Fallas Michel F, Abu-Alhaija Elham S, Alkhateeb Susan N, Samawi Shadi S
Master student, Division of Orthodontics, Department of Preventive Dentistry, Faculty of Dentistry, Jordan University of Science and Technology, P.O. Box 3030, Irbid-Jordan.
Professor, Division of Orthodontics, Department of Preventive Dentistry, Faculty of Dentistry, Jordan University of Science and Technology, P.O. Box 3030, Irbid-Jordan.
J Clin Exp Dent. 2020 Nov 1;12(11):e1050-e1057. doi: 10.4317/jced.57538. eCollection 2020 Nov.
Extraction of upper bicuspids have been anecdotally blamed to increase the vertical gingival display (VGD) anteriorly. However, the extraction may be needed in some cases in order to correct the underlying orthodontic problem. Objectives: To investigate and compare vertical gingival display (VGD) changes associated with upper (first vs second) premolars extraction during orthodontic treatment.
Design: A prospective clinical trial. Setting: Postgraduate dental teaching clinics at Jordan University of Science and Technology (JUST). Sample population: Sixty orthodontic patients were included in the study. They were treated with upper first or second premolars extraction according to the underlying problem and the individualized treatment plan of each patient. Records (radiographs, study casts and clinical photographs) were taken for all subjects pre- and post- orthodontic treatment. Outcome measures: Pre- and post-treatment VGD, lip length in static and dynamic positions and the amount of upper teeth retractions were recorded. The paired and the independent t- test were used to detect differences within/between groups. Factors affecting VGD were investigated using backward stepwise linear regression analysis.
In both static and dynamic captures, VGD increased after orthodontic treatment in both premolars extraction groups. Pre- and post-treatment variables differed significantly in groups 1 and 2. VGD changes were similar in both treatment groups. A significant association was found between VGD change during orthodontic treatment and upper canine retraction (<0.001), pre-treatment ANB angle (<0.01) and upper incisor retraction(<0.05).
The amount of anterior VGD increases after upper premolars extraction. The increase in VGD after first and second premolars extractions was comparable. The increase in VGD after orthodontic treatment is associated with the amount of canine retraction, pre-treatment ANB and the amount of incisor retraction. Vertical gingival display, tooth extraction, dental esthetics.
拔除上颌双尖牙一直被认为会导致前部牙龈垂直暴露（VGD）增加。然而，在某些情况下，为了纠正潜在的正畸问题，可能需要进行拔牙。目的：研究并比较正畸治疗过程中拔除上颌第一双尖牙和第二双尖牙后牙龈垂直暴露（VGD）的变化。
设计：前瞻性临床试验。地点：约旦科技大学（JUST）的研究生牙科教学诊所。样本人群：60名正畸患者纳入研究。根据每个患者的潜在问题和个体化治疗计划，对其进行上颌第一或第二双尖牙拔除治疗。在正畸治疗前后，为所有受试者记录（X光片、研究模型和临床照片）。观察指标：记录治疗前后的VGD、静态和动态位置的唇长度以及上颌牙齿后移量。采用配对t检验和独立t检验检测组内/组间差异。使用向后逐步线性回归分析研究影响VGD的因素。
在静态和动态拍摄中，两个双尖牙拔除组正畸治疗后VGD均增加。第1组和第2组治疗前后变量差异显著。两个治疗组的VGD变化相似。正畸治疗期间的VGD变化与上颌尖牙后移（<0.001）、治疗前ANB角（<0.01）和上颌切牙后移（<0.05）之间存在显著关联。
拔除上颌双尖牙后前部VGD增加。拔除第一双尖牙和第二双尖牙后VGD的增加相当。正畸治疗后VGD的增加与尖牙后移量、治疗前ANB以及切牙后移量有关。牙龈垂直暴露、拔牙、牙齿美学
