Investigation of root and root canal of mandibular first permanent molars in adolescents by cone-beam computed tomography / 实用口腔医学杂志

ABSTRACT

Objective:To investigate the root and canal morphology of mandibular first permanent molars in adolescents by cone-beam computered tomography (CBCT).Methods:366 mandibular first permanent molars in 1 83 adolescents aged 1 2 -1 6 years were examined by CBCT from July,201 2 to December,201 3.The age,sex,the number of roots and canals and canal morphology were re-corded.The data were statistically analyzed by software SPSS 1 9.0.Results:365 mandibular first permanent molars showed single mesial root except one with C-shaped root;282(77.05%)teeth had one distal root,83(22.68%)had two.356(97.27%)teeth had two mesial canals and 9(2.46%)had one.229(62.57%)teeth had one distal root with one canal,53(1 4.48%)had one distal root with two canals.83(22.68%)had two distal roots with one canal in each root,one (0.27%)had C-shaped root with three canals. There were no significant differences between males and females and between the two sides on the number of roots and number of ca-nals.Conclusion:Majority of mandibular first molars have two roots,the root change occurs in distal root.The prevalence of three-rooted mandibular first molars has no significant difference between genders and 2 sides.