[Application of 3D computer-assisted printing technique combined with plastic titanium mesh in the reconstruction of maxillary defect].

Objective: To investigate the application and clinical outcomes of using 3D computer-assisted printing technique combined with plastic titanium mesh in the reconstruction of maxillary defect. Methods: Clinical data of 14 patients in Department of Otorhinolaryngology Head and Neck Surgery, Shanghai Ninth People's Hospital from January 2016 to June 2018, who were treated for partial or total removal of the maxilla due to benign or malignant tumors and those acquired maxillary defects caused by severe compound trauma were analyzed retrospectively. Twelve males and 2 females were included, with the age ranging from 16 to 51 years old. The sinonasal malignant tumors included squamous carcinoma ( n= 2) while benign tumors included hemangioma ( n= 1), maxillary fibrous dysplasia ( n= 3), maxillary cyst ( n= 2) and giant cell tumor of the maxilla ( n= 1). Five cases of post-traumatic maxillary defect were also included. According to preoperative thin-layer CT scanning data, computer modeling data was transmitted to a 3D printer to print out the original model and the reconstructed model. Preoperative simulation of tumor removal and maxillary reconstruction was done on the patient's original model, and the titanium mesh was shaped on the reconstructed model in order to properly reconstruct the area needed to be repaired. The pre-made titanium mesh was implanted into the defect area, the soft tissue flaps were reset, layered stitching and the local pressured bandage were used after surgery. Through postoperative clinical and CT examination, the patient's maxillofacial shape, nasal function and complications were evaluated. The results were analyzed by descriptive statistical method. Results: Lesions could be completely removed within the predicted range on the preoperative 3D-printed models of all cases. After debridement, titanium mesh could be implanted easily without re-shaping and trimming during surgery as in trauma cases. Titanium mesh could completely cover the missing bone surface closely, with titanium nails fixed smoothly, and the implanted titanium mesh was solid and stable. After the follow-up of 6 to 20 months, all patients were satisfied with the facial symmetry and the function was recovered well. Conclusion: Using 3D computer-assisted printing technique combined with plastic titanium mesh in the reconstruction of maxillary defect can accurately restore the maxillary structure for soft tissue support, and restore the facial shape and function.