Assessment of the Accuracy of Tooth Movement of 3D Printed Versus Thermoformed Aligners in Patients With Lower Anterior Crowding: A Randomized Clinical Trial
Phase: NA
Conditions: Lower Anterior Crowding
Sponsor: Cairo University

 
 
 
 
1 
 
Assessment of the Accuracy of Tooth Movement of 3D Printed Versus Thermoformed 
Aligners in Patients with Lower Anterior Crowding: A Randomized Clinical Trial 
 
 
 
 
 
A protocol submitted to 
Faculty of Dentistry, Cairo University. 
In partial fulfillment of the requirements for 
The Master’s degree in Orthodontics. 
By: 
 
 
 
 
 
        Code: ORTH 3-3-9 
 
 
Supervisors’ signature 
Head of department’s signature 
 
          
 
30/12/2025 
 
 
 
 
 
 
 
 
 
 
 

 
 
 
 
2 
Protocol checklist 
Section and topic 
Item no. 
Checked item 
Reported 
on page No. 
Reviewer’s 
check 
I. Administrative information 
1 
Title 
  
 
2 
Protocol registration 
 
 
3 
Protocol version 
 
 
4 
Funding 
 
 
5 
Roles and responsibilities 
 
 
 
II. Introduction 
 
 
 
A) Background and Rationale 
6 a 
Research question  
 
 
Statement of the problem 
 
 
Rationale for carrying out the trial 
 
 
Review of literature 
 
 
6 b 
Choice of comparators 
 
 
B) Objectives 
7 
Aim of the study  
 
 
Hypothesis 
 
 
C) Trial design 
8 
Trial design 
 
 
 
III. Methods 
 
 
 
A) Participants, interventions 
& outcomes 
9 
Study setting 
 
 
10 
Eligibility criteria 
 
 
11 
Interventions 
 
 
12 
Outcomes 
 
 
13 
Participant timeline 
 
 
14 
Sample size 
 
 
15 
Recruitment 
 
 
B) Assignment of interventions 
16 
Allocation 
 
 
16 a 
Random sequence generation 
(Randomization) 
 
 
16 b 
Allocation concealment 
mechanism 
 
 
16 c 
Implementation 
 
 
17 
Blinding (masking) 
 
 
C) Data collection, 
management, and analysis 
18 
Data collection methods 
 
 
19 
Data management 
 
 
20 
Statistical methods 
 
 
D) Monitoring 
21 
Data monitoring 
 
 
22 
Harms 
 
 
23 
Auditing 
 
 
 
IV. Ethics and dissemination 
24 
Research ethics approval 
 
 
25 
Protocol amendments 
 
 

 
 
 
 
3 
 
 
 
 
 
 
 
 
 
 
 
26 
Informed Consent  
 
 
27 
Confidentiality 
 
 
28 
Declaration of interests 
 
 
29 
Access to data 
 
 
30 
Ancillary and post-trial care 
 
 
31 
Dissemination policy 
 
 
 
V. Appendices 
 
32 
Informed consent materials 
 
 
 
33 
Biological specimens 
 
 
 
VI. References 
 
 
 
 
 
 
Evidence based committee (Reviewers) 
 
Name 
Signature 
Date 
1. 
 
 
 
2. 
 
 
 
 
Research plan committee 
 
Name 
Signature 
Date 
1.  
 
 
 
2.  
 
 
 

 
 
 
 
4 
I. 
Administrative information: 
 
1. Title:  
Evaluation of Accuracy of 3D Printed Aligners in comparison to Thermoformed 
Aligners in orthodontic patients: A Randomized Clinical Trial 
 
2. Protocol registration: 
The Protocol is not registered yet, but it will be registered on www.clinicaltrials.gov  
 
3. Protocol version: 
2025. Version 1 
 
4. Funding: 
Self-funding 
 
5. Roles and responsibilities 
Dr. Sahar Taher Abdel-Aziz, BDS, MSC, PhD (main supervisor), helped with 
developing the idea of the research, will help in the diagnosis of the samples, 
interpretation of the results, and drawing conclusions 
 
Dr. Ahmed Fouda (Co-supervisor), BDS, MSC, PhD, Mortho RCSEd, Department 
of Orthodontics, Faculty of Dentistry, Cairo University, will help formulate the study 
design, data analysis, assessing research writing, participate in the treatment plan of 
cases and designing, interpretation of results and drawing conclusions. 
 
