Those "ripped" teeth are intentional shift aids, to help lift the chain up and onto that ring from the smaller ring. There seem to be two primary methods for doing this -- the twisted or ripped teeth on your rings...and inserting or riveting very short pins near the outer circumference that end up looking like little buttons on the inside face of the ring. The pins and twisted teeth do the same thing...they're just different ways of getting there. Interestingly, the modern Suntour cranksets (lower grade stuff on hybrids and lower end MTBs) seem to use pinned shift aids vs. Shimano's typical method of twisted shift aids.
louky I'm guessing your crankset is an STX or Alivio crankset. It looks very "Shimano" to my eyes.