Root Of Mandibular Second Molar Research Articles

Cone-beam computed tomographic analysis of canal convolution in mesial root of mandibular second molars and a proposed new classification

Aim: The aim is to evaluate the anatomical characteristics of mesiolingual and mesiobuccal canals in mandibular second molars particularly in terms of its exit direction, distance of confluence from the minor constriction, and the angle of confluence. Materials and Methods: The cone-beam computed tomography images of hundred mandibular second molars were analyzed. Endodontically treated teeth and those with anatomical variations such as C-shaped canal configuration were excluded from this study. The distance of the confluence from the minor constriction, angle of confluence, and the exit direction of the mesiobuccal and the mesiolingual canals were assessed. Data were analyzed using an independent t-test. Results: The course of the mesiobuccal and mesiolingual canals beyond the confluence was towards the center of the root. The average angle of confluence was 32.75°–35.28°. The average distance of confluence from the minor constriction was 2.19 to 2.68 mm. The mesiolingual canal was straighter whereas the mesiobuccal canal had a tortuous course. Considering the results of the present study, a new classification has been proposed for the root canal morphology of the mesial root of mandibular second molars. Conclusion: The variation in the morphology of mandibular second molars highlights that the mesiolingual canal presented a mild curvature through and beyond the confluence when compared to the mesiobuccal canal which exhibited a tortuous course through the confluence.

Assessment of the Proximity of the Inferior Alveolar Canal with the Mandibular Root Apices and Cortical Plates-A Retrospective Cone Beam Computed Tomographic Analysis.

116 cone beam computed tomography (CBCT) scans were examined and the shortest distance of IAC with the root apices of mandibular canines, premolars and molars, and with cortical plates was analyzed. The data were statistically analyzed using SPSS. The shortest mean distance between IAC and lingual cortical plate (LCP) was found in the third molar area, and between IAC and buccal cortical plate (BCP) in the second premolar area. A high incidence of 60% direct communication (DC) was present in mandibular second molars; 38% in mandibular third molars; 13% in mandibular second premolars; 12% in mandibular first molars; and 1% in mandibular first premolars. Anteriorly, IAC was found to be significantly present in close approximation to the roots of mandibular canines. Posteriorly, IAC was found to be in significant proximity to the distal roots of mandibular second molars.

CBCT-Based Evaluation of Root Canal Configurations of Mandibular Second Molars and Their Relation to Mandibular Canal in Central Gujarat Population-A Cross-Sectional Study

Aim: To evaluate root canal configurations of mandibular second molars and their relation to mandibular canal in Central Gujarat population using CBCT. Materials and Methods: In this retrospective study 260 CBCT volumes from 5 different CBCT centres in Central Gujarat region were collected between November 2020 till May 2021. The parameters of the second mandibular molars assessed were: Vertucci’s root canal configuration, number of canals, distance of root apex from mandibular canal, degree of curvature, presence of extra root and C-shaped canal. The association between age and distance from root apex to mandibular canal was evaluated as secondary outcome. Chi- square test was used to analyse the relationship between the distance of the mandibular molar from the mandibular canal and age, a p-value of < 0.05 was judged statistically significant. Data were statistically analysed using IBM SPSS Version 21.0. Results: 3 canals were discovered in 73.8% of mandibular second molars, with Type II and Type I root canal configurations in the mesial and distal roots, respectively. With a mean curvature of 21.880, the incidence of C-shaped and Radix canal topologies was determined to be 5.3 percent and 6%, respectively. The average distance of mesial and distal roots from the mandibular canal was 3.04 and 2.78 respectively which decreased with age. The average distance between root of the tooth and mandibular canal is more in males than females and as the age advances the distance increases. Conclusion: In Central Gujarat population, mesial root of mandibular second molar shows Vertucci’s type II canal configuration while distal root presented with type I. C shaped canal configuration with fused roots and Radix Entomolaris was seen in (5.4% and 2.3% respectively). Additionally, as the age advances the distance of root apex from mandibular canal increases.

