Abstract
BackgroundThis study aimed to examine radiologic microarchitectural changes in the mandibles of ovariectomized (OVX) rats through a systematic review and meta-analysis and to identify factors of the OVX rat model that influence on the bone microstructure.MethodsEligible articles were identified by searching electronic databases, including Embase, Medline, Web of Science, and KoreaMed, for articles published from January 1966 to November 2017. Two reviewers independently performed study selection, data extraction, and quality assessment. The pooled standardized mean difference (SMD) with 95% confidence intervals was calculated using a random-effects model. Subgroup analysis and meta-regression were performed to explore the effect of potential sources on the outcomes. The reliability of the results was assessed by sensitivity analysis and publication bias.ResultsOf 1160 studies, 16 studies (120 OVX and 120 control rats) were included in the meta-analysis. Compared to the control group, the OVX rats’ trabecular bone volume fraction (SMD = − 2.41, P < 0.01, I2 = 81%), trabecular thickness (SMD = − 1.73, P < 0.01, I2 = 73%) and bone mineral density (SMD = − 0.95, P = 0.01, I2 = 71%) displayed the bone loss consistent with osteoporosis. The trabecular separation (SMD = 1.66, P < 0.01, I2 = 51%) has widen in the OVX mandibular bone in comparison to the control group. However, the trabecular number showed no indication to detect the osteoporosis (SMD = − 0.45, P = 0.38, I2 = 76%). The meta-regression indicated that longer post-OVX periods led to greater changes in bone mineral density (β = − 0.104, P = 0.017). However, the rats’ age at OVX was not linked to bone microstructure change.ConclusionsUsing meta-regression and sensitivity analysis techniques, heterogeneity across the micro CT studies of OVX-induced osteoporosis was found. The major factors of heterogeneity were the region of interest and post-OVX period. Our assessment can assist in designing experiments to maximize the usefulness of OVX rat model.
Highlights
We aimed to examine radiologic microarchitectural changes in the mandibles of OVX rats through a systematic review and meta-analysis and to identify factors of the OVX rat model that influence on the bone microstructure
We extracted data relating to study characteristics and outcomes using a pre-defined form including the name of the first author, the year of publication, the strain and number of the OVX and control rats, the rats’ age at OVX, the period after OVX surgery, the region of interest (ROI) of the mandible and microarchitectural outcome (BV/TV, Tb.Th, Tb.Sp, Tb.N, bone mineral density (BMD))
We discovered that the duration after OVX was the factor with a significant influence on the heterogeneity of BMD in the meta-analysis (β = − 0.106, 95% confidence intervals (CIs): − 0.20 to − 0.02, P = 0.017)
Summary
This study aimed to examine radiologic microarchitectural changes in the mandibles of ovariectomized (OVX) rats through a systematic review and meta-analysis and to identify factors of the OVX rat model that influence on the bone microstructure. Osteoporosis has become a major public health concern [3] which commonly occurs in postmenopausal women as a result of ovarian atrophy and the related decrease in circulating estrogens [4]. Ovariectomized (OVX) rats have been used as a preclinical model of postmenopausal humans to investigate mandibular changes [8, 9]. In OVX rats, bone mineral density (BMD) changes are similar to those in humans; BMD can be used as a common indicator of bone mass [10]. The divergent results in the previous literature make it challenging to draw firm conclusions
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
