Quinn G W
Angle Orthod. 1985 Jan;55(1):58-69. doi: 10.1043/0003-3219(1985)055<0058:EOFSM>2.0.CO;2.
The cases presented here clearly demonstrate that the removal of second permanent molars can be effective in many cases where removal of first or second bicuspids would otherwise be recommended. Third molars can be useful components of the dentition. The Author has found that when the proper diagnosis is made and the extraction of second molars is recommended, third molars will assume their position in juxtaposition to the first permanent molar in over 75% of the cases. Although we used several methods of measuring developing mandibular third molars, we were unable to predict accurately and consistently which teeth would erupt in the proper upright position (Fig. 10). With rare exception, maxillary third molars will erupt uneventfully, but in the mandibular arch there is a much greater possibility that it may be necessary to upright or reposition the third molars.
此处呈现的病例清楚地表明，在许多原本会建议拔除第一或第二双尖牙的情况下，拔除第二恒磨牙可能是有效的。第三磨牙可以是牙列的有用组成部分。作者发现，当做出正确诊断并建议拔除第二磨牙时，在超过75%的病例中，第三磨牙会在第一恒磨牙旁边就位。尽管我们使用了几种测量发育中的下颌第三磨牙的方法，但我们无法准确且一致地预测哪些牙齿会以正确的直立位置萌出（图10）。除极少数情况外，上颌第三磨牙会顺利萌出，但在下颌牙弓中，第三磨牙可能有更大的可能性需要直立或重新定位。
