Application Of Digital Technology In The Design Of Soft And Hard Tissue Defects In Oral And Maxillofacial Region

Objective:1.The data obtained by continuous thin layer(layer thickness0.625mm)CT scan of lower limbs was imported into the Mimics17.0software for three-dimensional reconstruction for showing three-dimensional relationship of the muscle,bone and vascular.The traversing location from the body skin and three-dimensional spatial relation with skin,muscle and bones was determined by perforator vessels originated from descending limb of lateral femoral circumflex artery,which is found by image fusion and matching.The pre-operative skin flap design and surgical operation was guided by doing it.The evidence was also provided for making individualized anterolateral thigh flap.2.Maxillofacial region three-dimensional CT data is imported into Mimics17.0 software to determine the scope of mandibular lesions.The computer virtual technology was used to cut the lesion area.The fibula CT data was imported into Mimics17.0 software to determine the location,extent,shape of the defect that was designed the length and shape of the fibula matched the defect area.In Mimics17.0 software,three-dimensional image of fibula to be cut and mandible osteotomy guide plate,fibula osteotomy moulding guiding plate were constructed and 3D printing technology was used to make mandible and fibula guiding plate and carryout mandible reconstruction.Based on above,it was used to discuss the clinical value of using digital fibula repairing mandible defect.Methods :1.From June 2016 to December 2016,7 patients with oral and maxillofacial malignant tumor patients(4 male ones,3 female ones)scanning parameters in room CT underwent CTA scanning of lower limb.The scanning parameters : layer thickness 0.625 mm,tube voltage120.0KV,tube current 250 mA.Nonionic contrast media iodixanol was used for the contrast medium and the scanning range was from the lower segment of abdominal aorta to patella.The data was imported to Mimics17.0 software in the DICOM form and data analysis was carried out on CTA examination results.The tube diameter,running,vessel pedicle length of lateral femoral circumflex artery descending limb and perforating branch were measured and a proper perforating branch was selected for the blood supply of skin flap.The location of the perforating branch was marked on the skin to stimulate the cutting range of skin flap.All the patients were divided into two groups: The one group underwent primary lesion and cervical lymph node dissection and the other group underwent preparation of anterolateral thigh flap.During the operation,the flap size was lined and marked based on pre-operative sign.After the preparation of skin flap,the donor region was sutured and closed directly,with negative pressure drainage tube builted in.The skin flap was transplanted to the tissue defect site.Arteriovenous anastomosis wascarried out and the skin flap and the defect wound surface were sutured closely,with negative pressure drainage tube installed in the neck.After the operation,the skin flap and the general condition were closely observed 2.From February 2016 to February 2017,6 patients(4 male patients and 2 female patients)with mandible lesions from our department were selected to undergo lower limb thin-layer CT scanning,The scanning parameters: layer thickness 0.625 mm,tube voltage 120.0KV,tube current 250 mA.Nonionic contrast media iodixanol was used for the contrast medium and the scanning range was from 5cm above superior border of patella to toes.Maxillofacial region three-dimensional CT data was imported into Mimics17.0 software and computer was used to split image and stimulate the cutting in fibula according to defect location and range of mandible.3D printing technology was used to prepare mandible osteotomy guide plate and fibula moulding guide plate.All the patients were divided into two groups:The one group underwent primary lesion excision or primary lesion plus cervical lymph node dissection and the other group underwent preparation of fibula myocutaneous flap or fibular flap.During the operation,fibula was shaped based on the design of guide plate to assure blood supply of skin flap.In the reconstruction plate,fibula was fixed and transplanted to the mandible defect site after pedicle division.Arteriovenous anastomosis was carried out and mandible from and function was reconstructed to observe the clinical curative effect.Results: 1.The skin,muscle,blood vessels and their neighboring relationships was showed by the skin flap of all reconstructed anterolateral femoral circumflex artery descending limb and perforating branch.According to the size of the defect region,the cutting skin flap was simulated by the Mimics17.0 software,which is basically consistent with the defect range.The main perforating branches and trunks of seven skin flaps were consistent with pre-operative examination and all skin flaps survived;the wound surface and the donor were all in stage I healing.After operation,patients were followed up for 1~6 months and the form,quality and function of skin flaps all recovered well.2.After three-dimensional reconstruction,the origin and the running of peroneal artery can all be displayed clearly.The needed osteotomy guiding plate accurately based on mandible lesion was designed by the Mimics17.0software.The fibula osteotomy and moulding guiding plate is made by determineing the cutting length and angle of fibula based on the mandible defect site and range in the Mimics17.0 software.The fibula moulding that was completed based on moulding plate was consistent with the intra-operative condition and there was no bias;fibula and skin flaps were cut successfully and were transplanted to the mandible defect site after pedicle division.The wound surface and the donor region of six patients were all in stage I healing;in one case,the venous return was blocked and blood vessels cannot be anastomosed after surgical detection;the fibularflap was removed and the reconstruction plate was used to replace mandible.Patients were followed up for 1~10 months: the appearance of the mandible was recovered well and there was distinct disorder in the lower limb function.Conclusion:1.The location of lateral femoral circumflex artery descending limb and perforating branchwas accurately located by CTA three-dimensional reconstruction technology,showing the spatial relationship among skin,muscle,blood vessels and bones.By combining with Mimics17.0 software,it can achieve three-dimensional and accurate design of anterolateral thigh flap,reduce the donor injury and improve the skin flap successful rate.2.The origin of peroneal artery and its relation with fibula CTA technology was well showed by CTA three-dimensional technology.Through the Mimics17.0 software,it can simulate cutting fibula and mandible,achieve digital pre-operative plate design,save the operation time,improve the survival rate of fibula and skin flap and improve quality and reliability of the overall operation.