A total of 183 articles were identified using the search strategy. Screening of these papers yielded four studies comparing mini-implant-retained overdentures and standard diameter implant overdentures and were found eligible to be included in the systematic review [8,9,10,11]. Two studies [8, 11] comparing patient satisfaction between the groups were included for the meta-analysis. The PRISMA flow diagram is depicted in Fig. 1. The key characteristics of the included studies are mentioned in Table 1 [8,9,10,11]. Risk of bias of the included studies is depicted in Fig. 2.

Two studies [8, 11] in a total of 177 patients compared patient satisfaction with mini-implant-retained overdentures compared to standard diameter implant-supported overdentures. The pooled result was −4.76 [−6.48, −3.04] favoring the use of mini-implants (Fig. 3).

One [9] of the included studies reported marginal bone loss, failure rate of implants, and clinical parameters and pooling of the study results was not possible indicating inadequate evidence. One study [10] reported post-operative pain and discomfort as measured by VAS and pooling of the study results was not possible due to inadequate evidence.

GRADE approach was used for only one of the eligible outcomes which was patient satisfaction and the strength of evidence was observed to be “low” (Table 2).