Application of a new scan body for face-driven fixed prosthetics

The current method of digitally designing dental prostheses mainly focuses on intra-oral soft and hard tissues, although the harmony of the facial soft tissue and the prosthesis is crucial, especially for esthetics. Here, we introduce a new method of digitally designing dental prostheses using a new device that generates a virtual patient and incorporates facial features into the prosthetic design.

A new extra-oral scan body for facial scanning was designed and developed. A definitive edentulous maxilla implant cast with four extra-oral scan bodies (regions: maxillary left and right lateral incisors, maxillary left and right premolars) was placed in the mouth of a dental mannequin. The dental mannequin was scanned with and without the extra-oral scan bodies. For reference data, an impression of the maxilla was taken and scanned with a laboratory scanner. By superimposing each acquired data, a virtual patient was generated, and the spatial location of the abutments relative to the face was clarified. Identifying the accurate location of the abutments enabled to design face-driven dental prosthesis.

Based on the color-coded deviation map created by the data acquired from conventional and extra-oral scan bodies, the divergence of the two data was mostly within 0.1 mm, which proves that the extra-oral scan bodies were as accurate as conventional scan bodies. Therefore, the facial scan data and the scan data of the oral cavity were successfully superimposed, which allowed to generate a virtual patient to design face-driven prosthesis.

The new method is effective for designing high-quality face-driven prostheses, especially when treating a patient with a full-arch implant-fixed prosthesis.