Farouk Khaled Mohamed, BDS (Principal Investigator), will be responsible for 
the practical part of the study, recruitment of samples, taking oral scans, writing the 
thesis, data management, interpretation of results and drawing conclusions. 
All authors contributed to the refinement of the study protocol. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

 
 
 
 
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II. 
Introduction: 
 
6. Background and rationale: 
 
Research question:  
Are 3D printed aligners as accurate as thermoformed aligners for the treatment of 
crowding cases? 
 
Statement of the problem: 
Clear aligner therapy, introduced in the late 1990s, has become a significant part of 
orthodontics due to its comfort and minimal aesthetic impact. However, the concept 
dates back to 1945 when Kesling developed a rubber-based tooth positioner capable 
of facilitating orthodontic tooth movement over time 1 
 
Santa Clara in 1998 introduced a new align technology called Invisalign, a 
revolutionary orthodontic system featuring a series of removable polyurethane 
aligners. These aligners serve as an aesthetic alternative to traditional fixed labial 
braces. The Invisalign system utilizes advanced Computer-Aided Design/Computer-
Aided Manufacturing (CAD/CAM) stereolithographic technology to predict treatment 
outcomes and fabricate multiple custom-made aligners from a single scan2 . 
At present, a variety of thermoplastic materials are utilized in the production of clear 
aligners. These include polyethylene terephthalate glycol (PETG), polypropylene, 
polycarbonate, thermoplastic polyurethanes (TPU), and polyester. 3  Additionally, 
multi-hybrid materials have been developed to address the limitations of single 
materials by enhancing their physical properties, particularly their maximum tensile 
load-bearing capacity 4. 
 
Despite all this progression in material, clear aligners continue to be produced using 
the traditional method of vacuum thermoforming machines. This manufacturing 
process is complex, demanding significant time and effort. Additionally, geometric 
inaccuracies can occur during the thermoforming process5. 
 
 
 
 
 
 
 

 
 
 
 
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The geometric inaccuracies introduced by the thermoforming process complicate 
clinicians' ability to predict the performance and treatment outcomes of clear aligners. 
Different predictions are made based on the type of tooth movement, but these are 
often ineffective for extrusion, rotation, and tipping movements, resulting in a low 
predictability rate of approximately 30%6. 
 
Recently, a new resin for 3D direct printed aligners (DPA) has been introduced. This 
resin, characterized by its viscoelastic properties, allows for precise control over 
material dimensions, structure, and properties. This enables the aligners to exert 
constant and gradual forces within the physiological limits of tooth movements7. 
 
 
 
Tera Harz Tc-58, a new direct-printed resin material introduced by Graphy Company, 
exhibits a significant shape memory effect. Approximately 90% of the deformation is 
recovered within 10 minutes, while 96% recovered after 60 minutes, whereas PETG 
maintains its deformed shape and shows no shape recovery.8 
 
DPA shows a significant enhancement in treating different moderate malocclusion 
cases by reducing the peer assessment rating (PAR) score by 86% and also reducing 
the need for attachment which simplifies treatment. 9 
 
This study aims to determine the accuracy of DPA in facilitating tooth movement and 
to identify which types of tooth movements are more accurately achieved with DPA 
compared to conventional aligners. 
 
Rationale for conducting the research: 
 
Tera Harz is a new material demonstrating good stability at high temperatures and 
excellent shape memory recovery. This technology helps reduce the amount of resin 
used to print dental models. If DPA shows greater accuracy in tooth movement 
compared to conventional aligners, it would be a significant breakthrough. 
 
 
Review of literature  
 
Hertan et al (2022);  Rapid Prototyping (RP) technologies, particularly 3D printing, 
have revolutionized the manufacturing of dental models, offered superior accuracy, 
and reduced the limitations associated with conventional plaster models.  Studies have 
demonstrated that DPA exhibits superior geometric accuracy and mechanical strength 
compared to traditional thermoformed aligners.  This suggests that DPA could 
provide a more effective and time-efficient solution for orthodontic treatments. 7 
 
 
 
 
 

 
 
 
 
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Islam Atta et al (2024) have demonstrated that Tera Harz exhibits excellent 
properties, including shape memory recovery under typical oral conditions and a 
favorable glass transition temperature of approximately 42 degrees Celsius, which 
facilitates shape memory activation. Additionally, Tera Harz shows higher flexibility 
and lower flexural force compared to thermoformed materials, as well as structural 
stability that can withstand elevated temperatures and sterilization chemicals.10 
 
