Accuracy of using computer-aided rapid prototyping templates for mandible reconstruction with an iliac crest graft.

BACKGROUND: This study aimed to evaluate the accuracy of surgical outcomes in free iliac crest mandibular reconstructions that were carried out with virtual surgical plans and rapid prototyping templates. METHODS: This study evaluated eight patients who underwent mandibular osteotomy and reconstruction with free iliac crest grafts using virtual surgical planning and designed guiding templates. Operations were performed using the prefabricated guiding templates. Postoperative three-dimensional computer models were overlaid and compared with the preoperatively designed models in the same coordinate system. RESULTS: Compared to the virtual osteotomy, the mean error of distance of the actual mandibular osteotomy was 2.06 ± 0.86 mm. When compared to the virtual harvested grafts, the mean error volume of the actual harvested grafts was 1412.22 ± 439.24 mm3 (9.12% ± 2.84%). The mean error between the volume of the actual harvested grafts and the shaped grafts was 2094.35 ± 929.12 mm3 (12.40% ± 5.50%). CONCLUSIONS: The use of computer-aided rapid prototyping templates for virtual surgical planning appears to positively influence the accuracy of mandibular reconstruction.

Digital surgical templates for managing high-energy zygomaticomaxillary complex injuries associated with orbital volume change: a quantitative assessment.

PURPOSE: This study sought to introduce 3-dimensional (3D) virtual surgical planning and digital rapid-prototyping templates for zygomaticomaxillary complex (ZMC) injuries associated with orbital volume change and to evaluate the surgical outcomes quantitatively. PATIENTS AND METHODS: Eight patients who underwent open reduction and fixation for a ZMC injury with orbital volume change were studied. Computed tomographic (CT) scan of the zygomaticomaxillary area was performed before the operation in each case. Scanned data were converted into 3D models using Mimics software (Materialise, Brussels, Belgium) for surgical designs. Virtual surgical reductions and correlated guiding templates were designed using Mimics and Magics software (Materialise). The operations were performed with the help of prefabricated templates to reduce the fractures. A postoperative CT scan of each patient was obtained within 2 weeks after surgery, and quantitative measurements were made to assess the surgical outcomes. Preoperative volumes of the bilateral orbits were compared, and concordance with postoperative volumes of the bilateral orbits was assessed. Twenty-one pairs of distances from 7 marker points to 3 reference planes were measured to assess postoperative facial symmetry. RESULTS: Volumes of the injured orbits were significantly different from volumes of the uninjured orbits preoperatively (P < .05), whereas bilateral orbital volumes showed no statistically significant difference postoperatively (P > .05). In addition, 19 of the 21 pairs of bilateral distances showed no significant difference postoperatively (P > .05). CONCLUSIONS: Quantitative assessment showed that digitally designed, rapid-prototyping templates for ZMC fractures have a positive impact on restoring facial symmetry and concordance of bilateral orbital volumes.

Superior biocompatibility and osteogenic efficacy of micro-arc oxidation-treated titanium implants in the canine mandible.

The aim of this paper is to test implantation outcomes and osteogenic efficacy of plasma micro-arc oxidation (MAO)-treated titanium implants in dogs. Thirty-six pure titanium implants (18 MAO-treated, 18 untreated) were inserted into the mandibles of nine adult beagles and allowed to heal under non-weight-bearing conditions. Implant stability and interface characteristics were evaluated at 4, 8 and 12 weeks post-implantation. Methods included scanning electron microscopy, mechanical testing, histological analysis and computer-quantified tissue morphology. Osseointegration was achieved in both groups, but occurred earlier and more extensively in the MAO group. Areas of direct bone/implant contact were approximately nine times higher in the MAO group than in the control group at 12 weeks (65.85% versus 7.37%, respectively; p < 0.01). Bone-implant shear strength in the MAO group (71.4, 147.2 and 266.3 MPa at weeks 4, 8 and 12, respectively) was higher than in the control group (4.3, 7.1, and 11.8 MPa at weeks 4, 8 and 12, respectively), at all assessments (all, p < 0.01). MAO treatment of titanium implants promotes more rapid formation of new bone, and increases bone-implant shear strength compared to untreated titanium implants.