Canal Pattern Research Articles

Building blocks of a fish head: Developmental and variational modularity in a complex system.

Evolution of the vertebrate skull is developmentally constrained by the interactions among its anatomical systems, such as the dermatocranium and the sensory system. The interaction between the dermal bones and lateral line canals has been debated for decades but their morphological integration has never been tested. An ontogenetic series of 97 juvenile and adult Amia calva (Actinopterygii) was used to describe the patterning and modularity of sensory lateral line canals and their integration with supporting cranial bones. Developmental modules were tested for the otic canal and supratemporal commissure by computing correlations in the branching sequence of groups of pores. Landmarks were digitized on 25 specimens to test a priori hypotheses of variational and developmental modularity at the level of canals and dermal bones. Branching sequence suggests a specific patterning supported by significant positive correlations in the sequence of appearance of branches between bilateral sides. Differences in patterning between the otic canal and the supratemporal commissure and tests of modularity with geometric morphometrics suggest that both canals form distinct modules. The integration between bones and canals was insufficient to detect a module. However, both components were not independent. Groups of pores tended to disappear without affecting other groups of pores suggesting that they are quasi-independent units acting as modules. This study provides evidence of a hierarchical organization for the modular sensory system that could explain variation of pattern of canals among species and their association with dermal bones.

A new petalichthyid placoderm from the Early Devonian of Yunnan, China

Pauropetalichthys magnoculus, a new genus and species within the Petalichthyida (Gnathostomata: Placodermi), is described from the Late Emsian (Early Devonian) of Qujing, Yunnan, southwestern China. A three-dimensional reconstruction of the skull roof and neurocranium based on high-resolution computed tomography reveals the pattern of sensory canals, the visceral surface of the skull roof, and the profile of the endocranium. The perichondral lining of the nasal capsules provides the first hard evidence of nasal capsules in petalichthyids. A phylogenetic analysis resolves the new taxon as the most basal member of the Quasipetalichthyidae, an endemic group sister to the Macropetalichthyidae. In light of the newly revealed endocranial features, we discuss the morphological disparity of petalichthyid endocrania. The paleogeographic distribution of the Petalichthyida is summarized to show the group's center of origin and routes of dispersal.

Endodontic Management and Cone Beam Computed Tomography Assessment in a Four Rooted Maxillary First Molar

The success of endodontic treatment not only lies in meticulous cleaning, perfect shaping and precise filling of canels, it also embodies vital importance on familiarity of unusual root canal patterns. This article presents a case report of a maxillary first molar that had two separate palatal roots with distinct canals and also an invitro assessment of an extracted tooth which had a a similar root canal morphology using cone beam computed tomography (CBCT). Both of them highlight the importance of knowing the anatomical variations to achieve a functional and biological favourable outcome in endodontic treatment.

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.

Report of a rare case: a maxillary first molar with seven canals confirmed with cone-beam computed tomography.

Coronal anatomic variations in permanent maxillary molars are unusual; conversely variations involving the number of root canals or number of roots are more common. This case report presents a successful nonsurgical endodontic therapy of left maxillary first molar with three roots and seven root canals. This unusual morphology was diagnosed using a dental operating microscope (DOM) and confirmed with the help of cone-beam computed tomography (CBCT) images. CBCT axial images showed that both of the palatal and distobuccal roots had Vertucci type II canal pattern, whereas the mesiobuccal root canal showed a Sert and Bayirli's type XV configuration. The use of a DOM and CBCT imaging in endodontically challenging cases can facilitate a better understanding of the complex root canal anatomy, which ultimately enables the clinician to explore the root canal system, and therefore treat it far more efficiently.

