Aim To determine cephalometrically the mechanism of the treatment effects of non-extraction and multiloop edgewise archwire （MEAW） technique on postpeak Class Ⅱ Division 1 patients. Methodology In this retrospectiv...Aim To determine cephalometrically the mechanism of the treatment effects of non-extraction and multiloop edgewise archwire （MEAW） technique on postpeak Class Ⅱ Division 1 patients. Methodology In this retrospective study, 16 postpeak Class Ⅱ Division 1 patients successfully corrected using a non-extraction and MEAW technique were cephalometrically evaluated and compared with 16 matched control subjects treated using an extraction technique. Using CorelDRAW software, standardized digital cephalograms preand post-active treatments were traced and a reference grid was set up. The superimpositions were based on the cranial base, the mandibular and the maxilla regions,and skeletal and dental changes were measured. Changes following treatment were evaluated using the paired-sample t-test. Student＇s t-test for unpaired samples was used to assess the differences in changes between the MEAW and the extraction control groups. Results The correction of the molar relationships comprised 54% skeletal change （mainly the advancement of the mandible） and 46% dental change. Correction of the anterior teeth relationships comprised 30% skeletal change and 70% dental change. Conclusion The MEAW technique can produce the desired vertical and sagittal movement of the tooth segment and then effectively stimulate mandibular advancement by utilizing the residual growth potential of the condyle.展开更多
目的对混合牙列期与恒牙列早期安氏Ⅱ类2分类错下颌生长发育特点进行分析比较。方法研究样本包括95名安氏Ⅱ类2分类错青少年与75名正常青少年。对每个对象拍摄手腕骨片和头颅侧位片,进行X线片头影测量分析。结果混合牙列期到恒牙...目的对混合牙列期与恒牙列早期安氏Ⅱ类2分类错下颌生长发育特点进行分析比较。方法研究样本包括95名安氏Ⅱ类2分类错青少年与75名正常青少年。对每个对象拍摄手腕骨片和头颅侧位片,进行X线片头影测量分析。结果混合牙列期到恒牙列早期的变化如下。1)角度:对照组SNB、S-Ba-Go增大,Ar-Go-Me、SN-MP、NSGn减小;实验组SNB、Ar-Go-Me、Cd-Go-Me、SN-MP、S-Ar-Go、S-Ba-Go变化无显著性。实验组Y轴角、NSGn增大,对照组Y轴变化无显著性。2)颏部:实验组除了颏凹陷增大外,其余各项指标变化差异无统计学意义。对照组除颏曲度减小外,颏高、颏厚、颏凹陷、颏厚/颏高、SL、Pog to NB增大。3)线距:对照组Cd-Go、Gn-Cd、Go-Me、Ar-Pog、Ar-Go的生长量大于实验组。结论本研究提出的混合牙列期与恒牙列早期安氏Ⅱ类2分类错下颌的生长发育特点有助于临床医生治疗中作出合理的计划。展开更多
文摘Aim To determine cephalometrically the mechanism of the treatment effects of non-extraction and multiloop edgewise archwire （MEAW） technique on postpeak Class Ⅱ Division 1 patients. Methodology In this retrospective study, 16 postpeak Class Ⅱ Division 1 patients successfully corrected using a non-extraction and MEAW technique were cephalometrically evaluated and compared with 16 matched control subjects treated using an extraction technique. Using CorelDRAW software, standardized digital cephalograms preand post-active treatments were traced and a reference grid was set up. The superimpositions were based on the cranial base, the mandibular and the maxilla regions,and skeletal and dental changes were measured. Changes following treatment were evaluated using the paired-sample t-test. Student＇s t-test for unpaired samples was used to assess the differences in changes between the MEAW and the extraction control groups. Results The correction of the molar relationships comprised 54% skeletal change （mainly the advancement of the mandible） and 46% dental change. Correction of the anterior teeth relationships comprised 30% skeletal change and 70% dental change. Conclusion The MEAW technique can produce the desired vertical and sagittal movement of the tooth segment and then effectively stimulate mandibular advancement by utilizing the residual growth potential of the condyle.
文摘目的对混合牙列期与恒牙列早期安氏Ⅱ类2分类错下颌生长发育特点进行分析比较。方法研究样本包括95名安氏Ⅱ类2分类错青少年与75名正常青少年。对每个对象拍摄手腕骨片和头颅侧位片,进行X线片头影测量分析。结果混合牙列期到恒牙列早期的变化如下。1)角度:对照组SNB、S-Ba-Go增大,Ar-Go-Me、SN-MP、NSGn减小;实验组SNB、Ar-Go-Me、Cd-Go-Me、SN-MP、S-Ar-Go、S-Ba-Go变化无显著性。实验组Y轴角、NSGn增大,对照组Y轴变化无显著性。2)颏部:实验组除了颏凹陷增大外,其余各项指标变化差异无统计学意义。对照组除颏曲度减小外,颏高、颏厚、颏凹陷、颏厚/颏高、SL、Pog to NB增大。3)线距:对照组Cd-Go、Gn-Cd、Go-Me、Ar-Pog、Ar-Go的生长量大于实验组。结论本研究提出的混合牙列期与恒牙列早期安氏Ⅱ类2分类错下颌的生长发育特点有助于临床医生治疗中作出合理的计划。
