Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Maxillofacial Prosthesis”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 613 records · Page 34Linked to original sources
PubMed1996

Comparison of techniques for reinforcing stone molds used to construct facial prostheses.

Dental stone molds are convenient for fabricating facial prostheses, but they tend to break when repeatedly used to make duplicate prostheses. This study investigated the use of an inexpensive plastic mesh, die hardener, and PVC pipe segment to reinforce stone mold test samples that were broken in compression on an Instron testing machine. The samples reinforced with PVC pipe surpassed the load limit of the Instron machine. The samples reinforced with both die hardener and mesh were 13% more resistant to breakage than the control samples made of stone alone. Samples reinforced only with mesh were 3% weaker than the control samples.

Analysis of Variance↗
PubMed1996

The relative value of provider work for maxillofacial prosthetic services.

The results of a national survey of members of the American Academy of Maxillofacial Prosthetics who estimated the relative value of provider work for nine existing and two proposed coded maxillofacial prosthetic services is reported. The work estimates are a necessary component of a larger effort by the Health Care Financing Administration to establish a resource-based relative value scale for reimbursement for all Medicare services. Analysis of the survey data reveals agreement regarding the relative value of work for maxillofacial services compared with other established medical procedures and that the median values for each service are acceptable initial estimates.

Centers for Medicare and Medicaid Services, U.S.↗
PubMed1997

Functional assessment testing for maxillofacial prosthetics.

STATEMENT OF PROBLEM: The health industry is now concerned with treatment outcomes and accountability to patients, payers, and referral sources. PURPOSE: The purpose of this study was to identify the functional tests that are available to maxillofacial prosthodontists and to provide a list of those tests that are applicable in treatment and documentation. METHODS: Functional assessment may be used to justify reimbursement on the basis of payer guidelines, define eligibility for service, and judge quality and effectiveness of care. Currently, most maxillofacial prosthodontists do not use functional assessment. A literature search resulted in a list of 125 available tests. On the basis of that list a questionnaire was submitted to speech-language pathologists and occupational therapists to identify which tests are being used by them. This article discusses a historic overview of assessment testing and the need for functional assessment testing by the maxillofacial prosthodontist. RESULTS: Outcome measurements used by other members of the rehabilitation team are discussed and summarized, and those useful for the maxillofacial prosthodontist are suggested.

Deglutition↗
PubMed1997

Dynamic mechanical thermal analysis of maxillofacial elastomers.

STATEMENT OF PROBLEM: Maxillofacial prosthetic materials should simulate the oral tissues as much as possible and therefore have a similar flexibility and resilience. In light of the oral tissues constantly moving, the dynamic deformation properties of maxillofacial materials would seem the most relevant. PURPOSE: In this study, dynamic mechanical thermal analysis was used to evaluate the deformation properties of five silicone rubber materials used to construct facial prostheses. The technique involves the application of a sinusoidally oscillating stress to a material and analyzes how the material elastically or viscoelastically responds to the stress. The dynamic mechanical thermal analysis can operate at a fixed frequency or range of frequencies over a specific temperature range and also isothermally as a function of time. RESULTS: Cosmesil and A-2186 materials were the most resilient materials and Silbione had the greater energy absorption capacity, which was particularly noticeable at the higher frequencies. Silbione also had a lower shear modulus (G'), which indicated it was more flexible than the other materials. CONCLUSION: The dynamic mechanical thermal analysis proved to be a rapid, reliable, and convenient method for the determination of viscoelastic properties of maxillofacial materials.

Analysis of Variance↗
PubMed1998

Use of low fusing alloy in dentistry.

STATEMENT OF PROBLEM: Low fusing alloy has been used in dentistry for remount procedures in both fixed and removable prosthodontics, in implant prosthodontics for the fabrication of solid implant casts, in maxillofacial prosthetics as oral radiation shields, and in dental research for its unique properties. Previously, the use of low fusing alloy was thought to offer a high degree of dimensional accuracy. However, multiple in vitro studies have shown that its presumed dimensional accuracy may be questionable. PURPOSE: This article reviews the physical properties, metallurgical considerations of low fusing alloy, its applications in dentistry, and a safe, simple method of using low fusing alloy.

Chemical Phenomena↗
PubMed1998

Pigments and their application in maxillofacial elastomers: a literature review.

PURPOSE: This literature review provides information about pigments used for facial and somatoprostheses. MATERIAL: This information includes common pigment and index names and numbers, lightfastness categories, chemical type and class, and the chemical formulas of the common pigments used in maxillofacial prosthetics. CONCLUSION: It can be deduced from this review that the pigments used with silicone elastomers do exhibit a color change, and that a color change is to be expected.

Humans↗
PubMed1999

Color stability of facial silicone prosthetic polymers after outdoor weathering.

