We used to have a specific tool in the bike shop for bending/straightening chainring teeth. It happened with steel chainrings much more often than with alloy. You can also file teeth to remove burrs and even them up. Remove the chain and hold a flat file at an angle on the side of the teeth and spin the crank. You can often improve shifting by beveling the teeth towards the inside of the crank so that the points of the teeth catch the chain quicker during a shift. This can be very useful if the chainring spacing is slightly too wide.