Department of Developmental Sciences/Orthodontics, Marquette University School of Dentistry, Milwaukee, Wis.
Division of Orthodontics, University of Connecticut Health, Farmington, Conn.
Am J Orthod Dentofacial Orthop. 2022 Apr;161(4):519-528. doi: 10.1016/j.ajodo.2020.10.030. Epub 2022 Mar 7.
The purpose of this study was to evaluate the long-term effects of bone-anchored and tooth-anchored expansion appliances on alveolar bone in vertical and horizontal dimensions, compared with controls, using cone-beam computed tomography.
We evaluated 180 cone-beam computed tomography scans for 60 patients at 3-time points: T1 (pretreatment), T2 (postexpansion), and T3 (posttreatment), for 3 groups: bone-anchored expansion appliance (BA), tooth-anchored expansion appliance (TA), and controls (T1-T3: BA, 2 years 8 months; TA, 2 years 9 months; control: 2 years 7 months). The intermolar width, molar angulation, palatal width, vertical buccal bone height, buccal bone thickness at the alveolar crest, and root apex were measured in the 3 groups at different time points.
In the short term, both BA and TA led to a statistically significant increase in the intermolar width and vertical buccal bone loss after expansion compared with controls. Vertical buccal bone loss was significantly greater in TA than in BA. In addition, TA led to significantly increased molar angulation (buccal tipping) compared with controls at T2. There were no significant differences in the 3 groups in the long term except vertical buccal bone loss, which was significantly greater in TA than controls. A substantial correlation was found between molar angulation and vertical buccal bone loss, and a moderate negative correlation was found between intermolar width and buccal bone thickness at the alveolar crest at T3.
There was no difference in the treatment outcomes between the 3 groups in the long term except vertical buccal bone loss, which was significantly increased in the TA group compared with controls.
本研究旨在通过锥形束 CT 评估骨锚定和牙锚定扩弓器在垂直和水平方向上对牙槽骨的长期影响，并与对照组进行比较。
我们在 3 个时间点（T1[治疗前]、T2[扩弓后]和 T3[治疗后]）评估了 60 名患者的 180 个锥形束 CT 扫描，共分为 3 组：骨锚定扩弓器（BA）、牙锚定扩弓器（TA）和对照组（T1-T3：BA 组 2 年 8 个月；TA 组 2 年 9 个月；对照组 2 年 7 个月）。在不同时间点，我们在 3 组中测量了磨牙间宽度、磨牙角度、腭宽度、颊侧牙槽骨垂直高度、牙槽嵴颊侧骨厚度和根尖。
短期内，BA 和 TA 均导致磨牙间宽度增加且颊侧牙槽骨垂直吸收量增加，与对照组相比差异有统计学意义。与 BA 相比，TA 导致的颊侧牙槽骨垂直吸收量增加更为显著。此外，与对照组相比，TA 在 T2 时导致磨牙角度（颊倾）显著增加。长期来看，3 组间无显著差异，除 TA 组的颊侧牙槽骨垂直吸收量明显大于对照组外。T3 时，磨牙角度与颊侧牙槽骨垂直吸收量之间存在显著相关性，磨牙间宽度与牙槽嵴颊侧骨厚度之间存在中度负相关。
除了 TA 组的颊侧牙槽骨垂直吸收量明显高于对照组外，3 组的长期治疗效果无差异。
