Root Resorption Of Teeth Research Articles

Tooth Root Resorption Conditioned by Orthodontic Treatment

Tooth Root Resorption Conditioned by Orthodontic Treatment

Delayed diagnosis of displaced and impacted canines – a prospective longitudinal study

Objectives: To assess the frequency and reasons for delayed diagnoses of displaced/impacted canines and to determine to what extent this causes complications. In addition, to assess whether any preventive measures were taken.Materials and methods: Patients with displaced/impacted canines that were diagnosed late; i.e. at an age ≥12 years, were consecutively collected during September 2015 to September 2018 in the County Region of Halland, Sweden. Additionally, patients who had undergone surgical exposure or extraction of an impacted canine during the same time period were identified.Results: Eighty-four individuals (58% girls, 42% boys, mean age: 13.75 ± 1.53 years) with 114 impacted canines were detected among 33,488 adolescents aged 12–20 years, resulting in a low-frequency rate: 84 cases per 100,000 persons. Eighty-six percent of the delayed canines were in the maxilla, the rest in the mandible. Deciduous canines were present in 80% of the cases. Most patients had a dental examination at 9–11 years of age but the position of the canine was not documented in many cases. Root resorption of adjacent teeth was noticed in 13% of the patients. No new clinical procedures or guidelines were developed.Conclusions: The frequency of delayed diagnoses of displaced/impacted canines was low. To minimize the frequency even more, documentation of the canine position during the dental examination should not be forgotten at ages 9–11. Presence of the deciduous canine can be used as a clinical indicator that the position of the permanent canine needs to be investigated.

CYCLICAL CHANGE IN THE APPEARANCE OF FLORID CEMENTO-OSSEOUS DYSPLASIA OVER 15 YEARS: A CASE REPORT

Background Florid cemento-osseous dysplasia is a dynamic dysplastic bone abnormality where normal bone is replaced with fibrous tissue and various patterns of nonmature bone. Over time, these changes can be appreciated on imaging with the appearance of an early radiolucent entity becoming a mixed radiopaque/radiolucent entity and finally a predominantly radiopaque entity with a radiolucent rim of variable width. Discussion/Conclusions We present a case of florid cemento-osseous dysplasia, which did not follow a typical pattern, with imaging spanning 15 years in a single patient. The patient, a 41-year-old female, first presented to our clinic in 2008. Previous images from 2002 demonstrated typical patterns of florid cemento-osseous dysplasia in the mandible; radiolucent foci; and mixed radiolucent/radiopaque foci with epicenters located inferior to the apices of the teeth. In 2006, the pattern then changed to a wholly radiolucent one, and we interpreted this as being a simple bone cyst developing within the mixed radiopaque/radiolucent focus in the left mandible. Later images in 2013 showed peripheral new bone deposition; an appearance that we interpreted as being consistent with healing. Similar changes in the foci in the right mandible were also seen between 2013 and 2016. The left mandible showed fluctuations between both bone resorption and deposition over the years of imaging. External root resorption of the mandibular teeth also occurred, and these eventually involved the apical one-third of the affected teeth—a process that is rare, but occasionally seen. This case illustrates the dynamic clinical behavior that can occur with florid cemento-osseous dysplasia. It is important to recognize the range of variations in the presentation of this dysplastic bone entity and to correlate imaging findings with a clinical history to avoid misdiagnosis and mismanagement. Monitoring in certain cases may be necessary to confirm an initial interpretation of florid cemento-osseous dysplasia. Florid cemento-osseous dysplasia is a dynamic dysplastic bone abnormality where normal bone is replaced with fibrous tissue and various patterns of nonmature bone. Over time, these changes can be appreciated on imaging with the appearance of an early radiolucent entity becoming a mixed radiopaque/radiolucent entity and finally a predominantly radiopaque entity with a radiolucent rim of variable width. We present a case of florid cemento-osseous dysplasia, which did not follow a typical pattern, with imaging spanning 15 years in a single patient. The patient, a 41-year-old female, first presented to our clinic in 2008. Previous images from 2002 demonstrated typical patterns of florid cemento-osseous dysplasia in the mandible; radiolucent foci; and mixed radiolucent/radiopaque foci with epicenters located inferior to the apices of the teeth. In 2006, the pattern then changed to a wholly radiolucent one, and we interpreted this as being a simple bone cyst developing within the mixed radiopaque/radiolucent focus in the left mandible. Later images in 2013 showed peripheral new bone deposition; an appearance that we interpreted as being consistent with healing. Similar changes in the foci in the right mandible were also seen between 2013 and 2016. The left mandible showed fluctuations between both bone resorption and deposition over the years of imaging. External root resorption of the mandibular teeth also occurred, and these eventually involved the apical one-third of the affected teeth—a process that is rare, but occasionally seen.

