## 2 Materials and Methods
### Data Collection Instrument  
The data were collected using a pre-tested, structured online questionnaire created on Google. The questionnaire was validated by a pilot group asked to review the content and format of the survey. Suggestions were compiled for improvement. There were six questions in total, two general questions, followed by questions dedicated specifically to orthodontists and periodontitis/oral surgeons (4 for each group). In the first question, participants indicated their field of dentistry, orthodontics, periodontology, or oral surgery, and whether they were a board-certified specialist or not. The second question related to the number of years of experience in the discipline. The third question asked about the timing of when a referral for soft tissue augmentation was made or received, while the fourth question asked about the optimal time for the required soft tissue augmentation. Responses to those two questions included \"before\", \"during\", or \"after orthodontic treatment\", \"dependent on the situation\", or \"other\", provided in order to minimize researcher bias by allowing open answers. The fifth question related to feasible factors undermining decision-making with respect to soft tissue augmentation. The final question concerned methods used by dentists in the evaluation of soft and hard periodontal tissues. Responses to this question included \"visual method\", \"gingival transparency using a periodontal probe\", \"bone sounding (under anesthesia)\", \"staining with iodine solution\", \"2D radiological examination: panoramic X-Ray\", \"cephalometric X-Ray\", \"3D radiological examination: cone-beam computed tomography\", \"ultrasonographic measurement\", and \"other\". The multiple-choice questions for periodontitis and surgeons are presented in Table 1, whereas the multiple-choice questions for orthodontists are detailed in Table 2. \begin{table}
\begin{tabular}{l l} \hline \hline
1. & In the case of a mucoginguival problem, for e.g., gingival recession or decreased width of \\  & keratinized gingiva, at what stage of orthodontic treatment are patients referred to you by \\  & an orthodontist for soft tissue augmentation? \\  & \\ (a) & Before orthodontic treatment \\  & \\ (b) & During orthodontic treatment \\  & \\ (c) & After orthodontic treatment \\  & \\ (d) & It depends on the clinical situation \\  & \\ (e) & Other \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Questions for periodontitis/oral surgeons. \begin{table}
\begin{tabular}{l l} \hline
1. & In case of mucogingival issues, for e.g., gingival recession or decreased width of keratinized gingiva, when do you refer your patients to a periodontitis? \\
2. & Before orthodontic treatment \\
2. & During orthodontic treatment \\
3. & After orthodontic treatment \\
4. & It depends on the clinical situation \\
5. & Other \\ \hline
2. & In the case of mucogingival issues, for e.g., gingival recession or decreased width of keratinized gingiva, what is the optimal timing for soft tissue augmentation? \\
2. & Before orthodontic treatment \\
2. & During orthodontic treatment \\
3. & After orthodontic treatment \\
4. & It depends on the clinical situation \\
5. & Other \\ \hline
3. & In the case of mucogingival issues, for e.g., gingival recession or decreased width of keratinized gingiva, what are the factors that determine the timing of soft tissue augmentation? \\
2. & Planned orthodontic tooth movement \\
2. & Baseline soft tissue status \\
3. & Scientific societies’ guidelines \\
4. & Patient’s opinion on esthetics, hypersensitivity, and discomfort \\
5. & Other \\ \hline
4. & What method do you use in the evaluation of soft and hard periodontal tissues? \\
2. & Visual method \\
2. & Gingival transparency using a periodontal probe \\
3. & Bone sounding (under anesthesia) \\
4. & Staining with iodine solution \\
5. & 2D radiological examination: panoramic X-Ray, cephalometric X-Ray \\
6. & 3D radiological examination: cone-beam computed tomography \\
7. & Ultrasonic measurement \\
8. & Other \\ \hline \end{tabular}
\end{table}