In cases of congenital ptosis with poor levator function, how do outcomes of frontalis flap suspension compare to silicone rod frontalis sling?

A frontalis flap procedure offers superior cosmesis in that only a lid crease incision is made, and no incisions are made above the brow. However, it does take significant additional operative time to dissect the flap from a single inferior incision. There is the thought that it might be less adjust...