GLANDULAR ODONTOGENIC CYST MIMICKING AMELOBLASTOMA IN A 78-YEAR-OLD FEMALE: A CASE REPORT

<h3>Background</h3> Glandular odontogenic cysts (GOCs) may show radiologically similar findings with ameloblastoma. It is also interesting to explore the growth pattern of GOCs in elderly patients. <h3>Objective(s)</h3> The aim of this report was to describe a case of GOC with characteristic radiographic jaw features. <h3>Study Design</h3> A cystic lesion in the posterior mandible of a 78-year-old female was incidentally found. Periodic radiographs showed a unilocular lesion with a scalloped margin, external root resorption of the adjacent tooth, and cortical perforation. This lesion had changed from a small ovoid lesion to a more expanded lesion in a period of 4 years. The small lesion showed unilocularity with a smooth margin and a well-defined border, but the expanded lesion produced cortical perforation and a lobulated margin. The biopsy was done for final diagnosis. <h3>Results</h3> The radiographic diagnosis was an ameloblastoma, whereas the histopathologic examination revealed a GOC. <h3>Discussion/Conclusions</h3> This case shows that a GOC can arise in people in their 70s, changing from a unilocular lesion to an expanded, lobulated lesion over a period. Periodic radiographs showed the changes in the lesion shape and the lobular margin that took place during a period of 4 years. Furthermore, it is a rare case in that the above-mentioned radiographic changes were observed in the posterior mandible of an elderly woman.

SEQUENTIAL CHANGES POST-SCLEROTHERAPY OF A LARGE MANDIBULAR INTRAOSSEOUS HEMANGIOMA

<h3>Background</h3> Intraosseous hemangiomas of the jaws are rare entities, for which the origin is still being debated. Some believe them to be hamartomatous lesions derived from mesodermal cells that undergo endothelial differentiation, while others believe they are true neoplasms. Clinical features reported are swelling, facial asymmetry, mobile teeth, and audible bruits. Patients may report pain, paresthesia, or a sensation of pulsation. The majority of the reported cases in the literature have been treated with en block resection. In this case presentation sclerotherapy was implemented as the primary treatment for a large, albeit low-flow, lesion, in part because of the patient's objection to extensive surgery. <h3>Discussion/Conclusions</h3> A 59-year-old female was referred to our clinic for treatment of a histopathologically confirmed intraosseous vascular malformation diagnosed 5 years earlier. She presented with mild swelling of the left mandible, pain on chewing, and paresthesia in that region. A pantomograph revealed a large, partially loculated, radiolucent area in the left mandible; the lesion had approximately doubled in size since her initial visit. Multidetector computed tomography (MDCT) revealed an expansile lesion with effacement of the buccal cortex. Root resorption of multiple associated teeth was present. Spiral computed tomography (CT) angiography demonstrated an expansile, hypervascular soft tissue mass with no evidence of arteriovenous malformation, consistent with focal hemangioma. In this case, the goal was to resolve or at least greatly reduce the size of the lesion; thus, if surgical intervention was deemed necessary, it would be more conservative. Sequential sclerotherapy was performed and resulted in the return of nonvascular stroma, although with delayed significant reossification. It appears the patient's resistance to surgery was rewarded and likely resulted in a more aesthetic outcome. Because of the risk for recurrence, periodic long-term follow-up is scheduled.

Does medication administration affect the rate of orthodontic tooth movement and root resorption development in humans? A systematic review.