A Semi-Automatic Method to Extract Canal Pathways in 3D Micro-CT Images of Octocorals

The long-term goal of our study is to understand the internal organization of the octocoral stem canals, as well as their physiological and functional role in the growth of the colonies, and finally to assess the influence of climatic changes on this species. Here we focus on imaging tools, namely acquisition and processing of three-dimensional high-resolution images, with emphasis on automated extraction of canal pathways. Our aim was to evaluate the feasibility of the whole process, to point out and solve – if possible – technical problems related to the specimen conditioning, to determine the best acquisition parameters and to develop necessary image-processing algorithms. The pathways extracted are expected to facilitate the structural analysis of the colonies, namely to help observing the distribution, formation and number of canals along the colony. Five volumetric images of Muricea muricata specimens were successfully acquired by X-ray computed tomography with spatial resolution ranging from 4.5 to 25 micrometers. The success mainly depended on specimen immobilization. More than of the canals were successfully detected and tracked by the image-processing method developed. Thus obtained three-dimensional representation of the canal network was generated for the first time without the need of histological or other destructive methods. Several canal patterns were observed. Although most of them were simple, i.e. only followed the main branch or “turned” into a secondary branch, many others bifurcated or fused. A majority of bifurcations were observed at branching points. However, some canals appeared and/or ended anywhere along a branch. At the tip of a branch, all canals fused into a unique chamber. Three-dimensional high-resolution tomographic imaging gives a non-destructive insight to the coral ultrastructure and helps understanding the organization of the canal network. Advanced image-processing techniques greatly reduce human observer's effort and provide methods to both visualize and quantify the structures of interest.

Root Canal Treatment of Mandibular Second Premolar with Three Separate Roots and Canals Using Spiral Computed Tomographic

Anatomic and internal morphology of a root canal system is more complex and differs for each individual tooth of which mandibular premolars have earned the reputation for having aberrant anatomy. The occurrence of three canals with three separate foramina in mandibular second premolars is very rare. A wider knowledge on both clinical and radiological anatomy especially spiral computed tomographic is absolutely essential for the success of endodontic treatment. These teeth may require skillful and special root canal special shaping and obturating techniques. This paper reports an unusual case of a mandibular second premolar with atypical canal pattern that was successfully treated endodontically.

Detection of Various Anatomic Patterns of Root Canals in Mandibular Incisors Using Digital Periapical Radiography, 3 Cone-beam Computed Tomographic Scanners, and Micro–Computed Tomographic Imaging

IntroductionThe purpose of this study was to compare the accuracy of digital periapical (PA) radiography and 3 cone-beam computed tomographic (CBCT) scanners in the identification of various internal anatomic patterns in mandibular incisors. MethodsForty mandibular incisors were scanned using micro–computed tomographic imaging as the gold standard to establish the internal anatomic pattern. The number of root canals and internal patterns were classified into type I (single canal, n = 12), type Ia (single oval canal, n = 12), and type III (2 canals, n = 16). The teeth were placed in a human mandible, and digital PA radiography and 3 CBCT scans (Kodak 9000 3D [Carestream Health, Rochester, NY], Veraviewepocs 3De [J Morita MFG Corp, Kyoto, Japan], NewTom 5G [QR Srl, Verona, Italy]) were performed. Two blinded examiners classified each tooth's anatomic pattern, which were then compared with the micro–computed tomographic determinations. ResultsConsidering type I and type Ia, which both presented with 1 root canal, there was a high degree of accuracy for all methods used (P > .05). The same result was found for type III. When identifying the shape of single canals (type I), CBCT imaging was more accurate compared with PA radiography. Concerning oval canals (type Ia), there was a significant difference between PA radiography and NewTom CBCT (PA radiography = 44%, NewTom = 88%). However, there were no significant differences between the 3 CBCT units. ConclusionsDouble-exposure digital PA radiography for mandibular incisors is sufficient for the identification of the number of root canals. All CBCT devices showed improved accuracy in the identification of single root canal anatomy when a narrow canal was present. However, the identification of oval canals was improved only with the NewTom CBCT device.

