Reconstruction of maxillofacial bone defects using patient-specific long-lasting titanium implants

Abstract

The objective of this retrospective study is to verify the effectiveness and safety of patient-specific titanium implants on maxillofacial bones, with a long-term follow-up. Total 16 patients with various maxillofacial defects underwent reconstruction using patient-specific titanium implants. Titanium implants, manufactured by electron beam melting, selective laser sintering, or milling, were inserted into the maxilla, mandible, or zygoma. Long-term follow-up (36.7 ± 20.1 months) was conducted after the surgery. Bone fusion of the titanium implant body, postoperative infection, implant malunion, functional results, patient satisfaction, subsidence, osteolysis around the implants, and complications were recorded and analyzed at the last follow-up. Of the 28 implants, only one failed to unite with the bone; therefore, revision surgery was performed. No osteolysis or subsidence around the titanium implants nor adverse events were observed; the mean VAS score for satisfaction was 9. All patients enrolled in this trial were esthetically and functionally satisfied with their surgical results, and fixation failure and esthetic dissatisfaction complications were well resolved. Patient-specific titanium showed satisfactory outcomes when used to treat various oral and maxillofacial defects. A 3D printed titanium implant can be effectively used in the reconstruction of the zygoma and mandible instead of autogenous bone without donor site morbidity.

Figure 1

Titanium reconstruction of tumor-induced mandibular defects. (A) A 25-year-old female patient was referred for the reconstruction of the left mandible and correction of facial asymmetry; (B) Postoperative photograph of the female patient. (C) A titanium three-dimensional (3D)-printed mandible was fabricated. The two abutments that faced the central fossa of the maxillary molar were designed for prosthetic restoration. Temporary crowns were also 3D-printed. (D, E) Preoperative and postoperative 3D reconstructed cone-beam computed tomography (CBCT) images. Reproduced from Lee UL et al. J Oral Maxillofac Surg. 2016 Jul;74(7):1501.e1-1501.e15, with permission of Elsevier Inc. (F) A 26-year-old female patient whose mandible was deviated to the left side by more than 10 cm. (G) Postoperative facial photograph shows that the face is symmetric, and the mandible is no longer shifted to left. (H) To overcome these problems, a titanium 3D-printed mandible was fabricated by Medyssey Inc. The Korean Food and Drug Administration does not approve patient-specific joints as of now. Hence, we connected a prefabricated temporomandibular joint to a 3D-printed mandible. (I, J) Preoperative and postoperative 3D reconstructed CBCT images. (K) A 78-year-old-female patient had a right segmental mandibular defect after a mandibulectomy due to malignancy; (L) the mandible was successfully reconstructed with a titanium 3D-printed implant.

Figure 2

Dental implant on a titanium mandible. (A) Initial panoramic radiography of the patient (27/M); s/p ameloblastoma resection and fibula free flap failed. (B) To restore the patient’s masticatory function, two holes were designed to place dental implants. (C) Two Osstem implants were placed in the titanium mandible; (D) A titanium three-dimensional printed mandibular implant with a prefabricated dental implant was placed under general anesthesia. (E) The second implant surgery was performed 6 weeks postoperatively. (F) Prosthetic treatment was performed using a custom abutment and temporary crowns. (G, H) The yellow jelly was chewed 30 times by the patient, and the surface area was measured to see how well the jelly was chewed. The mastication efficiency measured after surgery increased three-fold compared with that before surgery.

Figure 3

Photographs of patients with Treacher-Collins syndrome. (A) An 18-year-old woman with a depressed midface and downward lateral canthus and eyelids. (B) A three-dimensional (3D) rendering radiography of the facial skeleton. (C) A custom-made 3D-printed zygomatic implant. (D) Facial photographs before and 12 months after surgery. The volume of the orbital and zygomatic area increased. The patient has a normal face after simple surgery; (E, F) Facial appearance of a 9-year-old boy with Treacher-Collins syndrome. (G) Underdeveloped zygoma and orbital bone. (H, I) Considering growth, only three holes out of six were used to fix the zygomatic implant. The other remaining three holes were used for the second surgery. (J) A titanium 3D-printed zygoma was fabricated. (K, L) Facial photographs, taken 3 months after surgery, show that the volume of the zygoma and orbital area increased.

Figure 4

Restoring surgery. (A) A 31-year-old male patient underwent genioplasty at a local clinic. He wanted to restore the length of the jaw. (B) Computer-aided design of a chin implant and guide. (C) Chin augmentation, with two-piece titanium chin implants, was performed. (D) Three months after the surgery, the patient was satisfied with the chin length. (E, F) A 21-year-old woman wanted her upper and lower jaws to be restored the same as before the orthognathic surgery. We planned a downward movement of 5.31 mm at #16 (upper right first molar), 4.69 mm at #26 (upper left first molar), and 3.5 mm at #11 (upper right central incisor) and #21 (upper left central incisor). Three-dimensional (3D)-printed titanium plates that lifted and fixed the maxilla were designed to prevent maxillary collapse and support the block bones. (G) The block was well fixed and encased by 3D-printed titanium plates.