PURPOSE: The aim of this study was to evaluate radiographically the effectiveness of alveolar distraction osteogenesis (ADO) technique for vertical reconstruction of atrophy alveolar ridges in partially edentulous patients. MATERIALS AND METHODS: A total of 60 vertical distraction osteogenesis procedures were performed in 55 patients. Two panoramic radiographies were performed in all patients, one the day before the beginning of distraction, and one after consolidation period, 12 weeks postoperatively. The radiographic analysis consisted of obtaining the amount of the vertical bone gain (VBG) in each radiography. For this, we obtained initially the magnification factor (MF) of each panoramic radiography by dividing the real size (RS) of the activation rod among the image size (IS) of the activation rod. After this, to obtain the VGB, we measured initially the length of the distracton preactivation (LD1), which consisted of the distance between the superior portion of the basal plate and the superior portion of the transport plate, multiplying by the MF. Then, we measured the length of the distraction postactivation (LD2), using the same method described before, in radiographies performed 12 weeks postoperatively. The VBG was obtained using the following formula: VBG = LD2 - LD1. The results were applied to descriptive statistical analysis. Complications were also investigated during all of the treatments. RESULTS: The mean alveolar distraction achieved in 60 cases was 6.27 mm (range, 0 to 10.83 mm). According to the region treated, 51.6% were in the posterior mandible (mean VBG, 4.60 mm), 36.66% were in the anterior maxilla (mean VBG, 7.46 mm), 8.33% were in the anterior mandible (mean VBG, 6.73 mm), and 3.33% were in the posterior maxilla (mean VBG, 6.32 mm). The overall rate of complications that compromised the success of the technique was 8.44%. The increased radiopacity of the distracted region could be observed in the 12-week period after surgery. CONCLUSIONS: The ADO technique was demonstrated to be an effective tool to treat vertical defects of the alveolar ridge with a success rate of 91.66%. Our radiographic analysis seems to be an important tool in verifying the technique as well as planning implant placement after ADO.