A Rare Root Canal Configuration of Bilateral Maxillary First Molar with 7 Root Canals Diagnosed Using Cone-beam Computed Tomographic Scanning: A Case Report

IntroductionThe complexity of the root canal system of maxillary molars presents a constant challenge in the diagnosis and treatment of these teeth. This case report describes the importance of a surgical operating microscope and cone-beam computed tomographic (CBCT) imaging. MethodsRoot canal treatment of a left maxillary first molar with 3 roots and 7 canals was successfully performed. Seven canals were identified with the help of a surgical operating microscope and CBCT imaging. CBCT images also confirmed the 3 roots and 7 canals in the right maxillary first molar. ResultsCBCT images confirmed a type IV canal pattern in the distal and palatal root, whereas the mesial root had a type VIII canal pattern. ConclusionsThe use of a surgical operating microscope and CBCT imaging helps the clinician to diagnose unusual anatomy of a tooth and facilitate successful endodontic treatment.

The influence of seepage from canals and paddy fields on the groundwater level of neighboring rotation cropping fields: a case study from the lower Ili River Basin, Kazakhstan

In the large-scale irrigation schemes of the lower Ili River Basin of Kazakhstan, crop rotation combines paddy rice and non-rice crops. Continuous irrigation is practiced in paddy fields, whereas other crops are sustained from groundwater after only limited early irrigation. The water table in non-rice crops is raised by seepage from canals and the flooded paddy fields. We investigated the areal extent to which the groundwater level of non-irrigated fields is influenced by seepage from canals and paddy fields by examining the relationship between distance (from canal and paddy field) and groundwater level in upland fields. The groundwater level was influenced for up to 300 and 400 m from the canals and paddy fields, respectively. Geographic information system analysis of crop and canal patterns in the 11 selected years showed that if the zone of influence is 300 and 400 m from the canals and paddy fields, respectively, the groundwater level of most of the area of upland fields was raised by seepage. We conclude that the water supply to cropping fields by seepage from irrigation canals and paddy fields is adequate, but the spatial distribution of the paddy fields may be an important factor that needs more attention to help improve water use efficiency in this irrigation district.

Spiral computed tomographic evaluation and endodontic management of a maxillary canine with two canals

Aberrations in the root canal system can pose a considerable challenge to the endodontist during root canal treatment. These anatomical variations are more commonly seen in maxillary molars and mandibular teeth, but only a few cases have been reported with alteration in the internal canal anatomy of maxillary canine. The present report describes the diagnosis of bilateral occurrence of two root canals in maxillary canines with single root and the endodontic management of the right maxillary canine with the aid of spiral computed tomography (CT). The CT images revealed the presence of Vertucci's type-III canal configuration in the right maxillary canine. The same canal pattern was found in the contra-lateral canine, which was absolutely healthy; and also all the mandibular anterior teeth and first premolars showed bifid canal pattern.

Microbiological profile and antimicrobial susceptibility pattern of infected root canals associated with periapical abscesses

The aim of this investigation was to identify microorganisms from root canals with periapical abscesses and assess the susceptibility of specific anaerobic bacteria to selected antimicrobials and their β-lactamase production. Sixty root canals were microbiologically investigated. The susceptibility of Anaerococcus prevotii, Fusobacterium necrophorum, F. nucleatum, Parvimonas micra, and Prevotella intermedia/nigrescens to antimicrobials was evaluated with the Etest, whereas β-lactamase production was assessed with nitrocefin. A total of 287 different bacterial strains were recovered, including 201 strict anaerobes. The most frequently strict isolated anaerobes were A. prevotii, P. micra, and F. necrophorum. The selected bacteria were susceptible to all the tested antibiotics, except A. prevotii and Fusobacterium species to azithromycin and erythromycin, as well as A. prevotii and F. necrophorum to metronidazole. None of the microorganisms produced β-lactamase. Gram-positive anaerobic bacteria predominated in the root canals with periapical abscesses. All microorganisms tested were susceptible to benzylpenicillin, amoxicillin, amoxicillin + clavulanate, cefaclor, and clindamycin, producing no β-lactamase.

