Aim: To investigate the incidence and distribution of alveolar bony defects in the mandibular anterior area. Methods: A flap procedure was performed to expose the labial alveolar bone of the mandibular anterior area of 32 patients. The presence of alveolar defects including dehiscences and fenestrations were recorded. Results: Seventy-eight percent (25) of the examined patients had at least one tooth with an alveolar bony defect. Dehiscences were found to be most commonly associated with the midline of the labial surface of mandibular left and right canines followed by the mesiolabial line of the same teeth. Conclusions: The structure and topography of alveolar bone should be considered prior to the treatment planning and tooth movement. Moreover, there is a tremendous need to develop a noninvasive precise method for diagnosing alveolar defects. World J Orthod 2009;10:16–20.