Factory reset and then itunes back up?

Can i restore my iphone to factory settings and set it as a new phone. And then restore itunes backup to my device?

Yes. I've had to do it twice when my iPhone lost a bunch of my music for reasons unknown. Plug it into your computer, open iTunes, and there should be an option to restore from the most recent backup.

If I remember correctly, what I did was back it up, then restore to factory settings as a new phone, and then restored it again with the backup. That seems to have fixed the missing music issue.