Evaluation of Vestibular Bone Thickness in Class I Malocclusion Treatment With Corticotomy-Assisted Rapid Orthodontics, Background: Corticotomy-assisted rapid orthodontics is a widely used method for speeding up conventional orthodontics. This study evaluates the effects of corticotomy alone, corticotomy combined with bone graft, and corticotomy with platelet-rich fibrin (PRF) on vestibular alveolar bone thickness in patients with class I malocclusion;compares the treatment time with a conventional orthodontic therapy group, andinvestigates the periodontal health of patients who have undergone corticotomy-assisted rapid orthodontics. Methods: The patients were divided into 3 groups: Group 1 (n = 10) underwent corticotomy alone; Group 2 (n = 10) underwent corticotomy combined with bone graft, and Group 3 (n = 10) underwent corticotomy combined with PRF. In the following stage, vestibular alveolar bone thicknesses were evaluated using 3-dimensional cone-beam computed tomography images. Results: The findings showed that Group 2 achieved a more significant augmentation of the vestibular alveolar bone than Groups 1 and 3 (P = 0.001, P = 0.003), while corticotomy-assisted rapid orthodontics decreased treatment times. Sufficient alveolar bone thickness and preservation of the periodontal health were achieved when the corticotomy procedure was either combined with a bone graft or with PRF in the Class-I malocclusion patients. Conclusion: Bone grafts provided better bone thickness at the buccal surface of the anterior teeth of the mandible and maxilla, whereas the thickness of the keratinized gingiva was better with PRF. Address correspondence and reprint requests to Zeynep Burcin Gonen, DDS, PhD, Oral and Maxillofacial Surgery, Genome and Stem Cell Center, Erciyes University, 38039 Kayseri, Turkey; E-mail: zburcin@gmail.com Received 17 July, 2018 Accepted 8 May, 2019 The authors report no conflicts of interest. Supplemental digital contents are available for this article. Direct URL citations appear in the printed text and are provided in the HTML and PDF versions of this article on the journal's Web site (www.jcraniofacialsurgery.com). © 2019 by Mutaz B. Habal, MD.