无托槽隐形矫治远移磨牙不同支抗方式对上切牙位置的影响

Effects of different anchorage methods on the position of upper incisors in distal molars treatment with clear aligners

目的通过测量分析头颅侧位片对比种植支抗和颌间支抗对隐形矫治器远移上颌磨牙患者上切牙位置的影响。材料与方法选择2017年04月-2022年09月就诊于合肥市口腔医院正畸一科利用无托槽隐形矫治技术远移上颌磨牙的患者32例(种植支抗组16例颌间支抗组16例),分别在治疗前和治疗后拍摄头颅侧位片,测量两组患者骨性参数(SNA、SNB、ANB、MP-SN、MP-FH、S-Go/N-Me、ANS-Me/N-Me),软组织参数(UL-EP、LL-EP、Z角、N’-Sn-Pog’)及牙性指标(U1-Apo、U6-Ptm、L1-Apo、U1-PP、U6-PP、L6-MP、U1-SN、L1-MP),比较两组间的差异。结果两组治疗前各参数差异均无统计学意义(P>0.05);颌间支抗组治疗后OP-SN、L1-Apo、U1-PP、L6-MP增大,Ptm-U6减小,差异均有统计学意义(P<0.05);种植支抗组治疗后Ptm-U6减小,差异有统计学意义(P<0.05);治疗后两组间各参数差异无统计学意义(P>0.05)。结论无托槽隐形矫治器远移上颌磨牙时可以获得2~3mm远移量,根据需要选择不同支抗方式,对于磨牙远移量大于3mm的患者、上切牙过于唇倾或舌倾的患者建议使用种植支抗;使用Ⅱ类牵引增强支抗可能会使上颌矫治器发生形变,导致上切牙伸长、舌倾,临床需注意控制牵引时间并注意适应证的选择;在上颌磨牙远移时可能会发生腭尖下垂,建议设计方案时适当增加牙冠负转矩。

Objective To compare the effect of implant anchorage and intermaxillary anchorage on the position of upper incisors in patients with distal maxillary molars.Methods 32 patients(16 patients in implant anchorage group and 16 patients in intermaxillary anchorage group)who were treated in the Department of Orthodontics of Hefei Stomatology Hospital from April 2017 to September 2022 were selected.The lateral cephalograms were taken before and after treatment,and the bone parameters(SNA,SNB,ANB,MP-SN,MP-FH,S-Go/N-Me,ANS-Me/N-Me),the soft tissue parameters(UL-EP,LL-EP,Z angle,N’-Sn-Pog’)and dental indexes(U1-Apo,U6-Ptm,L1-Apo,U1-PP,U6-PP,L6-MP,U1-SN,L1-MP)were measured and analyzed.Compare the two groups regarding the achieved treatment.Results There is no significant difference in all parameters between the two groups before and after treatment;OP-SN,L1-Apo,U1-PP,L6-MP increased and Ptm-U6 decreased in intermaxillary anchorage group after treatment,the difference is statistically significant(P<0.05).Ptm-U6 decreased in implant anchorage group after treatment,the difference is statistically significant(P<0.05).There is no significant difference in parameters between the two groups after treatment(P>0.05).Conclusion The distal displacement of 2~3mm can be obtained when the maxillary molars move distally with clear aligners,and different anchorage modes can be selected according to the need.Implant anchorage are recommended for patients with maxillary molar distal displacement more than 3mm or upper incisors are too proclination or linguoclination.Using II traction to enhance anchorage may lead to maxillary appliance deformation,resulting in maxillary incisor elongation and lingual tilt.Clinical attention should be paid to the control of traction time and the selection of indications.Unwanted prolapse of molar palate may occur at the same time of distal displacement.It is suggested that the negative torque of tooth crown should be increased appropriately in the design scheme.