In maxillofacial surgery, there is a significant need for the design and fabrication of porous scaffolds with customizable bionic structures and mechanical properties suitable for bone tissue engineering. In this paper, we characterize the porous Ti6Al4V implant, which is one of the most promising and attractive biomedical applications due to the similarity of its modulus to human bones. We describe the mechanical properties of this implant, which we suggest is capable of providing important biological functions for bone tissue regeneration. We characterize a novel bionic design and fabrication process for porous implants. A design concept of "reducing dimensions and designing layer by layer" was used to construct layered slice and rod-connected mesh structure (LSRCMS) implants. Porous LSRCMS implants with different parameters and porosities were fabricated by selective laser melting (SLM). Printed samples were evaluated by microstructure characterization, specific mechanical properties were analyzed by mechanical tests, and finite element analysis was used to digitally calculate the stress characteristics of the LSRCMS under loading forces. Our results show that the samples fabricated by SLM had good structure printing quality with reasonable pore sizes. The porosity, pore size, and strut thickness of manufactured samples ranged from (60.95± 0.27)% to (81.23±0.32)%, (480±28) to (685±31) μm, and (263±28) to (265±28) μm, respectively. The compression results show that the Young's modulus and the yield strength ranged from (2.23±0.03) to (6.36±0.06) GPa and (21.36±0.42) to (122.85±3.85) MPa, respectively. We also show that the Young's modulus and yield strength of the LSRCMS samples can be predicted by the Gibson-Ashby model. Further, we prove the structural stability of our novel design by finite element analysis. Our results illustrate that our novel SLM-fabricated porous Ti6Al4V scaffolds based on an LSRCMS are a promising material for bone implants, and are potentially applicable to the field of bone defect repair.
Alloys ; Bionics ; Bone Substitutes/chemistry* ; Bone and Bones/pathology* ; Compressive Strength ; Elastic Modulus ; Finite Element Analysis ; Humans ; Lasers ; Materials Testing ; Maxillofacial Prosthesis Implantation ; Porosity ; Pressure ; Printing, Three-Dimensional ; Prostheses and Implants ; Prosthesis Design ; Stress, Mechanical ; Surgery, Oral/instrumentation* ; Tissue Engineering/methods* ; Titanium/chemistry*

OBJECTIVES: The role of alloplastic materials in maxillofacial reconstruction is still controversial. Determining the utility of porous, high-density, polyethylene implants as a highly stable and flexible, porous alloplast, with properties such as rapid vascularization and tissue ingrowth, is crucial in cases of maxillofacial deformities and aesthetic surgery. MATERIALS AND METHODS: Thirty high-density porous polyethylene implants were implanted in 16 patients that had been referred to a private office over a three-year period. These implants were used for correcting congenital deformities, posttraumatic defects and improving the aesthetic in nasal, paranasal, malar, chin, mandibular angle, body and orbital areas. RESULTS: The outcomes of the cases in this study showed good aesthetic and functional results. The majority of patients had no signs of discomfort, rejection or exposure. Two implants suffered complications: a complicated malar implant was managed by antibiotic therapy, and an infected mandibular angle implant was removed despite antibiotic therapy. CONCLUSION: Based on the results, the Medpor implant seems to be an excellent biomaterial for correcting various facial deformities. Advantages include its versatility and relatively ideal pore size that allows for excellent soft tissue ingrowth and coverage. It is strong, flexible and easy to shape.
Chin ; Congenital Abnormalities ; Humans ; Maxillofacial Prosthesis Implantation ; Polyethylene* ; Prefrontal Cortex ; Reconstructive Surgical Procedures

Mandibular defects lead to severe deformation and functional deficiency. Vascularized osteocutaneous tissue has been widely used to reconstruct the mandible. However, it is technically challenging to shape this type of grafts in such a manner that they resemble the configuration of the mandible. A 48-year-old female patient who underwent anterolateral thigh (ALT) flap coverage after a tongue cancer excision was diagnosed with a tumor recurrence during the follow-up. A wide excision mandibulectomy and mandibular reconstruction with an ALT flap and a titanium implant were performed. The prefabricated titanium implant was fixed to the condyle. Then, an ALT flap was harvested from the ipsilateral thigh and anastomosed. After confirming that the circulation of the flap was intact, the implant was fixed to the parasymphysis. On the radiograph taken after the surgery, the prosthesis was well positioned and overall facial shape was acceptable. There was no postoperative complication during the follow-up period, 1 year and 2 months. The prefabricated implant allows the restoration of facial symmetry without harvesting autologous bone and it is a safe and effective surgical option for mandibular reconstruction.
Female ; Follow-Up Studies ; Humans ; Mandible ; Mandibular Prosthesis Implantation ; Mandibular Reconstruction* ; Middle Aged ; Postoperative Complications ; Prostheses and Implants ; Recurrence ; Thigh ; Titanium* ; Tongue Neoplasms ; Transplants

Animals ; Dental Implantation, Endosseous ; adverse effects ; Dental Implants ; adverse effects ; Dental Prosthesis, Implant-Supported ; adverse effects ; Dentition ; Humans ; Malocclusion ; etiology ; Maxillofacial Development