Recently, the potential impact of different medications on the rate of orthodontic tooth movement and the associated root resorption has been systematically reviewed in animal studies and various effects have been shown. However, animal data cannot be extrapolated to human clinical situations directly. To systematically investigate the most up to date available evidence from controlled human studies regarding the effect of medication administration on the rate of orthodontic tooth movement and associated root resorption development. We searched eight databases (covering also grey literature) without restrictions and we performed hand searching up until October 2018. Controlled studies in humans assessing the effect of various medications on the rate of orthodontic tooth movement and root resorption development. Study selection was followed by data extraction and risk of bias assessment using the ROBINS-I tool for non-randomized and the Cochrane Risk of Bias Tool for randomized studies. Eight studies, at various risk of bias, were finally identified. With regard to the rate of orthodontic tooth movement, local injections of prostaglandin E1 were found to exert an increasing effect, whereas systemic intake of nabumetone decreased it. Following tenoxicam administration, drinking water with fluoride or local injections of calcitriol (vitamin D metabolite), no significant effects were demonstrated. Concerning root resorption development, nabumetone administration was shown to reduce it, whereas fluoride, overall, was not observed to exert any effect. Only in individuals subjected to heavy orthodontic forces, did fluoride show a protective effect for the period of force application, but not in the longer term during retention. The aforementioned substances may show varying effects on the rate of orthodontic tooth movement and root resorption development in human subjects. Despite the observed limitations, the orthodontist should be able to identify patients taking pharmaceuticals and consider any implications related to orthodontic treatment. PROSPERO (CRD42017078208).

Apical root resorption after orthodontic treatment in patients with unilateral cleft lip and palate.

The aims of this retrospective longitudinal study were to present the incidence of external apical root resorption (EARR) in the maxillary anterior teeth of patients with complete unilateral cleft lip and palate (CUCLP) and to evaluate the influence of orthodontic treatment variables on the development of EARR. Forty-one patients with CUCLP participated in the study. Orthopantomograms (OPGs), taken before (T2) treatment with multiband orthodontic appliances (MBA), and periapical radiographs (PAs) of the maxillary anterior teeth taken at the end (T3) of orthodontic treatment (OT) were assessed for EARR. The incidence of EARR at T3 (97.6%) was considerably higher than at T2 (51.2%). Central incisors and canines on the cleft side showed a significantly higher score (p < 0.01, p < 0.05 respectively) of EARR in comparison to the same group of teeth on the non-cleft side. Preexisting EARR and abnormal root morphology were identified as predisposing factors for EARR. Patients with CUCLP treated with MBA have higher incidence of EARR on the maxillary anterior teeth of the cleft side. Severe EARR is rather rare but more often seen on central incisors of the cleft side. As most of the patients with cleft lip and palate undergo a challenging and long-term OT with MBA, it is of importance to identify the predisposing factors related to the special anatomical features of the bone and teeth located in the cleft area, as well as the special OT needs of these patients.

Comparison of orthodontic root resorption of root-filled and vital teeth using micro-computed tomography.

To evaluate the difference in orthodontic root resorption between root-filled and vital teeth. Sixteen individuals who required bilateral premolar tooth extraction due to orthodontic treatment and had a previously root-filled premolar tooth on one side were included in the study. The experimental group consisted of root-filled premolar teeth, and the control group consisted of contralateral vital premolar teeth. A 150-g buccally directed force was applied to these teeth using 0.017 × 0.025-inch TMA cantilever springs. The premolars were extracted 8 weeks after the application of force. Images were obtained using micro-computed tomography. Resorption measurements were obtained using the Image J program. The mean values for resorption were 0.08869 mm3 for the root-filled teeth and 0.14077 mm3 for the contralateral teeth, indicating significantly less resorption for the root-filled teeth compared with the contralateral teeth after the application of orthodontic force (P = .003). In both groups, the most resorption was seen on the cervical-buccal and apical-lingual surfaces. The mean resorption value of the cervical region was 0.06305 mm3 in the control group and 0.0291 mm3 in the experimental group, and the difference was statistically significant (P = .002). Root-filled teeth showed significantly less orthodontic root resorption than vital teeth.

