A rare variation in the root canal anatomy of a premolar

Good endodontics is the foundation for any great dental work. The philosophy and techniques in endodontics have evolved tremendously in the last 30 years, and thanks to more research and advanced CT studies carried out on large samples, we are now aware of the vast and complex possibilities of the internal anatomy of single-rooted as well as multi-rooted teeth.

The Vertucci classification shows variations in the different anatomy configurations in premolars.

(Table 1. Vertucci’s classification for premolars)

Re-treatment was initiated under magnification with a Dental Operating Microscope that helped us locate the missing canal.

Close examination and canal exploration showed no perforation.

The canal was disinfected under isolation with a 5.5% sodium hypochlorite solution, and a calcium hydroxide dressing was placed for 3 weeks, followed by obturation with a bioceramic sealer by a 3-D obturation technique. 

The case can be classified as type 1-3-1 of the Additional group of Vertucci Classification (Figures 4 & 5)

Literature has documented multiple variations in canal configurations of the lower bicuspid. The current case shows a variation in Vertucci Classification Additional type 1-3-1.

The case was treated and the lingual canal was missed out leading to a large periapical lesion and drainage. 3-D imaging revealed a single root and a missed lingual canal. The internal anatomy was complex, and if you observe the post-operative radiograph closely, it shows the presence of a small lateral canal with an independent exit.

This brings us to discuss the significance of good irrigation protocols during endodontic treatment. Successful filling and sealing of lateral canals depends on good irrigation and disinfection techniques.

This clinical case shows a rare root canal configuration of 1-3-1 and highlights the importance of knowing the variant morphology of a mandibular bicuspid, reminding us that every endodontic case needs full attention to detail on close inspection of the radiographs before making the diagnosis and treatment plan.

Sound knowledge of anatomical variations in anatomy is essential for excellent clinical outcomes. A combination of knowledge, tactile sensation, good radiographic technique, 3-D imaging, followed by magnification, perfect isolation, and irrigation, along with adequate 3-D sealing of the canals lead to successful endodontic outcomes.

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2. Patel S, Brown J, Pimentel T, Kelly RD, Abella F, Durack C: Cone beam computed tomography in endodontics – a review of the literature. Int Endod J. 2019, 52:1138-52. 10.1111/iej.13115
3. Low JF, Dom TNM, Baharin SA: Magnification in endodontics: a review of its application and acceptance among dental practitioners. Eur J Dent. 2018, 12:610-6. 10.4103/ejd.ejd_248_18
4. Albuquerque D, Kottoor J, Hammo M: Endodontic and clinical considerations in the management of variable anatomy in mandibular premolars: a literature review. Biomed Res Int. 2014,