Microgenia is that the mental protuberance is small state because of symphysis did not developed properly while occlusion and size of mandible are normal. One or two-step sliding advancement genioplasty is mainly performed to make good aesthetic harmony with face, but in slight or moderate degree of microgenia patients who do not want general anesthesia or osteotomy, the multiporous high-density polyethylene(Medpor(R)) can be used. It is easy to carve and bend, and has a variety of size and shape to fit the contour of the chin anatomy. Under the local anesthesia. a vertical incision which can preserve mentalis muscle is made about 2 cm at inferior labial sulcus along inferior frenulum in the jaw midline. Subperiosteal dissection is performed to make a pocket. Seperated Medpor(R)s are inserted in each side and reassembled into one in the midline. To minimize bone erosion, implant has to be placed on the inferior side of mandible edge and fixed with screw. Bandage compression was applied for 3 days and antibiotics was treated for 7 days postoperatively. This technique has a small incision, easy procedure and faster recovery. During the follow-up period, there were no specific complications and patients were all satisfied to their result.
Anesthesia, General ; Anesthesia, Local ; Anti-Bacterial Agents ; Bandages ; Chin ; Follow-Up Studies ; Genioplasty ; Humans ; Jaw ; Mandible ; Mandibular Prosthesis Implantation ; Muscles ; Osteotomy ; Polyethylene

The application principle and procedure of reverse engineering and rapid prototyping techniques are introduced in this paper. The description is concentrated on the applications of the above techniques in medical field, especially in reconstructive surgery of mandibular bone defect.
Biomedical Engineering ; Bone Substitutes ; Computer Simulation ; Computer-Aided Design ; Humans ; Mandible ; surgery ; Mandibular Prosthesis Implantation ; methods ; Reconstructive Surgical Procedures ; methods

This study was aimed to develop a 3-D finite element (3-D FE) model of the mental fractured mandible and design the boundary constrains. The CT images from a health volunteer were used as the original information and put into ANSYS program to build a 3-D FE model. The model of the miniplate and screw which were used for the internal fixation was established by Pro/E. The boundary constrains of different muscle loadings were used to simulate the 3 functional conditions of the mandible. A 3-D FE model of mental fractured mandible under the miniplate-screw internal fixation system was constructed. And by the boundary constraints, the 3 biting conditions were simulated and the model could serve as a foundation on which to analyze the biomechanical behavior of the fractured mandible.
Adult ; Bone Plates ; Bone Screws ; Computer Simulation ; Finite Element Analysis ; Fracture Fixation, Internal ; instrumentation ; Humans ; Imaging, Three-Dimensional ; Male ; Mandible ; diagnostic imaging ; Mandibular Fractures ; surgery ; Models, Biological ; Prosthesis Design ; Prosthesis Implantation ; instrumentation ; Tomography, X-Ray Computed

The new method of manufacturing individual mandibular prostheses, in combination with CT data and CNC technique, can duplicate bone tissues accurately, and can have the individual mandibular prosthesis made to order, and repair the mandibular defect (especially the lager mandibular segmental defect).
Computer-Aided Design ; Imaging, Three-Dimensional ; Mandible ; diagnostic imaging ; Mandibular Prosthesis ; Mandibular Prosthesis Implantation ; Prosthesis Design ; Tomography, X-Ray Computed ; methods

OBJECTIVETo provide objective data for position and orientation of zygomatic-area implant used in zygo-buccal flange osseointegrated implant obturator for patients with large maxillary defect.

METHODSFifty cases of normal unilateral zygomatic body with dentition were measured on three-dimensional spiral CT images. Measurements included the slope angle of zygomatic body on sagittal sectional image, the maximal horizontal distance from the buccal boundary of maxillary alveolar to outboard of maxillary sinus. Furthermore, the configuration of zygomatic body was observed on coronal sectional image.

RESULTSThe average rearward slope angle of zygomatic-body was 80.03 degrees. Forty-eight cases showed straight zygomatic-body configurations and two cases quite curvy. The maximal horizontal distance from the buccal boundary of maxillary alveolar to outboard of maxillary sinus was 6.77 mm.

CONCLUSIONSIn a normal condition, implants can be upright inserted tilting about 10 degrees ahead to utilize much zygomatic bone-volume in high site. In order to improve security and validity of implantation, it is better to take spiral CT examination to evaluate the bone volume and shape of zygomatic body before zygomatic-area implant.

Adolescent ; Adult ; Aged ; Female ; Humans ; Male ; Maxillofacial Prosthesis Implantation ; methods ; Middle Aged ; Tomography, Spiral Computed ; Young Adult ; Zygoma ; diagnostic imaging ; surgery

At present, the treatments of hemifacial microsomia such as the missing of ear and eye still rely on the skill of technician to make the wax model of contralateral apparatus of patient in China. In this paper, CAD/CAM and rapid prototyping (RP) techniques are integrated to successfully create a silastic prosthesis by using the patient's data of CT or laser scanning. The clinical results suggest that a high accuracy has been achieved in shape, size, and protrusion of the facial prostheses, which indicates that the application of RP techniques in conjunction with CAD/CAM is a suitable approach for fabricating facial prosthesis.
Biocompatible Materials ; chemistry ; Computer-Aided Design ; instrumentation ; Facial Asymmetry ; surgery ; Humans ; Image Processing, Computer-Assisted ; instrumentation ; methods ; Imaging, Three-Dimensional ; instrumentation ; methods ; Maxillofacial Prosthesis Implantation ; methods ; Numerical Analysis, Computer-Assisted ; Prostheses and Implants ; Prosthesis Design ; methods