<abstract xmlns="http://www.w3.org/1999/xhtml"><sec><h3>Background</h3><p>To investigate the effect of combined oral contraceptives (COC) on orthodontic tooth movement (OTM) and periodontal remodelling in a female rat model.</p></sec><sec><h3>Methods</h3><p>A total of 80 three-month-old female, Sprague-Dawley rats were randomly divided into experimental and control groups. The maxillary first molars were moved mesially using nickel-titanium coil springs (50 g force). The experimental group (N = 40) ingested 1.5 ml COC (Marvelon, 0.12 mg/d, N.V. Organon, Oss, The Netherlands) daily. The control group (N = 40) ingested 1.5 ml saline (0.9% sodium chloride) daily. After 7, 14, 21 and 28 days of force application, 10 rats in each group were euthanased and a vernier calliper was used to measure the orthodontic movement of the first molar. Root resorption at pressure areas was assessed by H and E staining. Micro-CT was used to detect alveolar bone mineral density.</p></sec><sec><h3>Results and conclusion</h3><p>The amount of OTM in the experimental group (0.46 ± 0.16 mm) was significantly less than in the control group (0.85 ± 0.25 mm; <italic>p</italic> = 0.003) during the 28 days of observation. There were significantly smaller (<italic>p</italic> = 0.002) root resorption lacunae in the experimental group (111710 ± 4037 pixels) compared with the control group (204962 ± 21318 pixels) after 28 days. There was no statistically significant difference in the bone mineral density between the experimental and control groups throughout the study period (<italic>p</italic> > 0.05 at each time point). The short-term administration of COC may retard tooth movement and reduce the level of root resorption during OTM in female rats.</p></sec></abstract>

BackgroundTo investigate the effect of combined oral contraceptives (COC) on orthodontic tooth movement (OTM) and periodontal remodelling in a female rat model.MethodsA total of 80 three-month-old female, Sprague-Dawley rats were randomly divided into experimental and control groups. The maxillary first molars were moved mesially using nickel-titanium coil springs (50 g force). The experimental group (N = 40) ingested 1.5 ml COC (Marvelon, 0.12 mg/d, N.V. Organon, Oss, The Netherlands) daily. The control group (N = 40) ingested 1.5 ml saline (0.9% sodium chloride) daily. After 7, 14, 21 and 28 days of force application, 10 rats in each group were euthanased and a vernier calliper was used to measure the orthodontic movement of the first molar. Root resorption at pressure areas was assessed by H and E staining. Micro-CT was used to detect alveolar bone mineral density.Results and conclusionThe amount of OTM in the experimental group (0.46 ± 0.16 mm) was significantly less than in the control group (0.85 ± 0.25 mm; p = 0.003) during the 28 days of observation. There were significantly smaller (p = 0.002) root resorption lacunae in the experimental group (111710 ± 4037 pixels) compared with the control group (204962 ± 21318 pixels) after 28 days. There was no statistically significant difference in the bone mineral density between the experimental and control groups throughout the study period (p > 0.05 at each time point). The short-term administration of COC may retard tooth movement and reduce the level of root resorption during OTM in female rats.

Effect of combined oral contraceptives on orthodontic tooth movement in a female rat model

Orofacial Reconstruction and Regeneration Laboratory

The Third People’s Hospital of Dongguan City

Australasian Orthodontic Journal

This work is licensed under the Creative Commons Attribution 4.0 International License.

BackgroundTo investigate the effect of combined oral contraceptives (COC) on orthodontic tooth movement (OTM) and periodontal remodelling in a female rat...

Effect of combined oral contraceptives on orthodontic tooth movement in a female rat model

Published Online: Jul 20, 2021

Page range: 127 - 133

Received: Dec 01, 2018

Accepted: May 01, 2019

DOI: https://doi.org/10.21307/aoj-2020-041

© 2019 Jinghong Yu et al., published by Sciendo

This work is licensed under the Creative Commons Attribution 4.0 International License.