Help with my iPhone screen?

Hi, awhile ago I cracked the very top right hand side of my iPhone screen, but I haven't fixed it yet. Then, two days ago I finally did the IOS 6 update. Last night I was using my phone and the complete right hand side of the screen has lost sensitivity, it won't detect my touch. I just want to know if it is because of the cracking, or could be for another reason? Should I just get the screen repaired?

Thank you!