Not to worry about it?! Get a better dentist. Else it'll probably get worse as time passes and more damage accumulates. I went thru exact same thing, and now wish I'd acted a lot earlier. It took a lot of (expensive) splint therapy to get everything fixed. But it's better than being in pain or ending up needing surgery. During the day I wear a regular splint, and at night I wear a splint (a bionator), which keeps my top and bottom jaws in alignment, moves the lower jaw forward, opens up the TMJ's, and also prevents me from grinding my molars. Now I have no pain or clicking in my TMJs.

thanks for your reply! i didnt know that TMJ can worsen over time. i will make a dentist appointment as soon as i can. thanks!

TMJ can worsen over time, but if your only problem is cracking joints, DO NOT do anything drastic, or you can cause pain and TMJ dysfunction. Many joints crack, like fingers, and some people can crack all or many of their joints loudly. Unless you start to have other symptoms (pain, numbness, limited jaw opening) don't do anything you may later regret.

If you are still worried, see about having a MRI or CT scan done to put your mind at ease.