Purpose: To compare median lingualized and monoplane occlusion in Implant retained mandibular overdenture with ball and socket attachment. Materials and Methods:Ten completely edentulous patients were selected to receive with dental implants. Each patient received two cylinders with reversed screw and hydroxyapetite coated dental implants, one implant on each side in the canine regions of the mandible. The implants were left submerged (unloaded) for a healing and osseointegration period of four months. The patients were divided into two groups, five patients in each. Group I patients received overdenture retained by ball and socket attachment, the artificial teeth were arranged in a median lingualized occlusion, and Group II patients received overdenture retained by ball and socket attachment but the artificial teeth were arranged in a monoplane occlusion. All patients were evaluated clinically and radiographically immediately after overdenture delivery and after 6 and 12 months. Results and conclusion:There was no statistically significant difference between median lingualized and monoplane occlusion in implants supporting a mandibular overdenture retained by ball & socket attachment. From the clinical point of view, satisfactory results were obtained when two dental implants were placed in the intraforaminal region of the mandible and connected with ball and socket attachment to support and retain mandibular overdenture. These satisfactory results were obtained with median lingualized occlusion as well as with monoplane ones.