Gulabivala K, Opasanon A, Ng Y L, Alavi A
Department of Conservative Dentistry, Eastman Dental Institute for Oral Health Care Sciences, University College London, UK.
Int Endod J. 2002 Jan;35(1):56-62. doi: 10.1046/j.1365-2591.2002.00452.x.
To investigate the root and canal morphology of 351 mandibular permanent molars collected from an indigenous Thai population.
The cleaned teeth were accessed, the pulp dissolved by sodium hypochlorite under ultrasonication and the pulp system injected with Indian ink. The teeth were rendered clear by demineralization and immersion in methyl salicylate. The following observations were made: (i) number of roots and their morphology; (ii) number of root canals per tooth; (iii) number of root canals per root; (iv) root canal configuration in each root using Vertucci's classification, with additional modifications; and (v) presence and location of lateral canals and intercanal communications.
Of 118 mandibular first molars, 13% had a third disto-lingual root. In three-rooted teeth, 80% of the main distal roots and 100% of the disto-lingual roots had type 1 canal systems. Of 60 mandibular second molars, 10% had C-shaped roots, the majority of which had type 1 (33%) or type IV (33%) canal systems. Of 173 third molars, 68% had two separate roots, 20% had fused roots and 11% had a single C-shaped root; the majority had two canals (61%).
This study suggests that Thai molars exhibit features of both Caucasian and Chinese teeth.
研究从泰国本土人群收集的351颗下颌恒牙磨牙的根管形态。
对清洁后的牙齿进行开髓，在超声作用下用次氯酸钠溶解牙髓，并向牙髓系统注入印度墨水。通过脱矿和浸入冬青油使牙齿变透明。进行了以下观察：（i）牙根数量及其形态；（ii）每颗牙齿的根管数量；（iii）每个牙根的根管数量；（iv）使用韦尔图奇分类法并进行额外修改来观察每个牙根的根管形态；（v）侧支根管和管间交通支的存在及位置。
在118颗下颌第一磨牙中，13%有第三远中舌侧根。在三根牙齿中，80%的主要远中根和100%的远中舌侧根具有I型根管系统。在60颗下颌第二磨牙中，10%有C形根，其中大多数具有I型（33%）或IV型（33%）根管系统。在173颗第三磨牙中，68%有两个独立的根，20%有融合根，11%有单个C形根；大多数有两个根管（61%）。
本研究表明泰国磨牙呈现出白种人和中国人牙齿的特征。
