Accessory Canals Research Articles

Assessment of accessory mandibular canal in mandibular third molars using cone-beam computed tomography

Purpose: This study was performed to examine distribution of accessory mandibular canal and its characteristics in mandibular third molars. Materials and methods: A total of 251 subjects (166 males and 85 females) having mandibular third molars bilaterally were included in the study. Cone-beam computed tomographic images were reviewed for bifid or trifid accessory mandibular canal. The prevalence of accessory mandibular canal was evaluated according to gender, side and its branching type. Proximity and crosssectional position of accessory mandibular canal to mandibular third molar was analyzed. Results: Accessory mandibular canals were found in 66 (26.3%) of 251 patients and 86 (17.1%) of 502 hemi-mandibles. Gender and sides showed no statistically significant differences in prevalence. Retromolar canal (46.1%) was the most common branching type. Proximity of accessory canal to mandibular third molars showed mean distance of 2.8 mm from third molar and a statistically significant difference was found among types of accessory canal. Dental canal was the closest to tooth among branching types and closer to tooth than main canal. On cross-sectional view, accessory canal was generally located on buccal side of mandibular third molar. Conclusion: Accessory mandibular canal was common and well detected with cone-beam computed tomography. Their localization is significant in all anesthetic and surgical procedures involving mandibular third molars.

Comparison of mandibular first molar mesial root canal morphology using micro-computed tomography and clearing technique

Objective. Micro-computed tomography (MCT) with alternative image reformatting techniques shows complex and detailed root canal anatomy. This study compared two-dimensional (2D) and 3D MCT image reformatting with standard tooth clearing for studying mandibular first molar mesial root canal morphology. Materials and methods. Extracted human mandibular first molar mesial roots (n = 31) were scanned by MCT (Skyscan 1172). 2D thin-slab minimum intensity projection (TS-MinIP) and 3D volume rendered images were constructed. The same teeth were then processed by clearing and staining. For each root, images obtained from clearing, 2D, 3D and combined 2D and 3D techniques were examined independently by four endodontists and categorized according to Vertucci’s classification. Fine anatomical structures such as accessory canals, intercanal communications and loops were also identified. Results. Agreement among the four techniques for Vertucci’s classification was 45.2% (14/31). The most frequent were Vertucci’s type IV and then type II, although many had complex configurations that were non-classifiable. Generally, complex canal systems were more clearly visible in MCT images than with standard clearing and staining. Fine anatomical structures such as intercanal communications, accessory canals and loops were mostly detected with a combination of 2D TS-MinIP and 3D volume-rendering MCT images. Conclusions. Canal configurations and fine anatomic structures were more clearly observed in the combined 2D and 3D MCT images than the clearing technique. The frequency of non-classifiable configurations demonstrated the complexity of mandibular first molar mesial root canal anatomy.

On the Anatomy of the ‘Hook' Region of the Human Cochlea and How It Relates to Cochlear Implantation

Background: The optimal insertion route for an electrode array in hearing preservation cochlear implantation (CI) surgery is still tentative. Both cochleostomy (CO) and round window (RW) techniques are used today. In the present study we analyzed size variations and topographic anatomy of the ‘hook' region of the human cochlea to better comprehend the Testo effects of various electric array insertion modes. Material and Methods: Size variations of the cochlear ‘hook' region were assessed in 23 human, microdissected temporal bones by measuring the distances between the oval and round windows, also outlining the spiral ligament/spiral lamina. Influence of size variations on spiral ligament position and fundamentals for different surgical approaches were evaluated in a subset of ‘small' and ‘large' cochleae performing different types of CO. In addition, the relationship between the microdissected accessory canal housing the inferior cochlear vein and the RW was analyzed. Results: The lateral vestibular wall and the cochlear ‘hook' displayed large anatomic variations that greatly influenced the size of the potential surgical area. Results showed that only very inferiorly located CO entered the scala tympani without causing trauma to the spiral ligament and spiral lamina. An inferior approach may challenge the inferior cochlear vein. Conclusion: Preoperative assessment of the distance between the round and oval windows may direct the surgeon before CI hearing-preservation surgery. CO techniques, especially in ‘small' ears, may lead to frequent damage to the inner ear structures. In those cases with substantial residual hearing, CI surgery may be better performed through a RW approach. i 2014 S. Karger AG, Basel

