Mandibular prostheses on implants/retainers have three crucial elements: the implant fixations (02 or more), the choice of fixation (bars, dowels or magnets) and the prosthesis. The McGill consensus reported that as a minimum treatment goal, the two-implant mandibular overdenture (as opposed to a conventional overdenture) should be considered a first-choice standard of care for the edentulous patient5. Mericske-Sterne also concluded that retention, stability, and occlusal balance of implant-supported mandibular overdentures improved only slightly with increasing number of implants.7 Implant survival rates did not vary with number of implants. implants and varied between 93% and 100%.8-19 These results suggest that the number of implants is greater to support a prosthetic superstructure which may be in the form of a bar, stud or magnets for optimal load distribution. The results of this study showed that interocclusal space and interforaminal distance dictated the number of implants and superstructure selection for implant supported/retained mandibular overdentures. Prosthetic complications in mandibular dentures have remained a topic of interest in the literature. Berglundh in 2002, in his systematic review, concluded that prosthetic complications reported in mandibular implant prostheses were 4 to 10 times greater than in fixed implant prostheses20. Looking at the literature above, it becomes increasingly important to pay close attention to the planning phase of implant treatment. supported/retained mandibular prosthesis. The individual anatomical variations of the patients should be respected and the treatment plan regarding the number of implants and the choice of superstructure should be the basis...... middle of paper ......mm. For class IIIa, a four implant option could be used with ball clips or locators during prosthesis design. Class IIIb in which IFD ≤ 30 mm and IOS is between 6 and 8 mm. For class IIIb, one option out of two could be used with locator type attachments when designing the prosthesis. The deciding factor for the rehabilitation of edentulous patients with an implant-supported mandibular prosthesis is the interforaminal space, however the final selection is modified by the IOS. ConclusionThe classification system described here is intended to help clinicians assess and effectively communicate their patient's dimensional relationship. This classification system would also facilitate decisions regarding pre-surgical tissue manipulation, final prosthesis design, choice of number of implants and fixation systems at the treatment planning stage...