Descripción morfométrica de la anatomía externa e interna del Ambystoma mexicanum / Morphometric description of the external and internal anatomy of Ambystoma mexicanum

RESUMEN: El Ambystoma mexicanum o comúnmente llamado axolote, es un anfibio miembro del género Ambystoma que comprende 32 especies presentes desde el sur de Canadá hasta la región central de México. Actualmente esta especie se encuentra en peligro de extinción debido a cambios fisicoquímicos en su medio ambiente y la depredación por organismos introducidos en su hábitat. Dentro de las múltiples estrategias para su conservación se encuentran el desarrollo de programas de investigación, educación y desarrollo del manejo clínico. El objetivo del presente trabajo estuvo enfocado en obtener y analizar datos morfométricos acompañados por una descripción de la anatomía externa e interna de la especie Ambystoma mexicanum con el propósito de contribuir a su conservación. Por lo anterior, cinco ejemplares de la especie Ambystoma mexicanum de 2 años, criados en cautiverio, fueron estudiados para obtener valores morfométricos externos e internos utilizando un calibrador vernier, balanzas analíticas y rayos X. Los resultados de la observación externa mostraron el dimorfismo sexual característico de estas especies presentes en la zona peri cloacal, además, el análisis radiográfico permitió observar y señalar algunas estructuras óseas del esqueleto axial y apendicular. Los ejemplares presentaron un peso promedio de 31,6 g y una longitud de 15,7 cm. Los miembros anteriores mostraron una longitud de 2,92 cm y 2,8 cm en los miembros posteriores. El análisis de los órganos internos mostró que el corazón tiene un peso de 0,036 g y una longitud de 0,75 cm, los pulmones un peso de 0,019 g y una longitud de 2,6 cm, el estómago arrojó una longitud de 4,86 cm y el intestino 10,88 cm. En conclusión, los valores presentados en el presente trabajo sirven de referencia en futuros trabajos de investigación clínica veterinaria y manejo zootécnico del axolote para su conservación y preservación.

SUMMARY: The Ambystoma mexicanum commonly known as axolotl, is an amphibian and member of the genus Ambystoma which includes 32 species that can be found from southern Canada to central Mexico. Currently this species is in danger of extinction due to physicochemical changes in its environment and predation by organisms introduced into its habitat. Among the multiple strategies to aid in its conservation are the development of research programs, education and development of clinical management. The objective of this work is focused on obtaining and analyzing morphometric data accompanied by a description of the external and internal anatomy of the species Ambystoma mexicanum with the purpose of contributing to the conservation of this species. Therefore, five 2-year-old specimens of the Ambystoma mexicanum species, raised in captivity, were studied to obtain external and internal morphometric values using a vernier caliper, analytical balances and X-rays. The results of external observation showed the characteristic sexual dimorphism of these species present in the pericloacal zone. Furthermore, the radiographic analysis allowed to observe and point out some bony structures of the axial and appendicular skeleton. The specimens presented an average weight of 31.60 g and a length of 15.70 cm. The forelimbs showed a length of 2.92 cm and 2.8 cm in the hindlimbs. Analysis of the internal organs showed that the heart had a weight of 0.036 g and a length of 0.75 cm, the lungs a weight of 0.019 g and a length of 2.6 cm, the stomach had a length of 4.86 cm and the intestine 10.88 cm. In conclusion, the values presented in this work serve as a reference for future veterinary clinical research and zootechnical management of the axolotl for its conservation and preservation.

