Objective To investigate the preliminary efficacy of 3D printed individualized genioglossus advancement(GA)for the treatment of obstructive sleep apnea(OSA)in adults with micrognathia.Methods The OSA patients with retropalatal and retroglossal collapses due to micrognathia underwent 3D printed individualized GA combined with Uvulopalatopharyngoplasty(UPPP)in Department of Otolaryngology,Head and Neck Surgery,Sun Yat-sen Memorial Hospital,Sun Yat-sen University.Clinical data including pre-and post-operative polysomnography(PSG),cephalometric measurements of genioglossus advancement,patient-reported symptom and surgical complications were collected.A comparison of pre-and post-operative data was conducted using paired t-tests.Results Nineteen OSA patients with micrognathia successfully underwent 3D printed individualized GA combined with UPPP,and achieved an actual mean genioglossus advancement distance of(9.0±1.4)mm compared to the planned distance of(9.4±1.0)mm preoperatively(t=0.81,P=0.427).Among the 14 patients followed up for more than 6 months,the mean AHI reduced by 60.4%at 6 months postoperatively,with 5 cases(5/14)cured and 5 cases(5/14)showing significant improvement,resulting in an overall surgical response rate of 10/14.All patients expressed satisfaction with their postoperative facial appearance,with 13 cases perceiving an improvement in attractiveness.Two patients reported temporary genial numbness,and one patient experienced temporary mandibular occlusal asthenia.Conclusion The 3D printed individualized GA combined with UPPP effectively reduces AHI in adult OSA patients with micrognathia,accompanied by a low incidence of surgical complications and high patient satisfaction regarding postoperative facial appearance.