## 6 Field Experiments
### Two Case Reports: Materials and Methods  
In accordance with the Declaration of Helsinki, the clinical study was approved by the Regional Paediatric Ethics Committee at the University of Florence (protocol number 124/2022; chairperson of the Ethics Committee: Dr. [PERSON]). The approval was based on the results of the preliminary observational study described above, which consolidated the effectiveness and safety of the innovative manufacturing process adopted in the project. The aim of the study was to monitor the effective patient wear time by comparing the reported wear time in questionnaires with objective data obtained by sensors integrated into the forehead pad of the facemask. Patients were included or excluded from the study according to two eligibility criteria [49]:  
* Display of indications for early treatment of Class III malocclusion;
* Absence of dental abnormalities in the upper arch, cleft lip and/or palate, any congenital craniofacial syndrome. Each patient went through the following step-by-step process. * Active expansion: patients received treatment using a Hyrax-type rapid maxillary expander (RME). This appliance was activated only when a transverse discrepancy between the dental arches was identified. The RME was adjusted incrementally, at a rate of one-quarter turn per day, which corresponds to an expansion of 0.2 mm per turn. * Face scanning at the Orthodontic Clinic: patients' anatomies were digitally acquired through a facial scanning by using either an iPad Pro 2018 (Apple Inc., Cupertino, CA, USA) with the Bellus3D DentalPro app (Bellus3D, Campbell, CA, USA), or the Face Scanner Maxi 6 (Polishape 3D, Bari, Italy) with Agisoft Photoscan Professional Edition software V1.4 (Agisoft LLC, St. Petersburg, Russia). This process took place in a well-lit environment, and patients wore disposable caps to keep their hair from obstructing the scan. Patients were asked to sit calmly with their teeth in occlusion and their lips relaxed. \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Questions** & **After** & **After** & **After** & **After** \\  & **1 Week** & **3 Months** & **6 Months** & **9 Months** \\ \hline Do you feel pain? & 4 & & & \\  & (tooth) & 0 & 0 & 0 \\ Are you happy with & - & 10 & 10 & 6 \\ the new facemask? & 9 h & 9 h & 10 h & 9 h \\ Daily weartime & 9 h & no & yes & yes \\ Do you wear the facemask & & yes & no & no \\  & remove the mask? & & yes & yes \\ Do your parents explain the & & & & \\ importance of wearing the facemask when you do not & yes & yes & yes & yes \\ want to? & & & & \\ Any skin irritations? & forehead & chin & no & chin \\ Did you sleep badly & no & no & no & yes \\ with the mask on? & & & lacerations & \\ Have you had any other & & due to hooks & no & no \\ ailments due to the mask? & & moving & & \\  & & outwards & & \\ Any other occurrences? & no & no & no & tooth decay \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Answers to observational study questionnaire—patient X.G. Digital design and manufacturing of the personalised facemasks: after receiving patients' face scans, the production of the personalised facemask followed the eight steps of the manufacturing process described in paragraph 2. 4. Delivery of the personalised facemask to the patient: upon completion of facemask production, the orthodontist received the personalised facemasks and distributed them to the patients. During the fitting session, the orthodontist performed three essential steps: first, the orthodontist attached the sliding crossbar, then applied 500 g extraoral elastics, and finally instructed patients and caregivers on proper facemask use and daily wear time. 5. Monitoring and evaluation of the therapy: therapy progress was monitored through regular questionnaires at one week, three months, six months, and nine months from the beginning of the therapy. Patients, with the help of their parents, rated pain and satisfaction using visual analogue scales.