If your one-year-old is grinding their teeth excessively and you hear a popping or clicking sound as they open or close their mouth, it could be TMJ disorder. It's common in babies with dental problems, joint problems, trauma to the jaw or face, or stress. It's essential to watch out for other issues such as headaches, dizziness, pain or swelling around the jaw, ear pain, hearing loss, or constant ringing in the ears.  Seeking immediate medical advice if you observe any of the above signs is best. TMJ disorder is treatable; if you seek early treatment, you can prevent your child from being in constant discomfort.