Efficiency and Temperature Rise of File Ablation by Neodymium:Yttrium-Aluminum-Perovskite Laser In Vitro

IntroductionRetrieving a separated file in the root canal system requires a skilled clinician. A metal file can be removed by ablation via the neodymium:yttrium-aluminum-perovskite (Nd:YAP) laser; however, the efficiency and potential hazards of the ablation procedure are still unclear. The aim of this study was 2-fold: to investigate the efficiency of file ablation using the Nd:YAP laser and to evaluate the rise in temperature of the root surface in vitro. MethodsIn part 1 of this study, #10 and #15 C-files (VDW GmbH, Munich, Germany) and ProTaper Next X1 and X2 files (Dentsply Maillefer, Ballaigues, Switzerland) were selected. Under 8.5×, the Nd:YAP laser was used to ablate the files starting at the tip of the file. The length of the file was recorded after each 5-pulse ablation. In part 2 of this study, 3 files each of the #15 C-file and the ProTaper Next X2 were separated in 6 distal roots of mandibular second molars with single canals. Two-pulse and 5-pulse modes were used to ablate the separated files, and the rise in root surface temperature was recorded with an infrared camera. Another 3 unaltered distal roots served as the negative control. For scanning electron microscopic evaluation, the teeth were split with bone scissors and observed under a scanning electron microscope to evaluate the surface change of the file and the root canal wall. ResultsThe average length of the ablated files after each 5-pulse interval was 0.113–0.158 mm with no statistical difference between the different files.The temperature rise of the negative control group (mean ± standard deviation = 1.86° ± 0.11°C and 5.81° ± 0.35°C for the 2- and 5-pulse group) was significantly lower than the roots with separated files (mean ± standard deviation = 3.74° ± 0.20°C and 4.02° ± 0.11°C for 2-pulse C-file and ProTaper Next X2; 8.47° ± 0.19°C and 9.04° ± 0.20°C for 5-pulse C-file and ProTaper Next X2). The temperature rise of all groups was lower than 10°C. The 2-pulse group showed a lower temperature rise than the 5-pulse group. The diameter or the type of alloy had no effect on the temperature rise. ConclusionsSeparated files (stainless steel or nickel-titanium alloy) can be ablated by the Nd:YAP laser. When the number of pulses is less than 5, the temperature rise of the root surface is considered safe to the surrounding periodontium.

Variability associated with mandibular buccal shelf area width and height in subjects with different growth pattern, sex, and growth status

The primary objective of the study was to quantitatively analyze the width and height of the mandibular buccal shelf area (MBS) at 3 different potential locations for mini-implant placement. In addition, we aimed to compare and contrast the bone parameters of the MBS to study the correlation between different growth status (growing or nongrowing), facial types (hypodivergent, normodivergent, and hyperdivergent), and sex differences (male or female). In this retrospective cone-beam computed tomography study, 678 subjects were included. They were divided into groups according to growth status, facial type, and sex. Scans were imported into the reconstruction program and were aligned in 3 different steps. Measurements were made at 6 different coronal sections: mandibular first molar distal root, secondmolar mesial root, and secondmolar distal root (bilaterally). The roots of mandibular molars were used as a reference to measure the width and the roof of the inferior alveolar canal to measure the height of the buccal shelf area. Intraobserver reliability was assessed by measuring the width and height of MBS in 20 randomly selected subjects. No significant difference (P>0.05) was found in the width of MBS between males and females. MBS width increased, and height decreased (P<0.0001) as moved distally from the first molar distal root to the secondmolar distal root in all 3 facial types irrespective of age or sex. The hypodivergent facial type had significantly greater bone width than the hyperdivergent facial type at all the 3 locations in both males and females. The hypodivergent facial type had significantly less (P<0.0001) bone height than the hyperdivergent group at all the 3 locations irrespective of age or sex. The optimal site for MBS mini-implant is the buccal region of the distal root of mandibular secondmolars. Hypodivergent patients have more width and less height of MBS compared with hyperdivergent patients. MBS mini-implants are not advised for growing patients because of proximity to developing roots.

