The Application Of 3D Printing Technology For Improved Reconstruction In Orbital Wall Defects

BackgroundThe incidence of maxillofacial trauma accounts for 34%of the total body trauma,and the incidence of maxillary fracture is still on the rise with the change of injury factors.The orbital wall is the connecting part of maxilla and skull,so it is easyto fracture in maxillofacial trauma,and the defects of orbital wall is often formed after fracture because of the thin bone.In addition,oral and maxillofacial lesions,especially maxillary space occupying lesions,can also lead to orbital wall defects if the tumor projects into the orbit.So orbital wall defects is a common clinical problem in oral and maxillofacial surgery.Because the orbital wall is irregular in shape and the important nerves and blood vessels are dense.the reconstruction of orbital defects caused by trauma or tumor is a difficult point in oral and maxillofacial surgery.Titanium mesh or thermoplastic absorbable materials have the advantages of good biocompatibility and easy to repair or shape,so it is widely used in the repair and reconstruction of orbital wall defects.But there are many unpredictable factors in traditional methods of titanium mesh implantation and empirical surgery with absorbable materials.The titanium mesh or absorbable material need a lot of time to shape during surgery and the final shape often does not fit well with the bone wall,and the optic nerve may be damaged if implanted too deeply.In addition,,it is easy to cause stress fatigue after repeated bending for titanium mesh.Therefore,how to reconstruct the orbital defect s accurately is a clinical problem to be solved.ObjectiveHow to reconstruct the orbital defect caused by oral and maxillofacial trauma or tumor is a difficult point in oral and maxillofacial surgery.The purpose of this study is to evaluate the feasibility and clinical effect of the reconstruction of orbital floor defects assisted by 3D printing technology,and to provide the basis for the application of 3D printing technology in the reconstruction of orbital floor defect.MethodsEight patients with orbital floor defect were selected.All the patients underwent 64 slice spiral CT scan before reconstruction,the thickness of which was 0.625 mm,the CT scans were evaluated and images were stored in digital imaging ’and medical communication(Digital Imaging and Communications in Medicine,DICOM)formats.Simpleware 6.0 software(Simpleware Ltd,Exeter,United Kingdom)was used to generate 3D images,and transmitted DICOM data to the triangulation language(STL)file for digital operation in workstation,the 3D craniofacial bone disease model was printed on a scale of 1:1 with the human body.The injured side was mirrored with normal maxillary and orbital bone using Mimics 3D image technique,and then the mirror image model was printed out.Finally,the titanium mesh was precisely plastic on the mirror model.If the absorbable material was used,the secondary shaping needed to be done,the orbital floor defect was reconstructed by pre-forming orbital defect implants during the operation.ResultsEight patients were performed according to the preoperative design.The trauma patients underwent anatomical reduction and accurate reconstruction of the bone defect at the fracture site.The patients diagnosed as occupying lesions underwent accurate excision and reconstruction.The operation process was smooth and the operation time was shortened.All the patients had improved their facial and orbital symptoms.There were no complications such as diplopia,infection,foreign body reaction,exophthalmos,enophthalmos,malocclusion and hematoma.Conclusions3D printing technology can achieve preoperative design,surgical simulation and implant precise molding.Preoperative preoperation of the disease on 3D model and the use of mirror 3D prefabricated artificial implants can effectively improve the accuracy and safety of the reconstruction of orbital floor defects.