## 2 Materials and Methods
### Clinical Case  
[PERSON] is a female 17-year-old patient who sought treatment at the Department of Orthodontics at the University of Naples \"Federico II\", and in the end she gave consent to the publication of the records and the results obtained.  
She presented an oval face and a good smile exposure with a 1 mm right deviation of the upper middle line with respect to the facial middle line. She has an orthognathic and retrusive profile, and increased chin-neck distance and flattened cheekbone contouring. At the intraoral analysis, there was persistence of the deciduous maxillary right canine and the absence of the corresponding permanent tooth. She had both molar and canine class I relationship on both sides, minimal crowding (1 mm), a 2 mm overjet (OVJ) and a 2 mmoverbite (OVB). White spot lesions (WSL) due to a previous orthodontic treatment were present on most of the dental surfaces. She was in permanent dentition and at panoramic X-ray analysis we could see the inclusion of the maxillary right permanent canine (Figure 2).  
Figure 1: Flowchart of the proposed model.  
A skeletal III class with a bi-retrusion and a brachi-facial growth pattern resulted from the cephalometric EBO analysis results (Table 1).  
In this patient, the treatment plan needed to provide the recovery of the impacted canine: the first step was surgical exposure of the canine crown, then the canine was pulled through a Temporary Anchorage Device (TAD) [24; 25]. At first, the canine was surgically exposed then, a miniscrew OrthoEasy(r) (FORESTADENT Bernhard Forster GmbH, Pforzheim, Germany) 10 \(\times\) 1.7 mm was inserted from the palatal side between 1.5 and 1.6, and a Titanium Molibdenum Alloy (TMA) rectangular wire (0.019 \(\times\) 0.025) was used to shape a lever activated to pull the palatal canine (Figure 3).  
\begin{table}
\begin{tabular}{c c c} \hline \hline \multicolumn{2}{c}{**Sagittal Jaw Relationship**} \\ \hline \hline  & **Patient Value** & **Normal Value** \\ \hline Maximly position SNA (\({}^{\circ}\)) & 81.4 & \(82\pm 3.5\) \\ Mandibular position SNB (\({}^{\circ}\)) & 81.8 & \(80\pm 2.5\) \\ Sagittal jaw relation ANPg (\({}^{\circ}\)) & \(-0.4\) & \(2\pm 2.5\) \\ \hline \multicolumn{2}{c}{**Vertical jaw relationship**} \\ \hline Maximly inclination SN’ANS-PNS (\({}^{\circ}\)) & 5.7 & \(8\pm 3\) \\ Mandibular inclination SN’GoGn (\({}^{\circ}\)) & 28.4 & \(33\pm 2.5\) \\ Vertical jaw relation ANS/PNS’GoGn (\({}^{\circ}\)) & 25.5 & \(25\pm 6\) \\ \hline \multicolumn{2}{c}{**Dento-basal relationship**} \\ \hline Maximly incisor inclination U1’ANS-PNS (\({}^{\circ}\)) & 111.9 & \(110\pm 6\) \\ Mandibular incisor inclination L1’GoGn (\({}^{\circ}\)) & 81.8 & \(94\pm 7\) \\ Mandibular incisor compensation (L1-Apo) (mm) & 1.5 & \(2\pm 2\) \\ \hline \multicolumn{2}{c}{**Dental relationship**} \\ \hline Overjet (mm) & 2.9 & \(3.5\pm 2.5\) \\ Overbite (mm) & 2.1 & \(2.5\pm 2.5\) \\ Interincisal angle (\({}^{\circ}\)) & 143.5 & \(132\pm 6\) \\ \hline \end{tabular}
\end{table}
Table 1: Cephalometric data before treatment.  
Figure 2: Initial documentation: extra-oral (**a**) and intraoral photographs (**b**), cephalometric tracing, teleraliography and panoramic X-ray (**c**).  
After the disinclusion, the canine was correctly positioned, and this could be achieved by a traditional fixed orthodontic treatment (brackets) or by aligners.  
According to the literature, we classified this patient in the \"high-risk\" group for the onset of WSL [26], so we decided to treat her with a set of aligners. Moderate-quality evidence reveals less plaque accumulation and less salivary caries-associated bacteria in clear aligners, which might be related to the reduced incidence and severity of WSLs associated with CA when compared with fixed-multibracket appliances [27].  
When the tooth was close to its correct position, the patient was ready to start the treatment with aligners. Figure 4 shows the patient's documentation before starting treatment with aligners.