BOSTON -- Millions of Americans take the antidepressants Zoloft, Prozac and Paxil -- also known as SSRIs.

While the SSRIs have some well-known side effects, many clinicians aren't aware of one that's causing problems for a lot of people.

After her daughter was born two years ago, Judy Soto-Pastor suffered from postpartum depression symptoms. A doctor at a woman's clinic prescribed Zoloft.

"They said it was good for hormones and regulating your period," Soto-Pastor said.

What they didn't say was that it can also cause some people to grind and clench their teeth. Soto-Pastor had been grinding hers for years, but the doctor hadn't asked about it. After she started taking Zoloft, she'd wake up with a painful jaw.

"It felt that my jaw was stiff and if I felt it I could feel that the muscles were very sore, sore to the touch," Soto-Pastor said.

Dr. Robert Rosenbaum specializes in head and neck pain. Many patients come to him after taking Zoloft or Prozac.

"The clenching, grinding, jaw problems, tooth problems have significantly increased and gotten more painful," Rosenbaum said.

SSRIs are considered an effective new class of antidepressants. The problem is that primary care doctors who aren't as familiar with all their side effects often prescribe them.

Rosenbaum said that they should be asking patients key questions.

"One of the questions one should ask is: Are your jaw muscles feeling worse after having started the antidepressants?" Rosenbaum said.

That question might have saved Soto-Pastor some dental work.

"Sure enough, I fractured a couple of molars," Soto-Pastor said.

One solution is to wear a night guard to reduce the pain, or lower the dosage or try a different medication. But above all, Rosenbaum said, patients need to be aware.

"My best advice is for patients to be aware of their own bodies and to communicate these side effects to their physicians," Rosenbaum said.

For many people, the drug Buspar taken along with an SSRI counteracts the clenching and grinding effects.