A study on Radix Entomolaris about prevalence and correlation of canal orifices location according to number of roots in mandibular first molars

하악 제1대구치에서 Radix Entomolaris의 발현빈도와 치근의 개수에 따른 근관 입구들 사이의 위치 관계에 대한 연구

  • Jang, Ji-Hye (Department of Conservative Dentistry, College of Dentistry, Gangneung-Wonju National University) ;
  • Kim, Jin-Woo (Department of Conservative Dentistry, College of Dentistry, Gangneung-Wonju National University) ;
  • Cho, Kyung-Mo (Department of Conservative Dentistry, College of Dentistry, Gangneung-Wonju National University) ;
  • Kim, Soo-Yeon (Department of Conservative Dentistry, College of Dentistry, Gangneung-Wonju National University) ;
  • Park, Se-Hee (Department of Conservative Dentistry, College of Dentistry, Gangneung-Wonju National University)
  • 장지혜 (강릉원주대학교 치과대학 치과보존학교실) ;
  • 김진우 (강릉원주대학교 치과대학 치과보존학교실) ;
  • 조경모 (강릉원주대학교 치과대학 치과보존학교실) ;
  • 김수연 (강릉원주대학교 치과대학 치과보존학교실) ;
  • 박세희 (강릉원주대학교 치과대학 치과보존학교실)
  • Received : 2018.09.03
  • Accepted : 2018.10.08
  • Published : 2018.11.30

Abstract

Objectives: The purpose of this study was to investigate the ratio of 4 root canals and the incidence of Radix Entomolaris in mandibular first molars and find out anatomical difference according to number of roots by analysis of cone-beam CT images in a Korean population. Materials and Methods: Total 142 images containing mandibular first molars were selected from CBCT images taken from 2013 to 2017 at Gangneung-Wonju National University Dental Hospital. After reconstructing the image with reference to the Cemento-enamel junction, the root canals were detected at the bottom of the pulpal floor and the number of roots and root canals were analyzed. Various lengths and MLO-DLO-DBO angle were measured between each canal orifices and the external contour line of the tooth, and the distolingual canal wall thickness was measured. Student t-test was used for statistical significance. Results: Among the total 142 teeth, 4 canals were 42.2% and Radix Entomolaris was 25.3%. As the results of measuring various lengths and the angle, the distolingual canal orifice in Group 2(with Radix Entomolaris) tends to deviate to the lingual side than the mesiolingual canal orifice and to the mesial side than the distobuccal canal orifice. Besides, thickness of the distolingual canal wall in Group 2(with Radix Entomolaris) was significantly thinner than that of Group 1 at every level except pulpal floor level. Conclusion: It is necessary to consider the difference according to the presence of Radix Entomolaris in endodontic treatment.

Keywords

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