Bone Resorption Rate of Moved and Fixed Teeth during Alveolar Bone Remodeling by Orthodontic Treatment.

Sclerostin (Scl) negatively regulates bone formation and favors bone resorption. Osteocytes, the cells responsible for mechanosensing, are known as the primary source of Scl and are a key regulator of bone remodeling through the induction of receptor activator of NF-κB ligand (RANKL). However, the spatiotemporal patterns of Scl in response to mechanical stimuli and their regulatory mechanisms remain unknown. We investigated the regulatory dynamics of the SOST/Scl expression generated by orthodontic tooth movement (OTM) in vivo and in vitro. In 8-wk-old male mice, coil springs were used to move the first molar mesially for 0, 1, 5, or 10 d. A regional histogram and the distribution patterns of the Scl expression showed that the Scl expression in the alveolar bone was increased on the compression side and peaked on day 5, with a gradual increase in the degree of significance. On day 10, the expression around the periodontal ligament (PDL)–alveolar bone boundary returned to the control level. Conversely, the expression of Scl on the tension side was only significantly decreased on day 1. Compressive force biphasically modulated the SOST/Scl expression in the isolated human PDL and thereby upregulated osteocytic SOST via paracrine activation in an osteocyte-PDL co-culture system designed to mimic OTM. This system did not affect the RANKL or OPG expression in osteocytes, suggesting that the bone resorption pathways are acted upon in a PDL-dependent and osteocyte-independent manner through RANKL/OPG signaling. Moreover, sclerostin neutralizing antibody significantly attenuated the upregulation of SOST that was induced by compressive force. In conclusion, our results provide evidence to support that factors secreted by the PDL, including SOST/Scl, control alveolar bone remodeling through osteocytic SOST/Scl in OTM.

Download Full-text

The Impact of Cannabis on Alveolar Bone Remodeling in Orthodontic Treatment

Journal of Oral and Maxillofacial Surgery ◽

10.1016/j.joms.2020.07.068 ◽

2020 ◽

Vol 78 (10) ◽

pp. e25

Author(s):

K.P. Klein ◽

F. Guastaldi ◽

Y. He ◽

M.J. Troulis

Keyword(s):

Bone Remodeling ◽

Orthodontic Treatment ◽

Alveolar Bone ◽

Alveolar Bone Remodeling ◽

The Impact

Download Full-text

Correlation between Dental Vestibular–Palatal Inclination and Alveolar Bone Remodeling after Orthodontic Treatment: A CBCT Analysis

Materials ◽

10.3390/ma12244225 ◽

2019 ◽

Vol 12 (24) ◽

pp. 4225

Author(s):

Cinzia Maspero ◽

Francesca Gaffuri ◽

Iury O. Castro ◽

Valentina Lanteri ◽

Alessandro Ugolini ◽

...

Keyword(s):

Bone Remodeling ◽

Orthodontic Treatment ◽

Alveolar Bone ◽

Linear Regression Analysis ◽

Three Dimensional ◽

3D Analysis ◽

Bone Thickness ◽

Anterior Teeth ◽

Alveolar Bone Remodeling ◽

Torque Values

The aim of this study was to evaluate the correlation between dental vestibular–palatal inclination changes and the cortical bone remodeling after fixed orthodontic treatment using cone beam computed tomography (CBCT). Twenty-two patients with Angle Class I malocclusion, permanent dentition, and mild to moderate dental crowding were included in the present three-dimensional (3D) analysis. Bone dimensions were evaluated by CBCT scans obtained before and after orthodontic treatment, whereas the torque values were calculated by means of digital models using the 3D VistaDent software. A paired t-test was used to compare the changes between the pretreatment and post-treatment measurements. The correlations between variables were analyzed with linear regression analysis. A significant correlation between torque variations and bone thickness changes was observed for the apical buccal level of the anterior side (P < 0.05). Limited and not significant alveolar bone resorption for the apical thickness of anterior teeth occurred at ± 5 degrees of torque variation, while for tooth inclination exceeding +5 or −5 degrees, the bone remodeling was more evident. The present study demonstrated that anterior region was the most affected area by bone remodeling and that torque variation was highly related to apical bone thickness adaptation for maxillary and mandibular incisors and maxillary canines.

Download Full-text

Orthodontic Force–Induced BMAL1 in PDLCs Is a Vital Osteoclastic Activator

Journal of Dental Research ◽

10.1177/00220345211019949 ◽

2021 ◽

pp. 002203452110199

Author(s):

Y. Xie ◽

Q. Tang ◽

S. Yu ◽

W. Zheng ◽

G. Chen ◽

...

