Purpose: This article presents a critical review of the literature on the prosthodontic maintenance requirements of mandibular mucosa- and implant-supported overdentures. Materials and Methods: A search of the literature produced 35 papers pertaining to prospective and retrospective studies. The relationship of these prosthodontic maintenance requirements to the axis of rotation treatment concept was examined. Results: More often than not, 2 anterior mandibular implants either splinted (round or ovoid bars) or unsplinted (balls or magnets) have been used to evaluate this prosthodontic follow-up. Wide variation existed in the categories used for prosthodontic complications. Although principally related to alterations of overdenture contour and aspects of patrix and matrix maintenance, they also provide subjective information on relines and the rationale for avoiding overdenture fractures. These prosthodontic maintenance requirements undoubtedly have a direct impact on the time to retreatment of mandibular mucosa- and implant-supported overdentures. Conclusion: There appears to be a need for a more uniform, standardized categorization with criteria for determining prosthodontic success, in terms of maintenance requirements and complications, for mandibular mucosa- and implant-supported overdentures. Controlled prospective evaluations of exact prosthodontic maintenance requirements of mandibular overdentures using different systems are lacking and encouraged. There is also an absence of prospective studies on such maintenance requirements of mandibular overdentures using multiple round bars on 3 or 4 implants.