Objective To evaluate the efficacy and safety of acellular dermal matrix (ADM) in preventing Frey syndrome.Methods Studies of acellular dermal matrix in preventing Frey syndrome were searched in The Cochrane Library (Issue 1, 2010), MEDLINE, EMbase, SIGLE, GreyNet, NTIS, CBMdisc, VIP, CNKI and WANFANG DATA from 1995 to 2010. All the studies were selected, extracted and evaluated by four reviewers independently, and meta-analyses were performed with RevMan 5.0.0 software. Results A total of 15 studies involving 472 participants were included in the review. The studies showed that implantation of the ADM was able to efficiently reduce the incidence of Frey syndrome, and the difference in both subjective and objective was significant between the two groups after the therapy (RR=0.11, 95%CI 0.06 to 0.18, Plt;0.01; RR=0.14, 95%CI 0.10 to 0.19, Plt;0.01). The rate of temporary facial nerve paralysis was lower than that of the control group but the difference was not significant (OR=0.78, 95%CI 0.37 to 1.66, P=0.53). The incidens of both seroma and mucocele were higher than that of the control group but the difference was not significant(OR=2.63, 95%CI 0.09 to 79.25, P=0.58) and they could be alleviated by placing drainage tube and partial pressure bandage. The incidence rate of salivary fistula was lower than that of the control group and the difference was significant (OR=0.24, 95%CI 0.08 to 0.69, P=0.009). Conclusion The result of this system review shows that, the ADM can effectively and safely reduce the incidence of Frey syndrome. To perform preoperative hypersensitivity check for iodine or iodophors, to conduct rapid frozen section for defining the character of tumor, to fix the ADM stably, to place vacuum-drainage and to make partial pressure bandage are suggested.
Objective To evaluate the effectiveness of four-handed dentistry versus two-handed dentistry in root canal therapy. Methods The CBM, VIP, CNKI, Wanfang, PubMed, EMbase, and CENTRAL were searched for collecting relevant randomized controlled trails (RCTs) in English or Chinese from establishment dates to August 31, 2011. After quality evaluation and data extraction independently conducted by two authors, the meta-analyses were performed using the RevMan 5.1, and the evidences were graded using the GRADEprofile 3.6. Results Fourteen studies involving 2 906 patients were included. The results of qualitative analysis and meta-analyses showed that compared with two-handed dentistry, four-handed dentistry could obviously shorten operating time, improve satisfaction of patients and doctors, lower the risk of hole pollution, and improve treatment quality, all the differences were significant; but there was no significant difference in postoperative pain during the first week. Based on the GRADE system, the importance of outcomes was “important” or “critical”, while the level of evidences was from “extremely low” to “high”. Conclusion Current evidence shows that four-handed dentistry is superior to two-handed dentistry, but it suggests a weak recommendation to dental workers. Due to the limitations of included studies, more large-sample and high-quality RCTs, and especially performing “cost-effectiveness analysis” as the key outcome are required.