I think sound is not necessarily needed. When you click on a bug, you see it flashing and after it another bug flashes. Note the order, and follow it, press each time the last flashed bug. With every new bug correctly pressed in order, the order gets longer. When you click on all the bugs in correct order, they play a song which you won't hear though, but you'll see them performing... kind of
Anyway, note this order and use it then in the same order on the teeth. When you click on one tooth, you see it's color. The rest should be easy to figure out.