Ontogenetic variation of the odontophore of Luidia superba (Asteroidea: Paxillosida) and its taxonomic implications

Introduction: The sea star odontophore is the structure positioned between the paired oral ossicles, with which they articulate through proximal and distal processes. The internal anatomy structures may be used as taxonomic characters for a precise differentiation between species, so it is necessary to describe the structures variation throughout growth. Objective: To describe the odontophore shape and variation of Luidia superba A. H. Clark, 1917 from specimens of the Gulf of California deposited in the Echinoderm National Collection, ICML UNAM. Methods: A total of 735 specimens were examined to describe the external characters, from which 55 selected specimens, within a range of R = 14 mm and R = 210 mm, were dissected to extract the odontophores and analyzed with geometric morphometrics. Results: Scanning electronic microscopy (SEM) images of the odontophores showing the variations in shape throughout growth are presented. Differences in shape between size groups were confirmed with a Canonical Variables Analysis (P < 0.05). Conclusions: There are three main groups in this size ranges where specialization of the stereom can be observed through the ontogenetic series; the variation in shape of the odontophore shown here is a precedent for the use of internal anatomy as new taxonomic characters of identification.

Introducción: El odontóforo es la estructura posicionada entre las placas orales pareadas con las que se articula a través de procesos proximales y distales. Las estructuras de la anatomía interna se pueden usar como caracteres taxonómicos para la diferenciación más precisa entre especies, por lo que es necesario describir la variación de las estructuras a lo largo del crecimiento. Objetivo: Describir la forma y la variación del odontóforo de Luidia superba A. H. Clark, 1917 de ejemplares del Golfo de California depositados en la Colección Nacional de Equinodermos, ICML UNAM. Métodos: Se revisaron un total de 735 ejemplares para describir los caracteres externos y de las cuales se seleccionaron 55 ejemplares, dentro de un intervalo de R = 14 mm a R = 210 mm, de los cuales se extrajeron los odontóforos y fueron analizados utilizando morfometría geométrica. Resultados: Se presentan imágenes de microscopía electrónica de barrido (MEB) de los odontóforos que muestran las variaciones de la forma durante el crecimiento. Se confirmaron diferencias significativas de la forma entre los grupos de tallas mediante un CVA (p< 0.05). Conclusiones: Se observa especialización del estereoma a lo largo de la serie ontogenética; la variación en la forma del odontóforo aquí mostrada es precedente para el uso de estructuras de la anatomía interna como nuevos caracteres de identificación.

Anatomia macroscópica interna e avaliação elétrica do coração de Bradypus variegatus / Internal macroscopic anatomy and electrical evaluation of the Bradypus variegatus heart

The Bradypus variegatus species presents peculiar anatomophysiological properties and many aspects of its organic systems still need to be clarified, especially regarding the cardiovascular system, given its participation in vital activities. Disorderly anthropic action has had drastic consequences in sloth populations and the need to treat sick and injured animals is increasingly common. To this end, the importance of knowing its characteristics is emphasized. Therefore, this study proposed to describe the internal macroscopic structures of the sloth's heart, as well as to measure the ventricular walls and indicate the electrical activity of the organ. For the dissections, 15 Bradypus variegatus cadavers were used (1 young female, 9 adults females and 5 adult males) belonging to the Área de Anatomia of the Departamento de Morfologia e Fisiologia Animal (DMFA), Universidade Federal Rural de Pernambuco (UFRPE), Recide, PE, Brazil. After they were fixed and preserved, the specimens received a midsagittal incision in the chest, followed by soft tissue folding and removal of ribs to access the heart. The organ was derived from the cavity and sectioned sagittal medially to identify its internal anatomy. Ventricular walls and interventricular septum were measured with a steel caliper (150 mm / 0.02 mm). An electrocardiogram was performed to determine the electrical profile on 5 healthy B. variegatus sloths, living under semi-livestock conditions at the Recife Zoo, PE, Brazil. The electrodes were taken from the regions, scapular and glutes of the animals that were called hugging a keeper during the procedure, carried out in the Zoo itself, using a portable device. Based on the data obtained, sloths have cardiac chambers separated by septa, however between atria and ventricles, in both antimeres, there are atrioventricular ostia, where valves are found, consisting of 3 valves on the right and 2 on the left. The atria are practically smooth inside and have their cavity enlarged by the atria, the right being larger than the left, these having a greater amount of pectineal muscles in relation to the atria. The ventricles have trabeculae and papillary muscles, 3 on the right and 2 on the left. These muscles hold the tendinous chords that connect the valves. The existence of trabeculae marginal septum was not evidenced. The thickness of the wall of the left ventricle, as well as that of the interventricular septum, proved to be greater than the thickness of the wall of the right ventricle, regardless of the age or sex of the animals. Based on the electrocardiographic recordings, the sloths presented sinus rhythm, with a heart rate between 67 and 100 bpm. The electrical axis ranged from -60º to -90º. The P wave is smoother than the QRS complex. While the S-T segment was classified as isoelectric. The T wave was shown to be + and predominantly > or = at 25% of the S wave, which characterized an rS type QRS deflection in both females and males. The general characteristics of the cardiac chambers in sloths are similar to those observe in other domestic and wild mammals. However, the presence of pectineal muscles associated with the atria and auricles differs from that observed in mammals such as the paca and raccoon and in birds such as the ostrich, which have trabecular structures in these cavities. The number of valves in sloths is equal to the anteater. However, it has a marginal trabeculae septum, not seen in Bradypus variegatus. According to the electrocardiographic findings, the rhythm was sinus, but much lower than that observed in the capuchin monkey, which also maintains arboreal habits.(AU)

