Development of a fully digital workflow for fabricating custom nasoalveolar molding appliances

Abstract

Objective: To develop a fully digital workflow for fabricating nasoalveolar molding (NAM) appliances for the treatment of infants born with cleft lip and palate, integrating commercially available intraoral scanning (IOS), computer-aided design/computer-aided manufacturing (CAD/CAM), and 3D printing tools. Methods: Digital dental models of three infants with cleft lip and palate were obtained using a direct intraoral scanner and compared to digital models derived from scans of conventional polyvinyl siloxane impressions of the same patients. The models were digitally superimposed to assess dimensional accuracy. Digital models were manipulated in MeshMixer to simulate sequential NAM adjustments, which were compared to clinical adjustments from a conventionally fabricated appliance. NAM appliances were digitally designed in 3Shape and SolidWorks and fabricated using SprintRay and Stratasys J850 Digital Anatomy printers with material customization for intraoral and nasal components. Results: Superimposition analysis demonstrated high dimensional accuracy of intraoral scans, with deviations of less than 0.5 mm in clinically relevant areas. Virtual model manipulation successfully replicated clinical NAM adjustments, with systematic modifications ranging from 0.5 mm to 2.0 mm. Quantitative comparison between conventional and digital adjustments revealed similar magnitudes of change. The fully digital workflow allowed for predictable appliance fabrication, with 3D-printed NAM appliances exhibiting satisfactory fit and function. Conclusion: A fully digital workflow for NAM appliance fabrication was successfully developed, demonstrating high accuracy, reproducibility, and feasibility using commercially available technologies. This approach eliminates the need for conventional impressions, streamlines appliance fabrication, and provides a systematic method for digital NAM adjustments, offering a promising alternative to traditional techniques.