Purpose: The aim of this study was to determine, before implant placement, the outcome of ridge preservation surgery after extractions of one or more adjacent teeth on the dimensions of the edentulous ridge. Materials and Methods: Nineteen extraction sites in four dogs were randomly divided into three groups: group 1 = single premolars (n = 7 sites); group 2 = two adjacent premolars (n = 6 sites); group 3 = three adjacent premolars (n = 6 sites). Extraction was followed by ridge preservation surgery using a combination of xenograft and collagen membrane after full-thickness flap reflection. All animals were sacrificed 4 months later, and each extraction site was sectioned in the sagittal plane so that alveolar bone measurements could be made in both the buccolingual and apicocoronal directions using microcomputed tomography. Results: Mean buccolingual width of the ridges postsurgery was 4.80 ± 2.78 mm, 4.98 ± 2.65 mm, and 4.79 ± 2.79 mm in groups 1, 2, and 3, respectively. The mean vertical distance from the cementoenamel junction to the crest of the ridge was 1.94 ± 0.42 mm, 2.05 ± 0.48 mm, and 2.60 ± 0.67 mm in groups 1, 2, and 3, respectively. No statistically significant difference was seen between single and multiple extraction sites. Conclusion: Ridge preservation surgery results in a similar pattern of bone remodeling in the horizontal and vertical dimensions of the edentulous ridge after single and multiple adjacent tooth extractions. Schlagwörter: ridge dimensions, ridge preservation surgery, tooth extractions