The Preliminary Clinical Application Study Of All-digital Orthognathic Surgery

Objective:To study the design and implementation of orthognathic surgery assisted by digital technology and explore more scientific and reasonable procedures of all-digital orthognathic surgery.Methods:Digital technology was applied to assist 3D reconstruction measurement,preoperative diagnosis,surgical simulation design,3D design and production of guide plates and occlusal plates,navigation verification and effect evaluation of orthognathic surgery.Twenty-five patients with congenital dento-maxillofacial deformity were selected,and basic information,clinical examination,cranio-maxillofacial CT scan,maxillary and mandibular dentition models,and facial images were collected before surgery.The collected CT data was imported into Mimics 20.0 software for processing and creating digital models,and the dental data and three-dimensional facial data were imported to establish digital design models.On the digital design models,a three-dimensional reconstruction measurement plane was established based on the hard tissue landmarks,and measurement and analysis were performed to obtain digital diagnosis information.Based on this,the design of the surgical plan and the production of the guide plates were performed.Digital surgical navigation system was used to confirm the design position of the maxillary bone,to verify its retention,and to accurately guide the bone grinding during the operation.Craniofacial spiral CT was conducted 1 week after the operation for purpose of postoperative validation of the surgical design protocol.The actual digital 3D reconstruction model and the digital terminal model designed before the operation were matched according to the non-surgical site of the brain.The three-dimensional coordinates(X,Y,Z)of 10 groups on the same landmarks were compared and verified after the actual postoperative and preoperative design.The landmarks include ANS(anterior nasal spine),A(subspinale),Incisive foramen,Pyriform aperture-R,Pyriform aperture-L,B(supramental),Pg(pogonion),Me(menton),Foramen-R,Foramen-L.Statistical analysis was performed using SPSS 24.0 software.The chromatographic analysis was performed after the bone tissue fused with the 3-matic module.Results:25 patients were performed according to the digital orthognathic surgery process.The results of postoperative follow-up of the patients met the requirements of preoperative design.There were no significant differences in the X,Y and Z three-dimensional directions between the postoperative actual head model and the preoperative predictive head model(P> 0.05).Chromatographic analysis show that there was no significant difference in the operation area of maxillary and mandible.The results of the operation met the design requirements.Conclusions:Orthognathic surgery diagnosis,surgical design and surgical implementation assisted by digital technology had the advantages of precision and minimally invasiveness.The application of the digital navigation system during the operation had the advantages of achieving a more accurate and safe surgical design.