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Background: Mandibular first molars typically have two roots but sometimes a supernumerary root presents distolingually called as radix entomolaris (RE). Aim: The present study evaluated the prevalence of permanent mandibular first molars featuring a distolingual root in Haryana (North India). Materials and Methods: Five hundred patients possessing bilateral mandibular first molars were selected for this study. The intraoral periapical radiographs were taken. The radiographs of these patients were evaluated under optimal conditions. A total of 1000 mandibular first molars were screened, and the incidence of three-rooted mandibular first molars, RE and the correlation between left and right side occurrence and between either gender were recorded. Statistical Analysis: The binary logistic regression test and Pearson's Chi-square test were used for statistical analysis. Results: The prevalence of three-rooted permanent mandibular first molars was 13% of the patients examined and 8.3% of the teeth examined. There was no statistically significant difference between gender and side of occurrence ( P ≥ 0.05). The bilateral incidence of a symmetric distribution was 27.6 (18/65) among the RE teeth examined. Conclusion: RE is considered as an Asiatic trait. The occurrence of this macrostructure in the Haryana (North India) population was found to be 13%. The clinician must thoroughly examine the radiographs before the initiation of endodontic therapy.

Knowledge about the possible existence and the racial prevalence is mandatory for successful endodontic treatment of cases ofRadix Entomolaris (RE). Factors such as an extra cusp usually buccal (protostylid), prominent distolingual lobe, complexity of the external contour of the furcation and convexity in the cervical region help to diagnose the presence of an RE. Radiographically, double periodontal ligament images or outline of the distal root contour can hint the presence of an RE. An angled radiograph (25-30°) can be more useful in this regard. Three-dimensional imaging techniques based on computed tomography (CT) and cone beam computed tomography (CBCT) have been able to predict the exact morphology of an RE non- invasively. This is a case report of a successful endodontic treatment of an 11 years old female patient with

The objective of this study was to evaluate the success rate of intraligamentary injections (ILI) using a two- or four-site injection technique. One hundred and fifty-one mandibular molars diagnosed with asymptomatic irreversible pulpitis received ILI at the mesiobuccal and distobuccal aspects of the roots. Patients who experienced pain when the access cavity was performed received additional supplemental ILI in the mesiolingual and distolingual aspects. Pulpal anaesthesia was considered successful when complete analgesia was achieved. The data were analysed by means of the Fisher's exact and Pearson's chi-square tests. IL anaesthesia was successful for 92.1% of the teeth. Forty-eight teeth (31.8%) were sufficiently anaesthetised using the two-site ILI and 91 teeth (60.3%) following supplemental IL anaesthesia in two more sites. The results of this study indicate that the use of four-site IL injections as a primary anaesthetic technique may be considered a favourable alternative to the common IANB.

Objectives: To develop a method to clinically identify the position of the lingual nerve within the lingual tissue in the third molar region by electro-stimulation. Methods: Following ethical committee approval a cross-sectional study was performed in 20 healthy participants. A proprietary Electric Pulp Tester (EPT) was used intra-orally to stimulate the lingual nerve and, to identify the vertical position of the lingual nerve, measurements were taken when subjects felt a projected tingling sensation in the tongue as the stimulation probe was placed directly over the nerve. The nerve location was investigated in three positions in relation to the third molar: Point A at the retromolar pad; Point C at the distolingual attached gingivae of the erupted lower second molar and; Point B at the midline of the erupted third molar (or when the third molar was unerupted, midway between Points A & C). Results: Out of 20 participants 18 (90%) were able to identify the projected tingling sensation on the tongue upon stimulating the nerve, allowing the nerve position to be identified. The mean vertical height of the lingual nerve relative to the third molar was 10.5, 10.75 and 12.5 mm for positions A, B and C respectively. The sensation related to nerve stimulation was well accepted by participants with minimal adverse events. Conclusion: We have demonstrated that stimulation of the lingual nerve with an EPT can clinically identify the position of the lingual nerve in situ. This technique may be useful for the clinical determination of lingual nerve position prior to third molar surgery. Keywords: Lingual nerve, Electric pulp tester, Anatomy, Extraction, Mapping