Mandibular First Molar with Three Roots and Five Canals: A Case Report.

Clinicians may encounter morphological variations in the form of extra roots and extra root canals. Favorable endodontic treatment requires extensive study of the internal anatomy of teeth. The literature reiterates the incidence of more than three canals in mandibular molar. Radix entomolaris (RE) may complicate the root canal treatment of the tooth if left undiagnosed. The middle mesial canal is more common when compared to the middle distal canal. The combination of RE and three distal canals is a rare occurrence. This case report presents a discussion of root canal therapy in a left mandibular first molar with RE and five root canals.

Bilateral mandibular canines with two roots and two separate canals: case report

The mandibular canine is usually considered a single-rooted tooth with a single root canal. However, two canals and more rarely two roots may also occur. This paper reports the case of a patient with bilateral mandibular canines with two roots and two root canals. The initial periapical radiographs of the mandibular right and left canines for endodontic treatment revealed the presence of two roots in each tooth. After coronal opening, the cervical third was prepared with a SX file of the ProTaper® system and root canal length was confirmed using Root ZX electronic apex locator. Root canal preparation was completed with the series of ProTaper® instruments and the root canal was filled with gutta-percha and an epoxy resin-based endodontic sealer according to Tagger's hybrid technique. The final radiographs showed two well-obturated canals ending at the electronically located apexes. The 6-month posttreatment follow-up showed apparent clinical and radiographic success. Clinicians should always consider the presence of anatomical variations in the teeth during endodontic treatments. Despite the low prevalence, variations may occur in the number of roots and root canals of mandibular canines, as demonstrated in this case report.

O canino inferior é tido como um dente unirradiculado e com apenas um canal. Todavia, pode ocorrer o aparecimento de dois canais e, mais raramente, duas raízes. Este artigo apresenta o caso clínico de uma paciente com ambos os caninos inferiores apresentando duas raízes e dois canais radiculares. A radiografia inicial periapical dos caninos mandibulares inferiores direito e esquerdo para tratamento endodôntico revelou a presença de duas raízes em cada um deles. Uma vez realizada a abertura coronária, o preparo do terço cervical foi feito com a lima SX do sistema ProTaper® e a odontometria foi determinada e confirmada eletronicamente com o localizador apical eletrônico Root ZX. O preparo foi finalizado com a série de instrumentos do sistema ProTaper® e a obturação foi realizada com cones de guta-percha e cimento obturador resinoso sob a técnica Híbrida de Tagger. As radiografias finais mostraram dois canais bem obturados terminando nos limites apicais estabelecidos pelos localizadores apicais eletrônicos. O controle de 6 meses mostrou sucesso clínico e radiográfico do tratamento endodôntico. Os clínicos devem sempre considerar a presença de variações anatômicas em todo tratamento endodôntico. A despeito da baixa prevalência, pode haver variações no número de raízes e canais de caninos inferiores, como demonstrado neste caso clínico.