Miglioratia et al (2024); DPA production is effective in office management. It shows 
promising results in treating mildly misalignment cases with accuracy reaching 67%, 
considering cytocompatibility within 14 days of wearing, resin found to be non-
cytotoxic. 11 
 
Jindal et al (2019); DPA exhibits maximum resistance load and minimal 
deformation, capable of withstanding masticatory forces of approximately 500N. In 
contrast, thermoformed aligners demonstrate deformation beyond 10 to 15% strain, 
resulting in permanent deformation of 1.5-2.5mm under a load of 200N, with no 
recovery. Conversely, DPA shows reversible deformation.5  
 
 
 
Explanation for choice of comparators: 
 
Thermoformed aligners are best as the comparator as they have many studies on them 
and have been used in clinics for many years, they show effective results in non-
extraction cases with less chair time and treatment duration.12 
 
 
7. Objectives: 
 
The study aims to compare the accuracy of DPA vs conventional thermoformed 
aligners. 
 
 
Hypothesis:  
 
The null hypothesis of this study is that DPA is as accurate in tooth movement as 
thermoformed aligners. 
 
8. Trial design: 
  
Randomized clinical trial parallel group, two arms, with a 1:1 allocation ratio. 
 
 
 
 
 
 
 
 
 

 
 
 
 
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III. Methods 
A) Participants, interventions & outcomes 
9. Study settings: 
The study will take place at the outpatient clinic of the orthodontic department in the 
faculty of dentistry, at Cairo University. 
 
10. Eligibility criteria: 
Inclusion criteria  
1. Age ranges from 12- 25 years old 
2. Non extraction treatment 
3. Lower anterior crowding <5mm 
4. Dental rotation <30 degree 
5. Relapse cases < 5mm 
Exclusion criteria 
1. Systematic disease 
2. Active or past periodontal disease 
3. Temporomandibular joint disorder 
4. Missing teeth 
 
 
 
11. Interventions 
 
Included participants will undergo extraoral and intraoral photography, as well as 
digital intraoral scans . The patients will be randomly divided into two groups. 
Group1  
1. The obtained STL files will be imported into Dentone software (Diorco Co., 
Korea) for virtual treatment planning. The planning will adhere to functional 
and esthetic principles, ensuring optimal outcomes 
2. The treatment will begin with leveling and alignment of the dental arch, following 
aligner biomechanics principles. Each aligner will be designed to achieve:  
o 0.4 mm linear movement per aligner 
o 3-degree long-axis rotation per aligner 
o  2.5-degree labio-lingual inclination per aligner 
3. The designed STL files will be exported and sent to a certified dental 
laboratory for aligner fabrication. 

 
 
 
 
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4. The aligners will be printed using the Graphy system (Graphy Co., Korea) 
with Tera Harz TC-85DAC resin, ensuring high precision and durability 
5. Participants will be instructed to wear their aligners for 22 hours per day, 
removing them only for eating and oral hygiene. 
6. Aligners will be replaced every 14 days as per the treatment plan. 
7. At the end of the treatment, participants will undergo a final intraoral scan to 
assess the outcomes and compare them with the initial scans 
 
GROUP 2  
1. The obtained STL files will be imported into Dentone software (Diorco Co., 
Korea) for virtual treatment planning. The planning will adhere to functional 
and esthetic principles, ensuring optimal outcomes 
2. The treatment will begin with leveling and alignment of the dental arch, 
following aligner biomechanics principles. Each aligner will be designed to 
achieve:  
• 0.2 mm linear movement per aligner,  
• 2-degree long-axis rotation per aligner 
• 2.5-degree labio-lingual inclination per aligner 
3. The designed STL files will be exported and sent to a certified dental 
laboratory for aligner fabrication. 
4. Digital dental cast models will be printed using a 3d printer (Anycubic 
photon mono M5s pro), using Duran sheets following the manufacturer’s 
instructions during the thermoforming process in a vacuum thermoformed 
machine, aligners will be trimmed 2 mm above the gingival margin  
5. Participants will be instructed to wear their aligners for 22 hours per day, 
removing them only for eating and oral hygiene. 
6. Aligners will be replaced every 14 days as per the treatment plan. 
7. At the end of the treatment, participants will undergo a final intraoral scan 
to assess the outcomes and compare them with the initial scans 
  Dental measurement, by using Medit link software (Medit Co, Seoul, South Korea) 
for superimposition to conclude the accuracy of tooth movement we will superimpose 
the planned treatment model (TP) with post-treatment scan(T1) and pre-treatment 
scan (T0), The superimposition will be on the medial part of the third rugae area as it 
provides more accurate, reproducible, and precise results. 13         
 