The Effect of Mandibular Symphysis Fracture on the Position of the Permanent Incisor Tooth Germ

Background: Among facial bones in children, mandible bone has the highest fracture rate, 8.4% of which is related to Symphysis fractures. Case Presentation: A 3.5-year-old girl with complaints about the mobility of the mandibular left primary central incisor without a history of recent dental trauma and caries referred to the Department of Pediatric Dentistry of Hamadan University. After radiographic evaluation, occlusal displacement of lower left permanent central incisor tooth germ and root resorption of lower left primary central incisor were seen. Conclusions: This case report implies that because of the close proximity of the root of the primary tooth to its developing permanent successor, jaw fracture and especially mandibular fracture combined with dental injuries (e.g., intrusion, avulsion, and extrusive luxation) can cause damages and significant displacement in permanent successor tooth germs.

Relationship between the Position of Impacted Third Molars and External Root Resorption of Adjacent Second Molars: A Retrospective CBCT Study.

Background and objectives: Impacted third molars (ITM) are the most commonly-impacted teeth. There is a risk for ITM to cause a number of pathological conditions, and external root resorption (ERR) of adjacent teeth is one of the most prevalent. Retaining or prophylactic extraction of ITM is a polemic topic. External root resorption of adjacent teeth is one of possible indications for prophylactic removal of ITM. The aim of this study was to assess the relationship between external root resorption (ERR) on the distal aspect of second molars’ roots and positional parameters of ITM. Methods: Cone beam computed tomography scans of 109 patients (41 males, 68 females; mean age 26.4 ± 7.9 years) with 254 ITM (131 in the maxilla and 123 in the mandible) were retrospectively analyzed. Positional parameters of ITM (mesio-distal position, angulation, impaction depth, and available eruption space) were evaluated. The presence, location, and depth of ERR of adjacent second molars were assessed. Results: Analysis showed a relationship between ITM impaction depth, mesial inclination angle, and the presence of ERR. Mesial inclination angle of more than 13.6° increased the odds of ERR occurrence by 5.439 (95% CI, 2.97–9.98). ITM presence at the level of ½ of roots of the adjacent second molar or more apically increased the odds of ERR occurrence by 2.218 (95% CI, 1.215–4.048). No significant correlation was detected between the occurrence of ERR and patient age, gender, or the available eruption space in the mandible. Depth of ERR did not depend on its location. Conclusions: Incidence of ERR in second molars is significantly associated with mesial inclination and a deep position of ITM.

Orthodontically induced root resorption – a literature review

Root resorption in moved teeth is a common undesirable side effect of orthodontic treatment. This pathology usually affects permanent teeth. Although any part of the root may be involved, the apical or cervical area is usually affected. The formation and development of these changes are a long-term process and depend on various factors. The etiology of resorptive changes associated with orthodontic treatment has been widely discussed by many authors, who proposed numerous classifications. Particularly noteworthy are the works on techniques for the treatment of malocclusion and their potential adverse effects. Modern diagnostic methods allow for an early detection of this pathology and the implementation of appropriate therapeutic measures. These techniques include periapical radiography (paralleling technique) combined with cone-beam computed tomography. Dentists not only notice the need to achieve a beautiful smile, but they also take into account possible root shortening. This process is not fully understood, but realizing its existence is important for planning and implementing both orthodontic and general dental treatment.

Effects of Photobiomodulation on Root Resorption Induced by Orthodontic Tooth Movement and RANKL/OPG Expression in Rats

The aim of this study was to evaluate the effects of photobiomodulation on the repair of induced root resorption (RR) after orthodontic tooth movement. Twenty male rats were used in this study. Forty right and left upper first molars were evaluated and divided into four groups (n=10): negative control group (NC), no tooth movement or irradiation; positive control group (PC), induced tooth movement and root resorption; conventional treatment group (CT), force was removed after 7days; and photobiomodulation group (PBM) after force removal molars were irradiated every 48h for 7days using GaAlAs diode laser (810nm). Energy per point was 1.5J (100mW, 15s, 75Jcm-2 ). NC and PC were euthanized on day 7; CT and PBM on day 14. Histomorphometric and immunohistochemsitry analyses showed increase in area of root resorption in all groups (P<0.05) compared to NC. RR lacunae were larger in CT compared to PC and PBM at the compression side of the distal root. OPG was higher in PBM group (P<0.05). PBM group showed low expression of RANKL compared to PC and CT on the tension side. PBM can potentially affect RR progression by increasing OPG expression in the compression area and decreasing number of clastic cells in the root surface.

