Comparison between transmission technique and MBT straight wire technique in correction of protruding in adults / 中华医学美学美容杂志

ABSTRACT

Objective To evaluate the curative effect by using transmission straight wire appliance in treatment of adult patients with protruding,to compare with MBT straight wire technique,and to discuss their similarities and differences.Methods Totally 40 protruding patients were assigned into two groups randomlythe transmission straight wire technique group were treated with transmission straight wire appliance,and the MBT straight wire technique group were treated with MBT appliance together with extraoral arch or screw implant anchorage.Cephalometric measurements were compared before and after treatment.Results Average period of treatment was (19 ±4) months for transmission group and (23 ± 4) months for MBT group.The difference was statistically significant (P＜0.05).After treatment,U1/SN,U1/NA,U1-NA,L1/NB,L1-NB,U1-AP,L1-AP,UL-EP,LL-EP were significantly reduced for both patients groups (P＜0.01).U1/L1,nasolabial angle and z angle were increased for both groups (P＜0.05).MP/SN increased by 1.93°(P＜0.05)for transmission group vs.0.81° (P＞0.05) for MBT group.There was no statistically significant difference between the two groups (P＞0.05) except MP/SN (P＜0.05).However,the retraction of anterior teeth in transmission group was greater than that of MBT group,and U1/NA changed (-20.95±8.79)° in transmission group vs.(-16.00 ± 6.52)° in MBT group.Conclusions Both techniques can achieve satisfactory results for protruding cases.The transmission technology can improve soft tissue profile quicker,but anterior teeth have excessive vertical trend,where attention should be paid to control torque on anterior teeth.