Edentulism is a contributing factor in the occurrence of periodontal disease. The aim of this study was the radiological investigation of the changes in the periodontal support as a result of edentulism and those related to the position of a tooth adjacent to an edentulous gap. Materials and methods: We examined 50 mandibular and 50 maxillary retroalveolar radiographs, scale 1:1, 100 panoramic radiographs, scale 1:1, with unidental edentulism, assessed with a digital electronic caliper, 150 mm rod depth. Results: The mean values of horizontal migration of teeth in the edentulous space are 6 mm in the case of the molars, and 2 mm in premolars. Tilting was more frequent than translation. Alveolar bone resorption recorded a mean value of 1.93 mm in the maxilla, 2.30 mm in the mandible, and a maximum value of 5 mm. Conclusions: The presence of a toothless gap can lead to damage to the deep parodontium of the nearby teeth