PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “TOOTH CALCIFICATION”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 55 records · Page 3Linked to original sources

Incorporation of tetracycline into impeded and unimpeded mandibular incisors of the mouse.

Twenty-four hours after a tetracycline injection, the unimpeded, and more rapidly erupting, mouse mandibular incisor contained 20% to 44% more tetracycline than the contralateral, uncut incisor. It was concluded that the increased tetracycline incorporation reflected a higher rate of mineralization associated with faster tooth formation in the unimpeded tooth. By measuring the amount of tetracycline which became incorporated at different times after an incisor was shortened, it was possible to investigate an early stage of the response of the incisor to cutting. A significant increase in the capacity of the tooth to incorporate tetracycline was detectable 4 h after shortening the tooth, and this was maximal after another 4 h.

Animals↗

[The effects of premature deciduous molar loss on the succeeding premolars].

By means of panoramic radiographs of 76 patients we investigated the development and eruption of lower premolars following premature loss of their deciduous predecessor. Following extraction of deciduous molars the mineralization of the bicuspids was accelerated. The eruption of the respective bicuspids took place earlier than expected. During eruption root length was shorter than usual for that stage of development. Although the bicuspids reached occlusion earlier than normal, root mineralization continued to normal length.

Bicuspid↗

[The adjustment of the canine teeth adjacent to the cleft depending on the time of late primary osteoplasty].

Timing for secondary bone-grafting is decisive for a successful orthodontic alignment of canines, adjacent to the cleft. This could be shown after evaluation of diagnostic data from 123 patients with unilateral cleft alveolus and cleft lip and palate and in a clinical follow-up of 29 former patients, 7.3 year after treatment. Concerning eruption and periodontal conditions of cleft adjacent canines, better results could always be seen, if bone was grafted, before mineralisation of canine root has reached 3/4 of its total length. If grafting was done after this stage, disturbances in eruption occurred more frequently. Most canines tended to erupt palatally but could successfully be aligned orthodontically. The follow-up study showed good results concerning probing depth, pulp reaction and periodontal stability. Using our own clinical data, best chronologic age for bone grafting lies between 9 1/2 and ten years.

Bone Transplantation↗

[Transfer of 45Ca during amelogenesis studied by autoradiography and electron microscopy].

45Ca transfer through the stratum intermedium and the secreting ameloblasts towards enamel has been studied by quantitative electron microscopical autoradiography in tooth-germs of newborn cats following intravenous injection of the isotope. Two transfer pathways were demonstrated. The relatively more important direct path passed through the stratum intermedium and ameloblast intercellular spaces and reached the enamel directly. The second pathway consisted in an intracellular transfer through the ameloblasts. 45Ca penetrated the cell through its basal pole. The mitochondria were the most highly labeled organelles at the different experimental time intervals studied. A maximum of radioactivity was respectively noticed at 30 min and 1 h in the endoplasmic reticulum and the Golgi apparatus. A total absence of silver grains was noted over the secretory ameloblastic bodies. At 6 h, the highest labeling was observed over enamel and especailly over the inner enamel along the enameldentin junction.

Ameloblasts↗

Development and fine structure of pharyngeal replacement teeth in juvenile zebrafish (Danio rerio) (Teleostei, Cyprinidae).

Teeth are commonly used model systems for the study of epithelial-mesenchymal interactions during organogenesis. We describe here the ultrastructural characteristics of developing pharyngeal replacement teeth in juvenile zebrafish, an increasingly important model organism for vertebrate development. Replacement teeth develop in close association with the dental organ of a functional tooth. Morphogenesis is well advanced prior to the start of cytodifferentiation. Fibrillar enameloid matrix is formed first, followed by the deposition of predentine. Initial mineralization of the enameloid proceeds quickly; maturation involves the presence of ruffled-bordered ameloblasts. Dentine mineralization is inotropic and is mediated by matrix vesicles. Woven-fibred attachment bone matrix is deposited before completion of dentine mineralization. Eruption of fully ankylosed teeth is a fast process and may involve degenerative changes in the pharyngeal epithelium. Mononucleated osteoclasts and clastic cells located in the pulp cavity intervene in tooth resorption prior to shedding. Structural differences with larval, first-generation zebrafish teeth include the presence of dentinal tubules and the absence of an electron-dense covering membrane. Part of these differences may relate to size differences of the teeth. Others, like the site of the replacement tooth bud, suggest that initiation may take place in already committed epithelium from the first initiation event in the larval stage.

Amelogenesis↗

Dental variables associated with differences in severity of fluorosis within the permanent dentition.

The aim of this study was to assess the influence of age at start, duration, and completion of enamel formation, as well as of tooth-eruption age and enamel thickness on the severity of dental fluorosis within the permanent dentition. The material comprised Ugandan children (n = 219), aged 10-14 years, with 28 teeth and at least 1 tooth with fluorosis. The children were permanent residents in districts with either 0.5 mg or 2.5 mg fluoride/l in the drinking water. Fluorosis was assessed on the vestibular surfaces of all teeth using the modified Thylstrup and Fejerskov (TF) index. In order to relate fluorosis to the dental variables, the material was divided into a test group (n = 103), with fluorosis on all teeth, and a reference group (n = 116), with fluorosis on up to 27 teeth. The reference group was used to confirm or refute the findings in the test group. Paired comparisons showed significantly higher median TF scores for the late than for the early mineralizing and erupting teeth. In multiple regression analyses, the age at start, duration, and completion of enamel formation as well as tooth eruption was significantly related to the severity of fluorosis after controlling for enamel thickness (P < 0.05, n = 14). The effect (R2change) of the dental variables on the variation in severity of fluorosis within the dentition was in decreasing order: the duration of enamel formation, age at completion of enamel formation, tooth-eruption age, and the start of enamel formation.

Adolescent↗