Root Resorption Of Deciduous Teeth Research Articles

Variant Carvajal syndrome with additional dental anomalies

This paper aims to review the case of a girl who presented with a number of dental anomalies, in addition to unusual skin, nail and hair conditions. Tragically an undiagnosed cardiomyopathy caused unexpected sudden death. The case is discussed with reference to a number of dermatological and oral conditions which were considered as possible diagnoses. AW had been under long term dental care for prepubertal periodontitis, premature root resorption of primary teeth, soft tissue and dental anomalies, and angular cheilitis. Separately she had also been seen by several dermatologists with respect to palmar plantar keratosis, striae keratoderma, wiry hair and abnormal finger nails. Tragically the patient suffered a sudden unexpected death and the subsequent post mortem identified an undiagnosed dilated cardiomyopathy. The most likely diagnosis is that this case is a variant of Carvajal Syndrome with additional dental anomalies. To date we have been unable to identify mutations in the desoplakin gene. We aim to emphasise the importance of recognising these dental and dermatological signs when they present together as a potential risk factor for cardiac abnormalities.

Primary teeth show less protecting factors against root resorption

Physiological root resorption differentiates primary from permanent teeth. The understanding of what protects and regulates root resorption might help to develop therapies to its control. To verify the presence and distribution of ECRM and the expression of CK14, OPG, TRAP and COX-2 in the periodontal ligament (PDL) of human primary and permanent teeth. Design. Eight primary teeth undergoing physiological or pathological root resorption and 4 permanent teeth were immunohistochemically processed for CK14, TRAP, COX-2 and OPG expression. PDL from primary and permanent teeth showed similar morphological features; however, fewer ECRM clusters and higher immunoreactivity to CK14 were found in primary PDL. In permanent teeth, ECRM were distributed along the entire PDL tissue. Howship's lacunae were found only in primary teeth, associated with the presence of TRAP-positive cells and increase in COX-2 expression. OPG expression in primary PDL was detected in nonresorptive cervical areas and in lacunae showing reparative tissue. It was observed higher expression of OPG in all permanent teeth when compared to primary specimens. It may be concluded that PDL from primary teeth shows less ECRM clusters and lower expression of OPG. These features may be associated with lower protection against root resorption in primary teeth.

The role of pulp in the root resorption of primary teeth without permanent tooth germs

To investigate the role of pulp in the root resorption of primary teeth without permanent tooth germs. The animal model without permanent tooth germs was established by surgery in Beagle dog. The root resorption was observed by taking periapical radiographs periodically. The samples of mandibular bone and pulp at different resorption stages were collected. The distribution of odontoclasts and the activating factor was analyzed by histological staining and semiquantitative reverse transcriptase polymerase chain reaction (RT-PCR). The role of pulp in the root resorption of primary teeth was tested by early pulpectomy. In the root resorption of primary molars without permanent teeth germs, a large number of odontoclasts were present on the pulpal surface of the root canal. Semi-quantification RT-PCR showed that the ratios of the expression of receptor activator of NF-κB ligand (RANKL) mRNA and β-actin in the pulp of permanent teeth and primary teeth without permanent teeth germ during different periods of root resorption are 0.1314, 0.1901, 0.2111 and 0.6058 (P > 0.05). The root resorption of primary teeth without permanent teeth germs in test groups was about 5 weeks later than that of control group. The pulp of primary tooth played an important role in the root resorption of primary tooth without permanent tooth germ.

Expression of TRAF6 mRNA on the Resorbed Surface of Deciduous Teeth Root

The replacement of deciduous teeth by permanent teeth was an in vivo controlled physiological course. Odontoclast is the main functional cell involved the physiological root resorption of human primary teeth. TRAF6 is the key molecule in the signals regulation during the procedure of differentiation and maturity of osteolasts/odontoclasts. This experiment was to study the expression of TRAF6 in physiological root resorption of deciduous and permanent teeth. In addition, the effect of TRAF6 during the physiological root resorption of human deciduous teeth was also discussed. Permanent and deciduous teeth in physiological resorption period were decalcified, embedded and sliced. TRAF6 antibody and TRAF6 in situ hybridization agent were used to detect samples’ expression of TRAF6 protein and mRNA. Im-pro-plas 6.0 analytical system was used to measure the photodensity of odontoclasts, odontoblasts and dental pulp fibroblasts respectively between study and control group. It was observed that TRAF6 protein and mRNA of odontoclasts, odontoblasts and dental pulp fibroblasts existed in deciduous teeth with physiological resorption showing positive stained results. However, in permanent tooth, odontoclast was not observed and TRAF6 in odontoblast and dental pulp fibroblasts displayed negative. For the same cells of the two groups, t-test showed that p‹0.01. The optical density of the deciduous teeth odontoclasts was higher than that of the odontoblasts and dental pulp fibroblasts, P‹0.01; the odontoblasts and dental pulp fibroblasts showed no difference. TRAF6 activated the root resorption of deciduous teeth by participating in cellular differentiation and function.

