Facial Cartilaginous Reconstruction—A Historical Perspective, State-of-the-Art, and Future Directions

3D Printing promises to produce complex biomedical devices according to computer design using patient-specific anatomical data. Since its initial use as pre-surgical visualization models and tooling molds, 3D Printing has slowly evolved to create one-of-a-kind devices, implants, scaffolds for tissue engineering, diagnostic platforms, and drug delivery systems. Fueled by the recent explosion in public interest and access to affordable printers, there is renewed interest to combine stem cells with custom 3D scaffolds for personalized regenerative medicine. Before 3D Printing can be used routinely for the regeneration of complex tissues (e.g. bone, cartilage, muscles, vessels, nerves in the craniomaxillofacial complex), and complex organs with intricate 3D microarchitecture (e.g. liver, lymphoid organs), several technological limitations must be addressed. In this review, the major materials and technology advances within the last five years for each of the common 3D Printing technologies (Three Dimensional Printing, Fused Deposition Modeling, Selective Laser Sintering, Stereolithography, and 3D Plotting/Direct-Write/Bioprinting) are described. Examples are highlighted to illustrate progress of each technology in tissue engineering, and key limitations are identified to motivate future research and advance this fascinating field of advanced manufacturing.

Autologous cultured chondrocyte transplantation was introduced in Sweden in 1987 for the treatment of large (1.5-12.0 cm2) full thickness chondral defects of the knee. The clinical, arthroscopic, and histologic results from the first 101 patients treated using this technique are reported in this study. Patients were assessed retrospectively using three types of endpoints: patient and physician derived clinical rating scales (five validated and two new); arthroscopic assessment of cartilage fill, integration, and surface hardness; and standard histochemical techniques. Ninety-four patients with 2- to 9-years followup were evaluable. Good to excellent clinical results were seen in individual groups as follows: isolated femoral condyle (92%), multiple lesions (67%), osteochondritis dissecans (89%), patella (65%), and femoral condyle with anterior cruciate ligament repair (75%). Arthroscopic findings in 53 evaluated patients showed good repair tissue fill, good adherence to underlying bone, seamless integration with adjacent cartilage, and hardness close to that of the adjacent tissue. Hypertrophic response of the periosteum or graft or both was identified in 26 arthroscopies; seven were symptomatic and resolved after arthroscopic trimming. Graft failure occurred in seven (four of the first 23 and three of the next 78) patients. Histologic analysis of 37 biopsy specimens showed a correlation between hyalinelike tissue (hyaline matrix staining positive for Type II collagen and lacking a fibrous component) and good to excellent clinical results. The good clinical outcomes of autologous chondrocyte transplantation in this study are encouraging, and clinical trials are being done to assess the outcomes versus traditional fibrocartilage repair techniques.

Extended soft tissue defects of the face are difficult to reconstruct, and autologous tissue transfers usually lead to poor cosmetic and functional outcomes. We judged that composite tissue transplantation could be valuable in facial reconstructive surgery. We transplanted the central and lower face of a brain-dead woman onto a woman aged 38 years who had suffered amputation of distal nose, both lips, chin, and adjacent parts of the cheeks. Transplantation consisted of revascularisation of right and left facial arteries and veins (ischaemic time 4 h), mucosal repair of oral and nasal vestibules, bilateral anastomoses of infraorbital and mental sensitive nerves, joining of mimic muscles with motor nerve suture on mandibular branch of the left facial nerve, and skin closure. Immunosuppressive treatment was with thymoglobulin, tacrolimus, mycophenolate mofetil, and prednisone. Two infusions of donor bone-marrow cells were given. Follow-up included routine tests, biopsies, physiotherapy, and psychological support. The initial postoperative course was uneventful. No surgical complication occurred. Bone-marrow graft and immunosuppression were well tolerated. Mild clinical signs of rejection were seen at day 20. Increased corticoids initially did not reverse rejection, but signs of rejection disappeared after three boluses of prednisone. Anatomical and psychological integration and recovery of sensation were excellent. At the end of the first postoperative week, the patient could eat, and speech improved quickly. Passive transmission of muscle contractions to the graft already exists; physiotherapy is being done to restore dynamic motions around the lips. The 4-month outcome demonstrates the feasibility of this procedure. The functional result will be assessed in the future, but this graft can already be deemed successful with respect to appearance, sensitivity, and acceptance by the patient.