1. ORTHOGNATHIC POSITIONING SYSTEM:INTRAOPERATIVE SYSTEM TO TRANSFERVIRTUAL SURGICAL PLAN TO OPERATING FIELDDURING ORTHOGNATHIC SURGERY

2. SOURCE Journal of Oral-MaxilloFac Surg2013;71: 911-920 3. AUTHORS John W Polley, Alvaro A Figueroa Department of plastic and reconstructive surgery ,School of Dentistry, Rush University medical centre,Chicago,Illinois 4. With all the new technology being developedone can can only wonder how we will bepositioning the condyles in future-Ellis 1994 5. INTRODUCTION There has been significant diagnostic advances andvirtual treatment planning , An equal innovation to assist surgeon intraoperativelyis missing The practical transfer of this information to theoperating room has been lacking. 6. PURPOSE Why Introduce Orthognathic Positioning Systemconcept (OPS) ??SIMPLIFY SURGERY Eliminate errors Prevent suboptimal outcomes Does not require mock surgery Decreases time for surgical planning Does not need guiding intermediate splint Translate accuracy of CAD/CAM to operating field 7. WHAT IS CAD /CAM ?The term CAD/CAM implies that an engineer can usethe system both for designing a product and forcontrolling manufacturing processes. 8. MATERIAL AND METHODS Two sets of maxillary and mandibular dentalimpressions for stone models Mandibular centric relation and centric occlusion orientation sensor readings-pitch roll and yaw-externalfiducial facebow attached to digitalorientation sensor High resolution helical computed tomography scan ofmaxilla and mandible Dental clinical photographs 9. INTEGRATE BITE REGISTRATIONDATAASSORTMENT LASER SCANS OF DENTAL CAST CT SCANFINALPRODUCT 3D DENTAL + SKELETALRECONSTRUCTION 10. VIRTUAL MERGING OF DETAILS 11. VIRTUAL PLANNING 12. VIRTUAL MOCK SURGERY Online web meeting (with assistance of software engineeers to manipulatethe scan in 3D with propietary software) TREATMENT PLAN- Clinical findings Dental cast assesment 13. SKELETAL REPOSITIONING Mandibular autorotation Saggital split osteotomies Inverted osteotomies Subapical osteotomies Genioplasty Repositioning of maxilla(single or multiple segments) 14. MULTIPLE ANGLE VISUALIZATIONS Simulated skeletal contacts Interferences Condlylar position- minimize condylar position Bone graft requirements Mandibular nerve position 15. TECHNIQUE IDENTIFICATION OF STABLE BONY LANDMARKS Bilaterally Landmarks placed on stable bone Will not be repositioned during surgery Bone thickness surveyed in CT data 16. USE OF LANDMARKS Serve as reference points that will be used to transferthe osteomized segment(s) to its final postoperativeposition P.S- All reference points should be positioned so as to notinterfere with the fixation process 17. LANDMARK LOCATION MAXILLA- Above the osteotomy line Above stable thick bone MANDIBLE Lateral and anterior surface of ramus(percutaneous approach)Medial aspect of coronoid ridgesIN GENIOPLASTYLateral to midline below the osteotomy 18. DIGITAL FABRICATION OF OCCLUSALSPLINT AND OPS 19. Occlusal splint ,the drilling and positioning guides aremanufactured by stereolithography and autoclaved forsterilization. 20. OCCLUSAL SPLINT Designed with occlusal relationship in final position Lateral attachment sites on right and left sides of thesplint Attachment for maxillary drlling guides 21. MAXILLARY DRILLING GUIDES Bone borne footplates are designed with anatomicallycontoured struts Splint footplates attach precisely to lateral attachmenton occlusal splints (attach and detach independently) The bone borne footplates have two large diameteropenings Designed to fit the metal drill guide(does not rotate) 22. MAXILLARY POSITIONING GUIDES Designed with maxilla in simulated final position A bone borne positioning plate with small diameterthat fit over the previously determined referencelandmark is designed Attached to occlusal splint and also secured to stablemaxillary bone using screws 23. Temporarily secures the Le-Fort 1 segment in its final positionbefore rigid skeletal fixation 24. DURING SURGERY Occlusal splint is permenantly secured tomaxillary dentition in Le-Fort 1 cases Temporarily secured to dentition in case ofmultiple segment osteotomies, double jaw cases 25. MaxillaexposedDrilling guideattachedTwo referencelandmarksdrilled 26. IN MANDIBLE Drilling and positioning of proximal segment is donewith similar concept Assists in maintaining the proximal segment in APplane and condyle position during fixation Prevents lateral torquing of condyles Precise repositioning of large advancements 27. CASE REPORT 17 yr/F Maxillary hypoplasia,mandibular prognathism Facial assymetry Le-Fort 1 6-7 mm advancement mand 4mm setback 28. Guides temporarily secured with 1.5 mm screws After rigid fixation, a methyl methacrylate splintocclusal splint is wired to maxillary dentition andpatient placed in elastic fixation Postoperative uneventful All desired functional, aesthetic, and occlusaloutcomes achieved 29. RESULTS Follow up for patients more than 15 months Since 2010 O.P.S used in more than 24 patients Facial asymmetry Cleft lip/palate Hemifacial microsomia Craniosynostosis syndromes Micrognathia Tumor reconstruction 30. CASES WITH O.P.S SINCE 20101 piece Le-Fort 132 piece Le-Fort 93 piece Le-Fort 2Sagittal splits 29inverted 1Mandibular subapical 2genioplasty 13 31. DISCUSSION A paradigm shift has revolutionized preoperative planningin orthognathic Despite great advances in imaging and virtualreconstruction the practical transfer of this informationwhich the OPS promises to fulfill. Enchanced accuracy 32. ELIMINATES Intermaxillary fixation Intermediate splints Experienced surgical assistant traditional face bow transfer, articulated studymodels and mock model surgery Exposure to laboratory dust and chemicals 33. CONCLUSION O.P.S bridges the gap between virtual ,computer aidedsurgical evaluation and actual O.S Conflict of interest authors have a patent pending on OPS 34. 3D PRINTER 35. CRITICAL APPRAISAL Fabrication Material not mentioned capital investment for full setup Assistant being a asset Virtual planning needs a software aquaintance Cost ? Patented rights? Introduced in 2010 ,Long term accuracy ? 36. REFERENCES Athwal GS, Bueno Jr RA,Wolfe SW:Radiation exposuremaintainance of condyle proximal segment position inorthognathic surgery: Surg Am 30: 1310-1316,2005 Choi EH,Seo JY, Jung BY, Park W: : three dimensionalsurgical planning in midface distraction review. OralSurg J Craniofac Surg 107:e21-e24,2009 Prasad R, Amstutz HC,Sparling EA:clinical feasibilityof surgical simulationJ Oral Maxillofac Surg 15, 806-808,2000