The Variation of Pulp Canal Configuration in Mandibular Posterior Teeth Using Cone Beam Computed Tomography in Indonesia Subpopulation Mongoloid Race

It is important to understand pulp canal configuration to have a successful endodontic treatment. Cone Beam Computed Tomography (CBCT) radiography is able to assess the pulp canal configuration, especially on the lingual/palatal, compared to the periapical radiography. The objective of the research is to know the prevalence pulp canal configuration of mandibular molar teeth in Indonesia subpopulation Mongoloid race using CBCT radiography. This research is a descriptive survey with a cross-sectional approach, using 38 CBCT radiographs from the patients undergoing dental treatments in hospitals in Medan. The subjects were selected based on research criteria; then their CBCT radiographs were interpreted and analyzed. The result shows the existence of mandibular mesial root type 2-1 (28.94%), 1-2-1 (5.26%), 2-2 (55.26%), 2-1-2-1 (2.64%), 3-2 (5.26%), 3-1 (2.64%), distal root type 1-1 (36.84%), 2-1 (23.68%), 1-2-1 (15.79%), 1-2 (2.63%), 2-2 (13.17%), 2-1-2-1 (5.26%), 1-3-1 (2.63%). The distolingual root of mandibular first molars consisted of type 1-1 (100%). Mesial root of mandibular second molars of type 1-1 (2.63%), 2-1 (50%), 1-2-1 (5.26%), 2-2 (36.85%), 2-1-2-1 (2.63%), 1-2-1-2 (2.63%), distal root type 1-1 (57.89%), 2-1 (15.79%), 1-2-1 (13.16%), 2-2 (10.53%), 2-1-2 (2.63%). This variation of the pulp canal can be influenced by the shape of roots. A flat root usually contains pulp canal configuration type II – VIII Vertucci, similarly to mandibular molar mesial canals. As a summary, there is a variation of pulp canal configuration in mandibular first and second molars on Indonesian Mongoloid race, as seen from the CBCT radiographs.

Photoelastic analysis of stress distribution in mandibular second molar roots caused by several uprighting mechanics.

Mandibular molar uprighting is indicated when mesial inclination of the secondmolars occurs because of missing first molars. There are many methodologies to perform such movement. In this study, we aimed to analyze and compare the stress distributions in different molar uprighting techniques. Four photoelastic models were designed to evaluate different mandibular secondmolar uprighting techniques: a miniscrew positioned in the retromolar region, a beta-titanium alloy cantilever spring, a beta-titanium alloy wire with a T-loop spring, and an 0.018-in stainless steel archwire with an open-coil spring between the second premolar and the secondmolar. On the miniscrew test specimen, the greatest concentration of strains was observed in the cervical zone of the distal root. The cantilever spring had many strains in the cervical zone of the mesial root. On the T-loop spring test specimen, mainly the observed strains were in the apical zone of the mesial root. The open-coil spring specimen showed fringes in the cervical zone and the apical zone of the mesial root without formation of large sequences of strains. The miniscrew mechanical action had the least and the cantilever spring mechanical action had the greatest strain means on the roots of mandibular secondmolars.

Root canal morphology and variations in mandibular second molar teeth of an Indian population: an in vivo cone-beam computed tomography analysis.

