Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “TOOTH RESORPTION”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

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

At least 19 recordsLinked to original sources

Tooth resorption.

Tooth resorption is a common sequela following injuries to or irritation of the periodontal ligament and/or tooth pulp. The course of tooth resorption involves an elaborate interaction among inflammatory cells, resorbing cells, and hard tissue structures. The key cells involved in resorption are of the classic type, which include osteoblasts and odontoclasts. Types of tooth resorption include internal resorption and external resorption. There are two types of internal resorption: root canal (internal) replacement resorption and internal inflammatory resorption. External resorption can be classified into four categories by its clinical and histologic manifestations: external surface resorption, external inflammatory root resorption, replacement resorption, and ankylosis. External inflammatory root resorption can be further categorized into cervical resorption with or without a vital pulp (invasive cervical root resorption) and external apical root resorption. Other variations of resorption include combined internal and external resorption and transient apical breakdown.

Humans↗

A morphometric study of bone and tooth volumes in the pipid frog Xenopus laevis (Daudin), with comments on the importance of tooth resorption during normal tooth replacement.

Volumetric estimations of teeth and bone on serial sections using a semiautomatic image analyzer indicate that, in the polyphyodont dentition of the pipid anuran Xenopus laevis (Daudin), the mean volume of the dentine composing the teeth is about 23.5% of the volume of the supporting maxillae and premaxillae. During tooth replacement, osteoclasts resorb up to 98% of the dentine. Teeth may be resorbed rather than shed in order to conserve tooth constituents because, if shedding of complete teeth did occur, a quantity of calcified tissue equal to perhaps 45 times the volume of the bone of the upper jaw might be lost over an animal's projected life span of about 13-15 years.

Animals↗

Contact microradiographic analysis of feline tooth resorptive lesions.

Feline tooth resorptive lesions were studied using contact microradiographic analysis of ground sections. Contact microdiagram films were developed with a PIAS-imaging device, and decalcification patterns were evaluated, revealing a clear boundary between normal tissue and the resorptive area, which was different from the image of dental caries in humans. By contrasting analysis, decalcification signs appearing in human caries were not observed in feline resorptive lesions.

Adult↗

Expression of matrix metalloproteinase-9 mRNA and protein during deciduous tooth resorption in bovine odontoclasts.

Matrix metalloproteinase-9 (MMP-9, or gelatinase B) is an extracellular proteinase that is highly expressed in osteoclasts and has been postulated to play an important role in their resorptive activity. Although MMP-9 has been reported to play a role in bone resorption, the association of this enzyme during deciduous tooth resorption has not yet been clarified. The purpose of the present study was to increase our understanding of the role of MMP-9 during deciduous tooth resorption. Reverse transcription-polymerase chain reaction (RT-PCR) and northern blot analysis of total RNAs extracted from bovine root-resorbing tissues, which lie between the root of a deciduous tooth and its permanent successor, revealed the expression of mRNA for MMP-9 in the tissue. These results indicate that MMP-9 may be involved in the process of deciduous tooth resorption. In addition, in situ hybridization and immunohistochemistry were also performed to identify the cells that produced MMP-9 in bovine root-resorbing tissue. MMP-9 mRNA was highly expressed in odontoclasts that were aligned along the surface of the tissue. Immunohistochemistry confirmed the predominant localization of MMP-9 in odontoclasts. The present data demonstrate that odontoclasts in deciduous root resorption express MMP-9, which may participate in proteolysis during root resorption of deciduous tooth.

Animals↗

[Studies on factors causing tooth resorption. 1. Role of prostaglandins as a chemical mediator on resorption of deciduous teeth in rabbits].

The aim of this study was to investigate the effects in the administration of indomethacin which is a specific inhibitor of prostaglandins (PGs) in order to understand the role of PGs in physiologic root resorption. For this study, 24 young rabbits aged 7 days which had been in utero for 31-32 days were used. The experimental group (N = 12) was injected with 5.0 mg/kg indomethacin every 12 h, and the control group (N = 12) was injected with normal saline solution every 12 h. 4 animals of each group were sacrificed at the 9th, 11th and 13th day, respectively. Their maxillary deciduous incisors embedded in paraffin were sectioned serially 7 mus in thickness. From each sample was counted the number of odontoclasts appearing on the root surface and measured the volume of the root in the maxillary deciduous incisor. The results were as follows: 1. The appearance of odontoclasts increased in a day-related manner from 9 days to 13 days on the resorption of maxillary deciduous teeth in the control and experimental rabbits. 2. The number of odontoclasts was significantly decreased by the administration of indomethacin (9 days P less than 0.05, 11 and 13 days P less than 0.01). 3. The amount of the root resorption was significantly inhibited by the administration of indomethacin at 9 days which was the initial stage of root resorption in the maxillary deciduous incisors, and then the effect of inhibition rapidly disappeared. These results strongly suggest that PGs can possibly act as a chemical mediator of odontoclastic root resorption occurred during tooth exchange.

