Source: Boston.com
Author: Neil Munshi

The usual dental checkup goes something like this: lean back, open wide, avoid flinching, rinse, spit. But in addition to looking for cavities, dentists are increasingly checking for oral cancer, too – and not just by peering and probing.

A relatively new screening tool allows dentists to better gauge whether a patient is in the early stages of oral cancer by looking at the mouth under a special light.

But the test may be overused, and it’s not yet clear whether it justifies its price tag.

A review of studies of the devices published in this month’s Journal of the American Dental Association concluded that for low-risk patients, there is “insufficient evidence to support or refute the use of visually based examination” devices, such as the ViziLite.

Still, roughly 10 to 15 percent of the 100,000 practicing dentists in the United States offer ViziLite or a similar scan, which some credit with helping them better identify lesions in the mouth than simply looking with the naked eye.

“Frankly, I’ve seen stuff I would normally just have glossed over and it doesn’t hurt to take a second look . . . at something that might not normally be looked at – that might save somebody’s life,” said Dr. Anjum A. Ansari, a downtown Boston dentist, who charges her patients $80 for the service. Insurance has only covered the scan for one of her patients, Ansari said.

That $80 is the test’s only actual advantage, said Dr. Mark Lingen, of the University of Chicago Medical Center.

“They may be of financial benefit to the dentist, but . . . the benefit to the dentist in terms of diagnosing lesions that might be premalignant or malignant is minimal at best,” said Lingen, who published a paper on the devices in the January issue of the journal Oral Oncology. “I think there’s very little evidence that these devices are of benefit to the patients.”

The July review involved previous studies of high-risk patients – smokers or those with family history of cancer – who were screened by cancer specialists, said co-author Dr. Joel B. Epstein, of the University of Illinois at Chicago. For high risk patients, the screen may be useful, said Epstein, who is a member of the medical advisory board for Zila Pharmaceuticals, which manufactures ViziLite.

There is not enough evidence to show whether the devices are useful in the hands of general dentists caring for low-risk patients, Epstein said.

ViziLite Plus with TBlue is used by 182 dentists in Massachusetts, and approximately 12,000 nationwide.

“Our take is it’s great to have oral cancer at the forefront of discussions because it’s so critical,” said Jeff Mazzarella, vice president of Zila. Each year, roughly 32,000 Americans are diagnosed with oral cancer – compared to about 250,000 for lung cancer – and 8,000 die from the disease.

To do the cancer screen, a dentist swabs the patient’s mouth with toluidine chloride (TBlue) and looks carefully with a specially lighted probe in a darkened exam room. The stain highlights rapidly dividing cells that can indicate cancerous growth.

There’s no scientific evidence suggesting the devices help dentists detect precancerous lesions any better than the naked eye, said Dr. Vikki Noonan, associate professor at the Boston University School of Dental Medicine. “Clinical trials are needed.”

But, a second look for lesions is never a bad thing, said Dr. Michael Kahn, chairman of the oral pathology department at Tufts University’s dental school.

“Whether the light helps you see it or not, you’re taking a second look,” said Kahn, who practiced general dentistry before becoming an oral pathologist. “The bottom line is we found it, and we found it earlier than we would have otherwise.”