Root resorption of Primary Teeth Without Permanent Successors

Root resorption of primary teeth usually occurs as the succeeding permanent teeth erupt, which induces differentiation of the hemopoietic cells into osteoclasts. Their root resorption pattern reflects the eruption path of the succeeding permanent teeth, and eventually the primary teeth shed as their succeeding permanent teeth erupt. Even when a permanent tooth germ is congenitally missing, root resorption of the corresponding primary tooth may still occur due to various factors, such as inflammation, traumatic occlusal force, and weakness of periodontium etc. Such congenital missing of permanent teeth is a commonly observed phenomenon in human be ing, and it often accompanies delayed retention of primary teeth. The etiologic factors for congenital missing in elude not only systemic diseases, but also local factors and human evolution process. In the radiographs of the cases in this report, the primary teeth without succeeding permanent teeth show pathologic root resorption. Root resorption progressed about 1/2~3/4 of the roots, and the surfaces of the resorption area were irregular. Considering high susceptibility of the periodontal ligament of primary teeth to root resorption, pathologic root resorption of primary teeth with delayed retention can be explained by the increased masticatory muscle force and abnormal occlusion developed during the mixed dentition. When the primary teeth without succeeding permanent teeth are lost, decision for space maintenance is required and long-term treatment plan for further prosthetic or orthodontic treatment should be establsihed.

Evaluation of a mixture of zinc oxide, calcium hydroxide, and sodium fluoride as a new root canal filling material for primary teeth

Endodontic treatment was performed on 25 pulpally involved mandibular primary molars in 4 to 9-year-old children; the root canals were obturated with a new root canal filling material consisting of a mixture of calcium hydroxide, zinc oxide, and 10% sodium fluoride solution, using hand-operated lentulo-spirals. All cases were evaluated clinically every 3 months and also radiographically every 6 months to assess the success of the treatment; we also examined the resorption of the root canal filling material from the root canals and the status of overpushed material, if any, as the tooth resorbed with the passage of time. At 6 months, endodontic treatment in 2 of the 25 teeth had failed and one tooth had exfoliated; the remaining 22 teeth were without any signs or symptoms. At the end of 2 years, 14 teeth could be evaluated; out of these 12 had physiologically exfoliated. It was observed that the rate of resorption of this new root canal obturating mixture was quite similar to the rate of physiologic root resorption in primary teeth. In three cases, where there was an overpush of the mixture, a gradual partial resorption was noted.

Physiologic root resorption in primary teeth: molecular and histological events

Root resorption is a physiologic event for the primary teeth. It is still unclear whether odontoclasts, the cells which resorb the dental hard tissue, are different from the osteoclasts, the cells that resorb bone. Root resorption seems to be initiated and regulated by the stellate reticulum and the dental follicle of the underlying permanent tooth via the secretion of stimulatory molecules, i.e. cytokines and transcription factors. The primary root resorption process is regulated in a manner similar to bone remodeling, involving the same receptor ligand system known as RANK/RANKL (receptor activator of nuclear factor-kappa B/ RANK Ligand). Primary teeth without a permanent successor eventually exfoliate as well, but our current understanding on the underlying mechanism is slim. The literature is also vague on how resorption of the pulp and periodontal ligament of the primary teeth occurs. Knowledge on the mechanisms involved in the physiologic root resorption process may enable us to delay or even inhibit exfoliation of primary teeth in those cases that the permanent successor teeth are not present and thus preservation of the primary teeth is desirable.

C3 Undiagnosed cardiomyopathy in a child with features of Papillon Lefevre syndrome

Presenting problem: We report on a child under long‐term dental care for prepubertal periodontitis, premature root resorption of primary teeth, granulomatous, furrowed cobblestone oral mucosa and gingivae, hypodontia and peg shaped lateral incisors, caries and angular cheilitis who suffered a sudden unexpected death. Subsequent post mortem confirmed an undiagnosed dilated cardiomyopathy. This may have triggered ventricular fibrillation, which caused her death. Prior to her death, she had also been seen by several dermatologists with respect to palmar plantar hyperkeratosis, striae keratoderma, wiry hair and abnormal finger nails.Discussion: In spite of being seen by a number of clinicians in several centres in the UK a satisfactory clinical diagnosis was never established. A detailed search of the literature revealed no previously reported link between Papillon Lefevre syndrome and cardiac pathology. This case report details the patient's specific clinical presentation, which included features similar to ectodermal dysplasia, Papillon Lefevre or oral Crohn's associated with skin pathology. Possible diagnoses are suggested. Clinicians seeing similar features in future should send the child for cardiac screening to rule out any potentially life threatening pathology.