 
According to Santos et al 14 . six measurement points will be placed on each tooth 
including  
• Distal point of the occlusal surface (DO) 
• Mesial point of the occlusal surface (MO) 
• Occlusal limit of the FACCs buccal axis (OL) 
• Gingival limit of the FACCs buccal axis (GL) 

 
 
 
 
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• Gingival limit of the lingual FACCs (continuation of the buccal FACC axis on the 
lingual face) (GLL) 
• Centroid of teeth (CT): The midpoint of a line passing from the gingival limit of the 
FACC buccal axis (GL) to the occlusal limit of the FACC buccal axis (OL) 
To improve adherence to treatment patients will be followed up with phone calls and 
clinic visits every two weeks. 
 
 
 
12. Outcomes: 
Accuracy of tooth movement is determined by knowing the difference between 
predicted tooth movement and the actual movement that occurred, it will be measured 
by using this formula: 
𝑝𝑜𝑠𝑖𝑡𝑖𝑜𝑛 𝑇1−𝑃𝑜𝑠𝑖𝑡𝑖𝑜𝑛 𝑇0
𝑃𝑜𝑠𝑖𝑡𝑖𝑜𝑛 𝑇𝑃−𝑃𝑜𝑠𝑖𝑡𝑖𝑜𝑛 𝑇0 × 100 
 
 
Where Position (T1) is the actual position after treatment, Position (T0) is the initial 
position, and Position (TP) is the predicted position 
  
Prioritization of 
Outcome 
Outcome  
Method of 
Measurement  
Unit of 
Measurement  
Primary outcome  
Accuracy of tooth 
movement 
Linear and angular 
measurement 
Numerical  
Secondary outcome Pain  
Questionnaire 
Visual analogue 
scale 
 
 
13. Participant timeline 
 
1. Screening patients at the Orthodontic department, Faculty of Dentistry, Cairo 
University and selecting potential participants through careful clinical examination.  
2. All recruited patients should fulfill the previously mentioned inclusion and 
exclusion criteria.  
3. Prior to study initiation, participants will be provided with detailed information 
about the study objectives and procedures, and written informed consent will be 
obtained.  
4. After enrollment, for each participant intraoral and extraoral photos and intraoral 
scans will be taken. In addition, each patient will be referred for panoramic and lateral 
cephalometric radiographs.  
5. Participants will be randomly assigned to either the intervention or control group 
according to the study’s allocation protocol 

 
 
 
 
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6. Each participant will be scheduled for follow-up visits at four-week intervals to 
monitor progress and ensure adherence to the treatment regimen 
7. After finishing the aligner set, new records will be taken for each participant.  
8. All patients will receive a fixed retainer after the treatment. 
8. Each participant will fill up a questionnaire regarding his pain experience with the 
appliance.  
 
 
 
14. Sample size: 
 
According to the results of Sachdev et al.  2021 in which intrusion tooth movement 
using clear aligners was 0.27±0.21.  If the true difference in the experimental and 
control means is 0.25, we will need to study 12 patients per group to be able to reject 
the null hypothesis that the population means of the experimental and control groups 
are equal with probability (power) 0.8. The Type I error probability associated with 
this test of this null hypothesis is 0.05. Sample size was increased by 15% to 
compensate for possible dropouts to reach 14 per group. Sample size was calculated 
using PS Power and Sample for windows version 3.1.6 using independent t test. 

 
 
 
 
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15. Recruitment: 
Subjects will be selected from the Diagnostic Centre at the Faculty of Dentistry, Cairo 
University by the principal investigator. 
 
 
B) Assignment of interventions 
 
16. Allocation: 
 
16a. Randomization: 
Randomization will be performed as a 1:1 allocation. The sequence of individuals in 
the intervention and the comparator group will be done by using computer generated 
random numbers. This will be done using Microsoft Office Excel version (Redmond, 
Washington) 15.24 sheet. 
 
 
16b. Allocation concealment mechanism:  
The randomization numbers produced from the sequence generation will be written 
on opaque papers folded 4 times sealed in opaque envelopes and kept in a sealed box. 
 
16c. Implementation 
On the day of starting, each subject will be allowed to choose one of the envelopes to 
detect his/her number to be able to detect the randomization sequence and detect in 
which group he/she is. The principal operator will have the code for each patient. 
 
