PMID- 34308514 OWN - NLM STAT- MEDLINE DCOM- 20210727 LR - 20210817 IS - 2196-1042 (Electronic) IS - 1723-7785 (Print) IS - 1723-7785 (Linking) VI - 22 IP - 1 DP - 2021 Jul 26 TI - The role of inhibition of osteocyte apoptosis in mediating orthodontic tooth movement and periodontal remodeling: a pilot study. PG - 21 LID - 10.1186/s40510-021-00366-4 [doi] LID - 21 AB - 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 + OTM(24-h) (n=6), and group 2, IG9402 administration + OTM(24-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 + OTM(10-day) (n=6); and group 4, IG9402 + OTM(10-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. CI - (c) 2021. The Author(s). FAU - Kaplan, Michele AU - Kaplan M AUID- ORCID: 0000-0002-6511-3984 AD - Division of Orthodontics, College of Dental Medicine, Columbia University, New York, NY, USA. michelekaplan22@gmail.com. FAU - Kalajzic, Zana AU - Kalajzic Z AD - Department of Oral Health and Diagnostic Sciences, Division of Oral Medicine, UConn Health, Farmington, CT, USA. FAU - Choi, Thomas AU - Choi T AD - Division of Orthodontics, College of Dental Medicine, Columbia University, New York, NY, USA. FAU - Maleeh, Imad AU - Maleeh I AD - Division of Orthodontics, College of Dental Medicine, Columbia University, New York, NY, USA. FAU - Ricupero, Christopher L AU - Ricupero CL AD - Division of Orthodontics, College of Dental Medicine, Columbia University, New York, NY, USA. FAU - Skelton, Michelle N AU - Skelton MN AD - Division of Orthodontics, College of Dental Medicine, Columbia University, New York, NY, USA. FAU - Daily, Madeleine L AU - Daily ML AD - Division of Orthodontics, College of Dental Medicine, Columbia University, New York, NY, USA. FAU - Chen, Jing AU - Chen J AD - Division of Orthodontics, College of Dental Medicine, Columbia University, New York, NY, USA. FAU - Wadhwa, Sunil AU - Wadhwa S AD - Division of Orthodontics, College of Dental Medicine, Columbia University, New York, NY, USA. LA - eng PT - Journal Article DEP - 20210726 PL - Germany TA - Prog Orthod JT - Progress in orthodontics JID - 100936353 SB - IM MH - Animals MH - Apoptosis MH - Bone Remodeling MH - Mice MH - *Osteocytes MH - Pilot Projects MH - *Tooth Movement Techniques PMC - PMC8310814 OTO - NOTNLM OT - Bisphosphonate OT - Orthodontic tooth movement OT - Osteocyte apoptosis COIS- The authors declare that they have no competing interests. EDAT- 2021/07/27 06:00 MHDA- 2021/07/28 06:00 PMCR- 2021/07/26 CRDT- 2021/07/26 06:57 PHST- 2020/12/08 00:00 [received] PHST- 2021/06/07 00:00 [accepted] PHST- 2021/07/26 06:57 [entrez] PHST- 2021/07/27 06:00 [pubmed] PHST- 2021/07/28 06:00 [medline] PHST- 2021/07/26 00:00 [pmc-release] AID - 10.1186/s40510-021-00366-4 [pii] AID - 366 [pii] AID - 10.1186/s40510-021-00366-4 [doi] PST - epublish SO - Prog Orthod. 2021 Jul 26;22(1):21. doi: 10.1186/s40510-021-00366-4.