Introduction The purpose of this study was to determine the position of the apical foramen (AF) in relation to root surfaces of human permanent teeth using cone-beam computed tomographic (CBCT) imaging and novel advanced imaging analysis software (e-Vol DX; CDT Software, Bauru, SP, Brazil). Methods The AF position was determined on CBCT scans viewed and analyzed using e-Vol DX of 1400 teeth (422 patients) according to the root surface as follows: buccal, mesiobuccal, mesial, mesiolingual/palatal, lingual/palatal, distolingual/palatal, distal, distobuccal, and central. Categoric variables were described as frequencies and percentages. Frequencies were reported with their confidence intervals (95%). Categoric variables were analyzed using the chi-square test with Yates correction. The level of significance was set at α = 0.05. Results The most frequent AF position in maxillary anterior teeth was central (46%–60%). The AF in mandibular central incisors was buccal in 44% of the cases. In maxillary first and second premolars, 39.98% and 42.56% of all AFs were central. In maxillary first and second molars, 46.12% and 57.49% of all AFs were central. The most frequent AF position in mandibular first and second premolars was central (42.85% and 50.98%). In mandibular first molars, 48.72% of all AFs were central. Conclusions The AF position in human permanent teeth was central in 48.95% and 42.08% of the maxillary and mandibular teeth. CBCT images analyzed by e-Vol DX can be used to determine the true anatomic position of the AF and can be a useful tool for the treatment planning of nonsurgical and surgical endodontic treatments.

Background The aim of this study was to evaluate the root canal morphology of mandibular first molars in a Chinese population by using cone-beam computed tomography (CBCT). Methods In this study, CBCT images of 900 mandibular first molars were evaluated for the following details: (1) number of roots, (2) number of apical foramina, (3) frequency distribution of root canal configurations defined in accordance with Vertucci’s classification, and (4) frequency of occurrence of middle mesial (MM) canal. Results Overall, 74.9% of the evaluated mandibular first molars possessed two roots, and 55.4% exhibited three apical foramina. The evaluated teeth exhibited a relatively high prevalence of type IV canals in mesial (M) roots (76.8%) and type I canals in the distal (D) (79.4%), distobuccal (DB) (98.7%), and distolingual (DL) (100%) roots. There were no significant differences in the number of roots, incidence of apical foramina, or distribution of different canal configurations of mandibular first molars between men and women (P > 0.05). 1.9% of mandibular first molars possessed three mesial canals, and the highest frequency of occurrence of MM canals (4.1%) was among Chinese people below the age of 30 years. Conclusions CBCT scanning facilitates identification of the root canal system. In order to increase the success rate of treatment, it is important to obtain information about the variable morphology of root canals before endodontic treatment. Trial registration TJSKE20160412. Registered 12 April 2016.

Knowledge about the external and internal anatomy of the tooth is essential for successful dental practice. Anomalies in the tooth are often encountered which poses difficulties in dental treatments. As like any other tooth, mandibular first molars are also prone for anatomic malformations. One such anatomic variation is the presence of extra root distolingually. This distolingual root is called radix entomolaris (RE). The presence of an additional root can lead to difficulties during endodontic therapy. This article is a report of two cases describing the management of the first mandibular molars with an RE and clinical guidelines for its management.

Aim: To confirm the effect of root canal treatment on radix entomolaris. Case: Radix entomolaris was an additional root that located on the distolingual of mandibular first molars. In this case, the radix entomolaris was detected clinically and radiographically with root canal configuration such as curves. An awareness and understanding of this unusual root and root canal morphology could contribute to the successful outcome of endodontic treatment. Conclusion: Root canal treatment on this case shows the lack of symptoms and normal radiographic presentation for two months follow-up.

Endodontic therapy of mandibular molars is a challenging task due to its varied root canal morphology. A mandibular first molar with additional buccal root (Radix paramolaris) and additional distolingual root (Radix Entomolaris) is an example of its varied anatomy. A successful management of atypical root canal configurations is an important aspect in determining the success rate of root canal therapy. The detail knowledge of the root morphology and canal anatomy allows the clinician for accurate location of the extra roots and canals and accordingly the refinement of the access cavity for the stress free entry of complex anatomy. Hence, for a successful root canal therapy, clinician must be aware of the external and internal anatomic variations .The aim of this clinical case report is to present and describe the unusual presence of two separate mesial roots and six root canals in mandibular first molar, detected during routine endodontic therapy.Kathmandu Univ Med J 2013; 11(4): 338-341

