps are advanced to cover the bone grafts and the soft tissues are repaired.
The advancement of the lateral segment flap leaves a soft tissue defect posteriorly over the alveolar bone. This must not be closed and is allowed to heal by secondary intention.
Pearl: When closing a vertical incision which overlies the bone graft, it is useful to use horizontal mattress sutures.
If a palatal fistula repair was carried out earlier in the procedure, the lesser segment flap is also sutured to the anterior part of the palatal flap(s).
This picture shows the final result.
6. Aftercare following alveolar bone grafting
Antibiotics Intravenous antibiotics are always administered during surgery and are generally continued for one to three days postoperatively. If the patient goes home early the antibiotics are continued orally at home.
Analgesics Potentially the most painful area is the donor site for bone in the anterior iliac crest. In practice long acting local anaesthetic are administered into the donor site at the end of surgery and postoperatively.
Local anaesthetic which has been administrated at the recipient site also helps with postoperative pain control.
Further oral pain medication should also be made available on a regular basis (eg, paracetamol) and for break-through pain.
When bone is harvested from the iliac crest, the patient should be checked for bowel sounds periodically following surgery. Once sounds of gut motility have been confirmed the patient can start to take oral clear fluids.
A sliding scale of fluids and soft food is prescribed for the few days following surgery.
Normally, patients should start to brush their teeth with a small soft children’s toothbrush and toothpaste from the morning after surgery. This should be followed 30-60 min later by a chlorhexidine mouth wash.
The patient should be mobilized as early as possible and absolutely no later than the morning after surgery. They should be encouraged to weight bear on the operated side until they can walk without any limp.
Discharge from hospital
As soon as the patient is eating and walking well and there are no other complications of surgery they should be able to be discharged from hospital.
Patient follow up
The patient is usually seen as necessary in the out patient department for review . The healing of all operation sites is checked. Usually, 6 months after surgery a single oblique occlusal radiograph is taken (two for a bilateral case). In some units this radiograph has been replaced with a cone beam CT. The quality of the result of the alveolar bone graft procedure is assessed and documented. The patient’s ongoing cleft care is mapped out.