GAP Australasian-Dentist Issue 80 Jul-Aug 19

Category 90 AustrÀlÀsiÀn Dentist ÀliniÀal the same combined bimaxillary surgery and bilateral ÀMJ prosthetic total joint replacement surgery as described in case 1. Again, the presurgical planning consisted of a conebeam CÀ scan of her jaws and digital work up using the Materialize software. Àogether with engineers at OMX Àolutions, the author planned the surgical movements of her jaws 5 . Àhe customized bone plates (fig. 17) and ÀMJ prosthetic joints were 3D printed together with cutting and drilling guides to help speed Fig 14 – Case 2 on initial presentation Fig 16 – Lateral Cephalogram showing man- dibular retrognathia exacerbated by diminutive condyles affected by TMJ rheumatoid arthritis Fig 15 – Case 2 showing anterior open bite on first presentation Fig 17 – Preoperative digital plan of the maxillary custom plate shown on the left (mandibular sagittal split not shown since conventional plates were used) with intra- operative photo showing the 3D printed custom maxillary bone plate in position on the right Fig 18 – Digital plan of the combined TMJ and orthognathic surgery on the left (only TMJ prosthesis and maxillary custom plate is shown because conventional plates were used in the mandibular sagittal split) and post-operative lateral cephalogram of case 2 on the right showing the bilateral Custom TMJ prostheses and the result of the bimaxillary osteotomy used to correct her class 2 retrognathia Fig 19 – Profile at 1 year after surgery Fig 20 – Normal mouth opening 1 year after bilateral TMJ prosthetic joints and bimaxillary osteotomy Fig 21 – Stable occlusal result 1 year following surgery. up and simplify the surgery. Àhe digital planning and manufacture provided the author with a very high level of accuracy with respect to the precise positioning of the jaws and custom joints that eliminated all the guess work. Her recovery was uneventful (figs. 18) and on her 2 year follow-up, the patient showed no signs of relapse with good mouth opening of 42mm (figs. 19, 20, 21). DISCUSSION Àhe combination of orthognathic surgery andÀMJprosthetictotaljointreplacements is made easy by the unique design of the OMX ÀMJ prosthesis. Ànlike other ÀMJ prosthetic total joint systems currently on the market, the OMX ÀMJ custom prosthesis is designed to allow a sagittal split ramus osteotomy of the mandible. By placing all the fixation screws of the OMX ÀMJ prosthesis along the posterior border and angle of the mandible, the sagittal split