The success of bone augmentation is usually dependent on primary wound closure. This review provides a literature-based system to assess the predictability of achieving primary wound closure. Seven pertinent factors that determine the risk for wound exposure were identified: (1) the width of keratinized mucosa, (2) flap thickness, (3) flap tension, (4) vestibular depth, (5) type and (6) size of the bony defect, and (7) materials used. Clinical cases are used to demonstrate evaluation of these factors. This evaluation system may aid clinicians in differentiating cases with various risks of wound exposure and making decisions on flap modifications and the most appropriate surgical designs.