Estudo da anatomia interna do canal radicular em incisivos inferiores pela técnica de diafanização / Root canal anatomy study of lower incisors by the clearing technique

Para o sucesso da terapia endodôntica, é indispensável o pleno conhecimento da anatomia radicular interna, assim como suas variações. Os incisivos inferiores são os menores dentes da arcada humana e apresentam uma raiz fortemente achatada no sentido mesodistal. Esse achatamento é, por vezes, tão grande que determina a divisão do canal radicular em dois, um vestibular e um lingual. O objetivo deste estudo foi analisar por intermédio de diafanização (método que permite observar por transparência a diversificada anatomia radicular) a incidência do número de canais presentes nos terços cervical, médio e apical da raiz de incisivos inferiores humanos. Para isso foram obtidos 150 dentes no banco de dentes da Faculdade de Odontologia da Universidade de Passo Fundo, nos quais se aplicou a técnica de diafanização e injeção de tinta nanquim no interior da câmara pulpar, seguida de conservação em salicilato de metila, o que permitiu observar tridimensionalmente, por transparência, a anatomia interna dos canais radiculares. Os resultados foram submetidos à análise estatística descritiva, e notou-se que 81,63% dos espécimes analisados apresentaram um canal no terço cervical, 53,06% tinham dois canais no terço médio e 71,42% possuíam um canal no terço apical. Com isso é possível concluir que há maior incidência de bifurcação do canal radicular no terço médio da raiz em relação aos terços cervical e apical

To succeed in the endodontic therapy, it's a requisite to have full knowledge of the inner root anatomy, as well as its variations. The lower incisors are the tinniest teeth of the human arcade having a root strongly flattened to the mesio-distal way. This flattening is sometimesas big to split the root canal in two, one vestibular and another lingual.This study has utilized the clearing technique (method that allows tosee through transparency the diverse root anatomy) to accomplish its objective of analyzing the incidence of the canals present in the cervical third, middle and apical of the incisors' roots of human lowers. Fort hat purpose, 150 teeth have been obtained from the Teeth Bank of the Odontology Faculty of the University of Passo Fundo, on which the clearing technique and the injection of Naquin ink in the pulp cavity interior were applied, followed by the conservation in the methylsalicylate, allowing to three-dimensionally observe, through transparency, the internal anatomy of the root canal. The results have been analyzed by descriptive statistics, in which it was observed that81,63% of the analyzed samples have presented one canal in the cervical third; 53,06% have two canals in the middle third and 71,42% have one canal in the apical third. With this it can be concluded that there is a major incidence of the root canal bifurcation in the middle third of the root in relation to the cervical and apical

Condições atípicas da anatomia de canais radiculares em pré-molares inferiores / Atypical situations in root canals anatomy of human mandibular premolars

O conhecimento da anatomia interna de dentes que terão seus condutos radiculares tratados endodônticamente é de fundamental importância para o sucesso do tratamento e do prognóstico desses dentes. Neste estudo, foram discutidas as variações morfológicas que podem ocorrer em relação ao número de canais radiculares presentes no grupo dental dos pré-molares inferiores, bem como os métodos mais eficazes de diagnosticar a presença dessas variações, a fim de ter um diagnóstico mais preciso quanto ao número de canais a serem tratados. Portanto, foi relatado um caso clínico de tratamento endodôntico de um pré-molar inferior com 4 condutos e demonstrados alguns casos de endodontia em pré-molares inferiores com 1, 2 e 3 condutos

The knowledge of the teeth internal anatomy that will receive endodontic treatment is very important for the success of the treatment and prognosis of those teeth. In this study, the morphological variations that may occur in relation to the number of root canals present in the premolar mandibular teeth group were discussed, as well as the most efficient methods to diagnose the existence of these variations, in order to have a clearer diagnosis of the number of root canals to be treated. A case of an endodontic treatment of a mandibular premolar with 4 root canals was reported and some cases of endodontic treatment in mandibular premolars with 1, 2 and 3 root canals were shown