| [Objectives] To investigate and compare the treatment effects of mini-implants as anchor on maxillary dentoalveolar protrusion patients with traditional methods of anchorage reinforcement in terms of skeletal, dental, and soft tissue changes.[Methods] Retrievalling relevant database:PubMed, OVIDSP, the Cochrane Library, CBM, VIP, CNKI and WanFang Data. What’s more, we manual search NLM, SIGLE, Campbell library, WHOLIS, Evidence based medicine, and the Journal of Orthodontics. Additionally, we used search engine such as Google to find out omissive studies. Literature filtering, data extraction and methodological quality evaluation were finished independently by two researchers and disagreements were solved by discussion. Original outcome data, if possible, were subjected to statistical pooling by Review Manager 5.3 for Meta analysis.[Results] Through a predefined search strategy, we finally included 14 eligible studies. Among them, eight were RCT trials and the others were CCT trials. Including 450 patients in all:RCTs have 262 patients, including 131 mini-implant anchorage patients and 131 traditional anchorage patients; CCTs have 188 patients, including 96 mini-implant anchorage patients and 92 traditional anchorage patients. This meta-analysis separately compared the maxillary incisor retraction, the maxillary molar movement distance, the axial inclination of the maxillary central incisor to the SN plane (U1-SN°), angle between the SN plane and the NA plane (SNA°), the inclination of the mandibular plane to the cranial base (SN-MP°), upper lip to E Plane (UL-E Plane, mm), nasolabial angle (NLA0) and facial convexity (G-Sn-Pg°). Additionally, we also made quality assessments of each study, found that all the RCT studies are regarded as high-quality and all the CCT studies are B grad.1 maxillary incisor retractionThirteen trials show that there was a significant difference between the mini-implant and the traditional anchorage technique in the maxillary incisor retraction (P<0.00001).2 maxillary molar movement distanceThirteen trials show that there was a significant difference between the mini-implant and the traditional anchorage technique in the maxillary molar movement distance (P< 0.00001).3 U1-SN°The results of the Meta analysis show that there was no difference between the mini-implant and the traditional anchorage technique in U1-SN° (P=0.41).4SNA°Eleven trials show that there was a significant difference between the mini-implant and the traditional anchorage technique in SNA° (P=0.71).5 SN-MP0Six trials show that there was a significant difference between the mini-implant and the traditional anchorage technique in SN-MP° (P=0.04).6 UL-E Plane (mm)Five trials show that there was a significant difference between the mini-implant and the traditional anchorage technique in UL-E Plane (P=0.001). 7NLA°Four trials show that there was a significant difference between the mini-implant and the traditional anchorage technique in NLA° (P=0.003).8 G-Sn-Pg°Three trials show that there was a significant difference between the mini-implant and the traditional anchorage technique in G-Sn-Pg° (P=0.06).[Conclusions] For the patients with maxillary protrusion, the mini-implant anchorage is much better than the traditional anchorage in the overjet and the maxillary incisor retraction. Meanwhile, smaller mesial movement of the maxillary molars and less anchorage loss were observed in mini-implants anchorage, which means that it provides more space for the retraction of the incisors. Moreover, it is more effective than the traditional anchorage on SN-MP° for the high-angle patients, because it can make mandible counterclockwise rotation more effectively. Both mini-implants anchorage and traditional anchorage have the same effect on U1-SN0 and SNA°. However, there is no exact conclusion in UL-E Plane, NLA° and G-Sn-Pg°, because of the quantity of the including trials is few and the quality of them is limited, so more qualified RCTs are required to provide reliable recommendations. |
