Orthodontically induced osteocyte apoptosis under different force magnitudes in rats: an immunohistochemical study

Kassem, Hassan; Talaat, Iman M.; El-Sawa, Afaf A.; Ismail, Hassan; Zaher, Abbas

doi:10.1111/eos.12366

Cited by 7 publications

(4 citation statements)

References 45 publications

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“…Although the distribution of apoptotic caspas3 + cells in the tension areas was unrelated to the force intensity. [30] According to the clinical study conducted by Leon et al, 8 months after the application of orthodontic force, the content of BCL2 protein in dental human pulp decreased in a time-dependent manner while the expression level of caspase9 increased. They reported that the orthodontic treatments reduced BCL2 expression time-dependently, resulting in increased cell death.…”

Section: Discussionmentioning

confidence: 99%

The Effect Of Light Compressive And Tensile Orthodontics Forces On Sclerostin And Periostin Expressions In Human Periodontal Ligament Cells: An Invitro Study

Sharifi

Akhoundi

Hodjat

et al. 2022

Preprint

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BackgroundOrthodontic treatment induces bone resorption on the compression side while on the tension side stimulates bone formation. The process involves a complex interaction of signalling molecules. The aim of the present study is to assess the expression of key regulatory proteins associated with bone remodeling, cell proliferation and apoptosis in response to different types of orthodontic forces at varied time points in periodontal ligament (PDL) cells. Materials and methods and ResultsPDL cells were isolated from extracted teeth and were divided into two groups based on the type and time of applied forces: Group 1 exposed to compressive forces for 0, 6, 24, 48, 72 hours and group 2 imposed to equi-axial tension forces in 1Hz frequency and 10% elongation in 0, 24, 48, 72 hours. Real-Time Quantitative Reverse Transcription PCR (qRT-PCR) was applied to evaluate the gene expression. The secretion of Sclerostin and Periostin was assessed using Enzyme-Linked Immunosorbent Assay (ELISA). 4′,6-diamidino-2-phenylindole staining (DAPI) was used to evaluate apoptosis.The expression of Sclerostin(SOST) elevated at protein and gene levels under compression force while the application of tensile force induced the expression of Periostin(POSTN), Runt-related transcription factor 2(RUNX2) and reduced SOST expression in a time-dependent manner. Proliferating cell nuclear antigen (PCNA), the marker of proliferation increased under tensile force. The compression forces induced apoptosis and increased gene expression of apoptotic regulators, Caspase9, and B-cell lymphoma 2(BCL2). ConclusionThe periostin and sclerostin play important role in orthodontic loads and their expressions under compressive and tensile forces are affected by both variables of time and type of applied forces. Application of compressive stress increases apoptosis while tensile force induces cell proliferation.

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Section: Discussionmentioning

confidence: 99%

The Effect Of Light Compressive And Tensile Orthodontics Forces On Sclerostin And Periostin Expressions In Human Periodontal Ligament Cells: An Invitro Study

Sharifi

Akhoundi

Hodjat

et al. 2022

Preprint

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“…We and others have shown that orthodontic forces cause a significant increase in osteocyte apoptosis and that its peak (24–48 h of OTM) precedes the appearance of osteoclasts [ 14 , 23 ]. Osteocytes are deeply embedded in mineralized matrix and are not accessible by scavengers that phagocytose cells undergoing apoptosis and prevent inflammation.…”

Section: Discussionmentioning

confidence: 99%

The role of inhibition of osteocyte apoptosis in mediating orthodontic tooth movement and periodontal remodeling: a pilot study

