Deciduous Premolars of Paleocene Litopterns of São José De Itaboraí Basin, Rio De Janeiro, Brasil

2010 ◽  
Vol 84 (5) ◽  
pp. 858-867 ◽  
Author(s):  
Lílian Paglarelli Bergqvist
Keyword(s):  
Rio De Janeiro ◽  
Deciduous Teeth ◽  
Tooth Replacement ◽  
X Ray ◽  
Lower Jaw ◽  
Replacement Pattern ◽  
Milk Teeth

The order Litopterna is represented in the São José de Itaboraí basin by four species belonging to the families Protolipternidae (Protolipterna ellipsodontoides, Miguelsoria parayirunhor and Asmithwoodwardia scotti) and Proterotheriidae (Paranisolambda prodromus). Only the deciduous teeth of P. prodromus are known so far. Isolated milk premolars are described for P. ellipsodontoides and M. parayirunhor. The known specimens assigned to P. prodromus are redescribed. No milk teeth are known for A. scotti. The upper and lower milk teeth of Protolipternidae, especially dP3, are more molarized than their successors, resembling, in several features later Proterotheriidae. They provide new support for the placement of this family within the order Litopterna. The analysis of the wear level of dp2-4/dP2-4 and X-ray images of the lower jaw of P. prodromus suggests that the second teeth of the premolar series, in upper and lower jaw, are retained milk premolars. Some information on tooth replacement pattern of P. ellipsodontoides and P. prodromus are also provided.

A STUDY ON CLINICAL AND X - RAY FEATURES OF PARTIALLY  EDENTULOUS PATIENTS WITH DENTAL IMPLANT

2011 ◽  
pp. 96-103
Author(s):  
Quang Hai Nguyen ◽  
Toai Nguyen
Keyword(s):  
Dental Implants ◽  
Dental Implant ◽  
Tooth Loss ◽  
Permanent Teeth ◽  
Missing Teeth ◽  
X Ray ◽  
Lower Jaw ◽  
Molar Teeth ◽  
Edentulous Patients ◽  
Missing Tooth

1. Background: Loss of permanent teeth is very common, affected chewing function, speech and aesthetics; restoration of missing teeth with dental implant has several advantages, but we need thoroughly study the clinical and X ray features at the position at missing teeth, then to select the type of implant and make the best plan for the dental implant patients. 2. Materials and method: Cross-section descriptive study. From January 2009 to November 2010, study with 56 patients with 102 implants of MIS and Megagen systems at the Faculty of Odonto-Stomatology, Hue College of Medicine and Pharmacy and Vietnam-Cuba Hospital in Ha Noi. 3. Results: Distributed equally in male and female, common ages 40 – 59 (55,4%), the majority of missing teeth occurs in the lower jaw (63,8%) and especially, the teeth 36 and 46 (25,4%). The majority of missing teeth due to dental caries, dental pulp and apical diseases (64,7%) of the molar teeth (51,9%); the most position of missing tooth have enough bone for dental implants (87,3%), time of tooth loss and bone status in the position of tooth loss are related to each other (p < 0,01). Diameter and length of implant usually used 4.0 – 6.0 mm (63,7%) and 8.5 – 13.0 mm (83,3%). 4. Conclusion: Clinical and X ray features of edentulous patients has an important role in determining the type of implants and treatment planning of dental implants. Key words: Loss of permanent teeth, X ray and clinical features, Dental implant.

Cranial and dental morphology in a bohaiornithid enantiornithine with information on its tooth replacement pattern

2021 ◽  
pp. 105021
Author(s):  
Di Liu ◽  
L.M. Chiappe ◽  
Becky Wu ◽  
Qingjin Meng ◽  
Yuguang Zhang ◽  
...  
Keyword(s):  
Dental Morphology ◽  
Tooth Replacement ◽  
Replacement Pattern

ANALYSIS OF THE TOPOGRAPHIC DISTRIBUTION OF THYROID ACTIVITY IN A TELEOST FISH: CARASSIUS CARASSIUS L.

1967 ◽  
Vol 56 (3) ◽  
pp. 533-546 ◽  
Author(s):  
Lars Frisén ◽  
Marianne Frisén
Keyword(s):  
Crucian Carp ◽  
Carassius Carassius ◽  
Caudal Part ◽  
Thyroid Activity ◽  
X Ray ◽  
Lower Jaw ◽  
Thyroid Uptake ◽  
Regression Functions ◽  
Sampling Intervals ◽  
High Degree

