Root Anatomy and Root Canal Configuration of Human Permanent Mandibular Premolars: A Systematic Review

Abstract

Introduction. Mandibular premolars have been reported with complex anatomical aberrations, making them one of the most difficult teeth to manage endodontically. Methodology. An exhaustive search was undertaken to identify associated anatomic studies of mandibular premolars through MEDLINE/PubMed database using keywords, and a systematic review of the relevant articles was performed. Chi-square test with Yates correction was performed to assess the statistical significance of any anatomic variations between ethnicities and within populations of the same ethnicity. Documented case reports of variations in mandibular premolar anatomy were also identified and reviewed. Results. Thirty-six anatomic studies were analyzed which included 12,752 first premolars and nineteen studies assessing 6646 second premolars. A significant variation in the number of roots, root canals, and apical foramen was observed between Caucasian, Indian, Mongoloid, and Middle Eastern ethnicities.The most common anatomic variation was C-shaped canals in mandibular first premolars with highest incidence in Mongoloid populations (upto 24%) while dens invaginatus was the most common developmental anomaly. Conclusions. A systematic review of mandibular premolars based on ethnicity and geographic clusters offered enhanced analysis of the prevalence of number of roots and canals, their canal configuration, and other related anatomy.

Intraoral radiographic diagnosis and management of an aberrant mandibular premolar-a case report

“…Zillich and Dowson reported 11.7% and 0.4% occurrence of two canals and three canals in mandibular premolars respectively [4]. Cleghorn et al in a literature review, reported that the incidence of an additional root (0.4%), an additional canal (9.9%), and an additional apical exit (8.2%) in the mandibular second bicuspids is lower than that of the mandibular first bicuspids (2.0%, 24.2%, and 21.1%, respectively) [5].Overall, an accessory root was present only in about 0.0-4.4% (average 0.61%) of teeth as reported in a systematic review by Kottoor et al [6].In Indian population, this presentation of second premolars with two root canals was reported to be 13.5-20% [7].Hence, the endodontic management of mandibular second premolars with variable canal configuration can be diagnostically and technically challenging. In light of these observations, this article highlights a case report of successful endodontic management of a mandibular second premolar with variable canal pattern.…”

Direct Measurements of Root Canal Length in Primary Anterior Teeth for Educational and Clinical Purposes

“…Knowledge of dental anatomy is essential for learning clinical operative dentistry procedures (Kottor, Albuquerque, Velmurugan, & Kuruvilla, 2013). Therefore, teaching clinical procedures substantiated by data on human dental anatomy reinforces its clinical relevance and the need for training (Hagen, Cooke, & Wright, 2017).…”

“…In vitro measurements of RCL in a large sample (n = 70) of extracted primary teeth obtained by the standard direct tactile method might contribute to the knowledge of the anatomy of such teeth and to clinical endodontic procedures (Kottor, Albuquerque, Velmurugan, & Kuruvilla, 2013), since few studies had been published (Mello-Moura et al, 2010;Subramaniam, Konde, & Mandanna, 2005;Oznurhan et al, 2014;Wankhade, Kumar, Singh, & Chandra, 2013), most with smaller samples (Mello-Moura et al, 2010;Subramaniam, Konde, & Mandanna, 2005;Oznurhan et al, 2014). In addition, teaching and exploring the dental anatomy in integration with clinical procedures emphasizes the clinical relevance of basic sciences (Hagen, Cooke, & Wright, 2017) while increases the clinical competence of dental students to perform endodontic procedures.…”

Differentiation of root canal morphology – a review of the literature

“…of canals Comments References 1st premolar 1 (73%-89%) One canal may separate into two; The C-shaped canal occurs in 10-14% of cases 2 or more canals in women 2 (25%-27%) Baisden et al 1992;Sikri and Sikri, 1994;Carrotte, 2004;Jafarzadeh, 2007;Kottoor et al 2013;Fernandes et al 2014 2nd premolar 1 (62%-85%) 1 canal may separate into two; C-shaped canal occurs Multiple canals in men Vertucci, 1984;Carrotte, 2004 2 (5%-15%) Carrotte, 2004;Kottoor et al 2013;Fernandes et al 2014 1st molar 3 (67%) 2 canals in the mesial root and 1 canal in the distal root occurs; C-shaped canal occurs; An additional canal occurs in distal root Vertucci, 1984Vertucci, , 2005Carrotte, 2004;Cleghorn et al 2006;Jafarzadeh and Wu, 2007;Cleghorn et al 2012 4 (25%-29% 1 ,…”

“…The precise etiology of accessory canal formation remains elusive. Among the factors believed to contribute to canal configura-tions are sex (Ahmed et al 2007;Kottoor et al 2013), geography (Sert and Bayirli 2004;Awawdeh et al 2008;Al-Qudah and Awawdeh 2009) and ethnicity (Kottoor et al 2013;Amardeep et al 2014).…”