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 1,279 records · Page 71Linked to original sources
PubMed2004

The role of parathyroid hormone-related protein in the regulation of osteoclastogenesis by cementoblasts.

BACKGROUND: Parathyroid hormone-related protein (PTHrP) promotes osteoclastogenesis by inhibiting expression of osteoprotegerin (OPG), a decoy receptor for the receptor activator of nuclear factor kappa B (RANK), and by enhancing production of RANK ligand (RANKL) by osteoblasts. However, little is known regarding the role of PTHrP in regulating cementoblast-mediated osteoclastogenesis. METHODS: This study determined the impact of PTHrP on osteoclastogenesis using: 1) OCCM-30 (immortalized murine cementoblasts), 2) RAW 264.7 cells (murine myeloid cells), or 3) OCCM-30 plus RAW 264.7 cells. Cells were treated with PTHrP (1-34), RANKL, or PTHrP and RANKL combined. Enzyme-linked immunosorbent assays (ELISAs) for OPG and RANKL were performed on media and cell lysates, and tartrate-resistant acid phosphatase (TRAP) and mRNA detection for the osteoclast associated receptor (OSCAR) were performed. RESULTS: The highest numbers of TRAP-positive cells and cells expressing OSCAR were found in the RAW cell group treated with either RANKL alone or RANKL and PTHrP. TRAP-positive cells were fewer when OCCM cells were co-cultured with RAW, but the greatest numbers were still with both PTHrP and RANKL. OPG levels were highest from OCCM cells and PTHrP decreased these levels. In contrast, RANKL levels were low in OCCM cell lysates and PTHrP increased RANKL. In vivo studies also revealed high osteoclastic activity surrounding developing teeth in mice administered PTH. CONCLUSIONS: These results demonstrate that PTHrP influences the balance of OPG and RANKL production by cementoblasts, and further indicate that this effect, in the context of surrounding cells, might have a significant impact on osteoclastogenesis, root resorption, and tooth eruption.

Acid Phosphatase↗
PubMed1999

The horizontally impacted maxillary canine situated in a labial position.

Surgical management of unerupted teeth depends upon a thorough understanding of anatomic, physiologic and pathologic factors. Attention has been given to problems of eruption in the maxillary anterior region. It is a region where a variety of anomalies occur. Since the maxillary anterior region influences appearance so greatly, early detection of difficulties and careful planning and treatment can be extremely beneficial to patients. The purpose of this case report is to present a case of maxillary permanent canine impaction in a horizontal displacement that developed after loss of the deciduous canine to chronic apical periodontitis, and incomplete root resorption of the deciduous canine.

Child↗
PubMed2002

SEM observations of resected root canal ends following apicoectomy.

The purpose of this study was to examine the apical foramen of root apices extracted during apicotomies. A total of 25 teeth extracted from 25 patients admitted to the Department of Conservative Dentistry at Tokyo Dental College's Chiba Hospital were used for the study. All patients were between 22 to 56 years of age at the time of the study, and each of the 25 cases was determined clinically on radiographs to be chronic apical suppurative periodontitis. Microsurgery was performed on all cases, and the extracted root apices were then observed using SEM. The results demonstrated a wide opening, greater than 350 microns as measured along the major axis, of the apical foramen in 80% of the cases. Various characteristics indicative of resorption were observed around the apical foramen. These features included those believed to have been caused by overinstrumentation during root canal treatment as well as irregularly shaped areas presumed to be apical lesions that had enlarged and eroded. We observed a high frequency of manifestations of cementum resorption surrounding the root apices of teeth with apical lesions. Furthermore, we concluded that in the majority of cases in the present study, due to the fact that the apical foramen exceeded normal opening dimensions as a result of overinstrumentation during root canal treatment or resorption around the root apex, prolongation of the lesions had occurred in response to direct contact of microbial infectious matter and tissues surrounding the root apex over a large area. The above finding suggested that, in cases in which the apical foramen is destroyed through overinstrumentation larger than #35 or in which the apical foramen opens up to dimensions greater than 350 microns due to pathologic resorption, surgical intervention may be indicated. On the other hand, in 64% of the cases, an accessory canal was observed in the root apical lesion. Based on this observation, the presence of an accessory canal in the root apex may contribute to some degree to the prolongation of the lesion.

Adult↗
PubMed1978

Therapeutic pulpotomies in primary molars with the formocresol technique. A clinical and histological follow-up.

The results of therapeutic pulpotomies in primary molars with formocresol technique were studied by systematic follow-up. Of 84 primary lower molars in the clinical study, 56 became available for histological examination. The radiographic follow-up revealed periradicular osteitis in 10 per cent of the teeth treated. Internal root resorption was seen in 37 per cent of the teeth, or one-fifth of the roots treated. The histological examination revealed a very capricious diffusion of the medicament throughout the pulp tissue. Vital pulp remnants in the apical part of the treated roots showed no signs of healing. All pulps presented a varying number of inflammatory cells in the border zone adjacent to the formocresol-fixed region. In 80 per cent of the roots the histological sections revealed signs signs of internal resorption with or without incomplete repair tissue formation.

Child↗
PubMed1978

Traumatized primary anterior teeth. Prognosis related to calcific reactions in the pulp cavity.

