Sometimes it happens after some sort of dental procedure. If you have had anesthesia, sometimes it takes time for feeling to come back in certain parts of your mouth. It could also be due to nerve damage.
You might have been on fasting for some days which can lead to numbness on the roof of your
mouth. Upper roof of mouth is called as pallate. Drink warm water daily for 3 times until this
soreness subsides. If pain occurs then you can take pain killers as per the advice of your
physician.
If I am experiencing numbness in the roof of my mouth, I may have an infection or nerve damage. I will need to see if numbness wears off within a certain period of time, otherwise I will need to see my dentist.
Well that could mean that your mouth has become very sore. It means that your gums are weakened as well. I would check it out with a dentist if I was you.