Double Channel Pylorus as a Complication of Peptic Ulcer Disease

Introduction: Double channel pylorus is a rare condition consisting of a gastro duodenal fistula extending from the gastric antrum to the duodenal bulb through an accessory canal. The double pylorus is a destructive but relatively benign complication of peptic ulcer disease. It could be congenital or acquired. Case Report: A 73-year-old female with history of cirrhosis secondary to non-alcoholic steatohepatitis with splenomegaly, thrombocytopenia, and peptic ulcer disease was admitted to the hospital for progressive shortness of breath and noted to have iron deficiency anemia. The patient underwent screening upper endoscopy as a part of screening for esophageal varices. She was noted to have some antral thickening extending to pylorus. Biopsies showed that the thickening was only focal fibrosis and reactive glandular atypia, but no tumor. Six months later, the patient was readmitted with worsening shortness of breath, and was found to have anemia and positive occult blood. Colonoscopy was done as a part of work-up, which was completely normal. Later, the patient underwent esophagogastroduodenoscopy (EGD). On EGD, the changes were consistent with mild gastritis and a duplicate opening lying adjacent to pyloric channel. The scope was passed through both the openings. First was the native pyloric channel. The duplicated pyloric channel seemed to open into the second part of the duodenum, and there was a large, clean bases ulcer, but no fistulas. There was shelve of normal tissue diving the 2 openings. Upper GI series was also done to confirm the diagnosis. Discussion: The prevalence of double pylorus varies from 0.06 to 0.4%; however, its real incidence remains unknown. It occurs more often in men (2:1), as well as with other peptic diseases. Malignant tumors resulting in formation of double pylorus is extremely rare. Clinical symptoms are similar to those of peptic ulcer disease. They are identified on upper endoscopy and can also be seen on barium meal study. Convergence of double pyloric canals resulting into 1 large gastrointestinal passage can predispose to bile reflux. Other complications, like hemorrhage or intractable pain, may require surgical intervention. Double channel pylorus is a rare but important complication of peptic ulcer disease, and should be identified early to prevent complications.

The Radix Entomolaris and Paramolaris: A Micro–Computed Tomographic Study of 3-rooted Mandibular First Molars

IntroductionThe morphology of the supernumerary third root (radix) in mandibular first molars was examined by micro–computed tomography (μCT) scanning. MethodsNineteen permanent mandibular first molars with radix were scanned in a μCT device to evaluate their morphology with respect to root length, root curvature direction, location of radix, apical foramen, accessory canals and apical deltas, and distance between canal orifices as well as 2- and 3-dimensional parameters of the canals (number, area, roundness, major/minor diameter, volume, surface area, and structure model index). Quantitative data were analyzed by 1-way analysis of variance and the Tukey test (α = 0.05). ResultsThe mean length of the mesial, distal, and radix roots was 20.36 ± 1.73 mm, 20.0 ± 1.83 mm, and 18.09 ± 1.68 mm, respectively. The radix was located distolingually (n = 16), mesiolingually (n = 1), and distobuccally (n = 2). In a proximal view, most radix roots had a severe curvature with buccal orientation and a buccally displaced apical foramen. The spatial configuration of the canal orifices on the pulp chamber floor was mostly in a trapezoidal shape. The radix root canal orifice was usually covered by a dentinal projection. The radix differed significantly from the mesial and distal roots for all evaluated 3-dimensional parameters (P < .05). The radix canal had a more circular shape in the apical third, and the mean size of the minor diameter 1 mm short of the foramen was 0.25 ± 0.10 mm. ConclusionsThe radix root is an important and challenging anatomic variation of mandibular first molars, which usually has a severe curvature with a predominantly distolingual location, and a narrow root canal with difficult access.

Double mandibular foramen leading to the accessory canal on the mandibular ramus.