The present study describes a new juvenile hominin mandible and teeth and a new juvenile humerus from level V of the GP2 gallery of Cova del Gegant (Spain). The mandible (Gegant-5) preserves a portion of the right mandibular corpus from the M1 distally to the socket for the dc mesially, and the age at death is estimated as 4.5-5.0 years. Gegant-5 shows a single mental foramen located under the dm1/dm2 interdental septum, a relatively posterior placement compared with recent hominins of a similar developmental age. The mental foramen in Gegant-5 is also placed within the lower half of the mandibular corpus, as in the previously described late adolescent/adult mandible (Gegant-1) from this same Middle Paleolithic site. The Gegant-5 canine shows pronounced marginal ridges, a distal accessory ridge, and a pronounced distolingual tubercle. The P3 shows a lingually-displaced protoconid cusp tip and a distal accessory ridge. The P4 shows a slightly asymmetrical crown outline, a continuous transverse crest, a mesially placed metaconid cusp tip, a slight distal accessory ridge, and an accessory lingual cusp. The M1 shows a Y5 pattern of cusp contact and a well-developed and deep anterior fovea bounded posteriorly by a continuous midtrigonid crest. Gegant-4 is the distal portion of a left humerus from a juvenile estimated to be between 5 and 7 years old at death. The specimen shows thick cortical bone. Although fragmentary, the constellation of morphological and metric features indicates Neandertal affinities for these specimens. Their spatial proximity at the site and similar ages at death suggest these remains may represent a single individual. The addition of these new specimens brings the total number of Neandertal remains from the Cova del Gegant to five, and this site documents the clearest evidence for Neandertal fossils associated with Middle Paleolithic stone tools in this region of the Iberian Peninsula.

Introduction Three-rooted mandibular molars are 1 of the anatomic variations of mandibular molars. The location of the additional root is distolingual (radix entomolaris) or mesiobuccal (radix paramolaris). The purpose of this retrospective study was to assess the prevalence of 3- and 4-rooted mandibular first and second molars in the Israeli population and to classify them according to dimension, curvature, and location of separation from the main root. Methods A total of 1020 Israel patients' cone-beam computed tomographic scans were screened and evaluated. The incidence of 3- and 4-rooted first and second mandibular molars were recorded and analyzed. One thousand four hundred sixty-five mandibular second molars and 1,229 mandibular first molars were evaluated. Results The overall incidence of patients with 3-rooted mandibular first and second molars was 2.6% and 1.78%, respectively. The bilateral incidence of 3-rooted mandibular first and second molars was 26%. The incidence of 4-rooted mandibular second molar was 0.55%. No significant difference was found regarding sex or side of occurrence. Conclusions The occurrence of 3-rooted mandibular first molars in the Israeli population was rare, but clinicians should be aware of the special characteristic of this anatomic variation to modify accordingly the form of pulp chamber opening and choose appropriate instrumentation.

Purpose: This study evaluated the mechanism of an abutment fracture by means of a case-based finite element (FE) stress analysis. Materials and Methods: A patient presented with a complaint of fracture of an implant-retained single posterior restoration that had been in place for 6 years. The retrieved restoration was examined on the original working cast and subjected to microscopic observation for fracture surface analysis. A case-based FE analysis was conducted to detect the location and magnitude of stress concentration in the implant structures. Results: The fracture occurred at the concave neck of the abutment, with an evidence of fatigue fracture on the titanium surface. Ratchet marks were shown at the distal lingual edge, indicating that the crack proceeded from distolingual to mesial direction. The highest maximum tensile stress at the distolingual concave neck of the abutment was shown when the load was directed on the internal and external surfaces of the mesial buccal cusp. Conclusions: It is suggested that an offset loading because of the cantilever structure caused a high tensile stress on the distolingual edge, resulting in the fatigue fracture of the abutment.

Abella F, Mercade M, Duran-Sindreu F, Roig M. Managing severe curvature of radix entomolaris: three-dimensional analysis with cone beam computed tomography. International Endodontic Journal, 44, 876–885, 2011. Abstract Aim To present a case of a mandibular first molar with an additional distolingual root [radix entomolaris (RE)] and to discuss the use of cone beam computed tomography (CBCT) for its identification and management during root canal treatment. Summary A 52-year-old Caucasian woman was referred for root canal treatment of the right mandibular first molar (tooth 46). After clinical and radiographic examination, a symptomatic irreversible pulpitis was diagnosed. Three periapical radiographs with different horizontal angulations revealed the presence of an additional distolingual root. This extra root, termed RE, has an incidence of

