Why is the ravioli cutter blade shaped like a gear instead of a smooth blade?

It uses a gear-shaped blade instead of a smooth, straight blade^[1]. While a typical blade only cuts through the dough, fresh pasta filled like dumplings can easily burst in boiling water if the top and bottom dough layers are not tightly bonded without gaps.

With Ottinetti's cutter, holding the handle and pressing down on the dough causes the circular serrated blade to firmly interlock the edges^[2]. The uneven texture of the serrations firmly presses the edges of the dough, sealing it so the filling cannot escape^[3]. Without the hassle of cutting the dough with a knife and pressing the edges again with a fork, simply pressing down once from above finishes both the cutting and sealing at the same time.