The knowledge of the variation in the mandibular foramen and canal is clinically significant in surgical procedures of the mandible. This study aims to evaluate the anatomical characteristics of double mandibular foramen leading to the accessory canal on the mandibular ramus using cone beam CT. The sagittal, cross-sectional, and three-dimensional images of cone beam CT data from 446 patients were evaluated in the presence of double mandibular foramen and the accessory canal passing through the foramen. The accessory canals were classified into two types according to the configuration (forward and retromolar type), and the location of double mandibular foramen was recorded. The eight double mandibular foramina leading to the accessory canals were observed in six patients out of 446 patients (1.35 % of population). Regarding the configuration of the accessory canal, there were two forward types and six retromolar types. All double mandibular foramina were located above the mandibular foramina on the medial aspect of the mandibular ramus. Three-dimensional images of cone beam CT data are useful in confirming the presence of double mandibular foramen leading to the accessory canal. The variation may cause failure in the routine mandibular nerve block anesthesia and it is often vulnerable during surgical procedures involving the mandibular ramus. Also, double mandibular foramen is considered as an easy route for tumor cell to spread following the radiotherapy. Therefore, the variation should be carefully investigated using reconstructed cone beam CT images in planning of dental surgery or radiotherapy in the mandible.

Root canal morphology of permanent maxillary and mandibular canines in Indian population using cone beam computed tomography.

Aim. To investigate the root canal anatomy of single-rooted permanent maxillary and mandibular canines in an Indian population using cone beam computed tomography (CBCT). Methodology. A total of 250 permanent maxillary canines and 250 permanent mandibular canines were selected and scanned using CBCT. The root anatomy of each tooth was evaluated for the following parameters: the pattern of the root canals, anatomic length of the crown and the root, the presence of accessory canals, the shape of the access cavity, the position of the apical foramina, root diameter, and dentin thickness of the root. Results. Majority of the teeth had a Type I canal configuration in both maxillary canines (81.6%) and mandibular canines (79.6%). In maxillary canine the other canal patterns found were Type III (11.6%), Type II (2.8%), Type V (2%), Type XIX (1.2%), and Type IV (0.8%). In mandibular canines the various other canal patterns found were Type III (13.6%), Type II (3.2%), Type V (2%), and Type XIX (1.6%). Apical foramina were laterally positioned in the majority of the teeth, 70.4% and 65.6% in maxillary and mandibular canines, respectively. 12% of the maxillary canines and 12.8% of the mandibular canines had accessory canals. Conclusion. The root canal anatomy of permanent maxillary and mandibular canines varied widely in an Indian population.

Cone beam computed tomographic analysis of neurovascular anatomical variations other than the nasopalatine canal in the anterior maxilla in a pediatric population.

This study aimed to analyze and assess the presence of accessory foramina and canals other than the nasopalatine canal (NPC) in the anterior palate region in a pediatric population, through cone beam computed tomography (CBCT) images, describing their location, direction, and diameter. Reformatted sagittal, coronal and axial slices of 368 individual CBCT images were analyzed. Any bone canal with a minimum diameter of 1.00 mm other than the nasopalatine canal was analyzed regarding size, location, and course, as well as patient gender and age. Eighty-two patients (22.3 %); presented additional foramina in the anterior palate (AFP) and in total 131 additional foramina were registered. A higher frequency of accessory canals was observed in girls (29.5 %) than in boys (15.7 %) (p = 0.012). The average diameter of AFP was 1.2 mm. Their location was variable, with most of the cases occurring in the alveolar process near the incisors or canines. Gender and age did not significantly influence the diameter. The study confirms the presence of bone channels within the anterior maxilla other than the NPC in a pediatric population. Over 22 % of the population studied had additional foramina other than the NPC in the anterior palate, between 1 and 1.7 mm wide, with variable locations.

Unique Feeding Morphology in a New Prognathous Extinct Porpoise from the Pliocene of California

Modern porpoises (Odontoceti: Phocoenidae) are some of the smallest cetaceans and usually feed near the seafloor on small fish and cephalopods [1-3]. Within both extinct and extant phocoenids, no evidence for specialized mandibular morphology has been documented [4-7]. Here we describe a new species of extinct porpoise, Semirostrum ceruttii, from the marine Pliocene San Diego (4.2-1.6 mega-annum, Ma) and Purisima (5-2.5 Ma) formations of California. The mandibles comprise a long, fused, and nearly edentulous prognathous symphysis, extending farther beyond the rostrum than in any known mammal. Phylogenetic analyses based on morphology reconstruct Semirostrum ceruttii as sister to extant (crown) porpoise species with moderate support. We describe the spectacularly preserved holotype specimen based on computed tomography (CT) scans, which allowed visualization of the elongate mental and accessory canals within the symphysis. The elongate canals are similar to those found in Rynchops birds [8] and were likely involved in sensory function. Oblique labial wear facets present on numerous small conical mandibular teeth posterior to the symphysis suggest regular contact with benthic substrate. The unique mandibular and dental characteristics, along with robust scapulae, sternum, and unfused cervical vertebrae, support the interpretation that this species employed a form of benthic skim feeding by using its mandible to probe for and obtain prey.

