OBJECTIVES: This study aimed to evaluate the stability of prosthetic screws from three types of craniofacial prostheses retention systems (bar-clip, ball/O-ring, and magnet) when submitted to mechanical cycling. MATERIALS AND METHODS: Twelve models of acrylic resin were used with implants placed 20 mm from each other and separated into three groups: (1) bar-clip (Sistema INP, São Paulo, Brazil), (2) ball/O-ring (Sistema INP), and (3) magnet (Metalmag, São Paulo, Brazil), with four samples in each group. Each sample underwent a mechanical cycling removal and insertion test (f=0.5 Hz) to determine the torque and the detorque values of the retention screws. A servo-hydraulic MTS machine (810-Flextest 40; MTS Systems, Eden Prairie, MN, USA) was used to perform the cycling with 2.5 mm and a displacement of 10 mm/s. The screws of the retention systems received an initial torque of 30 Ncm and the torque values required for loosening the screw values were obtained in three cycles (1,080, 2,160, and 3,240). The screws were retorqued to 30 Ncm before each new cycle. RESULTS: The sample was composed of 24 screws grouped as follows: bar-clip (n=8), ball/O-ring (n=8), and magnet (n=8). There were significant differences between the groups, with greater detorque values observed in the ball/O-ring group when compared to the bar-clip and magnet groups for the first cycle. However, the detorque value was greater in the bar-clip group for the second cycle. CONCLUSION: The results of this study indicate that all prosthetic screws will loosen slightly after an initial tightening torque, also the bar-clip retention system demonstrated greater loosening of the screws when compared with ball/O-ring and magnet retention systems.
Grassland ; Maxillofacial Prosthesis ; Prostheses and Implants* ; Prosthesis Failure ; Prosthesis Retention ; Torque

PURPOSE: This study aimed to create a digitized database of fabricated obturators to be kept for patients' potential emergency needs. MATERIALS AND METHODS: A chairside intraoral scanner was used to scan the surfaces of an acrylic resin obturator. The scanned data was recorded and saved as a single standard tessellation language file using a three-dimensional modeling software. A simulated obturator model was manufactured using fused deposition modeling technique in a three-dimensional printer. RESULTS: The entire obturator was successfully scanned regardless of its structural complexity, modeled as three-dimensional data, and stored in the digital system of our clinic at a relatively small size (19.6 MB). A simulated obturator model was then accurately manufactured from these data. CONCLUSION: This study provides a proof-of-concept for the use of digital technology to create a digitized database of obturators for edentulous maxillectomy patients.
Emergencies ; Humans ; Maxillofacial Prosthesis* ; Pilot Projects*

PURPOSE: Maxillofacial silicone elastomer is usually colored intrinsically with color pigments to match skin colors. The purpose of this study was to investigate the color stability of a maxillofacial silicone elastomer, colored with a thermochromic, color changing pigment. MATERIALS AND METHODS: Disc-shaped maxillofacial silicone specimens were prepared and divided into 3 groups: a conventionally colored control group, one group additionally colored with 0.2 wt% thermochromic pigment , and one group with 0.6 wt% thermochromic pigment. Half of the surface of each specimen was covered with an aluminium foil. All of the specimens were exposed to UV radiation in 6 hour cycles over 46 days. In between the UV exposures, half of the specimens were stored in darkness, at room temperature, and the other half was stored in an incubator, at a humidity of 97% and a temperature of +37degrees C. Color measurements were made with a spectrophotometer and registered according to the CIELAB L*a*b* color model system. The changes in L*, a* and b* values during artificial aging were statistically analyzed by using paired samples t-test and repeated measures ANOVA. P-values <.05 were considered as statistically significant. RESULTS: The UV exposure resulted in visually noticeable and statistically significant color changes in the L*, a* and b* values in both of the test groups containing thermochromic pigment. Storage in the incubator lead to statistically significant color changes in the a* and b* values of the specimens containing thermochromic pigment, compared to those stored at room temperature. CONCLUSION: The specimens containing thermochromic pigment were very sensitive to UV radiation, and the thermochromic pigment is not suitable, as such, to be used in maxillofacial prostheses.
Aging ; Darkness ; Humidity ; Incubators ; Maxillofacial Prosthesis ; Silicone Elastomers ; Skin

A case of a patient with a unilateral maxillary defect and restricted mouth opening was presented. The two-stage hollow maxillofacial prosthesis can be used to restore the above defect, thus promoting mastication, speaking, swallowing, and sucking, as well as improving the patient's appearance. Satisfactory results were achieved.
Humans ; Mastication ; Maxilla ; Maxillofacial Prosthesis ; Mouth ; Prostheses and Implants

OBJECTIVETo establish a CAD system of maxillofacial prostheses.

METHODSThe maxillofacial prosthesis CAD system, which included mirror technique, boolean operation and use of FreeForm software, was introduced in detail by use of two clinical cases of auricular and orbital prostheses.

RESULTSThe CAD system of maxillofacial prosthesis was successfully established. The 3-D digital images of defected sides of two cases were quickly and conveniently obtained, which were symmetrical and harmoniously match to the deficient sides.

