Americans are getting dental implants more than ever — and at costs reaching tens of thousands of dollars. Experts worry some dentists have lost sight of the soul of dentistry: preserving and fixing teeth.

TMJ disorders affect as many as 1 in 10 Americans and yet remain poorly understood and ineffectively treated. Many common treatments used by dentists lack scientific evidence.

Millions of Americans suffer from temporomandibular joint, or TMJ, disorders. The high cost and poor insurance coverage of TMJ care can bury patients in debt even as the treatments do more harm than good.