The effectiveness of supplemental vibrational force on enhancing orthodontic treatment. A systematic review.

The results from the literature regarding the influence of supplemental vibrational forces (SVFs) on orthodontic treatment are controversial. Therefore, this systematic review aimed to evaluate whether SVFs have positive effects, such as in accelerating tooth movement, alleviating pain, and preventing root resorption, in orthodontic patients. Searches through five electronic databases (PubMed, MEDLINE, EMBASE, Web of Science, and Cochrane Central) were complemented by hand searches up to January, 2019. Randomized controlled trials and controlled clinical trials reporting on the effects of SVFs in orthodontic patients in English were included. Study selection, data extraction, and a risk of bias assessment were independently performed by two reviewers. Study characteristics and outcomes were reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. A qualitative analysis of the effects of SVFs on orthodontic tooth movement, pain experience, and root resorption was conducted. Thirteen studies, including nine clinical trials, were eligible for inclusion in the systematic review. There was no significant evidence to support the positive effects of SVFs in orthodontic patients, neither in accelerating tooth movement nor in alleviating pain experience. According to the Grading of Recommendations Assessment, Development and Evaluation (GRADE) criteria, the quality of the evidence was very low for all the outcomes in the qualitative analysis. The results of this systematic review are based on a limited number of studies and the methodological heterogeneity and non-comparability of original outcomes made it difficult to conduct a meta-analysis. There is insufficient evidence to support the claim that SVFs have positive clinical advantages in the alignment of the anterior teeth. The potential positive effects of vibrational forces on space closure, pain experience, and root resorption in orthodontic patients are inconclusive with no sufficient information at present. High-quality clinical trials with larger sample sizes are needed to find more comprehensive evidence of the potential positive effects of vibrational forces. The protocol for this systematic review was registered on PROSPERO (CRD42018098788). This study has not received any contributions from private or public funding agencies. None.

Mechanical Stress Modulates the RANKL/OPG System of Periodontal Ligament Stem Cells via α7 nAChR in Human Deciduous Teeth: An In Vitro Study.

The aim of this study was to investigate the mechanism by which periodontal ligament stem cells (PDLSCs) modulate root resorption of human deciduous teeth under mechanical stress. In this investigation, the PDLSCs were derived from deciduous and permanent teeth at different stages of root resorption. A cyclic hydraulic pressure was applied on the PDLSCs to mimic chewing forces in the oral environment. The cultured cells were characterized using osteogenic and adipogenic differentiation assays, quantitative real-time polymerase chain reaction (qRT-PCR), and Western blotting analysis. The PDLSCs exhibited the ability to induce osteoclast differentiation under certain mechanical stresses. As the expressions of RUNX2, alkaline phosphatase (ALP), and osteoprotegerin (OPG) were significantly reduced, the receptor activator of the nuclear factor kappa-B ligand (RANKL) was upregulated increasing the RANKL/OPG ratio. Under hydrodynamic pressure at 0-135 kPa, the expressions of alpha 7 nicotinic acetylcholine receptors (α7 nAChR), p-GSK-3β, and active-β-catenin were markedly upregulated in PDLSCs from unresorbed deciduous teeth. Treatment with the α7 nAChR inhibitor alpha-bungarotoxin (α-BTX) and the Wnt pathway inhibitor DKK1 may reverse the mechanical stress inducing upregulation of RANKL and reduction of RUNX2, ALP, and OPG. Alizarin red staining confirmed these results. The mechanical stress applied on the deciduous tooth PDLSCs can induce osteoclastic effects through upregulation of α7 nAChR and activation of the canonical Wnt pathway. It can be suggested that chewing forces may play a major role at the beginning of the physiological root resorption of deciduous teeth.