Zhang R, Wang H, Tian Y-Y, Yu X, Hu T, Dummer PMH. Use of cone-beam computed tomography to evaluate root and canal morphology of mandibular molars in Chinese individuals. International Endodontic Journal, 44, 990-999, 2011. ABSTRACT: Aim To evaluate the root canal configuration of permanent mandibular first and second molar teeth in a Chinese subpopulation using cone-beam computed tomography (CBCT). Methodology Patients who required CBCT radiographic examinations as part of their routine examination, diagnosis and treatment planning, were enrolled. Cases where the anatomy was compromised by physiological or pathological processes and the original root canal morphology was not clear were excluded. A total of 389 healthy, untreated, fully developed mandibular molars in Chinese individuals were included. The following observations were recorded: (i) the number of roots and their morphology; (ii) the number of canals per root; (iii) the canal configuration; (iv) the frequency of distolingual roots in the mandibular first molars and (v) the frequency of C-shaped canals in the mandibular second molars. The root canal configurations were classified according to the method of Vertucci (Oral Surgery, Oral Medicine, and Oral Pathology58, 1984, 589). Results The majority of mandibular molars (70% of first molars, 76% of second molars) had two separate roots; however, three roots were identified in 29% of first molars. C-shaped roots occurred in 29% of second molars. Three canals were found in 56% of mandibular first molars and 43% had four canals. In the mandibular second molars, 46% had three canals and 38% had two canals. Most distal roots had a simple type I configuration, whereas mesial roots had more complex canal systems, with more than one canal. There were seven variants of the root canal morphology amongst the mandibular first molars and eight variants amongst the mandibular second molars, without considering the various root types. Conclusions Three-rooted mandibular first molars and C-shaped mandibular second molars occurred frequently in this Chinese population. CBCT is an effective tool for the detection of additional distolingual roots and C-shaped roots/canals, and it is a valuable aid for dentists providing root canal treatment.

Objectives: The aim of this study is to determine the prevalence of the first lower molars that have two roots or three roots and the number of the root canals of the mandibular first molars in the Vietnamese subpopulation using cone-beam computed tomography (CBCT). Materials and Methods: The study was conducted on 166 patients who had CBCT as indicated by dentists in Nguyen Trai Dental CT Center, Ho Chi Minh City using the Picasso Trio (Ewoo Vatech, Korea). The number of root canals of the first lower molars was examined by moving cross-sectional slices from the pulpal floor to the apex. The orifices, middle thirds, and apical thirds of the canals of the first lower molar were observed, and the root canals of each root of the mandibular first molars were observed in three planes. Results: The prevalence of two, three, and four root canals of the mandibular first molars was 4.5%, 66.8%, and 28.9%, respectively. For the distal roots of these molars, a classification of Vertucci type I was the most common at a rate of 80.8%–97.6%. Whenever these teeth had three roots, a Vertucci type I was the classification of 100% of distolingual roots. Conclusion: Majority of the mandibular first molars has two roots and three canals. CBCT is appropriate equipment useful in investigating the complex root canal morphology of human teeth.

Background: The human first maxillary molar provides clues about evolution and is functionally important. It has four main cusps, and each cusp has an independent growth pattern and different evolutionary background. Though less explored, the analysis based on measurement of each cusp appears to be more meaningful biologically than conventional measurements of the whole crown. Aim: This study aimed to demonstrate the extent of sexual dimorphism in permanent maxillary first molar cusp diameters and their potential utility in sex prediction among Indians using logistic regression analysis (LRA). Materials and Methods: The mesiodistal and buccolingual (BL) crown diameters along with cusp dimensions and cusp indices of right maxillary first molar were measured in an Indian sample (149 males, 151 females; age range of 18–30 years). The possible sex dimorphism in these parameters was evaluated, and LRA was performed to ascertain their usefulness in sex prediction. Results: BL crown dimension and the hypocone (distolingual) cusp showed the highest sexual dimorphism. The combination of metacone and hypocone, i.e., distal cusp diameters among cusp parameters showed the highest accuracy (61.3%). While, on combining all the crown and cusp diameters together the overall accuracy was raised (64.3%). Conclusion: This study supports the ontogeny hypothesis suggesting that early-forming mesial cusps demonstrate less sexual variation as compared to subsequently formed distal cusps in the maxillary molar. Though the sex identification accuracy for cusp diameters of the permanent maxillary first molar in Indians is relatively moderate (≈61%), it can be used as an adjunct for sexing of adult Indians in forensic contexts.

