Purpose: This study aimed to develop a classification of edentulous jaws for use as a diagnostic tool during implant-prosthodontic treatment planning. Materials and Methods: The morphology of 200 fully edentulous alveolar ridges (100 maxillae, 100 mandibles) was assessed with cone beam computed tomography. Generic implants (length: 8 mm; diameter: 4.1 mm) were used. To develop the classification system, the feasibility of virtually placing the implants without vertical ridge augmentation was considered. Potential implant sites were evaluated in terms of ridge width and described as either type A (no horizontal augmentation required) or type B (horizontal augmentation required). A descriptive statistical analysis of subjects' age, sex, and arch classification was performed. Results: In total, 880 implants were virtually planned. Based on alveolar ridge height, four arch patterns were identified (C1 to C4), providing a basis for prosthodontic planning with either removable or fixed implant-supported restorations. The frequencies of each category were as follows: C3 (n = 62, 62%), C4 (n = 16, 16%), C2 (n = 12, 12%), and C1 (n = 10, 10%) for the maxilla and C3 (n = 36, 36%), C4 (n = 31, 31%), C1 (n = 24, 24%), and C2 (n = 9, 9%) for the mandible. Conclusion: The proposed classification of the edentulous arch represents a useful tool for communication between clinicians when planning implantsupported rehabilitations.