不同扩弓方式对乳牙反(牙合)患儿软硬组织及恒切牙胚位移影响的比较研究

Comparative study on the effect of different expansion approaches on hard and soft tissues and the position of permanent incisor germs in children with deciduous anterior crossbite

目的研究不同扩弓方式对乳牙反(牙合)患儿软硬组织及恒切牙胚位移的影响。方法选取2008—2018年于河北医科大学第一医院口腔正畸科就诊的乳牙反(牙合)患儿40例进行回顾性分析,其中采用矢状扩弓矫治患儿20例(矢状扩弓组),采用横向扩弓矫治患儿20例(横向扩弓组)。对患儿治疗前后的头颅侧位片进行测量分析,比较2组治疗前后软硬组织及恒切牙胚位置的变化。结果 2组治疗前后上颌骨长度(Ptm-A)和水平向位置(A-X)、下颌骨全长(T;-Po)和位置(T;-S)、上乳中切牙突度(D1-NA、D1-SN)和位置(D1i-X、D1a-X)、上下乳中切牙夹角(D1-L1)及上恒中切牙胚位置(G1i-X、G1i-Y、G1a-X)均有改变,差异均有统计学意义(P<0.05)。2组上恒中切牙胚位置的改变有显著性差异,横向扩弓组G1i-X、G1i-Y、G1a-Y的改变量均大于矢状扩弓组,差异有统计学意义(均P<0.05)。比较2组上乳中切牙位置的改变发现,横向扩弓组D1a-Y的改变量大于矢状扩弓组,差异有统计学意义(P<0.05)。其他测量指标改变量的组间比较,差异均无统计学意义(均P>0.05)。结论 2种扩弓方式均能有效纠正乳牙反(牙合),对乳牙反患儿软硬组织的影响基本一致。横向扩弓方式比矢状扩弓方式更有利于上恒中切牙胚向前向下移动。

Objective To compare the effect of different expansion approaches on hard and soft tissues and the position of permanent incisor germs in children with deciduous anterior crossbite. Methods This retrospective study included the analysis of 40 deciduous crossbite children who visited the department of orthodontics of the First Hospital of Hebei Medical University from 2008 to 2018. According to the expansion approach,the cases were divided into two groups:20 cases were treated with maxillary sagittal expansion appliance(MSEA),and 20 cases were treated with maxillary transverse expansion appliance(MTEA). The lateral cephalograms of the children were measured and analyzed to make a comparison in the changes of soft and hard tissues and the position of permanent incisor germs between the two groups before and after treatment. Results In both groups,maxilla length(Ptm-A)and horizontal position(A-X),mandible length(T4-Po)and position(T4-S),convexity(D1-NA,D1-SN)and positions(D1i-X,D1a-X)of the deciduous incisors,angles of upper and lower deciduous central incisors(D1-L1),and positions of maxillary permanent incisor germs(G1 iX,G1i-Y,G1a-X)significantly changed after treatment compared with before treatment(P< 0.05). There was significant difference in the positions of maxillary permanent incisor germs between the two groups. Compared with the MSEA group,greater changes of G1i-X,G1i-Y and G1 aY were found in the MTEA group(P< 0.05). Comparisons on the positions of maxillary deciduous incisors,the MTEA group showed greater changes in D1 a-Y than the MSEA group. The changes in the other measurement indexes showed no statistically significant differences(P >0.05). Conclusion Two expansion approaches can effectively correct the deciduous crossbite and have the same effects on the soft and hard tissues. Compared with the sagittal expansion,the transverse expansion is more conducive to the forward and downward movement of the maxillary permanent incisor germs.