My beautiful trout picture

ResMed Narval CC Case Study: Size Matters!

My beautiful trout picture
My beautiful trout picture

One of the most intriguing features of the ResMed Narval CC is its small footprint. I find most patient’s transitioning from an acrylic appliance frequently comment on both the small size and the increase in comfort, as compared to their previous appliance. But what about new patients to Oral Appliance Therapy, where do they stand on this issue?

Sleep Herbst
Left Patient Herbst, Right Sample Herbst

Recently, I made a Herbst appliance for a patient that had many crowns that he was thinking of replacing in the future, but was not ready to act on. He had a very severe level of apnea (AHI = 36, 62 in supine position) and could not tolerate CPAP at all, even after trying several masks. So, we decided to proceed with an appliance that would be more forgiving when adjusting around future crowns, even allowing for a full reline if necessary; the Herbst.

Unfortunately, at the insert appointment, the patient could not tolerate wearing the Herbst at all. He had difficulty establishing lip seal and felt that it was too much of a mouthful. I sent it back to the lab to see if they could reduce the vertical and bulk of acrylic and re-inserted it. The patient took it home and returned the very next day, begging me to make him a Narval (the appliance we decided against due to the crown work he was planning to do in the future). Seeing the sincere distress in his eyes, I agreed.

Upon delivery of the Narval, he was very pleased and after a couple

Narval CC
Left: Patient Narval, Right Sample Narval

of adjustment appointments we established through a sleep study that his very severe sleep apnea had been resolved (AHI = 4.1, 5.3 in supine position). Needless to say, he was a Very Pleased Patient!


What makes this case interesting is the size of his appliances. This gentleman has a VERY large dentition. Quite frankly, I have never seen a dentition of this size and in fact, this was the very first time I had such an experience with a Herbst, an appliance I have used successfully for years. In the photo’s above you will find the Patient’s Narval and Herbst, alongside the standard Sample Narval and Herbst that I show patients at consults. Note the remarkable difference in size!

ResMed literature discusses the use of the Narval CC for very petite individuals that would logically have difficulty tolerating a bulky acrylic appliance, but in addition, I think this case study provides good support for the use of a Narval CC nylon appliance for very large dentitions, where the size of the final acrylic device would be so large as to reduce patient adherence to therapy. Of course, not everyone has as large a dentition as this gentleman and thankfully this is uncommon. However, if we think on these parameters as being on a continuum, small to large, I feel it prudent to consider the size of a patient’s dentition when selecting the most appropriate appliance. Clearly, fishing isn’t the only area that size matters!

  1. Stay tuned for an update to the “Practical Pearls” eBook on Nylon Appliances. It should be ready to post by late August. If you have an interesting case study you would like included please feel free to share.

Previously published in Breathless the online journal of the American Sleep and Breathing Academy

John Viviano B.Sc. DDS Diplomate ABDSM

John Viviano B.Sc. DDS Diplomate ABDSM

John Viviano B.Sc. DDS Diplomate ABDSM; from Mississauga ON Canada,obtained his credentials from U of T in 1983, he provides conservative therapy for snoring and sleep apnea and Sleep Bruxism in his clinic, Limited to the Management of Breathing Related Sleep Disorders. A member of various sleep organizations, he is a Credentialed Diplomate of the American Board of Dental Sleep Medicine, and has lectured internationally regarding management of Sleep-Disordered Breathing and the use of Acoustic Reflection. Dr Viviano has also conducted original research, authored articles and established protocols on the use of Acoustic Reflection for assessing the Upper Airway and its Normalization. For more info or to contact Dr Viviano click: Website SleepDisordersDentistry LinkedIn Discussion Group

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