Variation in the root and canal morphology of maxillary second molars is quite common. The most common configuration is three roots and three or four canals. But the presence of an additional palatal root is rather uncommon and has been reported to have an incidence of 1.4%. The extra root is located mesiolingual or distolingual to the primary palatal root. This is a unique case report that describes the successful endodontic management of a maxillary second molar with Radix Distolingualis (RDL). Identification of this variation was done through clinical examination, multi-angled radiographs, surgical operating microscope and an accurate assessment of this morphology was made with the help of Cone Beam Computed Tomography (CBCT) imaging. In addition, this article also discusses the literature review, guidelines for diagnosis and treatment of RDL.

Introduction The purpose of this study was to evaluate the root and canal morphology of mandibular first permanent molars in a western Chinese population by using cone-beam computed tomography (CBCT). Methods In this study, 558 samples were examined by CBCT. Details of sex, tooth position, the number of roots and canals, and the canal configuration were recorded. The root canal configuration was categorized and compared according to Vertucci’s criteria. Results Overall, 51.4% of the mandibular first permanent molars examined had four canals, and 25.8% had a separate distolingual root. In 48.1% of these, the fourth canal was in the separate distolingual root. In the two-rooted mandibular first permanent molars, 93.9% of the mesial root canals were of type IV, and 62.9% of the distal root canals were of type I. In the three-rooted samples, 94.4% of the mesial root canals were of type IV, and 98.6% of the distobuccal and 100% of the distolingual root canals were of type I. In addition, there was a higher incidence of three-rooted mandibular first permanent molars on the left side than on the right, but this relationship was not significantly correlated with sex. Conclusions Mandibular first permanent molars commonly have four canals and a higher prevalence for a separated distolingual canal in a western Chinese population.

Akhlaghi NM, Kahali R, Abtahi A, Tabatabaee S, Mehrvarzfar P, Parirokh M. Comparison of dentine removal using V-taper and K-Flexofile instruments. International Endodontic Journal, 43, 1029–1036, 2010. Abstract Aim To compare the dentine removal ability of V-Taper and K-Flexofile instruments in mesiobuccal canals of extracted mandibular first molar teeth. Methodology Preoperative images of 40 mesiobuccal canals of mandibular first molars (with a curvature between 20° and 35°) were obtained at 2, 4.5, and 7 mm from the root apices by CT-scan and divided into two groups. Group F was prepared with K-Flexofiles and Gates Glidden drills and Group V with V-Taper Ni–Ti rotary and stainless steel hand instruments. Post-instrumentation images were then obtained and compared with the preoperative images. The ratio of dentine removal based on pre- and postoperative images was calculated, and data was analysed by anova and Tukey post hoc test. Results In group F in the coronal sections, the least ratio of the dentine removal to the initial root thickness was on the buccal aspect (15.14% ± 6.72), and the greatest ratio was found on the distolingual (29.38% ± 8.19). In group V in the coronal, the least ratio of the dentine removal to the initial root thickness was on the buccal aspect (9.81% ± 3.26); the greatest ratio was found on the distolingual surface in the coronal sections (34.38% ± 10.51). In the middle sections, the least ratio was on the buccal (10.51% ± 3.39) and the greatest on the distolingual aspects (27.46% ± 12.34) of the roots. In the apical sections, the amount of the dentine removed from the mesial and distal surfaces in group V was significantly more than group F (P

The permanent mandibular second molars usually have two roots (mesial and distal), one mesial with two root canals (Mesiobuccal and Distobuccal) and another distal root, with one (distal)/two canals (Distobuccal and Distolingual). Multirooted posterior teeth more commonly show variations in root canal morphology. The present case report describes diagnosis and endodontic management of permanent mandibular left second molar having single root with Vertucci type II canal configuration.

In this paper we describe a hitherto undocumented modification of the dental enamel surface observed in an Early Bronze Age population from north- ern Italy. The defect, which can be described as a curvi- linear groove, is located on the lingual surface of incisors and canines in the upper jaw. This groove, documented both in the permanent and deciduous dentition, is located at approximately 1 mm from the cervix and extends from the mesiolingual to the distolingual surface. The occur- rence of the groove is not related to the sex of the affected individuals, but its degree of expression is related to age at death. Because of its morphology, the groove cannot be considered as a result of disruptions in the process of enamel deposition. At the present stage of research we suggest that the groove might have been the result of some kind of dental erosion caused by as yet unidentified chemical factors. Am J Phys Anthropol 154:609-614, 2014. V C 2014 Wiley Periodicals, Inc.

