All Articles
View
Split Viewer
Korean J Orthod
Copyright © The Korean Association of Orthodontists.
Jong-Chan Baik1(Resident), Youn-Kyung Choi2,5*(Clinical Professor), Yonghun Cho3(Professor), Yunju Baek3(Professor), Sung-Hun Kim1,5(Assistant Professor), Seong-Sik Kim1,5(Professor), Soo-Byung Park1,5(Professor), Ki Beom Kim4(Professor), Yong-Il Kim1,5(Professor),
1Department of Orthodontics, Dental Research Institute, Pusan National University Dental Hospital, Yangsan, South Korea.
2Department of Orthodontics, Biomedical research institute, Pusan National University Hospital, Busan, South Korea.
3School of Computer Science and Engineering, Pusan National University, Busan, South Korea.
4Department of Orthodontics, Saint Louis University, Saint Louis, Mo, USA.
5Dental and Life Science Institute, School of Dentistry, Pusan National University, Yangsan, South Korea.
Correspondence to:Youn-Kyung Choi
Clinical Professor, PhD
Department of Orthodontics, Biomedical Research Institute, Pusan National University Hospital, Gudeokro 179, Seogu, Busan, Republic of Korea, 49241 Dental and Life Science Institute, School of Dentistry, Pusan National University, Yangsan, South Korea.
Tel: 82- 51-240-7430, Fax: 82- 51-240-7706, E-mail: dolldsreaming@gmail.com
Objective: This study aimed to investigate the effect of 3D printed clear aligners (CA) with different designs on the extrusion of mandibular premolars using a force/moment measurement system and digital image correlation (DIC).
Methods: The forces and moments applied to the mandibular canines, first and second premolars were measured using a multi-axis force/moment transducer when an extrusion of 0.5 mm was planned, assuming that the mandibular first premolars were intruded by 1 mm. In addition, displacement and strain changes in the CA were analyzed using the DIC method. CA designs were categorized according to the presence of the first premolar attachment and then subdivided into equi-gingival margins, 1-mm extended margins, equi-margins with 1-mm thickness and height, and equi-margins with 1-mm reduced buccolingual width. The CA was printed directly with a thickness of 0.5 mm. The experiments were conducted at 37°C.
Results: The results showed that attachment played an important role in the extrusion of first premolars in both the force/moment measurement system and the DIC method. Intrusion was observed without attachment even though extrusion was planned. The CA designs apply a greater force to the cervical region by extending the margin or reducing the buccolingual width, improves the efficiency of extrusion.
Conclusions: Force and moment changes in direct 3D printed CA are complex systems that are difficult to predict; however, modifying the aligner designs such as extending the margin or reducing buccolingual width and using appropriate attachments could minimize unwanted tooth movement, optimize planned treatment, and increase treatment predictability.
Keywords: aligners, extrusion, force, moment
Korean J Orthod
First Published Date June 28, 2024
Copyright © The Korean Association of Orthodontists.
Jong-Chan Baik1(Resident), Youn-Kyung Choi2,5*(Clinical Professor), Yonghun Cho3(Professor), Yunju Baek3(Professor), Sung-Hun Kim1,5(Assistant Professor), Seong-Sik Kim1,5(Professor), Soo-Byung Park1,5(Professor), Ki Beom Kim4(Professor), Yong-Il Kim1,5(Professor),
1Department of Orthodontics, Dental Research Institute, Pusan National University Dental Hospital, Yangsan, South Korea.
2Department of Orthodontics, Biomedical research institute, Pusan National University Hospital, Busan, South Korea.
3School of Computer Science and Engineering, Pusan National University, Busan, South Korea.
4Department of Orthodontics, Saint Louis University, Saint Louis, Mo, USA.
5Dental and Life Science Institute, School of Dentistry, Pusan National University, Yangsan, South Korea.
Correspondence to:Youn-Kyung Choi
Clinical Professor, PhD
Department of Orthodontics, Biomedical Research Institute, Pusan National University Hospital, Gudeokro 179, Seogu, Busan, Republic of Korea, 49241 Dental and Life Science Institute, School of Dentistry, Pusan National University, Yangsan, South Korea.
Tel: 82- 51-240-7430, Fax: 82- 51-240-7706, E-mail: dolldsreaming@gmail.com
This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
Objective: This study aimed to investigate the effect of 3D printed clear aligners (CA) with different designs on the extrusion of mandibular premolars using a force/moment measurement system and digital image correlation (DIC).
Methods: The forces and moments applied to the mandibular canines, first and second premolars were measured using a multi-axis force/moment transducer when an extrusion of 0.5 mm was planned, assuming that the mandibular first premolars were intruded by 1 mm. In addition, displacement and strain changes in the CA were analyzed using the DIC method. CA designs were categorized according to the presence of the first premolar attachment and then subdivided into equi-gingival margins, 1-mm extended margins, equi-margins with 1-mm thickness and height, and equi-margins with 1-mm reduced buccolingual width. The CA was printed directly with a thickness of 0.5 mm. The experiments were conducted at 37°C.
Results: The results showed that attachment played an important role in the extrusion of first premolars in both the force/moment measurement system and the DIC method. Intrusion was observed without attachment even though extrusion was planned. The CA designs apply a greater force to the cervical region by extending the margin or reducing the buccolingual width, improves the efficiency of extrusion.
Conclusions: Force and moment changes in direct 3D printed CA are complex systems that are difficult to predict; however, modifying the aligner designs such as extending the margin or reducing buccolingual width and using appropriate attachments could minimize unwanted tooth movement, optimize planned treatment, and increase treatment predictability.
Keywords: aligners, extrusion, force, moment
PDF
Standard view
Export citation
Share 
