Lockjaw happens when your jaw muscles tighten up so much that you can't open your mouth properly. Tetanus is a serious bacterial infection that can cause lockjaw and muscle spasms. TMJ disorders can ...

Medically reviewed by Brian T. Luong, DMD Key Takeaways An uneven jaw can cause pain, ear popping, or clicking when chewing. TMJ disorders often cause a crooked jaw and can result in headaches and ...