How much is the maxilla impacted just from sawing and healing during LF1?

[secondtimearound]

Anyone who has sawed anything in their life will know that no saw has a 0 mm width in its physical dimensions or its method of action.

Sawing a piece of wood with a standard circular saw will take out 1 mm easily just from the sawing action.

Most jaw surgeries I see before and afters for where there isn't intentional distraction of the jaw tend to show some evidence of impaction (shortening of tooth or gum show) even when there was no obvious clinical need for the shortening.

Additionally I wonder if healing/remodeling processes at a freshly cut bone edge could theoretically impact it a bit as it heals under braces/elastics/jaw pressure.

Bottom line: How much does the process of sawing apart and refusing the maxilla intrinsically shorten/impact the maxilla?

Is this a known phenomenon where ~1 mm of impaction can be expected just from the surgical process?

Or is this insignificant in practice?

Thanks.

[PloskoPlus]

1mm and it is significant.  Very observant of you.  Where impaction is unwarranted it should be countered with some sort of minimal down grafting (a bit of HA paste, or even bone scraps from the osteotomy itself may suffice).  However, the more results I see the more I am convinced that most surgeons don't know basic geometry (can't plan) and have less precision than carpenters (can't execute).  They just follow the occlusal splint - too much tooth show, too little, jaws canted or off-centre - if the bite fits, it's good enough.

[kavan]

You would need to find out the type of saw used and thickness of blade. An oscillating micro-saw  can be 1/10th of a mm. So if they are using one of those, your loss will be negligible.