ObjectiveTo establish a method to prefabricate titanium plate with three-dimensional (3-D) printing technique for correction of mandibular prognathism in sagittal splint ramous osteotomy (SSRO). MethodsBetween January 2012 and May 2013, 12 patients with mandibular prognathism (Angle III malocclusion) were treated. Among them, 9 cases were male and 3 cases were female. Their ages ranged from 19 to 35 years (mean, 25.6 years). With the 3-D facial CT data of these patients, 3-D printer was used to print the models for preoperational simulation. SSRO was performed on 3-D models, and the titanium plates were prefabricated on the models after the distal segments were moved backward and rotated according to occlusal splint. During operations, the proximal segments were fixed to distal segments by the prefabricated titanium plates. 3-D CT scans were taken to examine the temporomandibular joint position changes before operation and at 6 months after operation. ResultsThe skull models were manufactured by 3-D printing technique, and the titanium plates were reshaped on the basis of them. Twenty-four prefabricated titanium plates were placed during operations, and they all matched with the bone segments well. Evaluation of 3-D CT scans showed that the temporomandibular joint position had no change. All patients were followed up 7-12 months (mean, 10.6 months). The face type and dental articulation were improved greatly. All cases obtained satisfactory opening function and occlusion. ConclusionWith the titanium plate fabricated based on 3-D models, surgeons are able to improve or refine surgical planning so that the operation can be performed according to preoperative simulation precisely and the complications, such as dislocation of temporomandibular joint, can be prevented.
ObjectiveTo study the treatment results of the pre-expanded flaps for scar contracture on face, neck, and joints by comparing with the skin grafts. MethodsA total of 240 cases of scar contracture between July 2004 and June 2014 were included in the study by random sampling; skin grafts were used in 120 cases (skin graft group), and preexpanded flaps in 120 cases (pre-expanded flap group). There was no significant difference in age, sex, injury sites, and disease duration between 2 groups (P>0.05). Re-operation rate and A&F 0-6 quantization score were used to evaluate the treatment results. ResultsThe patients were followed up 12 to 75 months (mean, 23.47 months) in the skin graft group, and 12 to 61 months (mean, 19.62 months) in the pre-expanded flap group. The re-operation rate of the skin graft group was 72.5% (87/120), and was significantly higher than that of the pre-expanded flap group (19.2%, 23/120) (P=0.000). The re-operation rate of the neck contracture in teenagers was the highest. It was 93.9% in the skin graft group and 35.0% in the pre-expanded flap group. In the patients who did not undergo re-operations, A&F 0-6 quantization score of the skin graft group was 2.85±1.12, and was significantly lower than that of the pre-expanded flap group (5.22±0.74) (t=13.830, P=0.000). ConclusionPre-expanded flap for scar contracture on face, neck, and joints has lower re-operation rate and better aesthetic and functional restoration than skin graft. It should be regarded as the preferred method for teenagers.
ObjectiveTo investigate the application of three-dimensional (3-D) printing technique combining with 3-D CT and computer aided-design technique in customized artificial bone fabrication, correcting mandibular asymmetry deformity after mandibular angle ostectomy. MethodsBetween April 2011 and June 2013, 23 female patients with mandibular asymmetry deformity after mandibular angle ostectomy were treated. The mean age was 27 years (range, 22-34 years). The disease duration of mandibular asymmetry deformity was 6-16 months (mean, 12 months). According to the CT data and individualized mandibular angle was simulated based on mirror theory, 3-D printed implants were fabricated as the standard reference for manufacturers to fabricated artificial bone graft, and then mandible repair operation was performed utilizing the customized artificial bone to improve mandibular asymmetry. ResultsThe operation time varied from 40 to 60 minutes (mean, 50 minutes). Primary healing of incisions was obtained in all patients; no infection, hematoma, and difficulty in opening mouth occurred. All 23 patients were followed up 3-10 months (mean, 6.7 months). After operation, all patients obtained satisfactory facial and mandibular symmetry. 3-D CT reconstructive examination results after 3 months of operation showed good integration of the artificial bone. Conclusion3-D printing technique combined with 3-D CT and computer aided design technique can be a viable alternative to the approach of maxillofacial defects repair after mandibular angle ostectomy, which provides a accurate and easy way.