1
|
Mikami N, Yonemitsu I, Takemura H, Kondou M, Soga K, Suga K, Kanno Z, Lai W, Uo M, Ono T. Mechanical analysis of the improved superelastic Ni-Ti alloy wire using the orthodontic simulator with high-precision sensors. J Mech Behav Biomed Mater 2023; 142:105861. [PMID: 37146519 DOI: 10.1016/j.jmbbm.2023.105861] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Revised: 04/13/2023] [Accepted: 04/16/2023] [Indexed: 05/07/2023]
Abstract
PURPOSE The authors have been using improved superelastic Nickel-Titanium alloy wire (ISW) to close and align extraction spaces simultaneously, instead of separately using rigid wires for closing extraction spaces and Ni-Ti alloy wires for leveling and aligning. ISW has a low stiffness, which makes it challenging to generate sufficient moments. This study aimed to demonstrate the forces and moments exerted on adjacent brackets using an orthodontic simulator (OSIM) attached to a high-precision 6-axis sensor. MATERIALS AND METHODS In experiment 1, a 0.016 × 0.022-inch ISW, stainless steel (SS) wire, and β-titanium wires were ligatured into the two brackets. The 0.018 × 0.025-inch slot self-ligating brackets were bonded to two simulated teeth at the same height, and the experiment was conducted using the high-precision OSIM. The distance between the brackets was 10 mm, the V-bend angles of the installed wires were 10°, 20°, 30°, and 40°, and the apex position was set at the center of the bracket. In experiment 2, 6.0- and 9.0-mm long elastomeric chains were placed on the same brackets as in Experiment 1 to measure forces and moments. The distance between the brackets was increased by 1.0 mm from 6.0 to 15.0 mm. Both experiments were conducted in a 37 °C thermostatic chamber similar to the oral environment. RESULTS AND DISCUSSION In experiment 1, we measured moments on both sides for all the wires. As the V-bend angle increased, the absolute values of the moments also increased. With a V-bend angle of 10°, there was a significant (p < 0.05) difference in the moment generated in the left and right brackets among the three wire types. In the ISW, -1.67 ± 0.38 N・mm was generated in the left bracket, while 0.38 ± 0.26 N・mm was generated in the right bracket at 10°. At 20°, -1.77 ± 0.69 N・mm was generated in the left bracket, while 2.37 ± 0.94 N・mm was generated in the right bracket. At 30°, -2.98 ± 0.49 N・mm was generated in the left bracket, while 3.25 ± 0.32 N・mm was generated in the right bracket. Moreover, at 40°, -3.96 ± 0.58 N・mm was generated in the left bracket, while 3.55 ± 0.53 N・mm was generated in the right bracket. Furthermore, in experiment 2, the moments increased in proportion to the increase in distance between the centers of the two brackets. Absolute values of the moments were approximately equal for the left and right brackets. The 6.0-mm elastomeric chain generated a minimum force of -0.09 ± 0.05 N in the left direction when the distance between brackets was 6.0 mm, while a maximum of 1.24 ± 0.3 N when the distance between brackets was 12 mm in the right bracket. In the left bracket, minimum and maximum forces of -0.09 ± 0.07 and 1.3 ± 0.4 N were generated in the right direction, respectively. The 9.0-mm elastomeric chain generated a minimum force of 0.03 ± 0.07 N in the left direction when the distance between brackets was 9.0 mm, while a maximum of 1.3 ± 0.1 N when the distance between brackets was 15 mm in the right bracket. In the left bracket, minimum and maximum forces of 0.05 ± 0.06 and 0.98 ± 0.2 N were generated in the right direction, respectively. CONCLUSION Mechanical data of the ISW have been collected in the study, which was previously difficult to perform owing to the low stiffness of the wire. It is suggested that the ISW can provide sufficient moments with the addition of V-bends to close the space by bodily movement.
Collapse
Affiliation(s)
- Naoaki Mikami
- Tokyo Medical and Dental University (TMDU), Graduate School of Medical and Dental Sciences, Department of Orthodontic Science, 1-5-45, Yushima, Bunkyo-ku, Tokyo, 113-8510, Japan
| | - Ikuo Yonemitsu
- Tokyo Medical and Dental University (TMDU), Graduate School of Medical and Dental Sciences, Department of Orthodontic Science, 1-5-45, Yushima, Bunkyo-ku, Tokyo, 113-8510, Japan.