ABSTRACT Combined autoradiography and X-ray photography has demonstrated that the tissues of the caudal part of the lower jaw and the pronephric region have a considerably larger uptake of radioiodine than other tissues in the immature crucian carp, Carassius carassius L. It is known from previous studies that thyroid follicles occur in these regions. The pronephric thyroid differs from the mandibular thyroid with regard to radioiodine turnover. On an average, the pronephric thyroid has a larger uptake than the lower jaw thyroid. The relative uptakes varied considerably in the population investigated. The ratio mandibular uptake/total thyroid uptake has been determined at several sampling intervals. The means of these ratios show no significant trend with time, a finding which strongly supports the view that the two regions are variably sized parts of a physiologically homogeneous thyroid gland. The analysis is based on a mathematical model of iodine turnover. The method of comparing complex regression functions (sums of exponential functions) should be widely applicable. The correlation between the radioiodine content of either region and total thyroid content is low. Thus, it is necessary to study simultaneously all follicle-carrying tissues in fish with more than one aggregation of thyroid elements. The net radioiodine turnover in the crucian carp indicates a comparatively high degree of thyroid activity and considerably higher than that reported for C. auratus L. This phenomenon is discussed.

scholarly journals Semi-Fixed Space Maintainer Treatment In Premature Loss Deciduous Tooth

2020 ◽  
Vol 5 (2) ◽  
pp. 9-21
Author(s):  
Nabila Clara ◽  
Jeffrey .
Keyword(s):  
Child Development ◽  
Growth And Development ◽  
Loop Space ◽  
Tooth Loss ◽  
Development Process ◽  
Deciduous Teeth ◽  
Lower Jaw ◽  
Space Maintainer ◽  
Fixed Space ◽  
Jaw Model

Introduction: The period of deciduous teeth is an important period in child development. Damage to deciduous teeth that occur and cannot be treated conservatively will cause premature decay of teeth which is often called premature loss. A space maintainer is a passive tool used to maintain dental arches due to premature loss of deciduous teeth. Method: An 11-year-old girl accompanied by her mother came to RSGMP Unjani in 2018 with complaints of lower right back teeth missing because they have removed. The patient's mother is worried that her replacement teeth will not grow properly. Intraoral examination revealed tooth loss 85. The study model was analyzed using the Moyers method. Results: Analysis of the lower jaw model showed excess space. Patients were treated with a semi-fixed band and loop space maintainer on teeth 85. Conclusion: Premature loss results in excess space in the arch, so as to prevent further occlusion abnormalities in the child's growth and development process, we need a special tool used to maintain space due to premature loss of deciduous teeth.

scholarly journals Mineralogical characterization of clay mineral assemblages from Rio de Janeiro pegmatites to identify kaolinite and/or halloysite deposits

Cerâmica ◽  
2020 ◽  
Vol 66 (380) ◽  
pp. 483-495
Author(s):  
V. M. J. Salgado-Campos ◽  
L. C. Bertolino ◽  
F. J. da Silva ◽  
J. C. Mendes
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Chemical Analysis ◽  
Rio De Janeiro ◽  
Mineralogical Characterization ◽  
X Ray ◽  
Mineral Assemblages ◽  
Saprolite Zone ◽  
Scanning Electron

Abstract This study reports the mineralogical characterization of kaolin occurrences in the State of Rio de Janeiro, Brazil, to identify new kaolinite and halloysite deposits. Samples were collected in 10 pegmatites with varying sizes for X-ray diffractometry, chemical analysis by X-ray fluorescence, and scanning electron microscopy studies. The results indicated that the kaolin occurrences were of weathered origin, wherein some places there were occurrences of tubular halloysite. Concerning the regolith stratigraphy, samples located in the saprock zone were found to contain kaolinite and/or halloysite contents from 0 to 10.1%, while those located in the saprolite zone contained kaolinite and/or halloysite contents from 16.3% to 34.9%. Kaolinite and/or halloysite-7Å were formed from plagioclase weathering instead of K-feldspar or mica, and the halloysite-7Å occurrence was related to samples in regions with a higher degree of weathering.

scholarly journals Morpho-Chemical Observations of Human Deciduous Teeth Enamel in Response to Biomimetic Toothpastes Treatment

Materials ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1803 ◽  
Author(s):  
Maurizio Bossù ◽  
Roberto Matassa ◽  
Michela Relucenti ◽  
Flavia Iaculli ◽  
Alessandro Salucci ◽  
...  
Keyword(s):  
Early Stage ◽  
Deciduous Teeth ◽  
Variable Pressure ◽  
Clinical Aspects ◽  
Biomimetic Mineralization ◽  
X Ray ◽  
Prevention And Cure ◽  
Mineral Loss ◽  
Enamel Layer

