## 4 Results and Discussion
### Macro-Staging and Micro-Staging
#### 4.3.2 Micro-Staging  
Micro-staging constitutes the biomechanics of movements for each individual tooth. This involves studying the movements in different planes of space that each tooth is programmed for independently, deciding if they are compatible, and having strategies to create space to avoid lack of expression and, consequently, unwanted intrusion. To review whether a plan has an effective micro-staging, the clinician must complete the following steps:  
Define the individual biomechanics of each tooth. Determine the need for spacing movements (priority of movements). Identify interproximal friction points and facilitate plastic push. Observe precontact or overlaps during movement. Define the Individual Biomechanics of Each Tooth  
The first exercise involves defining the positional defect of each tooth to establish what movements are necessary to correct its placement. The available movements are grouped into the following categories: (1) bucco-lingual crown inclination change, (2) bucco-lingual root inclination change, (3) rotation, (4) meso-distal inclination change, (5) bucco-lingual position change, (6) meso-distal position change, and (7) vertical position change. The dental movement table incorporated in most aligner planning software can assist the orthodontist in understanding the amount of correction for each movement. Determine the Need for Spacing Movements  
Like with macro-staging, it is necessary to know whether the movements required for dental correction can be performed simultaneously or if it is advisable to separate them into different phases. There is no absolute criterion that can be applied to all situations, but generally, it is favorable to start with movements that create space in the arch, such as expansion or proclination, as any movement that consumes space (such as compression or extrusion) can block the rest of the movements. Prioritizing movements of crown inclination before movements requiring displacements of the root apex is interesting, as they have a high predictability of success [4]. Lastly, more complex movements, especially absolute vertical movements, should be postponed, as they often require overcorrection or auxiliary elements. An example is shown in Figure 6, where the lower right canine requires several movements for correction. First, a buccal crown inclination (space creation) was performed  
Figure 5: Configuration of segmental movements for a 7 mm extraction space closure. Stages of movement are alternated over 8 aligners (0.25 mm per aligner, 2 mm encompassing 8 aligners) between canines and incisors. and combined with slight intrusion (favorable due to the relative intrusion component of the proclination of the tooth) and a distal-out hinge rotation (in favor of expansion). These combined movements created space on the distal face of the canine, allowing time for the rearrangement of the lower incisors to obtain space mesial to the canine. In a second set of movements, lingual root inclination with mesial root tipping was performed (so that the aligner would push near the mesial gingival margin of the canine). In the case shown in Figure 7, the expansion and alignment of the second quadrant molars were prioritized first (good predictability and space creation), and absolute intrusion was postponed to the end (in case the placement of miniscrews became necessary). Figure 6: The lower right canine of the patient was crowded, with a crown inclination towards mesial, the root apex distally positioned, and the distal face compressed (**A**,**B**). The micro-staging was divided into two phases; first, distal-out hinge rotation was programmed along with buccal crown inclination to create space (**C**), then radicular straightening towards mesial along with lingual root torque (**D**). Canine position at the end of the first set of aligners (**E**,**F**). Figure 7: Patient with left Class II, increased overjet, and gingival unevenness between the anterior and posterior segments (**A**).