The left side of Jacquelyn Garcia’s face throbbed fiercely. She had tried taking Tylenol and Excedrin for the pain, but threw them up. On a Monday morning straight after working the night shift as a custodian, she rushed to the N.Y.U. emergency dental clinic. Here a student delivered the verdict: decay so deep it had reached the nerve. The tooth needed to be pulled.

Paradoxically, this could make her mouth worse off. Dentists say pulling a tooth can lead to a cascade of other problems: the teeth start shifting, the bone diminishes, the skin sags and the risk of gum disease increases. But Ms. Garcia didn’t have any choice. Her tooth had been rotting from the inside out for more than a year. She didn’t have dental insurance and didn’t want to pay the high fees until the pain had surged and she couldn’t stand it anymore.

As Americans debate medical coverage, the problem of our teeth has remained almost entirely unaddressed. About 114 million Americans don’t have insurance coverage for their teeth – more than twice the number of people who didn’t have health insurance before the Affordable Care Act.

“Oral health is a neglected issue nationally,” said Julia Paradise, an associate director of the program on Medicaid and the Uninsured at the Kaiser Family Foundation. “This is a big problem. The mouth and the head – mental health and dental health – somehow remain outside of what people think of as general health.”

Lots of people (including politicians) think of dental care as a luxury – pleasant, sure, but not vital. But that’s just not true, experts say. Gum disease can increase the risk of heart disease and diabetes, and among pregnant women it is correlated with lower birth weights for their babies.

“It’s a lot more than just having a pretty smile,” said Peter Polverini, a dean emeritus at the University of Michigan School of Dentistry. “It’s not uncommon that you wind up with people being hospitalized because they can’t afford care.” Emergency room visits for dental problems – when teeth are often too ruined to save — cost the U.S. health care system an estimated $1.6 billion a year

By Zoe Greenburg