Copyright © 2019 American Society of Plastic Surgeons. Unauthorized reproduction of this article is prohibited. www.PRSJournal.com 823 A utologous free fat grafting has become the mainstay for management of craniofacial contour deformities. 1–6 Because craniofa- cial fat grafts have highly variable retention rates (33 to 94 percent), 7 some patients require a com- plementary (or secondary) procedure to obtain satisfactory craniofacial symmetry. 1–8 A complementary fat graft has been shown to achieve signifcantly better outcomes than an initial fat graft in adult patients with Parry-Rom- berg syndrome. 8 To the best of our knowledge, no craniofacial investigation has focused on evalu- ating complementary fat graft outcomes during the frst year of follow-up and/or in subgroups of Disclosure: None of the authors has a financial interest to declare in relation to the content of this article. There are no conflicts of interest to disclose. Copyright © 2019 by the American Society of Plastic Surgeons DOI: 10.1097/PRS.0000000000005389 Rafael Denadai, M.D. Cesar Augusto Raposo- Amaral, M.D. Simone Alves da Silva Celso Luiz Buzzo, M.D., M.Sc. Cassio Eduardo Raposo- Amaral, M.D., Ph.D. Campinas, São Paulo, Brazil Background: The purposes of this study were to (1) assess complementary fat graft outcomes, (2) compare initial and complementary fat graft retention rates, and (3) evaluate the infuence of different postoperative time points (3, 6, and 12 months after the initial procedure) for performing complementary fat grafting on fat graft outcomes. Methods: A prospective analysis was conducted on patients with unilateral cra- niofacial contour deformities (n = 115) who underwent initial and comple- mentary fat grafting. Complementary fat grafting was performed 3, 6, or 12 months after the initial fat grafts. Standardized ultrasonographic craniofacial soft-tissue thickness measurements were performed blindly to determine the initial and complementary fat graft retention rates at 1, 3, 6, and 12 months after surgery. Results: A signifcant (p < 0.05) reduction of fat graft retention was observed within the frst 3 postoperative months, and a maintenance of retention (p > 0.05) was observed at 3 through 12 months after surgery for both initial and complementary procedures. No signifcant (p > 0.05) differences were ob- served in comparative analysis of the postoperative time points. Complemen- tary retention rates were signifcantly (p < 0.05) superior to initial retention rates at 3, 6, and 12 months after surgery. Complementary retention rates at 3, 6, and 12 months after surgery were signifcantly (p < 0.05) superior to initial retention rates for patients aged 18 years or older, those with Parry-Romberg syndrome, those who had undergone previous craniofacial bone surgery, and those with a recipient site at the forehead unit. Conclusion: The complementary fat graft retention rates were superior to the initial retention rates, with no signifcant differences among the postoperative time points for performing complementary procedures. (Plast. Reconstr. Surg. 143: 823, 2019.) CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, II. From the Institute of Plastic and Craniofacial Surgery, SO- BRAPAR Hospital. Received for publication April 17, 2018; accepted August 27, 2018. Complementary Fat Graft Retention Rates Are Superior to Initial Rates in Craniofacial Contour Reconstruction Supplemental digital content is available for this article. Direct URL citations appear in the text; simply type the URL address into any Web browser to access this content. Clickable links to the material are provided in the HTML text of this article on the Journal’s website (www. PRSJournal.com). PEDIATRIC/CRANIOFACIAL