Effect of tumor necrosis factor α on ability of SHED to promote osteoclastogenesis during physiological root resorption

Physiological root resorption of deciduous teeth is a normal phenomenon, however, the potential mechanisms underlying this process remain unclear. This study aimed to investigate ability of stem cells from human exfoliated deciduous teeth (SHED) on promoting the osteoclastic differentiation of osteoclast precursors and clarify mechanisms underlying this process in vitro. SHED and dental pulp stem cells (DPSCs) were obtained from deciduous teeth and healthy permanent teeth. An indirect co-culture system of SHED or DPSCs were used. The osteoclast precursor peripheral blood mononuclear cells (PBMCs) were established. Ability of SHED and DPSCs in promoting osteoclastogenesis was determined using triiodothyronine receptor auxiliary protein (TRAP) staining, real-time real-time PCR (RT-PCR) and western blotting. The effect of inflammation on the pro-osteoclastogenesis ability of SHED was determined using enzyme linked immunosorbent assay (ELISA), RT-PCR and western blotting. The function of the nuclear factor-κB (NF-κB) pathway in promoting the osteoclastogenesis ability of SHED was determined using RT-PCR and western blotting. SHED exhibited an increased ability to promote osteoclastic differentiation. Expression of tumor necrosis factor-α (TNF-α) was significantly higher in SHED than in DPSCs. Expression of cathepsin K (CTSK), TRAP, and receptor-activator of nuclear-factor-κ B ligand (RANKL), RANKL/osteoprotegerin (OPG) ratio, and expression of cytoplasmic phosphorylated inhibitor of NF-κB α (p-IκBα) and nuclear p65 were markedly up-regulated in SHED post the TNF-α treatment but decreased following NF-κB inhibition. In conclusion, inflammatory cytokine TNF-α appeared to activate NF-κB pathway to up-regulate expression of NF-κB, enhancing ability of SHED in promoting osteoclastogenesis via regulating RANKL/OPG expression.

Učestalost patoloških promjena povezanih s impaktiranim trećim kutnjacima među kosovskim stanovništvom: ortopantomografska studija

ObjectiveThe aim of this study was to evaluate the prevalence of pathologies associated with impacted third molars radiographically noticeable in a Kosovar population, as currently no data are available.Methods and MaterialsThis was a retrospective study of 5515 panoramic images of patients who visited the University Dentistry Clinical Center of Kosovo. Of these 5515 patients, 2368 were males and 3147 were females. The age range was from 18 to 77 years. We reviewed panoramic images in order to determine the number of pathologies associated with impacted third molars. The following radiographic lesions were recorded: caries of impacted teeth and/or adjacent tooth, root resorption of adjacent tooth, periodontal bone loss of adjacent tooth of more than 5mm below the cemento-enamel junction and an increase in pericoronar gap over 4mm.ResultsThe prevalence of pathologies associated with impacted third molar in Kosovar population was 29.5%. Root resorption of adjacent tooth had the highest frequency of pathology 307 (23.7%). It was followed by periodontal bone loss of adjacent tooth of more than 5 mm 71 (5.5%) and caries 33 (2.5%). The lowest was an increase in pericoronar gap 15 (1.2%).ConclusionThe most common pathology was root resorption, with the highest incidence of pathology localized in the maxilla 159 (32.3%). The prevalence of periodontal bone loss, caries and increase in pericoronar gap was significantly lower. The findings of our research could have an impact on development of prevention strategies that will proficiently deal with pathologies that result from impacted teeth.

Inactivating Mutation in IRF8 Promotes Osteoclast Transcriptional Programs and Increases Susceptibility to Tooth Root Resorption.

