ObjectiveTo systematically review the efficacy of dexmedetomidine for controlled hypotension in orthognathic surgery. MethodsThe PubMed, Embase, Cochrane Library, CNKI, VIP and WanFang Data databases were electronically searched to collect randomized controlled trials (RCTs) on dexmedetomidine for controlled hypotension in orthognathic surgery from inception to May, 2024. Two reviewers independently screened literature, extracted data and assessed the risk of bias of included studies. Meta-analysis was then performed by using RevMan 5.4 software. ResultsA total of 8 RCTs involving 371 patients were included. The results of meta-analysis showed that the operation time of dexmedetomidine group was not significantly different from that of hypotensive drug group, but was shorter than that of saline group (MD=?23.20, 95%CI ?44.05 to ?2.35, P=0.03). There were no statistically significant differences in the mean arterial pressure and the intraoperative blood loss between dexmedetomidine group and the control group. Compared with those in the control group, the heart rate (MD=?18.78, 95%CI ?30.80 to ?6.77, P=0.002) and the incidence of postoperative adverse events (OR=0.25, 95%CI 0.08 to 0.76, P=0.01) in dexmedetomidine group were less than those in the control group significantly. ConclusionCurrent evidence shows that dexmedetomidine can be used effectively for controlled hypotension in orthognathic surgery. Due to the limited quality and quantity of the included studies, more high-quality studies are needed to verify above conclusion.