The presence of radix entomolaris (RE) in a mandibular first molar is a common occurrence in certain ethnic groups, but the presence of RE in a mandibular second molar is a rare occurrence. In the present case, RE was identified from preoperative radiographs and confirmed using cone-beam computed tomography (CBCT). The access cavity was modified to locate the RE. Cleaning and shaping were performed with nickel-titanium rotary instruments. Obturation was completed with gutta-percha cones using AH Plus (Dentsply Detrey GmbH) as sealer. From the CBCT axial images, the RE was determined to have a Type III curvature by the De Moor classification, Type B separate RE by the Carlsen and Alexandersen classification, and radiographically, a Type i image by the Wang classification. The presence of RE in the mandibular second molar makes it essential to anticipate and treat the distolingual root canal. This case report highlights the usefulness of CBCT for assessing RE in the mandibular second molar, which can help the clinician in making a confirmatory diagnosis and assessing the morphology of the root canal.

Radix entomolares, a supernumerary root on a mandibular molar, located distolingually, is an anatomical variation of the mandibular first molar. This variation requires special care in order to maintain a high success rate of root canal treatment. This paper describes the procedure for treatment of a mandibular first molar with three roots (one mesial and two distal) and four canals (two mesial and one in each distobuccal and distolingual root). This case report reveals the importance of anatomical knowledge of root canals and preoperative radiographs.

The presence of radix entomolaris (RE) in a mandibular first molar is a common occurrence, which accounts for 0.2%-32% of the population, but the presence of RE in a mandibular second molar is a rare occurrence in our ethnic group. This presence of additional root can lead to difficulties during endodontic treatment. A thorough knowledge of anatomy is necessary for the success of endodontic treatment. This article presents a review on clinical approach and a case series on the detection and management of RE on mandibular second molar. RE was identified using Same lingual opposite buccal (SLOB) technique with preoperative radiograph, modifying the access cavity preparation, locating the canals followed by cleaning, and shaping of canals with nickel-titanium instruments. Obturation was done with respective master cones and AH + resin sealer.

Introduction: Forensic odontology is one of the most unexplored and captivated branches of forensic sciences. Teeth are far excellent material for the anthropological, genetic, odontogenic, and forensic scenario as the morphology of teeth remains unchanged in extreme environmental conditions even after a long period. Aim and Objectives: The study aims to determine the sex of an individual by odontometric diagonal measurements using discriminant function. The objectives are to measure and compare the diagonal measurements of teeth in males and females using crown diagonal diameters of the permanent dentition and to evaluate their sexual dimorphism. Material and Methods: The study sample included 380 maxillary and mandibular dental casts obtained by alginate impressions of 190 subjects (95 males and 95 females) in the age range of 19–35 years selected from Out patient department of Oral Medicine and Radiology. Mesiolabioincisal-distolinguoincisal (MBDL) and distolabioincisal-mesiolinguoincisal (DBML) measurements of right permanent maxillary and mandibular teeth excluding third molars were taken separately using a digital Vernier caliper. Results: The highest mean tooth dimension of MBDL and DBML in both the jaws is of the first molar. The accuracy rate for males (100% for MBDL and 97.89% for DBML) is greater than females (MBDL 93.68% and DBML 94.21%). The overall accuracy rate of maxillary and mandibular MBDL is greater (96.8%) than DBML measurement (95.8% and 94.8%, respectively). Conclusion: The overall accuracy rate for sex determination is 96.8% for MBDL dimensions. The maxillary and mandibular second premolars are the strongest predictors for sex determination.

The well preserved anterior upper and lower jaw fragment of an adult specimen of Coloborhynchus robustus (Pterosauria: Ornithocheiridae), SMNK 2302 PAL, allowed investigations of the replacement pattern of the dentition macroscopically and by using CT scans. The quantification of the dentition by Zahnreihen, Z-Spacing, and replacement waves indicates a complex pattern of different replacement stages in which large gaps within the dentition were avoided. The specialized prey-catching apparatus of Coloborhynchus thus could retain its function even following tooth replacement. The replacement process in the specimen took about 2/3 of the total life-time of a tooth, and damaged teeth in the anterior jaw region may have been replaced more rapidly than posterior teeth. The distolingual replacement of the functional teeth delayed the time of their shedding in comparison with the circular resorption present in crocodiles. In contrast to these, the distolingual position of the replacement tooth did not decrease the biomechanical stability of the functional tooth, which can also be observed as a convergence in other thecodont dentitions, e.g., recent carnivore mammals. Teeth were shed when their replacement had reached about 60% of the full-grown height. A comparison of the observed pattern is constricted by the preservation and preparation of other specimens. Unfortunately, no known specimen in public collections reaches the quality of Coloborhynchus robustus, SMNK 2302 PAL, so that comparable patterns in other specimens are not likely to be detected. J. Morphol., 2008. © 2007 Wiley-Liss, Inc.

