The Application Of Computer Techniques In Cranio-maxillofacial Surgical Clinic

Background: Computer assisted techniques, including three dimensionalreconstruction, computer assisted design and computer assistedmanufacture, have more and more applications in clinical work. Ourresearch work was focused on how to solve problems in medical clinic bycomputer assisted techniques.Method: The first part of this research deals with the application ofpicture segmentation and partial reconstruction techniques, includingsegmenting mastication muscle from CT scans, measure the volume of it,and evaluate the relationship between volume changing of muscle and lengthchanging of famous. The segmentation of tumor tissue and normal bonetissue gives doctors an indication of massive tumor. The second part ofthis research focused on how to simulate the movement of bone segmentsduring distractive osteogenesis. We do simulate the track of bonesegments, design the direction and location of the distractor, andcalculate the length to gain the final segments position. Animalexperiments focused on how to carry out the virtual plan in famousdistracting. Firstly we made defect model by ramous resection and waitingfor obvious and steady malformation. We virtual distraction osteogenesisand use resection template, shaping template, and 3D skull model, whichwere all made by rapid prototyping technique, to translate the virtualmessage to real surgery. We test the consistency of virtual plan and realsurgical result by difference analysis between virtual and post-operative 3D reconstruction model. Clinical study was about one patients who hasmicrognathia accompanying obstructive sleep apnea syndrome. We do threedimensional analysis of its skull abnormal and virtual a consequencetreatment according to his malformation. We do mandible distractionaccording to virtual design and do pos-operative analysis the same as inthe animal experiments. The third part is a clinical research on theapplication of computer techniques in mandible tumor resection and onestage reconstruction using fibula flap. Five patients who had largemandible tumor were included in this study. We study the boundary of tumorand normal bone on the slice and 3D model and decide the area to be resectedaccording to its character. We design the shape of fibula flap accordingto its original counter or by mirror its normal side. We calculate theneeded length of fibula and the length of pedicle. The data of virtualflap was turned to a shaping template by rapid prototyping technique.Fibula flaps was countered with the indication of template during surgery.The consistency of virtual and real surgery was tested the same way asin the second part.Results: (1) Amethod of segmenting mastication muscle, tumor and skeletonimplantation through computer-people interaction program was gained; weget a smooth and highly repeatable 3D data of interested tissue; volumemeasurement show that the atrophy of mastication muscle has a relationshipwith the shorten of famous after mandible angle osteotomy.(2) The virtual tract of bone segments movement during distractionosteogenesis show a great consistence with clinic results, tested byX-ray study; animal experiment show that virtual plan could be carriedout accurately in surgery with the help of assistant template. (3) Theclinical research both on mandible distractive osteogenesis and one stagereconstruction by fibula flap showed a consistency between the virtualand pos-operative image. Conclusion: Computer assisted techniques do great help some problems inthe Cranio-maxillofacial surgical clinic. Virtual planning made surgerymuch more under controlled, it shortened surgical duration and improvedthe functional and cosmetic results.