Purpose: The purpose of this clinical study was to use the digital occlusal analysis to compare the maximum occlusal force and occlusal force distribution in mini-implants and standard-diameter implant mandibular overdentures. Also, to compare patient satisfaction and prosthodontic maintenance after two years of function. Materials and methods: Twenty–two edentulous patients were randomly divided equally into two groups. MIO group (test group) received mandibular overdentures retained by four mini-implants, and SDO group (control group) received mandibular overdentures retained by two standard diameter implants. Digital occlusal study was done to evaluate occlusal force distribution, maximum occlusal contact force, and tooth contact number. Patient satisfaction was assessed using a visual analogue scale questionnaire. Prosthodontic maintenance measures were analyzed. The follow-up period was two years after overdenture insertion. Results: Insignificant differences were found in occlusal force parameters between both groups. All domains of patients' satisfaction increased significantly in MIO and SDO groups. There were insignificant differences in patient satisfaction between both groups. Prosthodontic maintenance requirements for both groups were comparable during the two-year follow-up. The most frequent prosthodontic complication was the wear of female housing. This was followed by dislodgement and replacement of female parts. Conclusion: Within the study's limitations, mini-implants can improve mandibular overdenture performance regarding maximal occlusal force and tooth contact number without impairing force distribution by employing digital occlusal analysis. Mandibular overdentures retained by mini-implants can achieve similar outcomes as standard-diameter implant overdentures in terms of patient satisfaction and prosthodontic problems.