Aim To present cases of mandibular first molars with an additional distolingual root (radix entomolaris, RE) and to survey the literature on the incidence of this anatomical feature. Summary A major anatomical variant of the two-rooted mandibular first molar is a tooth with an additional distolingual and third root: the RE. The prevalence of these three-rooted mandibular first molars appears to be less than 3% in African populations, not to exceed 4.2% in Caucasians, to be less than 5% in Eurasian and Asian populations, and to be higher than 5% (even up to 40%) in populations with Mongolian traits. A total of 18 cases (12 root filled and six extracted mandibular first molars) with an RE were collected during the years 2000–2003 in patients of Caucasian origin. As far as the access was concerned, entering the root canal in the RE required a modification of the opening in a distolingual direction resulting in a trapezoidal opening cavity. None of the orifices was located midway between the mesial and distal root component. Based on the anatomy of the extracted samples and the bending of ISO 10 files after scouting of the root canal in the RE, three types of curvature were detected: (I) straight or no curvature (two cases); (II) coronal third curved and straight continuation to the apex (five cases); and (III) curvature in the coronal third and buccal curvature from the middle third or apical third of the root (11 cases). Key learning points • Clinicians should be aware of this unusual root morphology in mandibular first molars in Caucasian people. • 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.

Aim To determine the root canal anatomy of mandibular second molars in a Korean population by analysing cone-beam computed tomography (CBCT) images. Methodology The CBCT images of 960 subjects were examined. The number and configuration of roots and canals were categorized according to Vertucci's and modified Melton's classifications. Results Of the 1920 mandibular second molars, 41% had one root, 58% had two roots, and

Purpose. Supernumerary roots in permanent mandibular molar teeth make endodontic treatment more complicated. The aim of this study was to determine the prevalence of Radix Entomolaris (RE) in permanent mandibular first and second molars in the population of Kerman, in the southeast of Iran. Materials and Methods. From a collection of 500 mandibular first and second molar teeth extracted over 2015-2016 at dental clinics in Kerman, teeth were scored for an additional distolingual root, and the average root length and root morphology of this extra root were determined using the De Moor classification scheme. Results. In this population, RE occurred in 6% of mandibular first molars (4% with a straight apex (Type I) and 2% with buccal apical curvature (Type III)). In all cases, RE was the shortest root, with an average root length of 18.37 mm. RE occurred in only 0.8% of mandibular second molars, with an average root length of 18.0 mm. All mandibular second molars with RE were of Type III. Fisher’s exact test showed that the difference in frequency between first and second molars was statistically significant (two-sided P=0.002). Conclusion. Radix Entomolaris occurs more frequently in mandibular first molars than in mandibular second molars in this sample of 500 mandibular molars. The reported rate of 6% in first molars is expected to be higher than reported rates in European or Caucasian populations where the prevalence is typically less than 2%.

Aim: Characterize the permanent dentition morphology of a group of Afrodescendants of Istmina (Chocó, Colombia). Materials y methods: This quantitative cross-sectional study determined the frequency and variability of 35 incisor, canine, premolar and molar morphological features of the Arizona State University Dental Anthropology System in 100 self-described individuals as Afrodescendants (50 Female and 50 male), aged between 5 and 18 years. Results: Significant frequencies of winging (99%), double blade of the central incisors (86%), convexity of the lips (41%), crest of the shoulder (35%), and distal crest (39% to 45%) were identified (95% to 98%), central ridge (82% and 80%), mesolingual groove (79%), distolingual groove (81%), hippocampus reduction (86%), Carabelli cusp ) And cusp 7 (64%). No sexual dimorphism and bilateral asymmetry were found in the MCDS studied. Conclusions: The frequency and variability of the MCDD included in the dendrogram showed that the Isthmian group had a typical dental morphology of the Afrodescendant populations distributed on the Colombian Pacific coast, which were derived from groups of the West African coast included in The dental complex of Saharan Africa. Likewise, it was possible to detect the influence of mestizo and indigenous populations occupying the same geopolitical space.

