Reaney P, BDS, MFGDP(UK), DPDS, Dip PCOrth RCS(Eng), MDTFEd

For the past few years, dentists have been exploring the role they play in sleep medicine. Recently, COVID-19 has highlighted the importance of the airway and clear breathing, making dental sleep medicine an important tool in offering patients’ crucial treatment. In addition to life-changing treatment, the non-aerosol generating procedures required for managing obstructive apnoea (OSA) may appeal to patients during a time when many routine dental procedures are restricted. Even before the pandemic, sleep medicine had been a fast-rising global topic in the medical and dental fields, and even among patients. 

But before you make the leap to sleep dentistry, it all starts with the right training, tools and partnerships. For example, intraoral scanners, like Carestream Dental’s CS 3600 and CS 3700, have long been recognised for their accuracy when compared to traditional methods of taking impressions; and accuracy is, of course, crucial for any appliance. Other digital technology that can aid our medical colleagues includes software for CBCT systems that help visualise the maxillary sinuses and nose to detect pathology and anatomical abnormalities that may compromise the airway. For the dentist, working with third-party labs that specialise in sleep devices take some of the burden off the practitioner so that they can focus on what they do best: Capture scans and manage patients, while the lab designs the device. 

Case

A 53-year-old woman was referred to the practice from her medical doctor (Fig1, 2). She had suffered a stroke early in her life (before the age of 50) and was experiencing extreme fatigue that affected her quality of life. She had completed a sleep study through a hospital, which showed an Apnoea/Hypopnoea Index (AHI) score of 34 consistent with severe Obstructive Sleep Apnoea (OSA), making her unfit to drive – life-altering and career-changing news for a professional driving instructor. 

With an OSA diagnosis, an appliance would be necessary. As the mechanics of oral appliances for OSA closely resemble the form and function of an orthodontic functional appliance, the patient was assessed in a similar way to an orthodontic case.

As with any orthodontic/OSA exam, a panoramic radiograph was captured using a CS 8100 3D extraoral imaging system to better view the roots; understand any previous orthodontic work; assess the periodontal condition; find undetected pathology; examine the TMJ; and be aware of any restorations and/or relieve retention if those restorations were compromised (Fig 3). 

A clinical evaluation found the patient to have a moderate Class 2 skeletal case relationship, a retrognathic mandible and the lack of space for the tongue were found to be contributing factors for the tongue compromising the airway during sleep (Fig 4, 5). 

Full guidelines for patient assessment and management were also followed as laid out in the British Society of Dental Sleep Medicine guidelines, including examining for signs of sleep-related bruxism; dental erosion; soft tissue indicators such as scalloped tongue.

The patient was also asked to complete a screening questionnaire and was sent home with an Ectosense Night Owl home sleep monitor that used Peripheral Arterial Tenometry to record data. The monitor was an essential requirement to effectively screen the patient and titrate the oral appliance and provided the optimum patency in the airway. The sleep reports were set up and downloaded remotely by the supervising clinician. 

Considering the lack of space in the lower arch and the results of the patient’s sleep reports, it was decided using a digital CAD/CAM workflow would be best to deliver an appliance that would be smaller and better tolerated – in this case, a ResMed Narval CC Mandibular Advancement—rather than an appliance created through by traditional workflow.

Intraoral scans were captured with the CS 3600 intraoral scanner using the orthodontic workflow, which allowed for the multiple bite capture necessary for such appliances. Carestream Dental’s Mesh Viewer allowed us to confirm that protruded bites were not recorded with any inaccurate deviations of the mandible. Within the CS IO 3D Acquisition v3.1 software, the use of undercut tools helped identify if tooth anatomy could be altered to improve the appliance outcome, e.g. use of direct composite attachments to create undercuts. The software allowed for measurement of overjet/overbite at the initial scan and future reviews to monitor tooth movement (an unwanted side effect of the MADs). This visualisation tool also helped to communicate with the patient the protrusion of the mandible and how it brought the tongue forward/caused tension in the muscles of the airway and stopped airway collapse during sleep (Fig 6, 7). 

Once the full arch scans had been acquired, they were exported to ResMed so that the 3D model could be aligned with a virtual articulator. The Narval CC appliance was then designed using a completely digital workflow (Fig 8, 9, 10, 11). 

On the day the device was fitted, the following were checked: Retention, the occlusion, the TMJ, demo connectors/elastics, insert/removal, OHI and ensuring the protrusion had not deviated as recorded. The accurate and comfortable fit of the device re-emphasised the benefits of using intraoral scanners to capture digital impressions and following a fully digital device design workflow. Most important, the patient’s sleep score after management with the ResMed Narval CC Mandibular Advancement Appliance was an AHI score of 2.6, with a value below 5 considered normal (Fig 12, 13, 14). 

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Conclusion

For this particular patient, sleep dentistry gave her back her livelihood and her quality of living. As dentists look for opportunities to expand their treatment options, combining a fully digital workflow with the right sleep lab or partner can help them change the lives of countless patients. 

This case would not have been possible without David Claridge, of Carestream Dental; Margaux Piazzon, of ResMed; and Ciaran McCourt at Ectosense.

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About the author

Dr Paul Reaney is a dentist with special interest in orthodontics and has successfully incorporated a dental sleep medicine clinic within his general practice. He gained accreditation by examination to the European Academy of Dental Sleep Medicine and is currently a committee member of the Irish Society of Dental Sleep Medicine. Dr Reaney has a specific interest in digital technology to provide dental sleep medicine and his workflow has been recognised by winning the Best Digital Practice at the 2019 International Digital Dentistry Awards and winner of Best High Technology Practice category in the 2020 Irish Dental Awards. He has recently been invited by ResMed to their Narval cc  Advisory Board.