This study aims to investigate the root canal morphology of permanent mandibular second molars of an Indian population in vivo using cone-beam computed tomography (CBCT) images. CBCT images (n=983; males=489, females=494) of untreated, completely developed permanent mandibular second molar teeth were examined. CBCT scans were acquired as part of diagnosis and treatment planning for treatments unrelated to the present study. The number of roots and root canals were recorded. Canal configuration was classified based on Vertucci's and Fan's classifications. The most common configuration was two-root (79.35%) and three-root canals (53.50%). The incidence of three-rooted molars was 7.53%, whereas 13.12% of the studied teeth studied have fused roots with C-shaped canals. The predominant canal morphology in the mesial roots was Vertucci's type IV (45.17%), followed by type II (32.55%), type I (7.23%), type V (1.02%), and type III (0.91%). The distal root in contrast showed type I (61.14%) as the predominant canal configuration, followed by type II (18.21%) and type IV (7.53%). The incidence of three-rooted molars was higher in males (n=55; 5.59%) than in females (n=19; 1.94%) (p<0.01). The canals in the extra roots exhibited type I (100%) root canal morphology. In teeth with C-shaped root canal (13.12%), the variations in the coronal, middle, and apical third ranged from C1 to C4. Root canal systems of the mesial roots of mandibular second molars of the study population demonstrated a high degree of variability. While three roots were rare, there was a sexual predisposition. Fused roots with C-shaped canals were rare and demonstrated significant variations from the coronal to apical third. Root canal morphology can demonstrate variations based on race and sex of patients. Clinicians must always consider the possible variations to ensure successful endodontic treatment.

Cone Beam Computed Tomography Evaluation of Root Canal Anatomy in Primary Molars: An in vitro Study

ABSTRACT Introduction Endodontic treatment requires knowledge of root canal morphology and its commonly occurring variation. The utility and relevance of cone beam computed tomography (CBCT) to the practice of endodontics is reported with increasing frequency in the field of endodontics for successful procedures. Therefore, the present study is undertaken to assess the variation in number and morphology of the root canals of primary molars. Materials and methods Extracted primary molars with at least two-thirds of intact root, and 7 to 12 mm length were cleaned in water and stored in 0.5% sodium hypochlorite for 1 week. Thereafter, the anatomy of the root canals of these primary molars was assessed through CBCT. Results In the present study, the majority of canals were ribbon shaped. Accessory canals were few and maximum number was found to be present in mesiobuccal root of maxillary first molar and the least in mesiobuccal root of mandibular second molar. Conclusion The CBCT proved to be as accurate as the gold standard in studying the presence of accessory canals with clinical applicability. This study highlights the usefulness of CBCT imaging for accurate diagnosis of the unusual canal morphology. How to cite this article Joshi N, Deshpande A, Poonacha KS, Bargale S, Naik K, Mehta D. Cone Beam Computed Tomography Evaluation of Root Canal Anatomy in Primary Molars: An in vitro Study. Int J Clin Dent Res 2017;1(1):15-19.

The anatomical relationship between the roots of mandibular second molars and the inferior alveolar nerve.

To evaluate the anatomical relationship between the roots of mandibular second molars and the inferior alveolar nerve (IAN) in relation to the risk of potential nerve injury during root canal treatment. Cone-beam computed tomography (CBCT) images from the patient record database at a dental hospital were selected. The anonymized CBCT images were reconstructed and examined in three planes (coronal, axial and sagittal) using 3D viewing software. The relationship between each root apex of mandibular second molars and the IAN was evaluated by measuring the horizontal and vertical distances from coronal CBCT sections, and the actual distance was then calculated mathematically using Pythagoras' theorem. In 55% of the 272 mandibular second molar roots evaluated, from a total of 134 scans, the distance between the anatomical root apex and the IAN was ≤3mm. In over 50% of the cases evaluated, there was an intimate relationship between the roots of mandibular second molars and the inferior alveolar nerve (IAN). Therefore, root canal treatment of mandibular second molars may pose a more significant potential risk of IAN injury; necessary precautions should be exercised, and the prudent use of CBCT should be considered if an intimate relationship is suspected.

Endodontic treatment modalities for external root resorption associated with impacted mandibular third molars

This article concerns the complications of external resorption of the distal root of mandibular second molars caused by mesioangular impacted third molars. One 6-yr follow-up and several recent clinical cases support the proposed endodontic treatment modalities available to the endodontist for patients affected with this pathological process.