Success rate and factors affecting stability of infrazygomatic miniscrew implants: a systematic review and meta-analysis

Abstract Background The infrazygomatic miniscrew implants (IZC-MSI) serve as innovative temporary anchorage devices placed parallel to the roots of molars in the infrazygomatic crest region, leveraging their extra-radicular location to support the en masse distalization and intrusion of the maxillary dentition. The efficacy and stability of these screws are crucial for their application in contemporary orthodontic practices. Objectives This systematic review aimed to estimate the success rate and factors affecting the stability of IZC-MSI. Search methods An electronic search was conducted on 7 February 2024 across the following databases: PubMed, Scopus, EMBASE, and Cochrane databases without any restriction on language and time of publication. Selection criteria The review included clinical trials (both randomized and non-randomized) and retrospective cohort studies that utilized infrazygomatic miniscrew anchorage for orthodontic tooth movement in human participants. Data collection and analysis The proportion of success rate was calculated and factors affecting stability (patient and implant-related factors) such as age, sex, implant position, and loading characteristics were subjected to subgroup analysis and meta-regression. The quality assessment of studies was done using the Cochrane risk-of-bias tools for randomized (RoB 2.0) and non-randomized trials (ROBINS-I). Results Fourteen studies (n = 1683 IZC-MSI) were included in the meta-analysis revealing a 92% success rate of IZC-MSI (C.I. 87%–95%; prediction interval: 66%–99%; I2 = 80%). Studies with sample size > 100 presented a 94% success rate (C.I. 91%–96%; I2 = 63%) and moderate heterogeneity. Meta-regression analysis revealed no significant relation between age and success rate. Significant heterogeneity was observed in the subgroup analysis of host-, implant- and other related risk factors affecting stability and limited correlation was found. The risk-of-bias assessment revealed high risk in five, moderate in five, and low in four studies. Conclusions IZC-MSI have shown a good success rate for their clinical application. Although some factors appear to influence IZC-MSI stability, the majority of them necessitate additional investigation due to the low quality of evidence. Furthermore, high-quality studies are needed to confirm the results of this meta-analysis and address other important factors such as operator’s experience, insertion torque, and sinus penetration that could not be analysed due to limited data. Registration CRD42024469048.