Kong Lei, Liu Xin-Qiang
Department of Stomatology and Orthodontics, The Affiliated Hospital of Qingdao University, Qingdao 266003, Shandong Province, China.
Department of Stomatology, Qingdao University, Qingdao 266003, Shandong Province, China.
World J Clin Cases. 2023 Feb 26;11(6):1299-1309. doi: 10.12998/wjcc.v11.i6.1299.
Mandibular retraction is the main etiological mechanism of class II malocclusion in China and the subsequent distal molar relationship can cause functional discomfort in mastication, breathing and the temporomandibular joint. The use of mandibular advancement (MA) devices has recently emerged as an adolescent mandibular retraction treatment; however, current studies regarding the effect thereof are relatively few, and there is lack of sufficient clinical support.
To investigate the clinical effect of invisalign MA on the treatment of mandibular retraction in adolescents.
This study included 30 adolescent patients who underwent treatment with the MA appliances from December 2017 to June 2021. The lateral cephalometric data before and after treatment were collected and imported into Dolphin Imaging software. The changes were measured by linear measurement superimposed with lateral cephalometric trajectory based on the Pancherz technology.
There was no significant difference in the length and position of maxilla before and after the treatment. The position of the mandible moved 3.13 mm, the length increased 4.14 mm, the mandibular ramus length increased 4.09 mm, the body length increased 4.25 mm, and the position of the condyle moved 1.03 mm forward after treatment. Additionally, changes in the incisor sagittal position and labial inclination were observed. The position of the upper incisor point moved back 1.33 mm, without statistical difference, the inclination and tooth angle decreased by 3.44° and 4.06°, respectively; the position of the lower incisor point was moved 2.98 mm, and the inclination and tooth angle increased by 2.62° and 1.23°, respectively. Furthermore, changes in the incisor overjet and molar relationship were seen. Overjet decreased by 4.31 mm, of which 1.78 mm was due to dental factors, accounting for 41.3% of the effect as opposed to 58.7% due to skeletal factors. Molar relationship improved 3.87 mm, with 1.34 mm due to dental factors, and dental and skeletal factors were accounted for 34.6% and 65.4% of the effect, respectively.
For adolescent patients with mandible retraction, invisalign MA can effectively promote the mandible growth, and it was proven to be mainly due to skeletal effects.
下颌后缩是我国安氏II类错牙合畸形的主要病因机制，随后出现的磨牙远中关系可导致咀嚼、呼吸及颞下颌关节功能不适。下颌前导（MA）装置的使用近来已成为青少年下颌后缩的一种治疗方法；然而，目前关于其效果的研究相对较少，且缺乏足够的临床支持。
探讨隐适美MA矫治器治疗青少年下颌后缩的临床效果。
本研究纳入了2017年12月至2021年6月期间使用MA矫治器进行治疗的30例青少年患者。收集治疗前后的头颅侧位片数据，并导入Dolphin Imaging软件。基于潘切尔兹技术，通过线性测量叠加头颅侧位片轨迹来测量变化。
治疗前后上颌的长度和位置无显著差异。治疗后，下颌位置前移3.13mm，长度增加4.14mm，下颌升支长度增加4.09mm，体部长度增加4.25mm，髁突位置向前移动1.03mm。此外，观察到切牙矢状位置和唇倾度的变化。上前牙点位置后移1.33mm，无统计学差异，倾斜度和牙角分别减小3.44°和4.06°；下前牙点位置前移2.98mm，倾斜度和牙角分别增加2.62°和1.23°。此外，还观察到切牙覆盖和磨牙关系的变化。覆盖减小4.31mm，其中1.78mm归因于牙齿因素，占总效果的41.3%，而骨骼因素占58.7%。磨牙关系改善3.87mm，其中1.34mm归因于牙齿因素，牙齿和骨骼因素分别占总效果的34.6%和65.4%。
对于下颌后缩的青少年患者，隐适美MA矫治器可有效促进下颌生长，且已证明主要是骨骼效应。