Animals↗

Tooth resorption associated with the eruption of maxillary canines.

Six cases of root resorption of lateral incisors, associated with buccally displaced maxillary canines are presented. In each case, the clinical appearance is described followed by a discussion drawing attention to the possible common features and the importance of a detailed radiographic investigation.

Adolescent↗

Expression of adhesion molecules during tooth resorption in feline teeth: a model system for aggressive osteoclastic activity.

Tooth resorption, a common feline dental problem, is often initiated at the cemento-enamel junction and hence is called cat 'neck' lesion. Studies have demonstrated that osteoclasts/odontoclasts are increased and activated at resorption sites, and that areas of resorption are partly repaired by formation of tissues resembling bone, cementum, and possibly dentin. However, the cellular/molecular mechanisms/factors involved in resorption and repair are unknown. In this study of tissues from cats with 'neck' lesions, we used specific antibodies and immunohistochemical analyses to examine adhesion molecules associated with mineralized tissues, bone sialoprotein (BSP) and osteopontin (OPN), and a cell-surface receptor linked with these molecules, alpha v beta 3, for their localization in these lesions. In addition, to determine general cellular activity during repair, we performed in situ hybridization using a type I collagen riboprobe. Results showed OPN localized to resorption fronts and reversal lines, while BSP was localized to reversal lines. However, some osteoclasts and odontoblasts "sat" on mineralized surfaces not associated with OPN. The cell-surface receptor, alpha v beta 3, was localized to surfaces of osteoclasts/odontoclasts. Type I collagen mRNA was expressed where osteoblasts attempted to repair mineralized tissue. In contrast, odontoblasts did not express mRNA for type I collagen. This study suggests that osteoclastic resorption is the predominant activity in 'neck' lesions and that this activity was accompanied, at least in part, by increased concentrations of OPN and an associated integrin, alpha v beta 3, at resorption sites. Lack of collagen expression by odontoblasts indicates that odontoblasts do not play an active role in attempts at repair.

Animals↗

Mononuclear odontoclast participation in tooth resorption: the distribution of nuclei in human odontoclasts.

Osteoclasts and odontoclasts have been considered multinucleated giant cells which resorb hard tissue by ruffled borders. Recently, the authors reported the presence of a mononuclear osteoclast and odontoclast with a ruffled border. However, the relative frequency of such cells and the distribution of the number of nuclei including mononuclear cells in them have not been elucidated. Six human deciduous teeth were used in this study. After fixation and decalcification, tartrate-resistant acid phosphatase (TRAP) activity was detected with the azo dye method, and then TRAP-positive cells were observed on resorbing areas of teeth by light microscopy. The cells for investigation were serially sectioned by semithin sections to observe the presence of resorptive lacuna and the number of nuclei. The TRAP activity was detected in both multinucleated and mononuclear odontoclasts from serial semithin sections, and 242 TRAP-positive cells which formed lacunae on dentin were investigated to determine the frequency distribution of the number of nuclei. The mean number of nuclei per cell was 5.3, and median was 4. Only 2.9% of odontoclasts were mononucleus and 93.8% had 10 or fewer nuclei. The majority of odontoclasts forming lacunae on the dentin were cells with 10 or fewer nuclei, and mononuclear odontoclasts participated in human deciduous tooth resorption together with multinucleated ones.

Acid Phosphatase↗

[Differential diagnosis of resorptive tooth diseases and caries].

Feline Odontoclastic Resorptive Lesions (FORL, previously known as "neck lesions") on cat teeth are compared to caries and differentiated with the use of new methods. Radiological examination reveals typical odontoclastic resorptive processes, which take place at the dental root and at the periodontium. These lesions demonstrate the destruction on the desmodontium and the following ankylosing reaction. The rhodamine B stain which is selective for caries, stains regions which are softened by caries in a dark red way. Fuchsin/Acetic-Light Green stained histological preparations demonstrate the resorptive lacunae, resorptive lagoons and resorptive canals. Giant cells with multiple nuclei and reparative cementum can also be shown with the same stain. Hardness measurements using a Knoop diamond (KHN Knoop hardness number) give information about the degree of hardness of the different tissues. Electron microscopic investigations are performed to show the dentinal tubules and allowing the differentiation between FORL and caries. Since FORL also has been found in wild cats we deduced that alimentation has no effect on the pathogenesis of the disease.

Animals↗