Root resorption in deciduous teeth after applying orthodontic forces

The relation between orthodontic forces applied to deciduous teeth and the occurrence of root resorption, as a possible outcome of these forces, has not been studied to date. The aim of this work was to study root resorption in deciduous teeth of patients receiving orthodontic treatment. Twenty-four deciduous molars extracted for therapeutic purposes were studied: nineteen molars treated with light orthodontic forces and five untreated molars that served as control. Histological and histomorphome tric studies were performed to determine the magnitude of root resorption. Location of root resorption in treated deciduous teeth was different from that of physiological root resorption. Extent and volume of root resorption were more extensive and deeper in treated than in untreated teeth. These results suggest that radiographic follow-up of deciduous teeth subjected to orthodontic forces would be useful to prevent root fractures.

A flow cytometric analysis of the biodefensive response of deciduous tooth pulp to carious stimuli during physiological root resorption

The present study observed biodefensive responses of deciduous tooth pulp to advancing caries lesions and analysed the role of physiological root resorption on pulpal defense potential. For this purpose, immunocompetent cell content of deciduous tooth pulp was examined using flow cytometry. A total of 49 deciduous incisor and molar teeth at various stages of physiological root resorption (carious or non-carious) to be extracted for clinical reasons were used in this study. Teeth were classified according to carious lesion depth and root resorption stage. CD3+ lymphocytes were observed to be most prevalent in the pulp and to show remarkable increase along with increase in carious lesion depth. Numbers of CD8+ lymphocytes also increased significantly as carious lesions approached the pulp. However, increase in the number of CD3+ and CD8+ cells did not significantly alter CD4+/CD8+ ratios. The study also found that while B-lymphocytes increased significantly in association with root resorption, there were no significant differences in B/CD3+ lymphocyte ratios. Thus, there was no evidence of irreversible pulpal pathosis in any groups. It can be concluded that pulp maintains its healing and defense capacity against advancing carious lesion and progressive root resorption in deciduous teeth.

Localization of cathepsin K in bovine odontoclasts during deciduous tooth resorption.

Cathepsin K is a cysteine proteinase, which is abundantly and selectively expressed in osteoclasts. It is believed to play an important role in the proteolysis of bone resorption by osteoclasts. The objectives of this study were to investigate the association of cathepsin K in the physiological root resorption of deciduous teeth and to identify the cathepsin K-producing cells in deciduous root resorption. RT-PCR and Northern blot analysis of the total RNAs extracted from bovine active and resting root-resorbing tissues, which lie between the root of deciduous tooth and its permanent successor, were performed. The active root-resorbing tissue, which has a high population of odontoclasts on its surface that is attached to resorbing root surface, showed an extremely high expression of cathepsin K in comparison with the resting root-resorbing tissue. By in situ hybridization, cathepsin K mRNA was highly and selectively expressed in multinucleated odontoclasts that aligned along the surface of the tissue and apposed to the resorbing root surface of the deciduous tooth. Western blot analysis of the active root-resorbing tissue was used to characterize the anti-cathepsin K antibody. A band of 27 kDa, corresponding with the predicted size for mature cathepsin K, was demonstrated. Immunohistochemistry confirmed the specific localization of cathepsin K protein to the odontoclasts. These results demonstrate that odontoclasts in the deciduous root resorption express cathepsin K mRNA and protein that may participate in the proteolysis of root resorption of the deciduous tooth.

Cellular events at the onset of physiological root resorption in rabbit deciduous teeth.

For elucidation of how physiological root resorption of deciduous teeth is initiated, the cellular events that occur surrounding the root of rabbit deciduous teeth before and at the onset of physiological root resorption were observed by means of light and electron microscopy. In addition, the cytodifferentiation of odontoclasts during the initial phase of this root resorption was evaluated by histochemical staining of tartrate-resistant acid phosphatase (TRAP) activity as a marker odontoclasts and their precursors. The present investigation was focused on the physiological root resorption of the deciduous lower second molar of rabbits from Day 0-5 postnatally. At birth, the deciduous molar had not erupted yet, and no TRAP-positive cell could be found surrounding the tissue adjacent to the root of the deciduous tooth. TRAP-positive mononuclear cells were initially detected in the coronal portion of the dental follicle of the permanent tooth at Day 1 postnatally. Ultrastructurally, these mononuclear cells had moderate numbers of mitochondria and short-strand rough endoplasmic reticulum, as well as scattered free ribosomes throughout their cytoplasm. TRAP-positive mononuclear cells then appeared in the cementoblast layer immediately adjacent to the surface of the deciduous roots. These mononuclear cells projected cytoplasmic extensions between the cementoblasts and made contact with the cementum. At that time, cell-cell contact was frequently observed between these mononuclear cells and cementoblasts. During 3-5 days postnatally, the number of TRAP-positive multinucleate odontoclasts on the root surface gradually increased. They had well-developed ruffled borders and made typical resorption lacunae on the root surface of the deciduous tooth. During this early postnatal period, neither inflammatory cells nor necrotic tissue could be observed surrounding the deciduous root. This study demonstrates that the dental follicle of the permanent tooth as well as the connective tissue adjacent to the deciduous root might play important role in site- and time-specific recruitment, development, and activation of odontoclasts before and at the onset of physiological root resorption.