A micro-computed tomography study of the root canal morphology of the mandibular first premolar in a population from southwestern China

This study aimed to investigate the root canal morphology of mandibular first premolar teeth in a population from southwestern China by micro-computed tomography (micro-CT). Human mandibular first premolars (115) were selected and prepared for micro-CT analysis with a slice thickness of 30 μm. Details of root canal orifices, canals, accessory canals, apical foramina-apical delta intercanal communication, loops and isthmuses, and mesial invagination were analyzed from reconstructed three-dimensional (3D) images. Canal patterns categorized according to the classification defined by Vertucci (Endod Top 10:3-29, 2005) as types I (65.2%), III (2.6%), V (22.6%), and VII were identified (0.9%). Accessory canals were present in 35.7% of the samples and were predominantly located in the apical third of the root. A single apical foramen was observed in 50.4% of the samples and two or three foramina in 28.7% and 14.8%, respectively. Apical delta was identified in 6.1% of the samples and the prevalence of intercanal communication and loops was 3.5% and 7%, respectively. Mesial invagination of the root was identified in 27.8% of the samples, the majority of which contained multiple canals. The data obtained in this study revealed complex root morphology with high prevalence of multiple canals, more than half of which exhibited type I canal patterns. Micro-CT was used as a noninvasive technique for 3D investigation of root canal morphology in the mandibular first premolars of a population from southwestern China. Furthermore, data obtained revealed complex anatomy of various types.

Importancia del microscopio en el análisis de pelos en la Criminología y en la Criminalística

Introduction: The use of the microscope in hair analysis as forensic evidence at the scene of the crime continues to be an extremely important tool. It is macroscopically impossible to identify characteristics of hair, such as the presence or absence of medulla, pigmentation, medullary canal pattern, which permit determination of which animal species the hair belongs to. By using the microscope, it is also possible to find elements which contribute to explain a criminal event, such as adherences or inclusions, which could be related to the victim or aggressor. Material and Method: In the present article, different samples of animal and human hair were analyzed by microscope, in order to observe their microscopic characteristics. Results: Differences were observed in hair elements according to animal or human origin, especially in the medullary canal and the quantity of pigment the hair element had. Conclusions: The use of the microscope allows the observation of characteristic differences between hair elements of human and animal origin; it is therefore an indispensable tool in the criminalistic investigation process.

DIVERSITY OF WATERSIDE SPACE IN PHRA NAKHON AS WALLED DISTRICT OF BANGKOK, IN EARLY TWENTY CENTURY

This study aims to demonstrate how the diverse waterside spaces were coexisted in Phra Nakhon area as the walled district of Bangkok in early twentieth century by using century-old cadastral maps, land-ownership registers and our own architectural surveys of existing buildings. Focusing on the patterns of canals, roads, land parcels and buildings of the century-old cadastral maps, firstly, we classify waterside spaces to five types and explains spatial composition of each type. Secondly, we analyze and characterize the relationship between spatial compositions, their locations, and land uses of waterside space into five types. Our study is the first study that integrates the century-old cadastral maps and corresponding land-ownership registers of Bangkok.

Root canal treatment of a mandibular second premolar with atypical canal pattern

To present a unique case of mandibular second premolar with an atypical canal pattern. Thorough knowledge of root canal morphology, appropriate assessment of the pulp chamber floor, and critical interpretation of radiographs are a prerequisite for successful root canal treatment. Mandibular premolars frequently exhibit variable and complex root canal morphology and are one of the most difficult cases to treat endodontically. These teeth may require skillful and special root canal preparation and obturation techniques. This article reports an unusual case of a mandibular second premolar with atypical canal pattern that was successfully treated endodontically.

