Ventä Irja
Institute of Dentistry, Department of Oral and Maxillofacial Surgery, Helsinki University, Helsinki, Finland.
J Oral Maxillofac Surg. 2012 Sep;70(9 Suppl 1):S41-7. doi: 10.1016/j.joms.2012.04.037.
The preventive removal of third molars (M3s) should be based on evidence. To optimize the timing of removal of M3s, it is essential to predict the eruption of the tooth and, even more importantly, to recognize beforehand which teeth will become involved in pathologic conditions later in life. The first aim of this review was to determine how well physicians currently can predict the eruption of an M3. The second aim was to review how frequently impacted M3s are removed. The third aim was to summarize the indications for preventive removals as presented in the evidence-based Current Care Guideline for the management of M3s in Finland. The prediction of eruption can be made at accuracies from 80% to 97%. In addition, the decrease in the number of M3s is very rapid, with only 31% remaining at 38 years of age. According to the Current Care Guideline, preventive removals at a young age are justified for 3 groups of teeth in the mandible: partially impacted teeth in the horizontal position, partially erupted teeth in the vertical position, and incomplete roots growing close to the mandibular canal. In conclusion, one fourth of retained and disease-free M3s need to be removed preventively at a young age, whereas the rest should be treated according to signs and symptoms.
第三磨牙（M3）的预防性拔除应以证据为依据。为了优化M3的拔除时机，预测牙齿萌出至关重要，更重要的是，要提前识别哪些牙齿在日后的生活中会出现病理状况。本综述的首要目的是确定医生目前对M3萌出的预测能力如何。第二个目的是回顾阻生M3的拔除频率。第三个目的是总结芬兰基于证据的M3管理现行护理指南中提出的预防性拔除指征。萌出预测的准确率可达80%至97%。此外，M3的数量减少非常迅速，到38岁时仅剩下31%。根据现行护理指南，下颌骨中的三组牙齿在年轻时进行预防性拔除是合理的：水平位置的部分阻生牙、垂直位置的部分萌出牙以及靠近下颌管生长的未完全形成的牙根。总之，四分之一保留且无疾病的M3需要在年轻时进行预防性拔除，其余的则应根据体征和症状进行治疗。