Cone beam CT evaluation of the presence of anatomic accessory canals in the jaws

To assess the prevalence, location and anatomical course of accessory canals of the jaws using cone beam CT. A retrospective analysis of 4200 successive cone beam CT scans, for patients of both genders and ages ranging from 7 to 88 years, was performed. They were exposed at the School of Dentistry, University of Michigan, Ann Arbor, MI. After applying the exclusion criteria (the presence of severe ridge resorption, pre-existing implants, a previously reported history of craniofacial malformations or syndromes, a previous history of trauma or surgery, inadequate image quality and subsequent scans from the same individuals), 4051 scans were ultimately included in this study. Of the 4051 scans (2306 females and 1745 males) that qualified for inclusion in this study, accessory canals were identified in 1737 cases (42.9%; 1004 females and 733 males). 532 scans were in the maxilla (13.1%; 296 females and 236 males) and 1205 in the mandible (29.8%; 708 females and 497 males). A network of accessory canals bringing into communication the inner and outer cortical plates of the jaws was identified. In light of these findings, clinicians should carefully assess for the presence of accessory canals prior to any surgical intervention to decrease the risk for complications.

A novel methodology providing insights into removal of biofilm‐mimicking hydrogel from lateral morphological features of the root canal during irrigation procedures

To introduce and characterize a reproducible hydrogel as a suitable biofilm mimic in endodontic research. To monitor and visualize the removal of hydrogel from a simulated lateral canal and isthmus for the following: I) Ultrasonic-Activated Irrigation (UAI) with water, ii) UAI with NaOCl and iii) NaOCl without UAI. A rheometer was used to characterize the viscoelastic properties and cohesive strength of the hydrogel for suitability as a biofilm mimic. The removal rate of the hydrogel from a simulated lateral canal or isthmus was measured by high-speed imaging operating at frame rates from 50 to 30,000 fps. The hydrogel demonstrated viscoelastic behaviour with mechanical properties comparable to real biofilms. UAI enhanced the cleaning effect of NaOCl in isthmi (P < 0.001) and both NaOCl and water in lateral canals (P < 0.001). A greater depth of cleaning was achieved from an isthmus (P = 0.009) than from a lateral canal with UAI and also at a faster rate for the first 20 s. NaOCl without UAI resulted in a greater depth of hydrogel removal from a lateral canal than an isthmus (P < 0.001). The effect of UAI was reduced when stable bubbles were formed and trapped in the lateral canal. Different removal characteristics were observed in the isthmus and the lateral canal, with initial highly unstable behaviour followed by slower viscous removal inside the isthmus. The biofilm-mimicking hydrogel is reproducible, homogenous and can be easily applied and modified. Visualization of its removal from lateral canal anatomy provides insights into the cleaning mechanisms of UAI for a biofilm-like material. Initial results showed that UAI improves hydrogel removal from the accessory canal anatomy, but the creation of stable bubbles on the hydrogel-liquid interface may reduce the cleaning rate.

Can MTA be: Miracle trioxide aggregate?

Mineral trioxide aggregate (MTA) has been used for more than 10 years in the dental community and has often been thought of as a material of choice for the endodontist. The dental pulp is closely related to periodontal tissues through apical foramina, accessory canals, and dentinal tubules. Due to this interrelationship, pulpal diseases may influence periodontal health and periodontal infections may affect pulpal integrity. It is estimated that pulpal and periodontal problems are responsible for more than 50% of tooth mortality. Thus, these associations recommend an interdisciplinary approach. MTA appears to exhibit significant results even in periodontal procedures as it is the first restorative material that consistently allows for over-growth of cementum and may facilitate periodontal tissue regeneration. Thus, in the present review, an attempt is made to discuss the clinical applications of MTA as an interdisciplinary approach.

Bilateral accessory mental foramina and canals: Report of an extremely rare anatomical variation

The mental nerve is a somatic afferent sensory nerve of the mandibular nerve that emerges from the mental foramen and which presents as a single circular, or elliptical, bilateral radiolucent area in the premolar region. The mental foramen is an important anatomical structure of particular importance in local anesthesia and surgical procedures in terms of achieving effective mandibular nerve blocks and avoiding injuries to the neurovascular bundles. Accessory mental foramen is a rare anatomical variation. Even so, in order to avoid neurovascular complications, particular attention should be paid to the possible occurrence of one or more mental foramen during surgical procedures involving the mandible. The purpose of the present report was to present a case the bilateral accessory mental foramina observed on cone-beam computed tomography and review the relevant literature.

