Prevalence of Various Anatomic Variations in Cross-sectioned Apices of Maxillary Second Molars in Korean and Their Effect on Canal Cleanliness

Park,  Jinwoo; Bae,  Jihyun; Choi,  Yonghoon

J Korean Dent Assoc > Volume 56(2); 2018 > Article

The Journal of The Korean Dental Association 2018;56(2):84-93.
Published online February 28, 2018.

한국인의 상악 제 2대구치 치근단면 형태에 대한 연구

박진우¹, 배지현², 최용훈³

^¹분당서울대학교병원 치과보존과
^²분당서울대학교병원 치과보존과
^³분당서울대학교병원 치과보존과

Prevalence of Various Anatomic Variations in Cross-sectioned Apices of Maxillary Second Molars in Korean and Their Effect on Canal Cleanliness

Jinwoo Park¹, Jihyun Bae², Yonghoon Choi³

¹Department of Conservative Dentistry, Section of Dentistry, Seoul National University Bundang Hospital
²Department of Conservative Dentistry, Section of Dentistry, Seoul National University Bundang Hospital
³Department of Conservative Dentistry, Section of Dentistry, Seoul National University Bundang Hospital

Abstract

Purpose
This study evaluated the apical root canal system of maxillary second molars, in which conventional endodontic treatment had failed. Materials and Methods: One hundred eighteen extracted endodontically failed maxillary second molars were examined to investigate the root canal morphology using clinical photographs. High-resolution cross-sectional images at the 3mm level from the root apices were taken to evaluate the anatomic variations and canal cleanliness. The incidence of anatomic variations and canals containing debris were evaluated statistically. Results: One (0.85%) maxillary second molar had four separate roots, while 52 (44.07%) had three separate roots. The remaining 65 (55.08%) showed 6 different types of fusion in their roots. As the number of fused roots increased from none to three, the incidence of isthmuses in the cross-sectional images increased significantly from 43.40% to 76.92% in 2-root fusion and 88.46% in 3-root fusion. In addition, the occurrence of less-cleansed canals increased from 22.64% to 38.46% and 53.85%, respectively (p<0.05). Sixty four teeth (54.24%) had 3 canals while 38(32.2%) had additional canals; most of them were located in the MB roots (81.58%). Seventy six (64.41%) had isthmuses in the apical region and 58 out of 76 were located in MB roots. Condlusions: Logistic analysis indicated that the less division of roots was associated significantly with the occurrence of insufficient cleaning during endodontic treatment (OR=1.765, p<0.05), while the presence of an additional canal showed no association.

Key Words: Endodontics;Retreatment;Root canal anatomy;Maxillary second molar;