Clinical Application Of Additive Manufacturing Personalized Titanium Alloy In Reconstruction And Reconstruction Of Mandibular Defects

Background:The mandible is located in the middle third of the face and is the largest bone in the maxillofacial region.It plays a decisive role in human facial support.Due to inflammation,trauma,maxillofacial tumors and other reasons,the mandibular defect will cause the patient to engage in chewing and mastication.Obstacles,face facial deformities,seriously affect the quality of life of patients.Reconstruction of the mandibular defect repair treatment has always been the focus of attention in the field of maxillofacial surgery,the purpose of repair is to restore the continuity and integrity of the mandible,maximize the retention of mandibular function,correction of maxillofacial deformity.In recent years,significant advances have been made in the reconstruction of mandibular defects.There are currently a variety of repair methods,such as reconstructive titanium plates,autologous vascularized iliac myocutaneous flap grafting,and so on,along with digital medical imaging technology,computer-assisted technology,and additive manufacturing.With the development of technology,porous titanium alloy bone tissue substitute materials with similar shape,size,and weight can be individually designed and manufactured based on the patient's computed tomography scan data to achieve personalized repair and reconstruction of mandibular defect.Purpose:To investigate the effect of custom titanium alloy restorations based on additive manufacturing techniques on the repair and reconstruction of mandibular defect,and to repair the two mandibular defects with the traditional reconstructed titanium plate and autograft iliac myocutaneous flap.Retrospective controlled studies.Method:1.General Information: Two male patients and one female patient were diagnosed with a relapse of mandibular ameloblastoma.The patients were between 20 and 40 years of age.They are scheduled to undergo surgical treatment and have been reviewed by the ethics committee of our hospital.Agreed that,during the same period,additive manufacturing of personalized porous titanium alloy implants was used to repair mandibular defects.At the same time,10 cases of non-malignant tumors of mandibular defect repaired with titanium plate reconstruction and autologous vascularized iliac myocutaneous flap grafting were randomly selected from 2014 to 2017 in our hospital.Preoperative and postoperative CT and image data were completely preserved for all patients as a retrospective study.2.Production of custom titanium alloy restorations: The patient CT data were dumped into Mimics(Materialise's interactive medical image control system,version 15.0,Materialise,Belgium)software,using its image cutting function to simulate the mandibular segmental defect,by mirroring technology,reversed Generation of mandibular surface model,data import into UG(Unigraphics NX,version 10.0,Siemens PLM Software,Germany)software for custom product design,including the internal structure design of the three-dimensional mesh structure,with the implant and the corresponding surgery.The guide,after the completion of the export STL format file,and then import Magics(Materialize,version 20,Belgium)software to repair,fill the grid,layout,add support and slicing,and finally enter the additive manufacturing equipment.Used additive manufacturing equipment model: Arcam Q10 Plus(Arcam,model 2016,Sweden),Material: Ti6-Al-4V ELI* powder supplied by Arcam AB,Sweden,in line with national GB/T13810 surgical implants Titanium and titanium alloy processing materials standard requirements.3.Surgery: Under general anesthesia,the titanium alloy implants were ultrasonically oscillated and cleaned before operation,and the sterilization effect was good through biological detection.The osteotomy line designed according to the surgical guide plate was osteotomized with a dynamic system to completely resection the lesion.The titanium alloy was added to the corresponding mandibular defect and added to the defect.The titanium screw was fixed and the antibiotic was used to prevent infection.4.Prognosis evaluation: Design of the prognosis of the efficacy of the grade,through the clinical examination and CT images,the patient's subjective feelings to evaluate its recovery.Result:The custom titanium alloy restorations made through additive manufacturing technology can meet the clinical requirements.Two male patients who have undergone additive manufacturing custom titanium alloy restoration have restored the continuity of the mandible,and the shape of the repaired posterior part has recovered well.General food,no rejection.In the third female patient,due to a large soft tissue defect in the mouth,the wound was opened and part of the metal was exposed,and finally the implant was removed.No tumor recurrence was observed in all patients at the subsequent stage.The CT scan of the patient showed that all the tumors had been removed after surgery.The titanium alloy restorations and the mandibular defects were in a good fit.The CT scan also showed the accuracy of the reserved titanium implants.There were significant differences in the outcomes of the three different mandibular reconstructive repair methods.The patients with two types of reconstructive titanium plates and autologous vascularized iliac myocutaneous flaps had less probabilities of achieving Class I criteria.The prognosis of patients with alloy repair was significantly better than that of the latter two groups.Combined with clinical data,this difference was mainly reflected in the satisfaction of facial restoration and recovery of occlusal function.Conclusion:Custom titanium alloy prostheses prepared using additive manufacturing techniques can be applied to the reconstruction of mandibular defect with good results.The repair effect is better than the two traditional methods of reconstructive titanium plate and autograft iliac myocutaneous flap grafting.