Objectives: The aim of the study was to evaluate horizontal distraction osteogenesis of thin alveolar ridge using modified micro bone screw and subsequent implant placement. Patients and Methods: Eight patients were seeking for restoring their missing anterior maxillary teeth with implant supported prosthesis. They had a residual alveolar ridge with an adequate height but insufficient width for implant placement. All patients were scheduled for ridge augmentation procedure before implant placement. Horizontal DO using modified micro screw was performed. After osteotomy a latency period of seven days was allowed before activation of the distraction screw at a rate of 0.5 mm / 10 days once daily. Then distraction screw was left for a consolidation period of three months. Postoperative CBCT scan was performed to assess the bone width and area gained after distraction process. After consolidation period the distractor was removed, bone core biopsy was harvested from the implants sites and implant was placement. The obtained bone specimens were histologically examined. Data were collected and statistically analyzed. Results: The mean preoperative bone width was 3.06 mm that was increased to reach 5.5 mm. And mean preoperative bone area was 64.82 mm2 that was increased to reach 85.75mm2. Histological examination revealed native bone with well organized cancellous bone with wide marrow spaces. Conclusion: Horizontal DO using modified micro screw proved to be an effective method for augmenting the width of the deficient alveolar ridge and micro bone screw serving as the distraction device does not considerably add to the overall costs of the surgical procedure.