For kinds of reasons you would lost your important iphone messages or contacts, and if you want to recover them, we can still extract them from iTunes backup file as long as you've made a back before. And we need an iphone data recovery to help, I'll guide you how to restore lost iphone messages easily with Coolmuster Data Recovery for iPhone.

Don't sync your iPhone to the computer with iTunes, because the backup file will be updated if you connect your iPhone to computer and sync it with iTunes.

Step 1: Select Backup Device
Launch the iPhone backup extractor on Mac, then app would retrive all the devices that you have backuped on the computer before, and select your previous iPhone backup files from the list. Next, click "Start Scan", the problem will scan and display all the contents contained in the backup files.

Step 2: Recover Messages from iPhone backup
Just like the image below shows, you can click the icon to preview the messages. Then select and check those messages you want extract. At last, click "Recover" to start the extract. Then, there will be a dialog ask you to choose save address, you just need to choose where you want.

Great, that's all!
Resource:
http://www.coolmuster.com/ios-recovery/how-to-recover-deleted-sms-from-iphone.html