# Restorative Space Analysis by Jaw Motion Tracking Using a Template in Completely Edenulous Patients
## 2 Materials and Methods  
### Attaching Target Materials to the Template and Performing Anterior jaw Movement Tracking  
The patient selected for this technique had a completely edentulous maxillary arch and a dentulous mandibular arch. The retention and overall quality of the patient's old denture were evaluated. If the retention and/or fit between the intaglio surface of the denture and residual ridge were not adequate, border molding and relining/rebasing procedures would be used to improve the intaglio surface and retention of the denture. For this technical note, a target in the form of a double circle was used, and it was attached to the upper and lower central incisors and canines, respectively. The selection of the shape of the target and the location of attachment were determined through the results of tracking accuracy identified through preliminary research (Figure S1). Four target materials (Target Stickers, Medit, Seoul, Korea) were attached to the central incisor and canines of the patient's denture and antagonist arch (Figure 1A), and an intraoral scanner (i500, Medit) was used to scan the maxillary and mandibular anterior teeth with the attached target materials and record the relationship between the target materials and teeth (Figure 1B). An optical scanner (Rexcan CS2, Medit) for target tracking was placed at an appropriate distance from the anterior dentition where the teeth were adequately focused, and the locations of the targets were detected after retracting the patient's cheeks using a mouth retractor. The patient was asked to open and close their mouth repeated while the optical scanner was used to record the jaw movements by tracking the movements of the targets. When a template such as dentures is placed in the oral cavity, it is necessary to evaluate whether the facial midline matches the dental midline and whether the lip support is sufficient. Those information was reflected in the subsequent design process. Implementing Appropriate Jaw Movement of Complete Edentulous Patients by Aligning with the Scanned Data of the Template  
The patient's denture and antagonist arch were scanned, and the obtained data were aligned with the scan data obtained using an intraoral scanner as described above (Figure 2A). In this step, the movement of the target materials was converted into movement of the denture and antagonist arch (Figure 2B,C). The intaglio surface of the scanned denture was selected using mesh modeling software (Meshmixer, Autodesk, San Rafael, CA, USA). The \"flip\" function of the software (Figure 3A) was used to obtain the residual ridge data of the completely edentulous arch (Figure 3B). By selecting the negative region of the intaglio surface to be flipped and using the flip function, we were able to obtain positive mesh data in the form of residual ridges (Video S1). Since the scanned denture data and residual ridge data obtained via flipping had the location information aligned in the same coordinate system, the recorded tracking data was able to be converted into new tracking data between the residual ridge and antagonist arch during opening and closing of the mouth (Video S2). Figure 1: (**A**) Target materials were attached to the anterior teeth of the patient’s old denture and antagonist arch. (**B**) Anterior regions of both arches were scanned using an intraoral scanner to detect the targets. Figure 3: (**A**) Selecting the intaglio surface of the denture. (**B**) Producing a digital edentulous model using the “flip” function. Figure 2: (**A**) Data scanned from all areas of the denture and plaster model were aligned. (**B**) The mouth was in closed state while tracking was in progress. (**C**) Tracking movement while opening the mouth. Figure 4 shows that an old denture that is severely worn would restrict the restorable space. The vertical dimension can be altered during opening and closing of the mouth, and in the tracking trajectory, the maxillary and mandibular mesh files corresponding to the desired height can be extracted from the prototype software (Figure 4C).