This is the first study to our knowledge to report a novel mutation in the interferon regulatory factor 8 gene (IRF8G388S ) associated with multiple idiopathic tooth root resorption, a form of periodontal disease. The IRF8G388S variant in the highly conserved C-terminal motif is predicted to alter the protein structure, likely impairing IRF8 function. Functional assays demonstrated that the IRF8G388S mutant promoted osteoclastogenesis and failed to inhibit NFATc1-dependent transcriptional activation when compared with IRF8WT control. Further, similar to subjects with heterozygous IRF8G388S mutation, Irf8+/- mice exhibited increased osteoclast activity in the mandibular alveolar bone surrounding molar teeth. Immunohistochemistry illustrated increased NFATc1 expression in the dentoalveolar region of Irf8-/- and Irf8+/- mice when compared with Irf8+/+ controls. Genomewide analyses revealed that IRF8 constitutively bound to regulatory regions of several thousand genes in osteoclast precursors, and genetic aberration of IRF8 significantly enhanced many osteoclast-specific transcripts. Collectively, this study delineates the critical role of IRF8 in defining osteoclast lineage and osteoclast transcriptional program, which may help in better understanding of various osteoclast-mediated disorders, including periodontal disease. © 2019 American Society for Bone and Mineral Research.

Dental trauma on primary teeth at different root resorption stages-A dynamic finite element impact analysis of the effect on the permanent tooth germ.

Dental trauma is a common emergency in children with primary teeth. The aim of this study was to determine stress propagation to the permanent tooth germ and surrounding bone and soft tissues during dental trauma to primary central incisors with three levels of physiological root resorption. Stresses were determined using finite element analysis (FEA). Cross-sectional models were created using cone-beam computed tomography images of 3.5, 5, and 6years olds, representing three different physiological root resorption stages of a maxillary primary central incisor. The models included periodontal ligament, bone, and soft tissues. An impact with an asphalt block moving at 1m/s,was simulated for two impact two directions, frontal on the labial tooth surface, and on the incisal edge. Stresses and strains were recorded during impact. The impact caused stress concentrations in the surrounding bone and soft tissues and permanent tooth germ, regardless of the direction of impact and the primary tooth resorption stage. Impact stresses in dental follicles and surrounding bone increased in models with more physiological root resorption of the primary tooth. Incisal impact generated higher stress concentrations in surrounding bone and soft tissues and permanent tooth germ regardless of physiological root resorption stage. The primary incisor with no physiological root resorption showed high stress concentrations at its root apex. During impact to a primary incisor, stresses most significant for potential damage to the formation of permanent enamel and dentin were at the dental follicle and surrounding bone tissue with the three levels of physiological root resorption.

Evaluation of the periodontal and pulpal healing of replanted rat molars with doxycycline root conditioning.

PurposeThis study aimed to evaluate periodontal and pulpal healing in replanted rat teeth, preserved under different storage conditions, with or without root conditioning using doxycycline.MethodsA total of 40 maxillary first molars extracted from 20 Sprague-Dawley rats were stored for different durations under different conditions (5 minutes in dry storage and 60 minutes in Hank's balanced salt solution [HBSS]) and subsequently replanted. The rats were divided into 2 groups based on the use of root surface treatment: the doxycycline group (root surface treated with doxycycline) and the control group (no doxycycline treatment). Eight weeks after replantation, the animals were sacrificed, and the teeth were evaluated using micro-computed tomography (micro-CT) and histomorphometric analysis.ResultsIn the micro-CT analysis, the doxycycline group showed the same rate of occurrence of periapical radiolucency as was observed in the control group, but a lower degree of root resorption in teeth replanted after 60 minutes of storage in HBSS (P<0.05). In the histomorphometric analysis, the doxycycline group exhibited no improvement in either pulpal or periodontal healing of the replanted tooth after 5 minutes of dry storage, but showed a lower grade of surface root resorption (1.37±0.77) and inflammatory resorption in the teeth stored for 60 minutes in HBSS (1.33±0.71).ConclusionsIn conclusion, doxycycline improved the periodontal healing of replanted teeth stored for 60 minutes in HBSS, whereas doxycycline did not improve periodontal healing of replanted tooth after 5 minutes of dry storage. Within the limits of this study, doxycycline showed more favorable periodontal healing despite delayed replantation.

Conservative Orthodontic Retreatment in a Patient with Class III Malocclusion and Root Resorption in Maxillary Teeth

Conservative Orthodontic Retreatment in a Patient with Class III Malocclusion and Root Resorption in Maxillary Teeth