Rahimi, Saeed, Hadi Mokhtari, Bahram Ranjkesh, Masoomeh Johari, Mohammad Frough Reyhani, Shahriar Shahi, and Sina Seif Reyhani. 2016. “Prevalence of Extra Roots in Permanent Mandibular First Molars in Iranian Population: A CBCT Analysis”. Iranian Endodontic Journal 12 (1):70-73. https://doi.org/10.22037/iej.v12i1.10549.