first check all your pages and double check that they aren't on one of them. next check to see if you've installed either poof or sbsettings. if you have poof, check inside the app to see if you've turned them off...same thing with sbsettings (swipe from left to right along the status bar on the top and then tap more, you'll see an option for hide apps. see if they're turned off). You can also try searching for them...sometimes hidden apps will show up in spotlight search depending on what you've installed.
if none of that works I'm afraid your only option is a restore