Root Canal Anatomy of Maxillary First Premolar by Microscopic Computed Tomography in a Chinese Adolescent Subpopulation

Table 5

Root canal taper in different levels of maxillary first premolar (mean ± SD, mm, n = 70).

Groups	Coronal third	Middle third	Apical third
SR1C
BP	0.30 ± 0.082^a	0.16 ± 0.042^a	0.25 ± 0.126^a
MD	0.12 ± 0.033	0.07 ± 0.035	0.12 ± 0.041
SR2C
Buccal canal
BP	—	0.20 ± 0.091^a	0.09 ± 0.027
MD	0.15 ± 0.026	0.14 ± 0.081	0.09 ± 0.039
Palatal canal
BP	—	0.16 ± 0.044^a	0.10 ± 0.051^a
MD	0.12 ± 0.039	0.05 ± 0.027	0.03 ± 0.018
2R2C
Buccal canal
BP	—	0.17 ± 0.043^a	0.11 ± 0.022^a
MD	0.14 ± 0.041	0.07 ± 0.027	0.06 ± 0.018
Palatal canal
BP	—	0.15 ± 0.031^a	0.03 ± 0.016^a
MD	0.12 ± 0.032	0.10 ± 0.042	0.06 ± 0.013

a represents vs. the corresponding MD, . SR1C, single root with 1 canal; SR2C, single root with 2 canals; 2R2C, 2 roots with 2 canals; BP, buccal and palatal aspects; MD, mesiodistal aspect.