scholarly journals Maxillary Incisors of the Horse before and at the Beginning of the Teeth Shedding: Radiographic and CT Study

Animals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1618
Author(s):  
Francisco Miró ◽  
Carla Manso ◽  
Andrés Diz ◽  
Manuel Novales

To gain insight into the radiographic appearance of maxillary deciduous incisors and dental germs of maxillary permanent incisors in the period prior to teeth shedding, radiographs and computed tomography (CT) of 25 horse skulls, with an estimated age of between 12 and 42 months, were studied. Data regarding morphology and development were obtained. Dental germs of first maxillary permanent incisors were identified radiographically as rounded radiolucent areas at the level of the apical parts of the first deciduous incisors, in skulls with an estimated age of twelve months. The first sign of crown mineralization of these dental germs appeared in skulls supposedly a few months older. Before teeth shedding, the unerupted, mineralized crowns of the first permanent incisor could be identified radiographically relatively caudal to the corresponding first deciduous incisors. The results of the present study indicate that radiographic intraoral images are suitable to identify the grade of development of the dental germs of maxillary permanent incisors. A detailed description of the radiographic appearance of deciduous incisors and dental germs of permanent incisors will help clinicians to expand their knowledge for diagnostic or treatment purposes.

2011 ◽  
Vol 50 (43) ◽  
pp. 10255-10255 ◽  
Author(s):  
Simon D. M. Jacques ◽  
Marco Di Michiel ◽  
Andrew M. Beale ◽  
Taha Sochi ◽  
Matthew G. O'Brien ◽  
...  

2013 ◽  
Vol 111 (2) ◽  
pp. 90-95.e2 ◽  
Author(s):  
Jae-Woo Jung ◽  
Jae-Woo Kwon ◽  
Tae-Wan Kim ◽  
So-Hee Lee ◽  
Kyung-Mook Kim ◽  
...  

Author(s):  
Cristiane Martins Rodrigues Bernardes ◽  
Luiz Eduardo Gregoris Rabelo ◽  
Cyntia Rodrigues DE Araújo Estrela ◽  
Orlando Aguirre Guedes ◽  
Brunno Santos DE Freitas Silva ◽  
...  

Introduction: The prevalence of Apical Root Resorption (ARR) after orthodontic treatment is high. It is associated with several factors, such as tooth group, type and duration of treatment, applied force and root morphology. Aim: To evaluate the apical root morphology of maxillary incisors in a Brazilian subpopulation using Cone Beam Computed Tomography (CBCT) images. Materials and Methods: In this retrospective and cross-sectional study, 400 maxillary incisors from 167 patients registered in the data base of Dental Radiology Clinics between January 2012 and April 2017 were analysed. The apical root configuration was verified by navigating 0.1 mm/0.1 mm, in the three planes, axial, coronal, and sagittal sections on CBCT images, from the root canal entrance to the apical foramen, as well as from the apical direction to the crown. The standard reference for apical root form corresponded to the long axis of the tooth. The root forms and their frequency were characterised according to the classification proposed by Levander and Malmgren (1988). The qualitative variables were analysed by the Chi-square test. The level of significance was p-value <0.05. Results: A total of 400 maxillary anterior teeth (central and lateral incisors; n=200 each) from 167 patients (101 women; mean age was 41.8±16.20 years) were analysed. The most common apical root form presented in the central incisors was the blunt root {99 (49.5%)}, followed by pipette-shaped root {69 (34.5%)}. The less frequent was the short root {13 (6.5%)} (p-value <0.001). In the lateral incisors, the highest frequency presented was lacerated root {111 (55.5%)}, followed by blunt root {47 (23.5%)}, and pipette- shaped root {37 (18.5%)} (p-value <0.001). Conclusion: Maxillary central incisors had a higher frequency of rhomboid (blunt) root morphology, while lateral incisors had a higher frequency of curved (lacerated) root form.


Author(s):  
Najlaa Raihana Juhari ◽  
Chong Aun Wee

<p class="abstract">An odontogenic myxoma is a benign odontogenic tumor with locally aggressive behavior. It is relatively rare in the oral cavity. The diagnosis poses a challenge because its features overlap with those of other benign and malignant neoplasms. We present an unusual case of odontogenic myxoma with involvement of the maxilla extending to the maxillary sinus in a 17-year-old lady. A unique computed tomography (CT) appearance revealed a well circumscribed lytic lesion arising from the left maxilla causing expansion and thinning of the maxillary cortex. There is a discernible tooth with adjacent amorphous calcification in a round formation noted within the lesion. Biopsy revealed an odontogenic myxoma. The patient however did not undergo surgical excision as was not consented at the time of this write ups. This paper highlights the unique radiographic appearance of the pathology that has not been reported so far as well as to discuss its clinical significance.  </p>


2015 ◽  
Vol 1 (1) ◽  
Author(s):  
Azra Akhtar ◽  
Noreen Akhtar ◽  
Sajid Mushtaq ◽  
Usman Hassan ◽  
Ali Raza Khan

