上颌窦底与上颌第一磨牙正畸移动的相互影响研究

Study on the interaction between the floor of maxillary sinus and maxillary first molar orthodontic movement

目的:研究正畸治疗过程中,上颌窦底与上颌第一磨牙正畸移动的相互影响。方法:通过锥形束CT(cone-beam computed tomography,CBCT)筛选出上颌第一磨牙至少1个牙根进入上颌窦底的正畸减数矫治患者病例,测量正畸治疗过程中,上颌第一磨牙各牙根的移动距离,评估治疗后牙根吸收情况,同时评估上颌第一磨牙牙根移动对上颌窦底改建的影响。结果:本研究共纳入正畸患者16例,共28颗牙根进入上颌窦底的上颌第一磨牙。正畸治疗过程中,上颌第一磨牙近中颊根、远中颊根、腭根均发生了大于2 mm的明显移动。正畸治疗后,多数牙根(88.10%)未见明显吸收;新增7个与上颌窦底之间无皮质骨间隔的近中颊根(P<0.05)。结论:进入上颌窦底的上颌第一磨牙牙根可以在适当正畸力作用下发生一定范围内的有效移动,且较少出现牙根吸收;但此类牙根发生正畸移动可能会造成上颌窦底皮质骨吸收。

Objective： To investigate the interaction between the floor of maxillary sinus and maxillary first molar orthodontic movement. Methods： Orthodontic patients with at least one root of maxillary first molar protruding into the floor of maxillary sinus were selected by cone-beam computed tomography（ CBCT）. The movement distances of maxillary first molar roots during orthodontic treatment were measured. Besides,the effects of orthodontic tooth movement on the remodeling of maxillary sinus floor were also evaluated. Results： A total of 16 individuals（ 28 maxillary first molar） were enrolled in present study. During orthodontic treatment,the mesiobuccal root,distal buccal root,and palatine root of the maxillary first molar were all moved remarkably. After orthodontic treatment,most of the patients had no obvious root absorption. In addition,the type II root,which has no cortical bone between the maxillary sinus floor and maxillary tooth roots,was increased in the mesial buccal root group after orthodontic treatment（ P〈0. 05）. Conclusion： If proper orthodontic system was applied,moving maxillary first molar through the maxillary sinus is achievable with mere or no root resorption. However,tooth movement may cause bone resorption of the maxillary sinus floor,which should be of concern to orthodontists.