Keyword(s):

Bone Remodeling ◽

Alveolar Bone ◽

Tooth Movement ◽

Orthodontic Tooth Movement ◽

Nuclear Factor Κb ◽

Periodontal Ligament Cells ◽

Orthodontic Force ◽

Periodontal Tissues ◽

Alveolar Bone Remodeling ◽

Biomechanical Stimuli

Orthodontic tooth movement (OTM) depends on periodontal ligament cells (PDLCs) sensing biomechanical stimuli and subsequently releasing signals to initiate alveolar bone remodeling. However, the mechanisms by which PDLCs sense biomechanical stimuli and affect osteoclastic activities are still unclear. This study demonstrates that the core circadian protein aryl hydrocarbon receptor nuclear translocator–like protein 1 (BMAL1) in PDLCs is highly involved in sensing and delivering biomechanical signals. Orthodontic force upregulates BMAL1 expression in periodontal tissues and cultured PDLCs in manners dependent on ERK (extracellular signal–regulated kinase) and AP1 (activator protein 1). Increased BMAL1 expression can enhance secretion of CCL2 (C-C motif chemokine 2) and RANKL (receptor activator of nuclear factor–κB ligand) in PDLCs, which subsequently promotes the recruitment of monocytes that differentiate into osteoclasts. The mechanistic delineation clarifies that AP1 induced by orthodontic force can directly interact with the BMAL1 promoter and activate gene transcription in PDLCs. Localized administration of the ERK phosphorylation inhibitor U0126 or the BMAL1 inhibitor GSK4112 suppressed ERK/AP1/BMAL1 signaling. These treatments dramatically reduced osteoclastic activity in the compression side of a rat orthodontic model, and the OTM rate was almost nonexistent. In summary, our results suggest that force-induced expression of BMAL1 in PDLCs is closely involved in controlling osteoclastic activities during OTM and plays a vital role in alveolar bone remodeling. It could be a useful therapeutic target for accelerating the OTM rate and controlling pathologic bone-remodeling activities.

Download Full-text

Effects of elcatonin, etidronate and indomethacin on bone resorption rate in growing rats

Bone ◽

10.1016/8756-3282(95)91658-t ◽

1995 ◽

Vol 16 (6) ◽

pp. 685

Author(s):

T.M. Skerry

Keyword(s):

Bone Resorption ◽

Growing Rats ◽

Resorption Rate ◽

Bone Resorption Rate

Download Full-text

Effects of sialoadenectomy and exogenous EGF on molar drift and orthodontic tooth movement in rats

AJP Endocrinology and Metabolism ◽

10.1152/ajpendo.1994.266.5.e731 ◽

1994 ◽

Vol 266 (5) ◽

pp. E731-E738 ◽

Cited By ~ 2

Author(s):

C. Dolce ◽

J. Anguita ◽

L. Brinkley ◽

P. Karnam ◽

M. Humphreys-Beher ◽

...

Keyword(s):

Bone Formation ◽

Bone Remodeling ◽

Alveolar Bone ◽

Tooth Movement ◽

Orthodontic Tooth Movement ◽

Alveolar Bone Remodeling ◽

Tooth Roots ◽

Epidermal Growth ◽

Tetracycline Labeling ◽

Distal Aspect

Effects on bone remodeling have been attributed to epidermal growth factor (EGF). Sialoadenectomy (SX) removes the major source of EGF in rodents and decreases both salivary and serum EGF levels. EGF effects on rat alveolar bone remodeling manifested by molar drift (MD) and orthodontic tooth movement (OTM) were examined using the following two approaches: 1) EGF depletion by SX and replacement by orally administered EGF (50 micrograms.animal-1.day-1); 2) sham rats supplemented with matching amounts of EGF. MD and OTM were measured using cephalometric radiographs; bone formation was measured histomorphometrically using tetracycline labeling. Normal MD was not detected after SX, and alveolar bone formation was significantly reduced both around the tooth and in nondental sites. Replacement EGF given to SX rats and supplemental EGF administered to sham rats changed the direction and enhanced the rate of MD. A mesially directed orthodontic force applied to the molars of SX animals increased bone formation on the distal aspect of the tooth roots. Supplemental EGF did not significantly affect OTM. EGF affects alveolar bone remodeling, as manifested clinically by alterations in normal maxillary MD.

Download Full-text