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FIGURE 4. Comparisons of 5 patients’ preoperative, planned, and postoperative outcomes

Figure 4 Comparisons of 5 patients’ preoperative, planned, and postoperative outcomes

Related Figures (5)

FIGURE 1. The creation of the computerized composite skull model. a, Bite jig was created with fiducial CT/MRI compatible fiducial markers. b, The patient was biting on the bite jig with fiducial markers during CT scan. c, Three separate but correlated computer models were reconstructed: a midface model, a mandibular model, and a 4-fiducia-marker model. d, The bite jig with fiducial markers was placed between the upper and lower plaster dental models during the scanning process. e, Three separate but correlated computer models were also reconstructed: an upper digital dental model, a lower digital dental model, and a 4-+fiduciatmarker model. f, The computerized composite skull model simultaneously displayed an accurate rendition of both the bony structures and the teeth.
FIGURE 1. The creation of the computerized composite skull model. a, Bite jig was created with fiducial CT/MRI compatible fiducial markers. b, The patient was biting on the bite jig with fiducial markers during CT scan. c, Three separate but correlated computer models were reconstructed: a midface model, a mandibular model, and a 4-fiducia-marker model. d, The bite jig with fiducial markers was placed between the upper and lower plaster dental models during the scanning process. e, Three separate but correlated computer models were also reconstructed: an upper digital dental model, a lower digital dental model, and a 4-+fiduciatmarker model. f, The computerized composite skull model simultaneously displayed an accurate rendition of both the bony structures and the teeth.
FIGURE 2. Using these coordinates and the triangular spline, the maxilla was repositioned and its pitch, roll, and yaw were corrected as required. a, The translational and rotational movements of the triangular spline. b, The maxilla automatically moved to the desired position following the movement of the triangular spline.
FIGURE 2. Using these coordinates and the triangular spline, the maxilla was repositioned and its pitch, roll, and yaw were corrected as required. a, The translational and rotational movements of the triangular spline. b, The maxilla automatically moved to the desired position following the movement of the triangular spline.
FIGURE 3. Surgical dental splints and templates were created using the authors’ computeraided designing/manufacturing technique. a, Digital surgical splint. b, Digital chin template. c, Physical surgical splint. d, Physical chin template. e, The use of physical surgical splint at the time of the surgery. f, The use of physical chin template at the time of the surgery. The final step of the CASS was to transfer the computer surgical plan to the patient. To accom- plish this, surgical dental splints and templates were created using the authors’ computer-aided designing/manufacturing techniques (Fig 3).*'7'® In surgeries that involved the teeth, surgical dental splints were created by a computational process after inserting a digital wafer between the maxillary and mandibular dental arches (Fig 3a). In surgeries that did not involve the teeth, the software was used to generate digital templates (Fig 3b) that were used during surgery to help the surgeons achieve the desired results. The templates recorded the 3D surface geometry of the area of interest so that the template fit on the bone in a unique posi- tion. In the surgeries that involved bone graft, the computerized mirror-imaging technique was used to mirror image the geometry from the healthy side to the defect side. The difference of geometries between the 2 sides was then computed, resulting in a digital bone graft template. The software ex- ported digital splints and templates on an -stl for- The third step of the CASS was to simulate the surgery in the computer. The composite skull model was initially prepared (pre-cut) to simulate various osteotomies. They included Le Fort I osteotomy, sag- ittal split osteotomy, inverted “L” osteotomy, and ge- nioplasty. After the model was prepared, the surgeon was able to move the bony segments to the desired position and rotate each bony segment around a pivot point according to quantitative guidance and the sur- geon’s visual judgment. In patients requiring bimaxil- lary surgery, the maxillary osteotomy is usually com- pleted first. The task of repositioning the maxilla to the desired position may require complex movements and rotations (transformations). To this end, we de- veloped a new technique that used a triangular spline to reposition the maxilla in the 3D space. In this
FIGURE 3. Surgical dental splints and templates were created using the authors’ computeraided designing/manufacturing technique. a, Digital surgical splint. b, Digital chin template. c, Physical surgical splint. d, Physical chin template. e, The use of physical surgical splint at the time of the surgery. f, The use of physical chin template at the time of the surgery. The final step of the CASS was to transfer the computer surgical plan to the patient. To accom- plish this, surgical dental splints and templates were created using the authors’ computer-aided designing/manufacturing techniques (Fig 3).*'7'® In surgeries that involved the teeth, surgical dental splints were created by a computational process after inserting a digital wafer between the maxillary and mandibular dental arches (Fig 3a). In surgeries that did not involve the teeth, the software was used to generate digital templates (Fig 3b) that were used during surgery to help the surgeons achieve the desired results. The templates recorded the 3D surface geometry of the area of interest so that the template fit on the bone in a unique posi- tion. In the surgeries that involved bone graft, the computerized mirror-imaging technique was used to mirror image the geometry from the healthy side to the defect side. The difference of geometries between the 2 sides was then computed, resulting in a digital bone graft template. The software ex- ported digital splints and templates on an -stl for- The third step of the CASS was to simulate the surgery in the computer. The composite skull model was initially prepared (pre-cut) to simulate various osteotomies. They included Le Fort I osteotomy, sag- ittal split osteotomy, inverted “L” osteotomy, and ge- nioplasty. After the model was prepared, the surgeon was able to move the bony segments to the desired position and rotate each bony segment around a pivot point according to quantitative guidance and the sur- geon’s visual judgment. In patients requiring bimaxil- lary surgery, the maxillary osteotomy is usually com- pleted first. The task of repositioning the maxilla to the desired position may require complex movements and rotations (transformations). To this end, we de- veloped a new technique that used a triangular spline to reposition the maxilla in the 3D space. In this
FIGURE 5. Surgical planning of onlay bone grafting. a, A mirror image of the unatfected side was created. The image was superim- posed over the affected side. b, A digital template that depicted the differences between the mirror image and the affected side was created. c, A physical form of the same template was fabricated. d, Autogenous bone was harvested and sculpted according to the shape of the template. e, The sculpted autogenous bone graft precisely replaced the missing bone.
FIGURE 5. Surgical planning of onlay bone grafting. a, A mirror image of the unatfected side was created. The image was superim- posed over the affected side. b, A digital template that depicted the differences between the mirror image and the affected side was created. c, A physical form of the same template was fabricated. d, Autogenous bone was harvested and sculpted according to the shape of the template. e, The sculpted autogenous bone graft precisely replaced the missing bone.
FIGURE 6. A physical model of the planned outcome was fabricated and used to pre-bend the bone plates that were used in the surgery.
FIGURE 6. A physical model of the planned outcome was fabricated and used to pre-bend the bone plates that were used in the surgery.
Related topics:
DentistrySurgeryOral and Maxillofacial SurgeryComputer assisted orthopaedic surgeryThree Dimensional ImagingSurgical SimulationX ray Computed Tomography
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