Measuring patients lying down flat, researchers at Hiroshima University Hospital simulated sleep conditions and measured the patients’ airways with oral appliances for sleep apnea using 3D imaging. The study confirmed that tested oral appliance is effective at opening the airways and the authors say this warrants further collaboration between dentists and doctors in treatment of sleep apnea.

With sleep apnea, “your eyes are closed but you’re not resting,” says Cynthia Concepción-Medina, PhD, research assistant at the Department of Orthodontics at Hiroshima University Hospital, who contributed to the study with her colleagues associate professor Hiroshi Ueda and Dr Yu Matsumura.

The Department of Orthodontics at Hiroshima University Hospital developed an oral appliance to help patients with mild to moderate sleep apnea. This appliance brings the jawbone forward to enlarge the air passageways at the back of their mouth. Each appliance is custom made for each patient and allows jaw movement.

“This is like when you have to use glasses, you have to wear them every time you want to see properly so [patients] have to wear this appliance every time [they] want to sleep better,” Ueda says.

To further investigate how well the appliance works the research team, led by Matsumura, scanned a group of patients with mild-to-moderate sleep apnea using multislice computed tomography (MSCT)—a type of X-ray where the machine rotates around an object, and it takes a picture each time it rotates. This data is then combined to see a 3D object and is a fast and precise method of scanning.

Previous research usually measured patients standing up, which does not simulate sleeping conditions. This study (published in Sleep Disorders, 2019) measured the change in airway space of 13 patients lying flat. The team found that the appliance had a positive effect on patients: wearing it almost halved the number of times the patients had sleep apnea episodes during the night and widened their airways to allow easier breathing.

“I think it’s unique research because we are dentists, but we can contribute to improve the [patient’s] sleep situation or breathing situation.” says Ueda.

This study indicates promising effects of this treatment and the team hopes that they can continue this collaboration between the dental and the medical field.

Image: The oral appliance is made of two parts that join together to bring the patient’s jawbone forward. Department of Orthodontics and Craniofacial Developmental Biology/Hiroshima University Hospital