Bifid mandibular canals
Bifid mandibular canals
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DOI：
10.1038/sj.bdj.2013.837
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发表时间：
2013-09
期刊：
影响因子：
--
通讯作者：
N. Patel;E. Andresen
中科院分区：
文献类型：
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作者：
N. Patel;E. Andresen
先生，下颌管裂的存在虽然不常见，但并不罕见。下颌管传导下牙槽神经和下牙槽动脉。据报道，正常根管解剖结构存在差异，其发生率范围为 0.08% 至 65%。 1 一名 42 岁的白人女士因左下第三磨牙阻生而出现复发性冠周炎，被全科医生转诊至曼彻斯特牙科医院的口腔外科。最初在全景X光检查中注意到下颌管的分裂（图1），随后进行了更详细的检查。锥形束 CT 扫描（图 2-3）显示下牙槽管的两个分支，其中一个上分支穿透智齿的远端根部，并从紧邻牙冠远端的颊骨上侧的孔中伸出。与该牙齿相关的神经的特殊形态排除了仅去除牙冠的任何可能性。在与患者充分讨论后，特别是关于拔除过程中神经损伤风险增加的问题，在全身麻醉下小心地拔除牙齿。术后复查，未发现下牙槽或舌神经损伤。临床医生必须意识到这种解剖学差异的影响。麻醉不充分可能是一个问题，特别是在有两个下颌孔的情况下。第三磨牙手术必须非常小心地进行，因为牙齿可能会侵犯或位于牙根管内。由于第二个神经血管束可能包含在双管内，因此由于未能认识到这种异常的存在，可能会出现创伤性神经瘤、感觉异常和出血等并发症。
Sir, the presence of bifid mandibular canals is an unusual but not rare occurrence. The mandibular canal transmits the inferior alveolar nerve and inferior alveolar artery. Variations of normal canal anatomy have been reported with an incidence ranging from 0.08% to 65%. 1 A 42-year-old Caucasian lady was referred to the oral surgery department at Manchester Dental Hospital by her general dental practitioner with recurrent pericoronitis associated with her impacted lower left third molar. Division of the mandibular canal which was initially noted on panoramic radiography (Fig. 1) instigated more detailed investigation. Cone beam CT scanning (Figs 2-3) revealed two branches of the inferior alveolar canal, with a superior branch penetrating the distal root of the wisdom tooth and emerging from a foramen on the superior aspect of the buccal bone just distal to the crown of the tooth. The particular morphology of the nerve relative to this tooth precluded any possibility of removal of only the crown. After full discussion with the patient, especially of the increased risks of nerve damage during removal, the tooth was carefully removed under general anaesthesia. At post-operative review, no inferior alveolar or lingual nerve damage was present. Clinicians must be aware of the implications of this variance in anatomy. Inadequate anaesthesia may be a problem, especially in cases where there are two mandibular foramen. Third molar surgery must be carried out with extreme care as the tooth may infringe on or be within the canal itself. As a second neurovascular bundle may be contained within the bifid canals, complications such as traumatic neuroma, paraesthesia and bleeding could arise because of failure to recognise the presence of this anomaly.