Background: Computed tomography (CT) imaging has improved the chances of detecting small indeterminate (<1 cm) lung nodules. The determination of the underlying malignant or benign nature of a lung nodule poses a great diagnostic challenge and depends on a number of factors, including the radiographic appearance of nodule, the presence of non-pulmonary metastases, characteristics of growth and histological criteria. Methods: The medical records of 89 patients admitted to our specialist cancer centre between 2008 and 2013 were reviewed. Patients of all age groups and tumour category were included in the study. Clinical data of these patients were collected and the following parameters were analysed: Radiographic diagnosis, location, size, laterality and number of nodules and histological impression. The radiological findings were then correlated with histopathological findings. The nodules were sub-classified into groups on the basis of size (A = 0–0.5 cm; B = 0.5–0.9 cm; C = 1.0–1.5 cm and D = >1.5 cm). Results: CT scan reports of 89 patients with lung nodules were reviewed. On radiology, 73/89 (82%) were reported to be malignant nodule. Histopathological review of the biopsies of these 89 nodules confirmed malignancy in 50/89 (56.2%) patients. CT scan was found to be highly sensitive (94%, 95% confidence interval [CI]: 83.43–98.68%) but with a very low specificity (33.3%, 95% CI: 19.10–50.22%). CT scan was found to have a higher negative predictive value (81.2%, 95% CI: 54.34–95.73%) and a lower positive predictive value 64.4% (95% CI: 52.31–75.25%) when correlated with histopathological findings. Pathology of these nodules included metastatic sarcoma (27/89; 30.3%) and carcinoma (18/89; 20.2%). The frequency of the biopsy-proven malignant nodules on the right side was 26/45 (57.8%) and on the left side was 24/44 (54.5%) (P = 0.832). Malignant nodules were more frequent in lower lobes (28/43, 65.1%) than in upper lobes (14/32, 43.8%). These two sites combined accounted for 84% of all malignant nodules. There was a significant correlation between nodule size and likelihood of underlying malignancy. The overall prevalence of malignancy in the larger nodules (C and D) was much higher (23/30 and 76.7%) compared to the smaller sized (A and B) nodules (27/58 and 46.8%), P < 0.05.Conclusion: CT scan is a useful tool in the initial clinical assessment of indeterminate lung nodules with high sensitivity (94%) and a high negative predictive value (81.2%).Key words: Computed tomography, fibrosis, indeterminate lung nodule, infection, lung nodule, malignancy, metastases


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Sergio J. Sanabria ◽  
Franziska Baensch ◽  
Michaela Zauner ◽  
Peter Niemz

AbstractWood-based composites hold the promise of sustainable construction. Understanding the influence on wood cellular microstructure in the macroscopic mechanical behavior is key for engineering high-performance composites. In this work, we report a novel Individual Cell Tracking (ICT) approach for in-situ quantification of nanometer-scale deformations of individual wood cells during mechanical loading of macroscopic millimeter-scale wood samples. Softwood samples containing > 104 cells were subjected to controlled radial tensile and longitudinal compressive load in a synchrotron radiation micro-computed tomography (SRµCT) setup. Tracheid and wood ray cells were automatically segmented, and their geometric variations were tracked during load. Finally, interactions between microstructure deformations (lumen geometry, cell wall thickness), cellular arrangement (annual growth rings, anisotropy, wood ray presence) with the macroscopic deformation response were investigated. The results provide cellular insight into macroscopic relations, such as anisotropic Poisson effects, and allow direct observation of previously suspected wood ray reinforcing effects. The method is also appropriate for investigation of non-linear deformation effects, such as buckling and deformation recovery after failure, and gives insight into less studied aspects, such as changes in lumen diameter and cell wall thickness during uniaxial load. ICT provides an experimental tool for direct validation of hierarchical mechanical models on real biological composites.


2015 ◽  
Vol 2 (7) ◽  
pp. 150090 ◽  
Author(s):  
Juan Carlos Cisneros ◽  
Fernando Abdala ◽  
Tea Jashashvili ◽  
Ana de Oliveira Bueno ◽  
Paula Dentzien-Dias

Anomodontia was a highly successful tetrapod clade during the Permian and the Triassic. New morphological information regarding two bizarre basal anomodonts is provided and their palaeoecological significance is explored. The osteology of the recently discovered Tiarajudens eccentricus Cisneros et al . 2011, from the Brazilian Permian, is described in detail. The taxon exhibits unusual postcranial features, including the presence of gastralia. Additional preparation and computed tomography scans of the holotype of Anomocephalus africanus Modesto et al . 1999 discovered in the Karoo Basin of South Africa allow a reappraisal of this genus. Anomocephalus is similar to Tiarajudens with regard to several traits, including a battery of large, transversally expanded, palatal teeth. Molariform teeth are present in the mandible of the African taxon, providing additional insight into the function of the earliest tooth-occlusion mechanism known in therapsids. At least two waves of tooth replacement can be recognized in the palate of Anomocephalus . The outsized, blade-like caniniforms of the herbivorous Tiarajudens allow several non-exclusive ecological interpretations, among which we favour intraspecific display or combat. This behaviour was an alternative to the head-butting practised by the contemporary dinocephalians. Combat specializations that are considered typical of Cenozoic herbivores likely evolved during the Middle Permian, at the time the first communities with diverse, abundant tetrapod herbivores were being assembled.


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