Dutch RelaxView offers head mounted displays for dental patients to relax.

Going to the dentist is for many people a painful experience and some actually just can handle it under anesthesia. RelaxView offers the RelaxView 5.0 Dental Pack to distract dental patients without side effects.
The dental Pack includes the latest premium pair of video glasses, together with a portable DVD player, model Discman and a disposable hygiene set makes the dental office a more relaxed place to be.
The included HMD has a very low weight and the RelaxView glasses actually feature two 640x480px LCD screens.

"It is all about focus" according to Dr. Rob Roef, dentist in Nijmegen, The Netherlands. "Patients that, only occasionally see, hear, taste and smell the things that happen in a dentistry tend to become very sensitive even for the more simple procedures." "The pain that people experience should not be minimized." "Some people are so frightened that they require anesthetic treatment, or they simply don't seek necessary treatment until it is too late." "Facilitating and helping to get the patients' focus away from pain to pleasure pays off for both the patient and the dentist."
Via the RelaxView site.