Downfracture
The lower part of the maxilla is then mobilized initially by digitally pushing it downwards. The term downfracture was coined to describe this downward movement and the fracture of the posterior wall of the maxilla which has not been cut with either saws or chisels.
The remainder of the clefted nasal mucosa can now be visualized and sharply separated from the palatal mucosa to allow completion of the mobilization.
Pitfall: Incomplete osteotomies and excessive force during the downfracture are thought to have caused fracture of the posterior wall of the maxilla running up into the orbit and as a result causing blindness. Consequently excessive force during downfracture and incomplete osteotomies should be avoided.
If major resistance is encountered, the following action should be taken:
Re-examine all of the osteotomy cuts especially in the posterior pterygoid region
Ensure all of the cuts have been completed successfully and if not, complete them
At downfracture it is usually possible to visualize the maxillary sinuses through the cuts and across the sinus to see the posterior wall of the maxilla. The posterior wall can be gently osteotomized under that direct vision using a fine osteotome taking care not to cause major bleeding.
During downfracture it is possible to visualize both the lateral wall of the nose, the nasal septum and the posterior wall of the maxilla across the maxillary sinus. Where the bone cuts are incomplete it is possible to complete the maxillary osteotomy with fine osteotomes under direct vision.
It may be necessary to trim the lateral wall of the nose and the nasal septum with bone rongeurs.
Mobilization
Digital manipulation (twisting) of the down fractured maxilla is performed to continue the mobilization.
Once initial mobilization digitally has been accomplished, Rowe's maxillary disimpaction forceps or similar devices may be used and the mobilization of the maxilla is completed. This should only be performed after inserting a custom made cast steel palatal protection plate to avoid damaging the palate or accidently fracturing the maxilla.
The mobilization is carried out by downward circular movements and then twisting the maxilla on each side in turn. During this procedure it is necessary to ensure that the mucoperiosteal pedicle to the maxilla postero-laterally does not tear.
It is often necessary to break down posterior scar tissue in the region of the soft palate either digitally or very carefully with blunt end dissection scissors. If this is not done, that scar tissue will be a major factor for future relapse.
It is sometimes useful also to use Tessier mobilizers which are inserted behind the maxilla on each side in order to pull the maxilla forwards.
At this point the mobilized maxilla should be free and able to be advanced by the surgeon by his or her hand much more than is actually required.
Trimming of osteotomy lines
With the maxilla displaced downwards, bony interferences on the lateral nasal wall and the anterior and posterior wall of the maxilla are removed. This can be done initially with rongeurs but usually bone has to be removed with a drill whilst carefully protecting the soft tissues. The greater palatine vessels may need to be sacrificed if they interfere with complete mobilization of the maxilla.
In order to prevent unfavourable pressure on the nose (widening of the alar base etc.) the piriform rims are rounded off and the anterior nasal spine reduced.
The lower part of the maxilla is then mobilized initially by digitally pushing it downwards. The term downfracture was coined to describe this downward movement and the fracture of the posterior wall of the maxilla which has not been cut with either saws or chisels.
The remainder of the clefted nasal mucosa can now be visualized and sharply separated from the palatal mucosa to allow completion of the mobilization.
Pitfall: Incomplete osteotomies and excessive force during the downfracture are thought to have caused fracture of the posterior wall of the maxilla running up into the orbit and as a result causing blindness. Consequently excessive force during downfracture and incomplete osteotomies should be avoided.
If major resistance is encountered, the following action should be taken:
Re-examine all of the osteotomy cuts especially in the posterior pterygoid region
Ensure all of the cuts have been completed successfully and if not, complete them
At downfracture it is usually possible to visualize the maxillary sinuses through the cuts and across the sinus to see the posterior wall of the maxilla. The posterior wall can be gently osteotomized under that direct vision using a fine osteotome taking care not to cause major bleeding.
During downfracture it is possible to visualize both the lateral wall of the nose, the nasal septum and the posterior wall of the maxilla across the maxillary sinus. Where the bone cuts are incomplete it is possible to complete the maxillary osteotomy with fine osteotomes under direct vision.
It may be necessary to trim the lateral wall of the nose and the nasal septum with bone rongeurs.
Mobilization
Digital manipulation (twisting) of the down fractured maxilla is performed to continue the mobilization.
Once initial mobilization digitally has been accomplished, Rowe's maxillary disimpaction forceps or similar devices may be used and the mobilization of the maxilla is completed. This should only be performed after inserting a custom made cast steel palatal protection plate to avoid damaging the palate or accidently fracturing the maxilla.
The mobilization is carried out by downward circular movements and then twisting the maxilla on each side in turn. During this procedure it is necessary to ensure that the mucoperiosteal pedicle to the maxilla postero-laterally does not tear.
It is often necessary to break down posterior scar tissue in the region of the soft palate either digitally or very carefully with blunt end dissection scissors. If this is not done, that scar tissue will be a major factor for future relapse.
It is sometimes useful also to use Tessier mobilizers which are inserted behind the maxilla on each side in order to pull the maxilla forwards.
At this point the mobilized maxilla should be free and able to be advanced by the surgeon by his or her hand much more than is actually required.
Trimming of osteotomy lines
With the maxilla displaced downwards, bony interferences on the lateral nasal wall and the anterior and posterior wall of the maxilla are removed. This can be done initially with rongeurs but usually bone has to be removed with a drill whilst carefully protecting the soft tissues. The greater palatine vessels may need to be sacrificed if they interfere with complete mobilization of the maxilla.
In order to prevent unfavourable pressure on the nose (widening of the alar base etc.) the piriform rims are rounded off and the anterior nasal spine reduced.
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