et al. 2021

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Background Orthodontic tooth movement (OTM) has been shown to induce osteocyte apoptosis in alveolar bone shortly after force application. However, how osteocyte apoptosis affects orthodontic tooth movement is unknown. The goal of this study was to assess the effect of inhibition of osteocyte apoptosis on osteoclastogenesis, changes in the alveolar bone density, and the magnitude of OTM using a bisphosphonate analog (IG9402), a drug that affects osteocyte and osteoblast apoptosis but does not affect osteoclasts. Material and methods Two sets of experiments were performed. Experiment 1 was used to specifically evaluate the effect of IG9402 on osteocyte apoptosis in the alveolar bone during 24 h of OTM. For this experiment, twelve mice were divided into two groups: group 1, saline administration + OTM24-h (n=6), and group 2, IG9402 administration + OTM24-h (n=6). The contralateral unloaded sides served as the control. The goal of experiment 2 was to evaluate the role of osteocyte apoptosis on OTM magnitude and osteoclastogenesis 10 days after OTM. Twenty mice were divided into 4 groups: group 1, saline administration without OTM (n=5); group 2, IG9402 administration without OTM (n=5); group 3, saline + OTM10-day (n=6); and group 4, IG9402 + OTM10-day (n=4). For both experiments, tooth movement was achieved using Ultra Light (25g) Sentalloy Closed Coil Springs attached between the first maxillary molar and the central incisor. Linear measurements of tooth movement and alveolar bone density (BVF) were assessed by MicroCT analysis. Cell death (or apoptosis) was assessed by terminal dUTP nick-end labeling (TUNEL) assay, while osteoclast and macrophage formation were assessed by tartrate-resistant acid phosphatase (TRAP) staining and F4/80+ immunostaining. Results We found that IG9402 significantly blocked osteocyte apoptosis in alveolar bone (AB) at 24 h of OTM. At 10 days, IG9402 prevented OTM-induced loss of alveolar bone density and changed the morphology and quality of osteoclasts and macrophages, but did not significantly affect the amount of tooth movement. Conclusion Our study demonstrates that osteocyte apoptosis may play a significant role in osteoclast and macrophage formation during OTM, but does not seem to play a role in the magnitude of orthodontic tooth movement.

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“…Ten of the extracted supernumerary teeth were stored in saline until processed for histopathological and immunohistochemical analysis. Sections from formalin-fixed paraffin-embedded (FFPE) blocks were prepared according to Kassem et al [ 16 ]; one section was stained with hematoxylin and eosin, and four unstained slides were prepared for immunohistochemistry (IHC). For IHC, FFPE sections were deparaffinized in xylene and rehydrated in graded ethanol concentrations.…”

Section: Methodsmentioning

confidence: 99%

Assessment of risk factors and molecular biomarkers in children with supernumerary teeth: a single-center study

et al. 2022

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Background Supernumerary teeth are considered one of the commonly observed dental anomalies in children. Several theories have been proposed to explain the presence of supernumerary teeth, including environmental and genetic factors. This study aimed to identify the different risk factors and molecular biomarkers in patients presented with supernumerary teeth. Methods This case–control study included 240 children, 6 to 12-year-old. They were divided into a test group (n = 120 children presented with supernumerary teeth) and a control group (n = 120 children with no supernumerary teeth). Questionnaires were distributed to assess demographics and exposure to several environmental factors. Ten extracted supernumerary teeth from the test group were processed for histopathological analysis. Results Male gender, dental history of severe oral infection or medical history of chemotherapy treatment, previous history of taking medication or illness during pregnancy, family history of neoplastic disorders, use of electronic devices, and living beside agricultural fields or industrial areas were found to be statistically significant associated with the risk of supernumerary teeth development. Immunohistochemistry panel revealed that supernumerary teeth showed enhanced expression of wingless (Wnt) and sonic hedgehog (SHH) proteins as well as a reduced expression of adenomatous polyposis coli (APC) protein, denoting molecular derangement in a group of pathways classically believed to be involved in its pathogenesis. Conclusions Males were more frequently affected by supernumerary teeth than females. Several risk factors were notably correlated with the existence of supernumerary teeth. Additionally, molecular biomarkers assessment demonstrated a high expression level of pro-tumorigenic proteins such as Wnt and SHH in patients with supernumerary teeth.

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Orthodontically induced osteocyte apoptosis under different force magnitudes in rats: an immunohistochemical study

Cited by 7 publications

References 45 publications

The Effect Of Light Compressive And Tensile Orthodontics Forces On Sclerostin And Periostin Expressions In Human Periodontal Ligament Cells: An Invitro Study

The Effect Of Light Compressive And Tensile Orthodontics Forces On Sclerostin And Periostin Expressions In Human Periodontal Ligament Cells: An Invitro Study

The role of inhibition of osteocyte apoptosis in mediating orthodontic tooth movement and periodontal remodeling: a pilot study

Assessment of risk factors and molecular biomarkers in children with supernumerary teeth: a single-center study

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