## 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
#### 2.1.1 Collecting Data, Planning, and Designing in Consideration of the Making of the Surgical Guide
The other option for the TAD's site in the palatal bone is between the first molar and the second bicuspid area; the first molar has only a single palatal root (two roots on buccal), and the distance to the second bicuspid's root is the widest space available between the root's placement in the posterior region [44]. The placement on the buccal side can also be performed with the surgical guide in the anterior teeth between the central and lateral teeth, interdental for the bicuspids, and the buccal ridge underneath the zygomatic process [45]. Figure 1a, explaining the location of Point A, is the area of the T-zone where plates with two screws are usually preferred rather than single-standing implantation. The reason is that the two screws will give more assurance to endure forces for en mass movement of various three-dimensional movements in space. Point B is the area of choice where there is less interference of the swallowing and deglutition but where it is still possible to perform en mass retraction of the whole teeth of the maxilla. Next, Figure 1b is an example of the use of the points of Figure 1a, a Hybrid-Hyrax, with its placement using the surgical guide for double TADs and an immediate appliance setting. The appliance aims to expand on one side of the maxillary alveolar bone to the left and move the opposite alveolar bone with the teeth palatally using an elastic tread (dotted line). This design is beneficial because it is used for one-side crossbite cases. The yellow arrows show the direction of the alveolar bone movements. Figure 2 shows several common points when placing TADs in the maxilla's buccal sites. Point C is a location between the lateral and canine to correct the gummy smile and  
Figure 1: (**a**) is the T-zone; (**b**) is the Hybrid-Hyrax. the canted anterior occlusal plane. The location also benefits underbite correction. Point D is the interdental root placement of the posterior buccal area, with its most preferable use for single-standing TADs in retraction of the anterior teeth, especially in bicuspid extraction cases. Point E is in the lower part of the zygomatic bone, a preference to retract the whole teeth without interfering with the root of the maxilla. Precautions should be taken to avoid irritating the flabby mucosa and buccal papilla. 2. In the mandible, TAD placement on the lingual side of the mandibular arch be challenging; there is an advantage if there are lingual tori that are large enough to provide the TAD's implantation [46]. Most of the time, the buccal region is the only choice. The anterior part of the buccal dental arch will have limited interdental bone availability, and the quality of bone is often questionable. A critical evaluation of available bone width is necessary before the implantation. Interdental space can be more suitable when appropriately placing the brackets to flare the crowded roots. Changing angulation of the roots by adjusting bracket placement beforehand is a common practice in placing TADs in the anterior region. The Figure 3a shows the most common buccal implantation is on three sides of the mandible; F is the inter-radicular point between the canine and the first bicuspids, G is the inter-radicular point between the second bicuspids and the first molars, and H is the symphysis of the mandible. Figure 3: **(a)** The common placement of TADs in the mandible; **(b)** The placement of TADs on the tori of the mandible. Figure 2: The common location of TADs in the maxilla. One of the most difficult cases in clinical orthodontics is correcting facial deformity in a shifted mandible in a crossbite relationship with the maxilla. The placement on the torus lingual of a plate fixed with double TADs and immediate appliance placement could help skeletal deformity in a mild posterior crossbite. This appliance is intended to restrict the arch form on the right side lingually, as shown in Figure 3b. Paralleling of the TADs calls for this kind of placement. The upper rows showed before, and the lower rows showed after three months after the placement of TADs. 3.