| | - Hiroshi Takemura
- Tokyo University of Science, Faculty of Science and Engineering, Department of Mechanical Engineering, 2641 Yamazaki, Noda, Chiba, 278-8510, Japan
| | - Mark Kondou
- Tokyo University of Science, Faculty of Science and Engineering, Department of Mechanical Engineering, 2641 Yamazaki, Noda, Chiba, 278-8510, Japan
| | - Kouhei Soga
- Tokyo University of Science, Faculty of Advanced Engineering, Department of Material Science and Technology, 6-3-1 Niijuku, Katsushika-ku, Tokyo, 125-8585, Japan
| | - Kazuhiro Suga
- Kogakuin University, Faculty of Engineering, Department of Mechanical Engineering, 1-24-2 Nishi-shinjuku, Shinjuku-ku, Tokyo, 163-8677, Japan
| | - Zuisei Kanno
- Tokyo Medical and Dental University (TMDU), Graduate School of Medical and Dental Sciences, Department of Orthodontic Science, 1-5-45, Yushima, Bunkyo-ku, Tokyo, 113-8510, Japan
| | - WeiJen Lai
- Tokyo Medical and Dental University (TMDU), Graduate School of Medical and Dental Sciences, Department of Orthodontic Science, 1-5-45, Yushima, Bunkyo-ku, Tokyo, 113-8510, Japan
| | - Motohiro Uo
- Tokyo Medical and Dental University (TMDU), Graduate School of Medical and Dental Sciences, Department of Advanced Biomaterials, 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8510, Japan
| | - Takashi Ono
- Tokyo Medical and Dental University (TMDU), Graduate School of Medical and Dental Sciences, Department of Orthodontic Science, 1-5-45, Yushima, Bunkyo-ku, Tokyo, 113-8510, Japan
| |
Collapse
|
2
|
Karkazi F, Karvelas N, Alexiou A, Gizani S, Tsolakis AI. Comparison between orthodontic and surgical uprighting of mandibular molars: a systematic review. Angle Orthod 2023; 93:104-110. [PMID: 36240427 DOI: 10.2319/041822-298.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Accepted: 08/01/2022] [Indexed: 12/30/2022] Open
Abstract
OBJECTIVES To evaluate and compare the efficiency of orthodontic treatment and surgical uprighting of first and second mandibular molars. MATERIALS AND METHODS An electronic literature search in PubMed, Science Direct, Embase, Scopus, Web of Science, Cochrane Library, LILACS, and Google Scholar, as well as a hand search was conducted by two independent researchers to identify relevant articles up to January 2022. In addition, a manual search was done that included article reference lists, grey literature, and dissertations. The risk of bias of the included prospective and retrospective studies was assessed with the Risk Of Bias Tool In Non-randomized Studies of Interventions (ROBINS-I) assessment tool. RESULTS A total of six nonrandomized clinical trials (non-RCT) evaluating the efficiency of mandibular molar orthodontic and/or surgical uprighting were included. The quality analysis showed certain defects of the Non-RCTs included and, according to the criteria used, the majority of the articles were judged to be of moderate quality. CONCLUSIONS Based on the evidence, orthodontic and surgical uprighting appear to be effective treatment methods for mandibular molars. Surgical uprighting may be associated with more complications than orthodontic uprighting. However, the existing literature on the subject is limited, heterogeneous, and methodologically limited. Therefore, the outcomes should be interpreted carefully.
Collapse
|
3
|
Turley PK. The management of mesially inclined/impacted mandibular permanent second molars. J World Fed Orthod 2020; 9:S45-S53. [PMID: 33023732 PMCID: PMC7532936 DOI: 10.1016/j.ejwf.2020.09.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Accepted: 09/07/2020] [Indexed: 11/28/2022]
Abstract
Mesially impacted mandibular second molars are a common occurrence in orthodontic practices, especially those using the lingual arch or lip bumper for alleviating anterior crowding. Horizontally impacted second molars, on the other hand, occur so infrequently that most practitioners have limited experience in treating such a patient. Because of this there is little consensus on the management of these cases. As opposed to vertically impacted molars that may be associated with ankylosis or other factors preventing eruption, the mesially angulated, horizontally impacted mandibular second molar usually has eruption potential, because its impaction is more commonly due to lack of space and/or abnormal eruption path. Hence, orthodontic uprighting shows the most promise and can commonly be done without extracting the third molar or surgically exposing the impacted second molar. Modern clinicians have at their disposal a myriad of biomechanical choices that can be used to successfully reposition these teeth and enable finishing with an optimal occlusion.
Collapse
Affiliation(s)
- Patrick K Turley
- Professor Emeritus, Sections of Orthodontics and Pediatric Dentistry, School of Dentistry, University of California at Los Angeles, Los Angeles, CA
| |
Collapse
|