Achieved intrusion amount of the maxillary incisors and the influencing factors in clear aligner extraction cases
10.12016/j.issn.2096-1456.2023.10.005
- Author:
LIAO Naiqi
1
,
2
;
QIAN Yuran
1
,
2
;
LI Yuan
1
,
2
;
TANG Zhenxing
1
,
2
;
ZHAO Zhihe
1
,
2
;
LI Yu
1
,
2
Author Information
1. State Key Laboratory of Oral Diseases &
2. National Clinical Research Center for Oral Diseases, Department of Orthodontics, West China Hospital and School of Stomatology, Sichuan University
- Publication Type:Journal Article
- Keywords:
clear aligner treatment / cone beam CT / tooth movement efficacy / intrusion movement / incisor / extraction / orthodontic treatment
- From:
Journal of Prevention and Treatment for Stomatological Diseases
2023;31(10):720-726
- CountryChina
- Language:Chinese
-
Abstract:
Objective :To investigate the achieved intrusion amount of the maxillary incisors and the influencing factors in clear aligner cases treated with extraction of premolars.
Methods :This study has been reviewed and approved by the Ethics Committee, and informed consent has been obtained from patients. Thirty adult female patients who underwent extraction of the bilateral maxillary first premolars followed by clear aligner therapy were included. CBCT data before and after treatment were obtained, and three-dimensional reconstruction with registration alignment was performed. A spatial coordinate system was established, and the achieved intrusion amount was measured, followed by calculation of the intrusion efficacy. The factors related to the achieved intrusion amount were investigated through multiple linear regression analysis.
Results :The overall efficacy of maxillary incisor intrusion was 54%, with the maxillary central incisors (48%) lower than the lateral incisors (59%), which was statistically significant (P<0.001). Regression analysis showed that the designed intrusion amount and the stepwise intrusion design were positively correlated with the achieved intrusion amount. The designed retroclination amount and use of class Ⅱ intermaxillary elastics were negatively correlated with the achieved intrusion amount. The initial overbite, overjet, crowding, upper central incisor inclination, amount of the first series of aligners, canine attachment type, posterior teeth attachment type and bite ramps had no significant correlation with the achieved intrusion amount.
Conclusion: In maxillary first premolar extraction cases treated with clear aligners, the upper central incisors have lower efficacy of intrusion movement than the lateral incisors. The achieved intrusion amount of maxillary incisors was influenced by multiple factors, which should be considered comprehensively for better vertical control in such cases.
- Full text:无托槽隐形矫治拔牙病例上切牙压低实现量及其影响因素分析.pdf