The main objective of successful endodontic therapy is thorough mechanical shaping and chemical cleaning of the entire root canal system followed by three-dimensional obturation. Variation of the root canal morphology especially in multirooted teeth is a constant challenge for diagnosis and successful endodontic therapy. Mandibular molars can have an additional root located lingually (the radix entomolaris) or buccally (the radix paramolaris). An awareness and understanding of presence of additional root and unusual root canal morphology is essential as it determines the successful outcome of endodontic treatment. The present article focuses on the identification, access cavity modification and contemporary management of the distolingual root of mandibular 1st molars. How to cite this article Pawar AM, Kokate SR, Hegde VR. Contemporary Approach in Successful Endodontic Intervention in ‘Radix Entomolaris’. World J Dent 2013;4(3):208-213.

Success of endodontic treatment depends on the proper identification of all the canals, thorough chemo-mechanical preparation followed by three dimensional obturation with hermetic seal. Failure of any of these steps may occur due to unusual tooth morphology. The endodontic treatment of a mandibular molar with aberrant canal configuration can be diagnostically and technically challenging. Radix Entomolaris (RE) is one such aberration where an extra root is present on the distolingual aspect of mandibular first molar (molar with 3 roots). This article presents a case report of mandibular first molar with extra distal root and five root canals.

This case report describes the successful non-surgical endodontic management of carious exposed three-rooted mandibular molar with four root canals detected on the pre-operative radiograph taken with 20 degrees mesial angulation and confirmed with a 64-slice helical computed tomography scan-assisted 3-D-reconstructed images. Access cavity shape was modified to locate the extra canal with respect to the distolingual root in the left mandibular first molar. Copious irrigation was accomplished with 5.25% sodium hypochlorite and 17% EDTA. Biomechanical preparation was done using protapers. Calcium hydroxide dressing was done for 1 week. The tooth was obturated using gutta percha and AH 26 root canal sealer, and it was permanently restored with composite. Clinical examination on follow-up visits revealed no sensitivity to percussion and palpation in the left mandibular first molar. Thorough knowledge of root canal variations and use of advanced diagnostic modalities lead to successful non-surgical management of the complex cases.

Anin vitrostudy was performed to determine the number of roots, root canals per tooth, root canal configurations, and frequency of isthmi and apical deltas in mandibular first permanent molars in an Indian population. Hundred and fifty mandibular first permanent molars were collected and subjected to clearing technique. The cleared teeth were examined in a stereomicroscope under 7.5x magnifications. The canal configurations were categorized using Vertucci's classification. Overall 94.6% of the mandibular first molars had two roots, and 5.3% had extradistal roots (distolingual root). In addition, 64% of the specimens had three root canals, and 36% had four root canals. The most common canal configurations of mesial and distal roots were Vertucci type IV (54%) and type I (65.3%), respectively. Clinician should be aware of the complex root canal morphology of mandibular first molars among the Indian population before and during the root canal treatment.

Purpose The use of resorbable collagen membranes (RMs) in the treatment of intraosseous defects and deep periodontal pockets on the distal side of a lower second molar (L2M) after surgical extraction of an impacted lower third molar (L3M) has shown contradictory results. This study evaluated the effects of RM placement on the healing of a bone defect distal to an L2M after surgical extraction of a horizontal or mesioangular impacted L3M. Patients and Methods A parallel-group randomized controlled trial with 2 independent groups of 30 patients requiring surgical extraction of an L3M was carried out. After extraction, patients received an RM (Bio-Gide, Geistlich Pharma AG, Wolhusen, Switzerland) or only suture. At the initial checkup and during postoperative monitoring at 1, 3, and 6 months, the distal vestibular, distal, and distolingual probing depths and distal vestibular attachment level of the L2M were measured. Results Age (control group, 33.8 ± 6.9 yr; guided tissue regeneration group, 35.6 ± 6.3 yr; P = .322) and the number of women (control group, 15 of 29; guided tissue regeneration group, 14 of 27; P = .992) were similar in the 2 groups. The distal vestibular, distal, and distolingual probing depths of the L2M, distal vestibular attachment level, distance from the cementoenamel junction, and distance from the alveolar crest to the base of the defect showed greater improvement 6 months after surgical extraction in the RM group (P Conclusions The use of RMs after surgical extraction of mesioangular or horizontally impacted L3Ms stimulates bone regeneration, improving the attachment level and bone fill distal to the L2M. Likewise, it decreases the distal probing depth and results in faster recovery. RM placement after surgical extraction of an impacted L3M is recommended because it prevents periodontal defects after L3M surgery.