17. Masking/blinding: 
Trial participants, outcome assessors, data analysts and statistician will be blinded. 
 
 
 
C) Data collection, management, and analysis: 
 
18. Data collection methods 
Data will be collected by the principal investigator for the primary and secondary 
outcomes. 
 
19. Data management: 
Data will be entered and organized electronically in Excel sheets and stored on the 
computer in the orthodontic department. 
 

 
 
 
 
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20. Statistical methods: 
Statistical analysis will be performed using Medcalc software, version 22 for 
windows (MedCalc Software Ltd, Ostend, Belgium). Continuous data will be 
presented as mean and standard deviation. Comparison between continuous variables 
will be performed using independent t test. The significance level will be set at P ≤ 
0.05 and all tests will be two tailed. 
 
D) Data monitoring: 
 
21. Monitoring 
Monitoring of the study will be strictly done by the supervisors periodically. They 
will monitor all the steps of the followed protocol and find solutions to all troubles 
that have occurred during the trial performance. 
 
22. Harms 
If any harm occurs to the patient before entry to the study, it will be reported as 
unrelated. If it happens after, it will be recorded and documented by the primary 
investigator. The severity of harm and potential causal relationship with intervention 
will be addressed. If the patient shows any allergic reaction from wearing aligners, the 
patient will withdraw from the trial.  
 
 
 
23. Audit 
The trial will be audited by the supervisors in the orthodontic department at Cairo 
University frequently. 
 
 
 
 
 
 
 
 
 
 
 

 
 
 
 
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IV. Ethics and dissemination 
24. Research ethics approval 
This protocol, the template, and the specific informed consent form will be reviewed, 
approved, and agreed upon by CEBD [Center For Evidence-Based Dentistry CU] 
Cairo University, Egypt, and approved by the Ethics Committee [Research Ethics 
Committee Cairo University Faculty of Oral and Dental Medicine]. The research 
Ethics committee will review the nature of interventions and will have the right to 
modify the study methods. 
  
 
25. Protocol amendments 
Any modifications to the protocol which may impact on the conduct of the study, 
potential benefit of the patient or may affect patient safety, including changes of study 
objectives, study design, patient population, sample sizes, intervention procedures 
will require a formal amendment to the protocol. Such amendment will be agreed 
upon by the Council of Orthodontics and Dentofacial Orthopedics department. 
 
26. Informed consent 
The principal investigator will introduce all the details of the study and the possibility 
of recruitment will be clearly introduced to the patients. 
The researcher will obtain written consent from the patients willing to participate in 
the study. 
The consent form is in Arabic. 
 
27. Confidentiality 
All study-related information will be stored securely at the Orthodontic department, at 
Cairo University. All participant’s personal information, family history, social and 
health status will be stored in locked file cabinets in areas with limited access. Access 
will be limited to the minimum number of individuals necessary for quality control, 
audit, and analysis. All records that contain names or other personal identifiers, such 
as informed consent forms, will be stored separately from study records identified by 
code number to secure the blinding of assessment. 
 

 
 
 
 
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28. Declaration of interest 
There is no conflict of interest between the supervisors and the principal investigator. 
Non-financial competing interests: this study is a part of an MSc degree in 
Orthodontics, Faculty of Dentistry, Cairo University. 
No financial conflicts of interest are to be declared. The study is self-funded by the 
principal investigator. 
 
29. Access to data 
The Principal Investigator and the study supervisors will be given access to the final 
data sets. All data sets will be password protected. The randomization sheet will be 
accessed only by the supervisor. The data analysts will be blinded from any personal 
identifier during data analysis. All the data have to be of no access to other parties 
until the study is terminated. 
 
30. post-trial care 
Complications that may accompany the intervention, will be managed by senior 
staff members in specialized centers and will be sponsored by Cairo University. 
 
31. Dissemination policy 
Besides reporting as a MSc thesis, study results will be available to the participants, 
health care professionals and the public by publication of the study. A copy of the 
thesis will be available at the faculty library and additional copies will be distributed 
among the main universities in Egypt. The results of the trial are planned for 
publication in high quality journals and presentations at national and international 
conferences. There will be no publication restrictions, regardless of the magnitude of 
effectiveness of the intervention that is indicated from the data analysis. 
 
