Fear of brushing teeth

I need guidance regarding my nine year old’s fear or anxiety of brushing his teeth.

About two years ago he developed this fear or anxiety of brushing his teeth. Just out of nowhere. He physically struggles putting the tooth brush in his mouth. He cries and says I’ve just can’t do it.

We thought we found the answer a few months ago when we discovered it seemed easier for him to place the brush in his mouth when a favorite song was played. This seemed to work for a while and now it’s hit or miss. He has cried and told me he doesn’t understand why he feels this way. He has even said he wished he could die. Of course that breaks my heart.

Once the brush gets into his mouth it’s ok. The problem is getting the tooth brush in his mouth. He truly doesn’t want to feel this way but neither he nor I can figure out how to fix this problem.

Any suggestions would be most welcome!

-Thank you!
Concerned Mom