Abstract： Objective To preliminarily evaluate the clinical effect of the three-dimensional (3D) printing individualized titanium mesh combined with guided bone regeneration technology for repairing alveolar bone defects.Methods Six patients with alveolar bone defects (4 males and 2 females,aged 18-27 years,mean 23.3 years) were selected from the Department of Oral Implantology,Stomatological Hospital of Chongqing Medical University from January to June 2018.The patients' cone-beam CT (CBCT) data was imported into the digital design software,and the individualized titanium meshes were designed based on the ideal bone mass around the implant,alveolar bone morphology and soft tissue condition.Then,the".stl" files were output and the meshes were fabricated by 3D printing technology.The individualized titanium meshes combined with the mixture of autogenous bone and bone substitute materials were used to augmentation during operation.All patients were reviewed at 1,3 and 6 months after surgery to observe the complications and evaluate the effect of bone augmentation.After taking out the titanium mesh,the CBCT was compared with the preoperative CBCT.The increased bone height and bone width were measured and the bone incremental volume was calculated.Results Titanium mesh exposure occurred in 2 patients with no obvious infection,and no early removal.In 6 patients,the bone width increased by 1.75-7.54 mm (mean 3.58 mm),the bone height increased by 0.91-11.80 mm (mean 3.37 mm),and bone incremental volume increased by 247-676 mm3 (mean 503 mm3).All of the cases showed sufficiently grafted volume for implant placement.Conclusions The individualized 3D printing titanium meshes combined with guided bone regeneration could repair alveolar bone defects with excellent clinical effect,but a better design needed to be explored in the future to solve or delay the exposure of titanium mesh.