V. Appendices 
32. Informed consent 
 
Patient's full knowledge of the research steps: Reading [   ] Oral 
explanation [*  ] Other [  ] 
1. I have carefully reviewed and understood the purpose of conducting the 
research and the nature of this study, and I understand what is necessary 
to accomplish these procedures. 
2. The researcher has informed me of the possible therapeutic alternatives 
for this research. 
3. The researcher has informed me of all the possible risks of this research 
and how to deal with it. 
4. I agree to the imaging, recording, and all types of radiology to be 
performed in this study, on condition of anonymity. 
5. I have made an accurate report on my health history and informed the 
doctor of all kinds of health reactions or unusual allergies to medicines, 

 
 
 
 
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food, insect bites, anesthetics, dust or any reactions that have occurred to 
me from any other substances, abnormal bleeding or any other related 
conditions for my health. 
6. I acknowledge that I am not involved in any other research from the 
beginning of this research until the end of this research and that I will 
inform the researcher if I enter any other research throughout the period 
of this research. 
7. I undertake to return the medical devices (instruments) used in the 
research in case of discontinuation or when the research is completed. 
After knowing the available information related to the research, the 
volunteer or the person in charge will be able to choose freely whether or 
not to subscribe. In case of approval, kindly fill out the data shown. The 
volunteer has the right to withdraw from the research without giving 
reasons anytime. 
  
The researcher in charge of the research undertakes to keep the 
information of the volunteer person confidential by participating in the 
research, stating the methods used, such as replacing names with code 
numbers or hiding facial features when photographing (etc.). 
 
       
 
                                                                                                                            Signature:
 
                                                                                                                         Date: 
 
 
 
 
32. visual analogue scale 

 
 
 
 
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34. Biological specimens 
No biological specimen in this study  
 
VI. References 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

 
 
 
 
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5406(03)00051-9 
3. Lombardo, L., Martines, E., Mazzanti, V., Arreghini, A., Mollica, F., & 
Siciliani, G. (2017). Stress relaxation properties of four orthodontic aligner 
materials: A 24-hour in vitro study. Angle Orthodontist, 87(1), 11–18. 
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(2015). Efficacy of clear aligners in controlling orthodontic tooth movement: 
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8. Lee, S. Y., Kim, H., Kim, H. J., Chung, C. J., Choi, Y. J., Kim, S. J., & Cha, 
J. Y. (2022). Thermo-mechanical properties of 3D printed photocurable 
shape memory resin for clear aligners. Scientific Reports, 12(1). 
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9. Knode, V., Ludwig, B., Retrouvey, J.-M., Pandis, N., Schmid, J. Q., Erbe, C., 
& Fleming, P. S. (2025). Directly printed aligner therapy: A 12-month 
evaluation of application and effectiveness. American Journal of 
Orthodontics and Dentofacial Orthopedics, 167(1), 73–79. 
https://doi.org/10.1016/j.ajodo.2024.08.013 
10. Atta, I., Bourauel, C., Alkabani, Y., Mohamed, N., Kimbe, H., Alhotan, A., 
Ghoneima, A., & Elshazly, T. (2024). Physiochemical and mechanical 
characterisation of orthodontic 3D printed aligner material made of shape 
memory polymers (4D aligner material). Journal of the Mechanical Behavior 
of Biomedical Materials, 150. https://doi.org/10.1016/j.jmbbm.2023.106337 

 
 
 
 
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11. Migliorati, M., Drago, S., Castroflorio, T., Pesce, P., Battista, G., 
Campobasso, A., Gastaldi, G., Valvecchi, F. F., & De Mari, A. (2024). 
Accuracy of orthodontic movements with 3D printed aligners: A prospective 
observational pilot study. Korean Journal of Orthodontics, 54(3), 160–170. 
https://doi.org/10.4041/kjod23.268 
12. Ait Addi, R. (2023). “The Efficacy and Efficiency of Clear Aligners in 
Comparison to Traditional Fixed Appliances: A Systematic Review.” 
Biomedical Journal of Scientific & Technical Research, 51(5). 
https://doi.org/10.26717/bjstr.2023.51.008167 
13. Hage, L., Kmeid, R., & Amm, E. (2024). Comparison between 2D 
cephalometric and 3D digital model superimpositions in patients with lateral 
incisor agenesis treated by canine substitution. American Journal of 
Orthodontics and Dentofacial Orthopedics, 165(1), 93–102. 
https://doi.org/10.1016/j.ajodo.2023.07.015 
14. Santos, R. de F., Santos, B. F. de O., Fernandes, V. M., Caldas, L. D., Baldo, 
T. de O., & Dominguez, G. C. (2021). Validity and reliability of a 
trigonometry-based method for the measurement of tooth movement on 
digital models. Dental Press Journal of Orthodontics, 26(3). 
https://doi.org/10.1590/2177-6709.26.3.e2119148.oar