Tired Teens - Orthodontists Diagnose Sleep Apnea More Easily with X-Rays

August 1, 2005 — Diagnosing sleep apnea -- a chronic condition that causes teen-agers to stop breathing during sleep -- is difficult and often means staying at an overnight sleep lab. A new test can spot with problem with simple X-rays, by checking the position of the tongue and hyoid bone. If the bone sits lower, patients are more likely to have the condition. In a recent study, the X-rays correctly identified 70 percent of teens with sleep apnea.

CLEVELAND--Being a teenager is tough these days, but it's especially tough if you're always tired. Now a simple X-ray taken at your children's orthodontist could hold the key to helping them sleep better.

Sixteen-year-old Andrew Dudash would come home from school each day and go straight to bed. "I actually got a detention in school for sleeping during a class," he says.

Doctors diagnosed him with sleep apnea, a chronic condition that causes him to stop breathing during sleep. Diagnosing the condition is difficult and often means staying at an overnight sleep lab. But orthodontist Mark Hans wants to make that diagnosis easier. He's studying whether the same X-rays teens get before getting braces will help determine if they're at risk for sleep apnea.

"We're trying to give the sleep doctor a better chance of examining the right patients for this condition," says Dr. Hans, of Case Western Reserve University School of Dental Medicine in Cleveland.

Dr. Hans looks at the position of the tongue and hyoid bone. If the bone sits higher, patients are not at risk for sleep apnea. If it falls lower, they are more likely to have the condition.

In a recent study, the X-rays correctly identified 70 percent of teens with sleep apnea. Dr. Hans says, "When you identify chronic illness early and treat it early, you really prevent more long-term problems."

Case School of Medicine pediatric pulmonologist and sleep specialist Carol Rosen, says the X-rays would help. "This would add another feature that we would look for in our evaluation." So teens like Dudash can get the treatment they need.

"There's definitely a difference in my sleep because I'm not waking up much during the night," Dudash says. And his sleep is not something he's willing to gamble on.

Dr. Hans says there's no disadvantage to performing the X-ray other than a minimal dose of radiation, which is equivalent to a day in the sun. He says most insurance covers the X-rays, which cost about $100. A sleep lab evaluation could cost thousands.

BACKGROUND: Researchers at Case Western Reserve University in Cleveland, Ohio, have identified two key factors in sleep apnea in teenagers. They used radiography (an imaging technique used by orthodontists) to study a group of teens to determine if they were likely to suffer from the condition. The technique will be used for earlier diagnosis for sleep apnea in teens before they become adults.

THE STUDY: The investigators studied the case histories of 590 patients between 7 and 8 years of age attending the orthodontic clinic at Case Dental School. Sixty of these patients -- a group least at risk and a group most at risk for sleep apnea -- underwent unattended in-home sleep monitoring.

WHAT IS SLEEP APNEA: Sleep apnea is a temporary suspension of breathing during sleep, which can have potentially serious consequences. People with sleep apnea can stop breathing for 10 to 30 seconds at a time, as many as 400 times a night. Most sleep apneas are the result of something blocking the passage of windpipe of the throat that brings air into the body. The tongue, tonsils, or uvula (the little piece of flesh that hangs down in the back of the throat) can all sometimes produce blockage, as can severe obesity: excess fat can block the airway. Some 12 million Americans suffer from sleep apnea, but men and those over 40 years of age are more likely to have the condition. Risk factors include heavy snoring, excess weight, high blood pressure, and any physical abnormality in the nose or throat.

WHAT ARE X-RAYS: X-rays are light waves.

The only difference between X-rays and the light that we see is that the X-rays have a higher energy level, and a shorter wavelength, making them undetectable to the human eye. Because they have so much energy, the particles that make up light, called photons, in X-rays can pass through most materials. It all depends on the size of the atoms that make up the material; larger atoms absorb X-ray photons. But smaller atoms do not, and the X-rays pass right through.

The soft tissue in the body is made of smaller atoms and doesn't absorb X-rays very well, but calcium atoms in the bones are much larger and do absorb X-rays. A camera on the other side of the patient records the patterns of X-ray light passing through the patient's body.

It's the same basic technology as that used in an ordinary camera, but X-ray light, instead of visible light, sets off the chemical reaction on the photographic plate.

Editor's Note: This article is not intended to provide medical advice, diagnosis or treatment.

Note: This story and accompanying video were originally produced for the American Institute of Physics series Discoveries and Breakthroughs in Science by Ivanhoe Broadcast News and are protected by copyright law. All rights reserved.