Neurovascular content of the mandibular canal and its clinical relevance: A literature review of the related anatomical and radiological studies

In literature, anatomical variations of the inferior alveolar nerve branches (infratemporal, extraosseous and intraosseous) are reported and their importance in clinical practice is discussed too. The spatial vessels ' position in relationship with the nerve in the mandibular canal was explored, which is of clinical significance in impacted third molar and implant surgery. It is believed that the neurovascular content of the main mandibular canal follows any variations of the mandibular canal i.e. bifid mandibular, retromolar and accessory mental canals. Retrospective studies and case reports reported the presence of multiple foramina on the medial surface of the ramus, near the main mandibular foramen. In some cases, one supplementary mandibular foramen was found to be connected with the lower third molar, which is called 'temporal crest canal'. Others found an accessory mandibular foramen that led into a second mandibular canal which joined the main mandibular canal (double) anteriorly. The bony canals contained a terminal branch of the anterior trunk of the mandibular nerve or a branch of inferior alveolar nerve before it entered the mandibular foramen. The aim of the study was to describe and classify anatomical structures of the mandibular canal and posterior foramina of the mandible through an extensive review of the corresponding studies via the PubMed, Scopus and Google Scholar databases.

Add a third dimension to your patient care with cone beam computed tomography

Cone-beam computed tomography (CBCT) has been specifically designed to produce undistorted three-dimensional information of the maxillofacial skeleton, including the teeth and their surrounding tissues with a significantly lower effective radiation dose compared with conventional computed tomography. The revolutionary introduction of CBCT in all fields of dentistry is unprecedented as it has created a true paradigm shift from a conventional two-dimensional approach to a three-dimensional understanding. In doing so it has expanded the role of imaging from its traditional one in diagnosis to image guidance of operative and surgical procedures. Clinical Relevance To Interdisciplinary Dentistry Detecting anatomical variants such as accessory neurovascular canals, bony undercuts, and local alterations in trabecular patterns, all of which influence implant treatment planning Identification of root canal system anomalies and determination of root curvature for successful endodontic practice Cone beam computed tomography, offers an opportunity to see inside the bone and pinpoint and measure densities in small localized areas such as a vertical periodontal defect or alveolar bone graft Three-dimensional and cross-sectional evaluation of the implant patient and it allows virtual implant placement that can guide the implantologist in terms of density and thickness of the alveolar bone.

Morphologic Classification of Root Canals and Incidence of Accessory Canals in Maxillary First Molar Palatal Roots: Three-Dimensional Observation and Measurements using Micro-CT

Morphologic Classification of Root Canals and Incidence of Accessory Canals in Maxillary First Molar Palatal Roots: Three-Dimensional Observation and Measurements using Micro-CT

The incidence and configuration of the bifid mandibular canal in Koreans by using cone-beam computed tomography

PurposeThis study was performed to investigate the incidence and configuration of the bifid mandibular canal in a Korean population by using cone-beam computed tomography (CBCT) imaging.Materials and MethodsCBCT images of 1933 patients (884 male and 1049 female) were evaluated using PSR-9000N and Alphard-Vega 3030 Dental CT units (Asahi Roentgen Ind. Co., Ltd, Kyoto, Japan). Image analysis was performed by using OnDemand3D software (CyberMed Inc., Seoul, Korea). The bifid mandibular canal was identified and classified into four types, namely, the forward canal, buccolingual canal, dental canal, and retromolar canal. Statistical analysis was performed by using the chi-squared test and one-way analysis of variance (ANOVA).ResultsBifid mandibular canals were observed in 198 (10.2%) of 1933 patients. The most frequently observed type of bifid mandibular canal was the retromolar canal (n=104, rate: 52.5%) without any significant difference among the incidence of each age and gender. The mean diameter of the accessory canal was 1.27 mm (range: 0.27-3.29 mm) without any significant difference among the mean diameter of each type of the bifid mandibular canal. The mean length of the bifid mandibular canals was 14.97mm(range: 2.17-38.8 mm) with only a significant difference between the dental canal and the other types.ConclusionThe bifid mandibular canal is not uncommon in Koreans and has a prevalence of 10.2% as indicated in the present study. It is suggested that a CBCT examination be recommended for detecting a bifid canal.