Humoral Immune Response to Physiologic Root Resorption of Deciduous Teeth in Dogs.

Humoral Immune Response to Physiologic Root Resorption of Deciduous Teeth in Dogs.

Effect of Physiological Root Resorption of Deciduous Teeth to Occlusal Function

Effect of Physiological Root Resorption of Deciduous Teeth to Occlusal Function

Detection of collagenase mRNA in odontoclasts of bovine root-resorbing tissue by in situ hybridization.

The odontoclast, which is morphologically similar to osteoclast, is thought to play a major role in root resorption of deciduous teeth. High collagenolytic activity has been detected in the root resorbing tissue. In order to identify collagenase-producing cells and the role of collagenase in root resorption of deciduous tooth, in situ hybridization of collagenase mRNA in bovine root-resorbing tissue sections was performed using a digoxigenin-labeled, nonradioactive RNA probe. Collagenase mRNA expression was clearly observed in odontoclasts in addition to the macrophages, fibroblasts, odontoblasts, and cementoblasts. Multinuclear odontoclasts showed intense tartrate-resistant acid phosphatase (TRAP) activity. We also examined interleukin-1 (IL-1) mRNA expression in the root-resorbing tissue by in situ hybridization. IL-1 transcripts were found to be expressed in odontoclasts, fibroblasts, and macrophages suggesting that IL-1 might be an important factor for promoting root resorption. These results suggest that the collagenase produced by odontoclasts may play a key role in dentin collagen degradation in root resorption.

A Study of Root Resorption of Deciduous Teeth in Dogs

A Study of Root Resorption of Deciduous Teeth in Dogs

Cellular Roles in Physiological Root Resorption of Deciduous Teeth in the Cat

This study has attempted to assess the importance of mesenchymal cells, fibroblasts, cementoblasts, and mononuclear phagocytes (i.e., macrophages) in physiological root resorption of feline deciduous teeth. Deciduous incisors of three- to six-month-old kittens undergoing root resorption were investigated by means of electron microscopy. In an early phase of root resorption, the resorption organ consisted of many fibroblasts and relatively few macrophages and odontoclasts, the last with a wide, clear zone and narrow, immature, ruffled border. In the active phase of root resorption, the resorption organ contained many odontoclasts with a well-developed ruffled border and a reduced clear zone, cementoblasts, fibroblasts, macrophages, neutrophils, and many blood vessels. Cementoblasts were present usually on the resorbing dentin surface adjacent to odontoclasts and, in many cases, these cells communicated with each other via gap junctions. Cementoblasts frequently extended broad cell processes with secretion granules and with phagosomes containing collagen fibrils into the dentinal tubules exposed to resorption lacunae. Some macrophages exhibiting a clear zone-like structure also appeared on resorbing dentin surfaces. In the resting phase of root resorption, the dentin surface was covered mostly with cementoblasts resembling bone lining cells. There was an occasional macrophage, but no odontoclasts were observed during this phase. During removal of the periodontal ligament concomitant with root resorption, many fibroblasts phagocytosed mature collagen fibrils, as well as amorphous fluffy material. These results suggest that these mesenchymal cells, as well as odontoclasts, are essential for the cellular removal of dental hard and soft tissues during shedding of feline deciduous teeth.

Root Resorption in Primary Teeth Observed on Panoramic Radiographs

Root Resorption in Primary Teeth Observed on Panoramic Radiographs

Ultrastructural Investigation of a Mechanism of Physiologic Root Resorption of Deciduous Teeth (Part 2)

Ultrastructural Investigation of a Mechanism of Physiologic Root Resorption of Deciduous Teeth (Part 2)

Ultrastructural investigation of a mechanism of physiologic root resorption of deciduous teeth (Part 1)

Ultrastructural investigation of a mechanism of physiologic root resorption of deciduous teeth (Part 1)