Cone Beam Computed Tomography – Assisted Morphological Analysis of Mandibular Second Molar’s Root Canals of Thai Subpopulation

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Uthaiwan Arayatrakoollikit
Nutthapong Kantrong
Thalerngsak Samaksaman
Thanat Jarasrungsichol
Itkun Bhudisaksang
Pipop Sutthiprapaporn


The aim of this study was to determine root canal morphology of mandibular second molars of Thai subpopulation in northeastern Thailand by using Cone Beam Computed Tomography (CBCT). A total of 215 extracted mandibular second molars were scanned by using CBCT. After three-dimensional reconstruction of the teeth, all studied teeth were subsequently analyzed by WhiteFox Imaging 3.0 computer software. Root canal morphology was categorized by using Fan’s classification and a cross-sectional radiography of canal configurations were investigated at 4 levels of the root canals. Nineteen of 215 mandibular second molars
(8.83%) were identified as C-shaped molars as determined by Fan’s classification. Among C-shaped molars, C1-C5 configurations were detected along root length, despite the highest incidence of C1 (55.50%) at the orifice level. An apical root canal configurational change was found in 6 of 19 teeth (31.57%). Half of non C-shaped molars exhibited two root canals in mesial root with varying number of root canal openings, while the majority of distal roots displayed one root canal with one opening at the apex. In conclusion, we reported a relatively low incidence of finding C-shaped molars in Thai population, despite a high incidence among Asians. Normal anatomy and variations of root canal morphology should necessarily be taken into an account when performing an endodontic treatment in multi-rooted tooth. CBCT is a useful diagnostic tool that might help identify root canal configuration and facilitates clinical procedures.


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Arayatrakoollikit U, Kantrong N, Samaksaman T, Jarasrungsichol T, Bhudisaksang I, Sutthiprapaporn P. Cone Beam Computed Tomography – Assisted Morphological Analysis of Mandibular Second Molar’s Root Canals of Thai Subpopulation. Khon Kaen Dent J [Internet]. 2019 Jun. 27 [cited 2022 Dec. 8];22(1):60-7. Available from:
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