## 2 The First and Second Parts of Making the Surgical Guide for TADs
### Part 1: Rationale for Using a Surgical Guide in the Implantation of TADs
#### 2.1.2 The Clinical Application of TADs Using the Surgical Guide, an Example Case  
One of the problems faced in constructing surgical guides is the location of the mandibular angle on the mandible's oblique ridge. First, the flabby mucosa and second the insertion angulation should be planned so that a contra-angle handpiece can be used easily. The first problem is holding the mucosa during the implantation, especially when making the pilot hole; the surgical guide will manage to exert light pressure so the mucosa will be caught and injured in the drilling process. The second problem is that we must calculate the length of the screw of the TAD, the thickness of the head of the contra-angle, and the size of the surgical guide beforehand to ensure such a placement is possible.  
Figure 4a-c are photographs of TADs placement on the mandible's oblique ridge. Figure 4a shows the intraoral photograph, Figure 4b shows lateral X-ray with the TADs on the symphysis, and Figure 4c shows the occlusal X-rays CBCT views. The white arrows are pointed out at the TADs of each image.  
Figure 5a,b shows the surgical guides as received from the laboratory. Placed the surgical guides on the model to check for accuracy before inserting them into the mouth, as shown in Figure 5a. There are two kinds of surgical guides for each side of the mandible. The left side is the surgical guide for the TAD, and the right is the surgical guide for the pilot drill (Figure 5b). The surgical guide is viewed from the side and should be analyzed for the vertical height, which is the most critical part, as it should be adjusted whenever a problem arises before placement, as shown in Figure 5b. The two surgical guides are needed because the size of the drill and the driver are different (Figure 5c).  
A CBCT is also taken immediately after the surgical procedure to ensure the placement result. A clinical error can happen in the collection of data used for the device planning, even when it was made correctly, when there is an anatomical situation, such as the posterior region of the oblique ridge of the mandible where the patient cannot open their mouth as wide as expected. When the contra-angle cannot be used for the intended angulation, we must consider an alternate placement site [50]. The thickness of the surgical guide and the thickness of materials and sleeves on the guide are also limited. The clinician should understand those limitations. A surgical guide may need final adjustments in the mouth via selective trimming. The surgical guide must be positioned correctly in the mouth, and its location and accuracy must be double-checked before surgery. The collaboration between the laboratory technician and the clinician is necessary to make an excellent surgical guide.  
Despite the advantages of using advanced technology, proper planning and sound clinical judgment of the clinician are essential for successful TAD implantation [51; 52; 53; 54; 55; 56].  
Table 1 compares the free-hand placement of TADs and the use of the surgical guide. Noted that in free-hand TADs placement, a panoramic X-ray may be sufficient. However, CBCT X-ray and Cad-Cam data are necessary in making a surgical guide.  
Figure 4: (**a**) is the symphysis placement of TADs; (**b**) is the X-ray shows the vertical placement in the symbiosis; (**c**) is the occlusal view of the CBCT shows the location of the TADs.  
Figure 5: (**a**) is the surgical guides on the model; (**b**) is two kinds of surgical guides; (**c**) is the drill and the TADs.