Today, biomaterial research on biomimetic mineralization strategies represents a new challenge in the prevention and cure of enamel mineral loss on delicate deciduous teeth. Distinctive assumptions about the origin, the growth, and the functionalization on the biomimetic materials have been recently proposed by scientific research studies in evaluating the different clinical aspects of treating the deciduous tooth. Therefore, appropriate morpho-chemical observations on delivering specific biomaterials to enamel teeth is the most important factor for controlling biomineralization processes. Detailed morpho-chemical investigations of the treated enamel layer using three commercial toothpastes (Biorepair, F1400, and F500) were performed through variable pressure scanning electron microscopy (VP-SEM) and energy dispersive X-ray spectroscopy (EDS) on deciduous teeth in their native state. A new microscopy methodology allowed us to determine the behaviors of silicate, phosphate, and calcium contents from the early stage, as commercially available toothpastes, to the final stage of delivered diffusion, occurring within the enamel layer together with their penetration depth properties. The reported results represent a valuable background towards full comprehension of the role of organic–inorganic biomaterials for developing a controlled biomimetic toothpaste in biofluid media.

Heterochrony, dental ontogenetic diversity, and the circumvention of constraints in marsupial mammals and extinct relatives

Paleobiology ◽  
10.1666/13034 ◽  
2014 ◽  
Vol 40 (2) ◽  
pp. 222-237 ◽  
Author(s):  
Analía M. Forasiepi ◽  
Marcelo R. Sánchez-Villagra
Keyword(s):  
South America ◽  
Deciduous Tooth ◽  
Deciduous Teeth ◽  
Evolutionary Mechanisms ◽  
Morphological Disparity ◽  
Morphological Diversification ◽  
Long Period ◽  
Dental Eruption ◽  
Replacement Pattern ◽  
Ontogenetic Diversity

In marsupial mammals and their extinct relatives—collectively, metatherians—only the last premolar is replaced, but the timing of dental eruption is variable within the group. Our knowledge of fossils metatherians is limited, but is critical to understanding several aspects of the evolution and morphological diversification of this clade. We analyzed the sequence of eruption of 76 specimens of metatherians, including Sparassodonta, an extinct clade of specialized carnivores from South America. In Sparassodonta (1) the P3/p3 erupt simultaneously, in common with some didelphids (in other didelphids, p3 erupts before P3, whereas in the remaining didelphids, some peramelids, one caenolestid, andPucadelphysthis order is reversed); (2) the upper and lower molars at the same locus erupt more in synchrony than in other carnivorous metatherians in which the lower molars clearly precede the upper equivalents; (3) the upper canine in thylacosmilids and proborhyaenids is hypselodont; (4) species with similar molar morphologies have different morphologies of the deciduous premolars, suggesting diverse diets among the juveniles of different taxa; (5) deciduous teeth are functional for a long period of time, with thylacosmilids even retaining a functional DP3 in the permanent dentition. The retention of the DP3 and the hypertrophied and hypselodont upper canine of thylacosmilids represent clear heterochronic shifts. Specializations in the timing of dental eruption and in the deciduous tooth shape of sparassodonts are evolutionary mechanisms that circumvent constraints imposed by the metatherian replacement pattern and increase morphological disparity during ontogeny.

Otolith-Based Chronology of Brazilian Shellmounds

Radiocarbon ◽  
2019 ◽  
Vol 61 (2) ◽  
pp. 415-433 ◽  
Author(s):  
Carla Carvalho ◽  
Fabiana Oliveira ◽  
Kita Macario ◽  
Tania Lima ◽  
Ingrid Chanca ◽  
...  
Keyword(s):  
Rio De Janeiro ◽  
Brazilian Coast ◽  
X Ray Diffraction ◽  
Geochemical Composition ◽  
X Ray ◽  
Human Bones ◽  
Native Populations ◽  
Micropogonias Furnieri ◽  
Over Time ◽  
Fish Otoliths

ABSTRACTThe radiocarbon (14C) chronology of hunter-fisher-gatherers’ archaeological settlements along the Brazilian coast is usually based on mollusk shells, charcoal from hearths, and eventually human bones. However, fish otoliths are found in several archaeological contexts and may represent a reliable option as a chronological record. In this work, we compare the 14C dates of whitemouth croakers (Micropogonias furnieri) otoliths with dates obtained from other materials (shell and charcoal), collected from shellmounds on the coast of Rio de Janeiro, with the aim of improving the accuracy in the 14C dating of Brazilian shellmounds, strengthening the comprehension of the native populations’ occupational trends and the coeval palaeoceanographic context. Based on x-ray diffraction results for archaeological otoliths, their geochemical composition indicates minimal diagenesis effect over time even under burial conditions in the studied sites. The comparison between otolith dates and dates obtained from other proxies revealed similar results but with decreased deviations in otolith dates in all of the studied sites.

X-Ray Quiz: Lower Jaw Swelling

2005 ◽  
Vol 12 (3) ◽  
pp. 185-187
Author(s):  
AYC Siu ◽  
CH Chung
Keyword(s):  
X Ray ◽  
Lower Jaw
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