By far the vast majority of them will die out with no help from you and those that are left can easily be controlled by whacking the leaves that do develop off. I often use a weed whacker to do that. Spraying with purchased poisons is an expensive and environmentally unsound way to do that.

If there are any further thoughts on this issue, please post. Like the OP, I am drowning in saplings in the front of my house. Merely cutting them only means the next year I have a sturdier trunk and more leaves growing up from it. My main issue is the visual - it makes the hill sloping down in front of my house look scrappy, and I hate it!

A flame torch / weed burner would work.

If they are really just little sprouts then Kimmsrs or Joe Pye's suggestions should work. Real saplings have to be pulled or cut and poisoned on the cut stem immediately thereafter. Cut stem application is supposed to work better in fall than in late spring or summer. Repeated cutting also works but you have to remember to constantly cut (maybe once a week). If the maples that are dropping the seed are Norway Maples that would explain high germination rates. Scooping up the seeds as they fall will help.