A morphological study of the multi infraorbital canals of the maxilla in the Japanese macaque by cone-beam computed tomography

The infraorbital canal in the Japanese macaque is composed of main and accessory canals. However, the morphological features of the infraorbital canal, such as the canal course and the supply of infraorbital vessels and nerves in the maxilla, are poorly characterized. In this study, we show the structure of the infraorbital canal of the Japanese macaque (adults; 10 male, 9 female), including the distribution of these vessels and nerves, using cone-beam computed tomography and a macroscopic apparatus. The superior and lateral margins of the orbit were correlated with the infraorbital canal on three-dimensional reconstruction images (P<0.05). We classified three types of multi infraorbital foramina as follows: type 1 had one accessory foramen, type 2 had two accessory foramina, and type 3 had three accessory foramina in the infraorbital canal. The infraorbital canal also formed three structures, specifically, a tube-like shape, a funnel shape, and a pinched shape. The accessory canals also contained nerves and blood vessels, and the canals ran downward and supplied the maxillary sinus, teeth, and midfacial region of the craniofacial skeleton, while passing through a few branch canals. These accessory canals proved valuable for blood vessels and nerves and allowed us to recognize the maxilla in the Japanese macaque skull.

Irrigant transport into dental microchannels

The root canal system of a tooth is a complex geometrical entity, consisting not only of the main root canal, but also of accessory and lateral canals. Bacteria can reside up to hundreds of micrometers inside those channels and may be difficult to reach for the antimicrobial agents with which root canals are irrigated during a root canal treatment. A combined numerical and experimental study was performed to assess the penetration rate of a root canal irrigant into the lateral canals and tubules, considering both diffusion and convection. The numerical model was validated experimentally using a fluorescent dye. Convection was studied separately using a Computational Fluid Dynamics model, validated with Particle Imaging Velocimetry experiments. Both diffusion and convection were found to be slow on the timescale of an irrigation procedure. The contribution of convection was limited to two canal diameters from the canal entrance, making diffusion the main irrigant transport mechanism. More than 10 min of fresh irrigant delivery was required to obtain an 86 % concentration of the irrigant at the far end of a tubule, in the ideal case of a straight tubule without reaction taking place. Diffusion was even slower when the concentration at the lateral canal entrance was not kept constant, as in the case of a single delivery, which suggests that frequent irrigant replenishment and/or irrigant activation during a root canal treatment are beneficial. Alternative methods should be considered to improve irrigant penetration into lateral canals and tubules.

Comparison of Alternative Image Reformatting Techniques in Micro–Computed Tomography and Tooth Clearing for Detailed Canal Morphology

IntroductionMicro–computed tomography (MCT) shows detailed root canal morphology that is not seen with traditional tooth clearing. However, alternative image reformatting techniques in MCT involving 2-dimensional (2D) minimum intensity projection (MinIP) and 3-dimensional (3D) volume-rendering reconstruction have not been directly compared with clearing. The aim was to compare alternative image reformatting techniques in MCT with tooth clearing on the mesiobuccal (MB) root of maxillary first molars. MethodsEighteen maxillary first molar MB roots were scanned, and 2D MinIP and 3D volume-rendered images were reconstructed. Subsequently, the same MB roots were processed by traditional tooth clearing. Images from 2D, 3D, 2D + 3D, and clearing techniques were assessed by 4 endodontists to classify canal configuration and to identify fine anatomic structures such as accessory canals, intercanal communications, and loops. ResultsAll image reformatting techniques in MCT showed detailed configurations and numerous fine structures, such that none were classified as simple type I or II canals; several were classified as types III and IV according to Weine classification or types IV, V, and VI according to Vertucci; and most were nonclassifiable because of their complexity. The clearing images showed less detail, few fine structures, and numerous type I canals. Classification of canal configuration was in 100% intraobserver agreement for all 18 roots visualized by any of the image reformatting techniques in MCT but for only 4 roots (22.2%) classified according to Weine and 6 (33.3%) classified according to Vertucci, when using the clearing technique. ConclusionsThe combination of 2D MinIP and 3D volume-rendered images showed the most detailed canal morphology and fine anatomic structures.