Study Objectives: The objective of this study was to examine the feasibility and patient preference of mandibular repositioning devices (MRDs) made from (1) a fully digital workflow including patient scanning, bite registration, and device manufacturing using an open platform intraoral scanner (iTero; Align Technology Inc., San Jose, California, United States) and a computer aided design/computer aided manufacturing (CAD/CAM) MRD (MicrO2 Sleep Appliance; ProSomnus Sleep Technologies, Pleasanton, California, United States), and (2) a conventional workflow using polyvinyl siloxane (PVS) impressions as the source of patient data. The fit accuracy and comfort level of devices from each workflow were compared. A method for capturing a digital scan using a stable open bite technique is tested for accuracy and ease of implementation.
Methods: This prospective feasibility study reports on selected patients (n = 5) recruited from a dental practice (ages 34 to 51 years; apnea-hypopnea index 1–32 events/h). Each patient received two MRDs. The first MRD was manufactured using a conventional workflow model (ie, PVS impressions, PVS bite registration, CAD/CAM of the MRD with quality control on physical stone models).
The second MRD was manufactured using a digital workflow model (ie, digital intraoral scanning using an open platform intraoral scanner, digital open bite registration, and CAD/CAM of the MRD). All patients were then followed up using our standard clinical protocol set based on the American Academy of Dental Sleep Medicine guidelines. The dental fit (ie, the accuracy of the fit against the teeth), the occlusal fit (ie, the accuracy of the upper and lower splint fitting together), and the patient preference (ie, which appliance they preferred using) was recorded.
Results: In the conventional workflow 2 appliances required minor dental adjustments and 3 appliances required occlusal adjustments. In the digital workflow, no dental or occlusal adjustments were required. All patients preferred the digital MRDs in terms of comfort.
Conclusions: It is feasible to utilize a fully digital workflow for manufacturing of MRDs for treatment of obstructive sleep apnea with predictable outcomes. Devices from a full digital workflow are preferred by patients compared to the standard process. The full digital workflow using the CAD/CAM MRD required fewer adjustments and patient satisfaction with the device and the process could make for a better experience for the patient and the doctor. Follow-up studies are required using larger sample size and different intraoral scanners and MRDs.
Citation: Charkhandeh S, Kuhns D, Kim S. A fully digital workflow and device manufacturing for mandibular repositioning devices for the treatment of obstructive sleep apnea: a feasibility study. Journal of Dental Sleep Medicine. 2017;4(4):97–102.