Incidence of third root in mandibular permanent first molar: An endodontic challenge

Abstract

Aim: To investigate the incidence and the morphology of third root for the mandibular permanent first molars from indigenous Iraqi population and their significance in the successful of endodontic treatment. Materials and Methods: A clinical, radiographical prospective evaluation of first mandibular permanent molar teeth (n= 788) and laboratory analysis of 695 extracted first mandibular permanent molars collected from University Mosul, College of Dentistry, Department of Conservative Dentistry and private dental clinic were collected and examined. All the clinical cases treated as third root present, unless otherwise both 90º, 20° mesial radiographical shift and trapezoidal access opening excluded the presence of this macrostructure. The third root was classified in three groups on the basis of the curve of the root/root canal according to Ribeiro and Consolaro (1997). Chi-square was used to determine the significance between both genders, whereas descriptive statistics was used to describe the result of observations. Results: Upon clinical and laboratory observation of total 1483 first mandibular permanent molars, 121 (8.1%) exhibited radix entomolaris (RE), 17 (14%) were classified as type I (straight root/root canal), 33 (27.2%) as type II (an initially curved entrance and the continuation as a straight root/root canals) and 71(58.6%) as type III (an initial curve in the coronal third of the root canal and a second buccally orientated curve starting from the middle to apical third). Statistical analysis with Chi-square indicated no significant differences between both genders regarding the occurrence of RE. In all cases, RE occurred bilaterally. Out of 71 teeth attended for clinic, 87.3% teeth required retreatment, while the apparent reason of extraction for 86% of 50 collected extracted teeth with RE seemed failure of endodontic treatment and the cleaning and obturation confined to the mesial and distal canals only. In all cases, the orifice of the RE was located distolingual from the main canal in the distal root. Conclusion: Clinicians should be aware of this unusual root morphology in mandibular first molars. Radiographs exposed at two different horizontal angles are needed to identify this additional root. The access cavity must be modified in a distolingual direction in order to visualize and treat the RE; this results in a trapezoidal access cavity.

Frequency of Three-Rooted Mandibular Permanent Molars in Anatolia from the Middle Ages to the Present

“…However, the ratio is much lower in the Caucasus; with 1,35% in Germans, 8,1% in Iraqis, 1,44% in Iranians, 0,65% in Egyptians and 2,33% in Saudis (Younes et al, 1990; Shahi et al, 2008; Garg et al, 2010). The maximum percentage in African populations is 3% (Rashid and Suliman, 2006). Even though the number of studies on Anatolian societies is quite low, two studies are of special importance.…”

“…The third root is frequently in the distolingual direction but only Sperber and Moreau (1998) have reported the existence of a third root in the distobuccal direction. This variation is observed more frequently in Mongoloids including the natives of Malaya, China, Japan, America and Canada while it is less frequent in European populations including British, German, Dutch, Fin as well as African populations including Caucasia and Bantu, Senegal and Bushmen (Younes et.al., 1990;Rashid and Suliman, 2006;Shahi et al, 2008;Garg et al, 2010;Kim et al, 2013). Literature records are generally comprised of clinical studies on modern populations, while the number of studies on skeletal material in ancient populations is less.…”

Radix Entomolaris

“…Morpho-anatomic changes in teeth may be divided according to the site of their occurrence; i.e., tooth crown, roots and root canals. Third root anomalies may develop during bud morpho differentiation as a result of a developmental aberration of both ectoderm and mesoderm 14 .…”

Prevalence of Radix Entomolaris &Radix paramolaris in the extraction of permanent mandibular first and second molar (5-year clinical study)

“…1An additional root at the mesiobuccal side is called theradix paramolaris (RP). (4,5) The identification and external morphology of these root complexes, containing a lingual or buccal supernumerary root, are described by Carlsen and Alexandersen (7,6) . Radix paramolaris (RP) was first described by Bolk in 1915 (8) .extraction of permanent first molar with RE is difficult compared with out RE.…”