Al-Falahi Bilal, Hafez Ahmad Mohammad, Fouda Maher
Mansoura University, Faculty of Dentistry, Department of Orthodontics (Mansoura, Egypt).
Dental Press J Orthod. 2018 Nov-Dec;23(6):56-63. doi: 10.1590/2177-6709.23.6.056-063.oar.
The objective of this study was to assess the external apical root resorption (EARR) of the maxillary posterior teeth after intrusion with miniscrews.
Fifteen patients (13 females and 2 males) with age ranging from 14.5 to 22 years (mean 18.1 ±2.03 years) were selected to participate in this study. All patients presented with anterior open bite of 3 mm or more. An intrusion force of 300 g was applied on each side to intrude the maxillary posterior teeth. Cone beam computed tomography (CBCT) scans were taken pretreatment and post-intrusion and were analyzed to evaluate the EARR.
The maxillary posterior teeth were intruded in average 2.79 ± 0.46 mm (p< 0.001) in 5.1 ± 1.3 months, and all examined roots showed statistically significant EARR (p< 0.05) with an average of 0.55 mm, except the distobuccal root of the left first permanent molars and both the palatal and buccal roots of left first premolars, which showed no statistically significant changes.
The evaluated teeth presented statistically significant EARR, but clinically, due to the small magnitude, it was not considered significant. Moreover, the CBCT provided a good visualization of all roots in all three planes, and it was effective in detecting minimal degrees of EARR.
本研究的目的是评估微型螺钉压低上颌后牙后的根尖外吸收情况。
选取15例年龄在14.5至22岁之间（平均18.1±2.03岁）的患者（13名女性和2名男性）参与本研究。所有患者均表现为3毫米或以上的前牙开颌。在每侧施加300克的压低力以压低上颌后牙。在压低治疗前和治疗后进行锥形束计算机断层扫描（CBCT），并进行分析以评估根尖外吸收情况。
上颌后牙在5.1±1.3个月内平均压低2.79±0.46毫米（p<0.001），除左侧第一恒磨牙的远中颊根以及左侧第一前磨牙的腭根和颊根外，所有检查的牙根均显示出具有统计学意义的根尖外吸收（p<0.05），平均吸收0.55毫米，而这几颗牙根未显示出具有统计学意义的变化。
评估的牙齿呈现出具有统计学意义的根尖外吸收，但在临床上，由于程度较小，不认为具有显著意义。此外，CBCT能在三个平面上很好地显示所有牙根，并且在检测最小程度的根尖外吸收方面很有效。
