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Updated: Jun 8, 2026
A Morphometric and Cellular Analysis Method for the Murine Mandibular Condyle
Published on: January 11, 2018
Three-dimensional morphologic analysis of isthmuses in the mesial roots of mandibular molars
Bing Fan1, Yihuai Pan, Yali Gao
1State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School and Hospital of Stomatology, Wuhan University, Wuhan, China. b.fan@163.com
Introduction:
The purpose of this study was to investigate the three-dimensional (3-D) morphology of isthmuses in the mesial roots of mandibular molars.
Methods:
One hundred twenty-six extracted mandibular molars including 70 first molars (MFMs) and 56 second molars (MSMs) from a Chinese population were scanned by micro-computed tomography, and the apical 5 mm of the root canals with or without isthmuses was reconstructed with 3D-Doctor software. Each reconstructed isthmus model was assigned to 1 of the following 4 categories: sheet connection, separate, mix, and cannular connection. The length of the isthmus (L(i)) and the distance from the bottom of the isthmus to apex (D(ba)) were measured and analyzed.
Results:
The incidence of an isthmus in the apical 5 mm of the mesial roots was 85%. MFMs had more isthmuses with separate type and mixed type, whereas MSMs had more isthmuses with sheet connections. The L(i) and D(ba) in mandibular molars were 2.331 mm and 1.850 mm, respectively.
Conclusions:
MFMs present different anatomical features of isthmuses in the apical part of the mesial roots than MSMs.
