下颌切牙中，双根管、根管分支和根管分歧都有一定的发生率。

The two root canals, root canal diverge and root canal branch et al have considerable incidence. Besides, mesial-distal root canal walls of mandibular incisor teeth are thin.

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如果需要栓塞多根分支，应总是从远端开始以避免血管痉挛导致后来的置管困难。

If several branches must be embolized, one should always tackle the most distal target first to avoid later loss of access due to vasospasm.

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