Geographies of Mars: seeing and knowing the red planet

One of the first maps of Mars, published by an Italian astronomer in 1877, with its pattern of canals, fueled belief in intelligent life-forms on the distant red planet - a hope that continued into the 1960s. Although the Martian canals have long since been dismissed as a famous error in the history of science, K. Maria D. Lane argues that there was nothing accidental about these early interpretations. Indeed, she argues, the construction of as an incomprehensibly complex and engineered world both reflected and challenged dominant geopolitical themes during a time of major cultural, intellectual, political, and economic transition in the Western world. Geographies of Mars telescopes in on a critical period in the development of the geographical imagination, when European imperialism was at its zenith and American expansionism had begun in earnest. Astronomers working in the new observatories of the American Southwest or in the remote heights of the South American Andes were inspired, Lane finds, by their own physical surroundings, and they used representations of the Earth's arid landscapes to establish credibility for their observations of Mars. With this simple shift to the geographer's point of view, Lane deftly explains some of the most perplexing stances on taken by familiar protagonists such as Percival Lowell, Alfred Russel Wallace, and Lester Frank Ward. A highly original exploration of geography's spatial dimensions at the beginning of the twentieth century, Geographies of Mars offers a new view of the mapping of far-off worlds.

“Regenten” (Gentlemanly) Capitalism: Saint-Simonian Technocracy and the Emergence of the “Industrialist Great Club” in the Mid-nineteenth Century Netherlands

The geometric pattern of Amsterdam's canals was iconic of its nineteenth-century social order. The spider's web of canals fanned out along the Amstel river in concentric rings, its barge traffic linking the city to its hinterland, the province of Holland, and to the wider Netherlands of which it is the nominal capital. These canals divided the “Venice of the North” into ninety islands linked by more than a thousand bridges. Imposing aristocratic and merchant houses stretched along the innermost canal ring, theGolden Curveof theGentleman's Canal. At the center of the web lay de Dam, the 200 m long market square built on the first medieval dike protecting the city from the encroaching sea. The three pillars of the Dutch state framed the market square: the Royal Palace of the Merchant King, the Dutch Reformed New Church, and in the nineteenth century, the Amsterdam stock market, the world's oldest exchange.

Assessing human impact on alluvial fan development: a multidisciplinary case-study from Lower Khuzestan (SW Iran)

This paper presents a multidisciplinary approach for studying the evolution of an alluvial fan system in Lower Khuzestan (SW Iran). The study draws on previously collected data from geological and archaeological field campaigns and new data derived from the interpretation of satellite imagery and historical textual sources. Three alluvial fans were identified, successively deposited by the Jarrahi river in progressively downstream/westward direction. Judging from archaeological and historical evidence, the successive phases appear to coincide with a relocation of settlement and irrigation activities. The distributary system of the present-day fan developed over a period of less than four centuries. It is suggested that management of levee breaks by man played a key role in such rapid fan development and in maintaining extremely low gradients. Judging from the extensive patterns of ancient irrigation canals, human activity also played an important role in the formation of the earlier fans.

“Regenten” (Gentlemanly) Capitalism: Saint-Simonian Technocracy and the Emergence of the “Industrialist Great Club” in the Mid-nineteenth Century Netherlands

The geometric pattern of Amsterdam's canals was iconic of its nineteenth-century social order. The spider's web of canals fanned out along the Amstel river in concentric rings, its barge traffic linking the city to its hinterland, the province of Holland, and to the wider Netherlands of which it is the nominal capital. These canals divided the “Venice of the North” into ninety islands linked by more than a thousand bridges. Imposing aristocratic and merchant houses stretched along the innermost canal ring, theGolden Curveof theGentleman's Canal. At the center of the web lay de Dam, the 200 m long market square built on the first medieval dike protecting the city from the encroaching sea. The three pillars of the Dutch state framed the market square: the Royal Palace of the Merchant King, the Dutch Reformed New Church, and in the nineteenth century, the Amsterdam stock market, the world's oldest exchange.