In order to investigate the influence of radiation therapy after the treatment of maxillary implant-supported prostheses, 27 patients received a total of 131 implants in maxilla after oral cancer treatment and/or reconstructive surgery. Among them, 25 received maxillary implant-supported prostheses. The cumulative survival rates of implants and prostheses were evaluated by the product-limit-estimates method according to Kaplan-Meier. The cumulative survival rate of implants and prostheses in irradiated patients was compared with that in non-irradiated patients by statistical Log-rank test. The results showed that 112 implants were observed after implant loading. The implants cumulative survival rate was approximately 65% for overall patients. The cumulative prosthesis successful rate was approximately 88% for all 25 patients. Log-rank test analysis revealed that there was a significant difference in cumulative implants survival rates between non-irradiated and irradiated maxillary bone (P < 0.01). It was concluded that the implants and prostheses in irradiated patients have significantly lower survival rates than in non-irradiated patients.
Aged ; Carcinoma, Squamous Cell ; radiotherapy ; surgery ; Dental Prosthesis, Implant-Supported ; Female ; Graft Survival ; radiation effects ; Humans ; Male ; Mandibular Prosthesis ; Maxilla ; surgery ; Maxillofacial Prosthesis ; Maxillofacial Prosthesis Implantation ; Middle Aged ; Mouth Neoplasms ; radiotherapy ; surgery ; Osseointegration ; Pilot Projects ; Radiation Injuries ; Retrospective Studies ; Survival Rate ; Titanium

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

OBJECTIVEThe feasibility and clinical effects of hollow obturator prosthesis for the repair of maxillofacial defect immediately after maxillectomy for cancer were assessed.

METHODSThirteen patients with T3-4aN0M0 maxillary neoplasm were treated by the prostheses immediately after maxillectomy. According to the 3D-CT reconstruction of nasal sinus, the 3D stereoscopic prototype was constructed before the surgery. Simulating surgery with Surgicare 5.0 software and then the prosthesis 3D stereoscopic model was shaped. The prosthesis was made quickly and precisely with methacrylate resins according to the model and the print mold before surgery, with supplementary tooth at the bottom of prosthesis. In the surgery, the prosthesis was installed instantly after maxillectomy. The patients were followed up at 1, 3 and 6 month after the surgery, respectively. The facial features and the pronunciation clarity were examined and the questionnaires were carried out in the patients, with comparation by paired t-test. The hollow obturator prosthesis would be replaced by permanent prosthesis made of methacrylate resins at 6 month after the surgery.

RESULTSThe hollow obturator prostheses were installed accurately and maxillofacial defects were repaired immediately after maxillectomy in the 13 patients. Postoperative follow-up showed there were significant differences in eyeball sagging (t = 4.67, P < 0.05), mid-facial region collapse (t = 5.67, P < 0.05), and pronunciation clarity (t = 16.38, P < 0.05) between patients with and without prostheses. Questionnaires showed that all the patients were satisfied with the retention of prostheses, the improvement of appearance, the improvement of the symptom of water choking and speech definition. Six months after the surgery, the hollow obturator prostheses were replaced smoothly by permanent prostheses in 11 of the 13 patients.

CONCLUSIONThe precise and instant repair of maxillofacial defect by prosthesis after maxillectomy can improve survival quality of patient.

Adult ; Aged ; Denture, Partial, Immediate ; Female ; Humans ; Male ; Maxillary Neoplasms ; surgery ; Maxillofacial Prosthesis Implantation ; Middle Aged ; Prosthesis Implantation ; Reconstructive Surgical Procedures ; instrumentation ; 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

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

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

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*

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 evaluate the feasibility of designing and fabricating customized titanium bone substitutes to restore mandibular bone defects using reverse engineering (RE) and rapid prototyping (RP) techniques.

METHODSTitanium tray for mandibular defects were designed and fabricated through multi-step procedures of reverse engineering and rapid prototyping, then in operation it was filled with cancellous bone and fixed.

RESULTSThe bone substitutes fabricated by this method had been successfully put into clinical use for maxillofacial surgery in 2 patients and got a satisfactory result.

CONCLUSIONSReverse engineering combining with rapid prototyping could accomplish the design and manufacture of implant for the restoration of mandibular bone defects.

Adult ; Biomedical Engineering ; Bone Substitutes ; Female ; Humans ; Male ; Mandible ; surgery ; Mandibular Prosthesis Implantation ; methods

OBJECTIVETo investigate the application of computer aided design-computer aided manufacture (CAD-CAM) technique in the reconstruction of mandible defect with individual titanium prosthesis.

METHODSSix patients with large mandibular ramus and angle tumor were spiral CT scanned preoperatively, and the CAD-CAM was used to design and make individual titanium prosthesis for reconstructing the mandibular defects after resection of the tumor. The prosthesis were assembled during operation. Postoperative follow-up period was 9 - 38 months.

RESULTSThe design and manufacture of titanium prosthesis by use of CAD-CAM technique was convenient and the prosthesis fitted the defects very well. The outline of the face, the occlusion and function were restored. After 9 - 38 months of follow-up, the mandibular symmetry was good.

CONCLUSIONSThe application of CAD-CAM provided accurate simulation and fast manufacturing process for the titanium prosthesis in the repair of mandibular defect.

Adult ; Ameloblastoma ; rehabilitation ; surgery ; Computer Simulation ; Computer-Aided Design ; Female ; Follow-Up Studies ; Humans ; Male ; Mandible ; surgery ; Mandibular Neoplasms ; rehabilitation ; surgery ; Mandibular Prosthesis Implantation ; Mandibular Reconstruction ; Middle Aged ; Prosthesis Design ; Titanium ; Tomography, Spiral Computed ; Young Adult