Dental changes evaluated with a 3D computer-assisted model analysis after long-term tongue retaining device wear in OSA patients.

Oral appliances (OAs) have been used to treat obstructive sleep apnea (OSA) patients for decades. However, detailed dental side effects in long-term OA cases analyzed with an accurate three-dimensional (3D) measurement tool have seldom been reported. The purpose of this study is to evaluate dental side effects in five OSA patients, who had used a tongue retaining device (TRD) (with occasional other OA wear) for an average of 6 years and 4 months. The baseline and follow-up orthodontic study models were measured with a newly developed MicroScribe-3DX analysis system. High compliance of TRD wear was confirmed in all cases and different patterns and amounts of dental changes were observed. The most common appliance-induced dental changes included anterior and/or unilateral posterior open-bites and reduced anterior overjets. It was hypothesized that there might be two possible mechanisms for the TRD side effects--one is the forward pressure of the tongue upon the anterior dental arch and the other is the lateral pressure of the tongue upon the posterior arch. Considerations to correct the TRD dental side effects should be guided by these different mechanisms of the tongue on the dental arch. Possible solutions to minimize occlusal changes and maximize the benefits for OSA patients are also discussed.