THE USE OF 3D VIRTUAL PLANNING AND 3D PRINTING FOR THE TREATMENT OF FACIAL ASYMMETRY: A CASE REPORT
3. Results The visual evaluation of the simulated and actual extensions revealed a good approximate in terms of shape and position. For the quantitative analysis, at the bone level via the part comparison, revealed a mean of 0.29 mm and standard deviation of 1.73 mm. Figure 6 shows the results of the part comparison with the simulated extension overlaid
on the postoperative extension and the color coded map ranging in mm. Extreme differences( 5 mm) were found at the region of mandibular angle while differences at the mandibular body region ranged between 0 and 3 mm. Figure 8 shows the extra-oral clinical images taken for this patient preoperatively( left) and 6 months postoperatively( right).
Figure 6. Color coded map for the part comparison analysis between the simulated and actual extensions
4. Discussion In this study we presented a case with facial mandibular asymmetry. As the patient’ s complaints and diagnosis were only esthetic with no functional problems, the recommended treatment was autogenous apposition bone graft. Even though other non-resorbable graft materials could equally be used by the same method, the patient opted for an autogenous graft material. The use of 3D planning and printing was investigated where the mirroring technique around the midsagittal plane was applied to simulate the symmetry of the mandible both sides. A 3D printed extension was used during the surgery as a guide for harvesting
and grafting for accurate positioning. For the quantitative postoperative evaluation for the bone in relation to the simulation revealed mean error of 0.29 mm(± 1.73 mm). Maximum differences were found at the mandibular angle part. This can be due to the difficulty of reshaping the bone in this region. Since it is recommended to evaluate the soft tissue minimum 6 months postoperatively( 7), quantitative evaluation one month postoperatively was not possible, but visually it was in line with the preoperative prediction( Fig. 7).
a. b. c.
d. e.
Figure 7. a. Preoperative soft tissue. b. Soft tissue simulation after mirroring procedure from right to left. c. One month postoperative soft tissue. d. Soft tissue postoperative( gray) superimposed on the preoperative simulation( blue). e. Differences between the two soft tissues in( d) enlarged at the operation side
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