Thumb joint problem

Hello,i'm 20 this year and i have had this thumb problem for many years due to a weird habit i had in my early years.I used to clench my fist with my thumb sticking inside the hole that is created. Its like a sushi rolled up with crab stick in the middle, that crab stick was my thumb.

And after awhile, my thumb first joint became a very wierd looking joint.

And i was wondering what is the device called that is placed on a finger to help straighten it? cause i might want to go to an orthopedic doctor to get it settled.

Rgds
Marcus