Digital Michigan splint - from intraoral scanning to plasterless manufacturing

Aim: To investigate whether the fully digital, plasterless fabrication of clinically usable Michigan splints can be accomplished in a time- and cost-efficient manner. Materials and methods: Digital scans of the maxillary and mandibular arches of 10 subjects were acquired with an intraoral scanner (3Shape, Copenhagen) and used to generate virtual models of the dental arches. Jaw relation records were made using jigs placed on the subjects' anterior teeth, and silicone registration material was referenced to the jaw models. The data sets were then sent via the company's online portal to the dental laboratory, where computer-aided design (CAD) of the Michigan-type maxillary splints was performed. After receiving the designs, the splints were milled in-office using computer-aided manufacturing (CAM) software, and finished manually. During try-in, the splints where checked for fit, retention quality, and occlusal contacts of the mandibular teeth on the splint surfaces in static and dynamic occlusion. Results: Fit and retention were clinically acceptable in 10 splints and 9 splints, respectively. The number of initial occlusal contacts on the splint surfaces ranged from 4 to 16. Conclusions: The question addressed in this study can be answered in the affirmative. Some of the main advantages of digital manufacturing of Michigan splints over traditional, conventional, impression-based manufacturing are the time-efficient manufacturing process, the high material quality, and the possibility of manufacturing duplicate splints. Keywords: workflow, digital impression, intraoral scanning, computer-aided design, computer-aided manufacturing, jaw relation record, occlusal splints, craniomandibular disorders, bruxism