Kurol J, Franke P, Lundgren D, Owman-Moll P
Departments of Orthodontics and Periodontology, The Institute for Postgraduate Dental Education, Jonkoping, and Goteborg University, Goteborg, Sweden.
Eur J Orthod. 1996 Feb;18(1):69-75. doi: 10.1093/ejo/18.1.69.
The aim of this investigation was to study the magnitude and variation of forces routinely applied by different orthodontists for buccal tipping of premolars and canines in the maxilla, and also to compare these forces with the individually considered ideal force. Nineteen clinically experienced orthodontists were asked to bend and activate sectional arch wires on a plastic model with bands on the first molars. Round 0.016 Australian wires were used on one side and square 0.016 x 0.016 Blue Elgiloy wires on the other. The tests were repeated a second time 3-4 weeks later. The applied mean force magnitude was 48.4 cN (g) for premolars and 40.0 cN for canines, with a considerable intra-individual variation (range 25-75 cN, and 21-62 cN) using the round Australian wire. In general, the activation of the square wire resulted in a higher force, mean difference 29 per cent (11.4 cN) for canines and 23 per cent (11.1 cN) for premolars when compared with the round wire. On each side, the shorter wire for premolars was activated with a higher force when compared with the longer canine wire, mean 16 per cent (8.0 cN) for the square wire and 21 per cent (8. cN) for the round wire. Sex, age and clinical experience had no major influence on the applied force magnitude. On average, the orthodontists considered an ideal force for tipping of canines and premolars to be mean 62.5 cN (range 30-100 cN) and mean 56.1 cN (range 30-100 cN) respectively. They also reported that a strain gauge was not often used in everyday clinical practice. This study showed substantial differences between applied forces and considered ideal forces. It is suggested that regular checks of the force magnitude should be performed in situations where a certain force is considered important.
本研究的目的是研究不同正畸医生对上颌前磨牙和尖牙颊向倾斜常规施加力的大小及变化，并将这些力与各自认为的理想力进行比较。邀请了19位临床经验丰富的正畸医生在带有第一磨牙带环的塑料模型上弯曲并激活分段弓丝。一侧使用0.016英寸的圆形澳大利亚弓丝，另一侧使用0.016×0.016英寸的方形Blue Elgiloy弓丝。3至4周后重复进行测试。使用圆形澳大利亚弓丝时，前磨牙施加的平均力大小为48.4厘牛顿（克力），尖牙为40.0厘牛顿，个体内部存在相当大的差异（范围为25至75厘牛顿，以及21至62厘牛顿）。总体而言，与圆形弓丝相比，方形弓丝的激活产生的力更高，尖牙的平均差异为29%（11.4厘牛顿），前磨牙为23%（11.1厘牛顿）。在每一侧，与较长的尖牙弓丝相比，较短的前磨牙弓丝激活时的力更高，方形弓丝平均为16%（8.0厘牛顿），圆形弓丝为21%（8厘牛顿）。性别、年龄和临床经验对施加力的大小没有重大影响。平均而言，正畸医生认为尖牙和前磨牙倾斜的理想力分别平均为62.5厘牛顿（范围为30至100厘牛顿）和56.1厘牛顿（范围为30至100厘牛顿）。他们还报告说，日常临床实践中不常使用应变片。本研究表明，施加的力与认为的理想力之间存在显著差异。建议在认为特定力很重要的情况下定期检查力的大小。