The frequency of a complicating pulp necrosis and the process of the physiologic root resorption were studied in traumatized primary teeth exhibiting partial or total pulp obliteration. The material comprised 88 incisors in 72 children aged 0.7--5.7 years (mean 2.9 years) at the time of injury. Trauma had resulted either in subluxation (25 teeth), or luxation (13 teeth), whereas the type of injury was unknown in 50 teeth. All cases were observed until eruption of the permanent incisors. Forty-four teeth initially displayed a reversible greyish color. The ultimate finding observed in all teeth was, however, varying degrees of yellow discoloration. Periapical pathologic findings indicative of pulp necrosis were observed in 9 teeth, from 1.6--4 years (mean 3 years) after the time of injury. Extraction was performed immediately, and none of the successional teeth showed developmental disturbances. The process of root resorption was classified as normal in all primary teeth. Subsequent eruption of the permanent successors occurred without any registered complications.

Child, Preschool↗
PubMed1981

The effect of limited drying or removal of the periodontal ligament. Periodontal healing after replantation of mature permanent incisors in monkeys.

The effect of limited drying or removal of the periodontal ligament upon periodontal healing after replantation of incisors was studied in green Vervet monkeys. All teeth were examined histologically either 2-, 4- or 8 weeks after replantation. The drying experiment demonstrated that an area of ankylosis was established after 2 weeks corresponding to the dried portion of the root and was removed by a resorptive process in the majority of cases after 8 weeks. The removal of the periodontal ligament led to development of surface-, inflammatory- and replacement resorption. Furthermore, 1 mm2 and 4 mm2 lesions on the root surface developed transient ankylosis which disappeared after 8 weeks while lesions of 9 mm2 or 16 mm2 in size resulted in an ankylosis which, in most cases, persisted after 8 weeks. Based on these findings, it is postulated that physical removal or extended drying of the periodontal ligament initiates a rapid osteogenesis in the alveolus which establishes an ankylosis. If the damaged area is placed next to a zone on the root surface with a vital periodontal ligament, a later resorptive process is established from this zone, whereby the ankylosis area is gradually resorbed. It is estimated that the extent of this process in this experiment amounted to possibly 1 -- 1.5 mm.

Animals↗
PubMed1981

Relationship between cell damage in the periodontal ligament after replantation and subsequent development of root resorption. A time-related study in monkeys.

The etiology of root resorption subsequent to replantation of incisors was examined in green Vervet monkeys. Cell damage to the root surface due to the extraction procedures was registered histologically 1 week after replantation. The topographical distribution of cell damage was then related to the development of root resorption in similar replanted teeth with longer observation periods. Histometric analysis showed that surface-, inflammatory- and replacement resorption was significantly related to certain topographical locations on the root surface. These surfaces represented the "corner" surfaces of the root, where the maximum damage presumably would occur during the extraction procedure. A positive and highly significant correlation between cell damage in the cementoblast layer and the presence of surface-, inflammatory- and replacement resorption was found: replacement resorption was associated with the greatest loss of vital cementoblasts per unit root surface length. Furthermore, the distance from a potential resorption site to the nearest location on the root surface with a normal number of cementoblasts was found to be related to the type of root resorption. Thus, replacement resorption was found to be significantly related to the greatest distance from a site with normal numbers of cementoblasts compared to sites with no resorption or inflammatory resorption. Based on these findings, as well as previous experiments, a theory is presented for the etiology and pathogenesis of external root resorption after immediate replantation of mature teeth.

Animals↗
PubMed1996

Root surface defects in rat molar induced by 1-hydroxyethylidene-1,1-bisphosphonate.

Cementum surface alterations induced by 1-hydroxyethylidene-1,1-bisphosphonate (HEBP) in the maxillary first molars in rats were studied by means of scanning electron microscopy. Single or triple injections of HEBP inhibit the formation of acellular extrinsic fiber cementum and delay the formation of cellular mixed-fiber cementum. The results indicate the importance of acellular extrinsic fiber cementum as a protection barrier against root resorption and the different mechanisms underlying the formation of the two cementum varieties.

Animals↗
PubMed1996

Orthodontically induced root resorption in rat molars after 1-hydroxyethylidene-1,1-bisphosphonate injection.

A single injection of 1-hydroxyethylidene-1, 1-bisphosphonate inhibits the formation of acellular cementum in rat molars. Instead, an atypical hyperplastic cementum is formed. In this study the resistance of this cementum to resorption was tested by applying an orthodontic force. It was found that roots lacking acellular cementum were readily resorbed. The readiness with which the atypical hyperplastic cementum was resorbed without any increase in multinucleated osteoblasts may offer useful opportunities to study the different phases of hard-tissue resorption.

Animals↗
PubMed1998

Anomalous dental morphology and root resorption during orthodontic treatment: a pilot study.

The present study investigated the relation between anomalous dental morphology and root resorption during orthodontic treatment. One hundred and eleven sets of orthodontic records (a total of 1,630 teeth) were examined. Root resorption was determined from post-treatment panoramic radiographs using a five-grade quantitative measurement. It was found that patients with short or blunt roots before treatment underwent significant root shortening during orthodontic treatment. Patients with any one dental anomaly had a significantly higher degree of root resorption compared with patients with no dental anomaly. Invaginated teeth, teeth with thin or pipette-shaped roots and teeth with short or blunt roots were likely to be more susceptible to root resorption than those without such anomalies. Possible linkages between the aetiological factors of dental anomalies and the susceptibility to root resorption were discussed. The presence of anomalous dental morphology should be taken into account in orthodontic treatment planning.

Adolescent↗
PubMedDate not supplied

Replantation of avulsed teeth: considerations and complications.

Avulsion of teeth is a traumatic dental injury which can be managed by replantation. Important considerations for successful replantations are highlighted. Several sequelae to replantation are discussed in relation to the clinical features observed in a patient seen 6 years after replantation of two avulsed upper incisors. Many of these complications might have been avoided if the patient had returned to the clinic for root canal therapy shortly after the teeth was replanted.

Adult↗