CONCLUSIONThe established CAD technique is a useful system in maxillofacial area. It may be applied in clinic in future.

Computer-Aided Design ; Humans ; Imaging, Three-Dimensional ; Maxillofacial Prosthesis

With the rapid development of 3D printing, it is widely used in the field of cranio-maxillofacial surgery. Through the individualized production of 3D printing, the backward mode of traditional production relying on manual shaping has been changed to meet the needs of different patients. However, as no clear specification exists for the performance requirements of 3D printing metal powder for cranio-maxillofacial surgery, its long-term development is not feasible. In this paper, the preparation technologies of 3D printing metal powder for cranio-maxillofacial prostheses (i.e., gas atomization, rotating electrode atomization, and radio frequency plasma spheroidization) and 3D printing forming technologies (i.e., selective laser melting, electron beam selective melting, and laser-engineered net shaping) are introduced. The performance requirements of 3D printing metal powder for cranio-maxillofacial prostheses are then summarized according to the characteristics of the preparation and forming technologies described.
Humans ; Lasers ; Maxillofacial Prosthesis ; Metals ; Powders ; Printing, Three-Dimensional

maxillofacial prostheses. Dr. Brenemark first introduced possibility of use of maxillofacial interosseous implant in patients with ablative tumor surgery in 1979. He did introduce the new type of maxillofacial implants system which widen the fixture flange on top of the bone. The advantages of fixed prostheses with implants were well known to various ways, easy to attach, keep clean prostheses, and not to disturb recipient bed. But there are some problems to install implants on maxillofacial regions, because mostly facial bone has very thin cortical bone and poor bone quality. It needs more retention between implant and bone which overcome that fault with fixture flange. To make maxillofacial prostheses, it should be understood general procedure of maxillofacial laboratory work. Ear and midface maxillofacial fabrication which include nose and eye defects will be described step by step.]]>
Ear ; Facial Bones ; Humans ; Maxillofacial Prosthesis ; Nose ; Prostheses and Implants

Surgical resection of the mandible due to presence of benign or malignant tumor is the most common cause of the mandibular deviation. Depending upon the location and extent of the tumor in the mandible, various surgical treatment modalities like marginal, segmental, hemi, subtotal, or total mandibulectomy can be performed. The clinicians must wait for extensive period of time for completion of healing and acceptance of the osseous graft before considering the definitive prosthesis. During this initial healing period prosthodontic intervention is required for preventing the mandibular deviation. This case report describes early prosthodontic management of a patient who has undergone a reconstructed hemi-mandibulectomy with modified mandibular guide flange prosthesis. The prosthesis helps patient moving the mandible normally without deviation during functions like speech and mastication.
Ameloblastoma ; Dental Prosthesis Design ; Humans ; Mandible ; Mandibular Osteotomy ; Mandibular Prosthesis ; Mastication ; Maxillofacial Prosthesis ; Moving and Lifting Patients ; Prostheses and Implants ; Prosthodontics ; Transplants

OBJECTIVETo investigate the feasibility of applying three-dimensional printing in the fabrication of facial prostheses cavity.

METHODSThe computer aided design (CAD) model of negative mold of a nasal prosthesis was generated with Magics RP software according to an existed CAD model of the positive pattern of nasal prosthesis (STL file). The negative mold and positive pattern of the nasal prosthesis were fabricated by three dimensional printing. The actual nasal prosthesis was produced by pouring silicon into the negative mold. The actual nasal prosthesis and rapid prototyping (RP) fabricated positive pattern were both scanned with a three-dimensional scanning system. Quantitative measurements of registration errors were calculated to evaluate the surface matching degree between the two models.

RESULTSThe max positive error between the models of the actual silicon nasal prosthesis and the RP-fabricated positive pattern was 0.98 mm. It was located at the apex nasi area, and the max negative error was -0.64 mm.

CONCLUSIONSFacial prostheses cavity direct three dimensional printing can be one of the methods for automated fabrication of the facial prostheses.

Computer-Aided Design ; Face ; Imaging, Three-Dimensional ; Maxillofacial Prosthesis ; Printing, Three-Dimensional ; Prostheses and Implants ; Prosthesis Design ; Software

OBJECTIVETo evaluate clinical results and technical characteristics of implant-retained facial prosthesis.

METHODSSix patients with facial defects underwent implant retained prosthesis treatment, of which 3 orbita defects (including upper and lower eyelids, eyeball) in 3 cases, 2 ears defects in 2 cases, and a nose defect in one case. Under local anaesthesia 21 extra-oral implant were placed, facial prosthesis were individually made six month postoperatively. Follow up ranged from 6 month to 6 years.

RESULTSAll 21 implants osseointegrated well, implant lost and peri implantitis was not found. All 6 cases had individual facial prosthesis and were satisfied with the prosthesis.

CONCLUSIONSExtra oral implants provided excellent retainment for facial prosthesis; result of current silicon with individual color shade is encouragable.

Dental Prosthesis, Implant-Supported ; methods ; Facial Injuries ; surgery ; Female ; Follow-Up Studies ; Humans ; Male ; Maxillofacial Prosthesis ; Osseointegration ; physiology