Huang J Q, Liu S Y, Jiang J H
Department of Orthodontics, Peking University School and Hospital of Stomatology, Beijing 100081, China;Department of Stomatology, the Third Affiliated Hospital of Guangzhou Medical University, Guangzhou 51000, China.
Department of Orthodontics, Peking University School and Hospital of Stomatology, Beijing 100081, China.
Beijing Da Xue Xue Bao Yi Xue Ban. 2016 Jun 18;48(3):555-61.
To evaluate the influence of Tweed-Merrifield technique in correction of severe bimaxillary protrusion adult patients on the measurement of the dental and skeletal changes after orthodontic treatment by Johnston analysis and the regular cephalomatric analysis.
Twelve adolescent patients with severe bimaxillary protrusion were included in this self-control retrospective study. Lateral cephalometric radiographs were taken before and after treatments. All the radiographs were traced and analyzed by the method of Johnston analysis. Other measurements were evaluated using a series of 13 linear and angular measurements including SNA, SNB, ANB, U1-SN, U1-NA, U1/NA, L1-NB, U1/NB, L1/MP, U1-L1, (U1+L1)/2-AB, MP/SN and MP/FH from regular cephalomatric analysis. These measurements were also applied to compare the differences between pre- and post-treatments, which clarify the dental and skeletal changes by Johnston analysis. The effect of orthodontic correction was determined using the non-parameters test.
The maxillary moved backforward by 1.3 mm according to the stable skull base, while the mandible moved forward by 2.12 mm. The relative position between the maxillary and mandible (ABCH) changed 3.42 mm. The upper and lower incisors retracted significantly. The upper and lower molars moved slightly forward and the relative positions of upper and lower molars and anterior teeth after treatment were 3.44 mm and 4.23 mm respectively. After treatment, the parameters of ANB, U1-NA, U1/NA, U1-SN, L1-NB, L1/NB and L1-M were reduced by -(1.98±1.55)°(P=0.012), - (5.08±4.6) mm (P=0.002), -(11.79±1.21)°(P=0.004), -(13.55±6.32)°(P=0.047), -(3.17±3.07) mm (P=0.010), -(6.84±2.55)°(P=0.038) and -(4.13±2.24)°(P=0.048) on average, whose changes had the statistically significant effects.
Tweed-Merrifield technique (directional force technique) can stabilize anchorage molar, retract anterior teeth and significantly improve the hard and soft tissue profile for patients with bimaxillary protrusion, and make a good vertical control which means this technique is applicable to the patients who need strong anchorage. Even for the severe bimaxillary protrusion adult patients, the Tweed-Merrifield technique can control the anchoragewell and make the profiles improved greatly.
采用约翰斯顿分析法和常规头影测量分析法，评估Tweed-Merrifield技术矫治成人严重双颌前突患者正畸治疗后牙齿和骨骼变化测量的影响。
本自我对照回顾性研究纳入12例青少年严重双颌前突患者。治疗前后拍摄头颅侧位X线片。所有X线片均采用约翰斯顿分析法进行描记和分析。使用常规头影测量分析法的一系列13项线性和角度测量值（包括SNA、SNB、ANB、U1-SN、U1-NA、U1/NA、L1-NB、U1/NB、L1/MP、U1-L1、(U1+L1)/2-AB、MP/SN和MP/FH）进行其他测量。这些测量值也用于比较治疗前后的差异，通过约翰斯顿分析法阐明牙齿和骨骼变化。采用非参数检验确定正畸矫治效果。
根据稳定的颅底，上颌向后移动1.3 mm，而下颌向前移动2.12 mm。上颌与下颌的相对位置（ABCH）改变3.42 mm。上下切牙明显内收。上下磨牙轻微向前移动，治疗后上下磨牙与前牙的相对位置分别为3.44 mm和4.23 mm。治疗后，ANB、U1-NA、U1/NA、U1-SN、L1-NB、L1/NB和L1-M参数平均降低-(1.98±1.55)°（P=0.012）、-(5.08±4.6) mm（P=0.002）、-(11.79±1.21)°（P=0.004）、-(13.55±6.32)°（P=0.047）、-(3.17±3.07) mm（P=0.010）、-(6.84±2.55)°（P=0.038）和-(4.13±2.24)°（P=0.048），其变化具有统计学意义。
Tweed-Merrifield技术（定向力技术）可稳定磨牙支抗，内收前牙，显著改善双颌前突患者的软硬组织侧貌，并实现良好的垂直控制，这意味着该技术适用于需要强支抗的患者。即使对于严重双颌前突的成年患者，Tweed-Merrifield技术也能很好地控制支抗，使侧貌得到极大改善。