STATEMENT OF PROBLEM: Color deterioration of silicone prosthetic elastomers affects the life expectancy of facial prostheses in a service environment. PURPOSE: This study investigated the color stability of 3 nonpigmented silicone elastomers (Silskin 2000, Elastosil M3500, Ideal) exposed to outdoor weathering for 1 year. MATERIAL AND METHODS: A tristimulus colorimeter was used to evaluate the color differences (DeltaE*) of the silicone elastomers every 2 months. Ten disk-shaped specimens for each material were tested. Data were analyzed with a repeated measures ANOVA and Student-Newman-Keuls test at a significance level of alpha = .05. RESULTS: All silicone elastomers showed visually detectable, mean color differences (DeltaE* > 2.0), that ranged from 2.13 to 3.98. Silskin 2000 showed greater color differences (P <.05) compared with Elastosil M3500 and Ideal, which showed similar behavior (P >.05). CONCLUSION: Outdoor exposure of silicone facial elastomers for 1 year resulted in visually detectable color differences. Duration of exposure and silicone elastomer were significant factors that affected color stability. Silskin 2000 was significantly less color stable than Elastosil M3500 and Ideal, which were not statistically significantly different from each other.

Analysis of Variance↗
PubMed1999

Color stability and colorant effect on maxillofacial elastomers. Part III: weathering effect on color.

STATEMENT OF PROBLEM: Maxillofacial prostheses are serviceable for approximately 6 months, after which they need to be refabricated because of the deterioration of color and physical properties. PURPOSE: This third article in a 3-part series evaluated the color stability of commonly used colorant-elastomer combinations as a result of exposure to weathering. METHODS AND MATERIAL: Fifteen specimens were fabricated for each of the 3 elastomers (Silastic medical adhesive type A, Silastic 4-4210, and Silicone A-2186) and 6 colorants (dry earth pigments, rayon fiber flocking, artist's oil paints, kaolin, liquid cosmetics, and no colorant) for a total of 270 specimens (18 groups of 15 specimens). The 15 specimens of each elastomer-colorant combination were separated into 3 test condition groups (control, time passage, and natural weathering) of 5 specimens per test condition group. Control specimens were evaluated within 1 month of fabrication. The time passage group was sealed in glass containers and kept in the dark for 6 months before testing. The natural weathering groups were placed on the roof of the dental school for 6 months and exposed to sunlight and weathering. Color and optical density data for each elastomer-colorant combination were subjected to a 1-way analysis of variance to examine effects among test conditions (control, time passage, and weathering). When significant differences were observed, the Student-Newman-Keuls multiple range test was performed to identify differences in elastomer-colorant combinations among each test condition at a significance level of .05. RESULTS: Changes in color, as a result of weathering, were noted in many of the colorant-elastomer combinations. Also, color change occurred not only to the colored, but also to uncolored materials over time without exposure to weathering. CONCLUSION: Clinically, the addition of colorants could have a stabilizing effect on the elastomer color when it is exposed to weathering.

Analysis of Variance↗
PubMed1999

Wettability of silicone rubber maxillofacial prosthetic materials.

STATEMENT OF PROBLEM: Maxillofacial prosthetic materials that contact skin or mucosa should have good wettability. A material that is easily wetted will form a superior lubricating layer between the supporting tissues and, thus, reduce friction and patient discomfort. The surface energy of a maxillofacial prosthetic material will give an indication of the amount of energy available for adhesion and of the susceptibility of the material to bacterial adhesion. PURPOSE: This study evaluated the wettability and surface energies of a range of commercially available silicone rubber maxillofacial prosthetic materials. MATERIAL AND METHODS: Contact angles and surface energies were measured by using a dynamic contact angle measuring technique. Four commonly used silicone maxillofacial materials were tested and their properties compared with those of an acrylic resin denture base material and a widely used denture soft lining material. RESULTS: There were no significant differences in the wettability of the silicone rubber materials. All materials were significantly less wetted than the denture acrylic resin material. There were no significant differences in the surface energies of the silicone rubber materials, but all were significantly lower than denture acrylic resin material. CONCLUSIONS: The Cahn dynamic contact angle analyzer was a quick and reproducible method for determining the contact angles and surface energies of maxillofacial materials. Further work is needed to improve the wettability of silicone rubber materials used for maxillofacial prostheses, thus, reducing their potential to produce friction with tissues.

Acrylic Resins↗
PubMed2004

In vitro evaluation of color change in maxillofacial elastomer through the use of an ultraviolet light absorber and a hindered amine light stabilizer.

STATEMENT OF PROBLEM: External prostheses composed of silicone elastomers exhibit an unwanted color change over time. PURPOSE: This study evaluated color stability when an ultraviolet light absorber and hindered amine light stabilizer were mixed in the maxillofacial elastomer containing either organic or inorganic pigments. MATERIAL AND METHODS: The materials used were an RTV silicone elastomer, 1 natural inorganic dry-earth pigment (burnt sienna) and 2 synthesized organic pigments (hansa yellow and alizarin red), ultraviolet light absorber (UVA) and hindered amine light stabilizer (HALS). Specimens (n=160) were fabricated in a custom mold and randomly assigned and exposed to weathering sites in Miami and Phoenix for approximately 3 months. Eight test groups (2 of each 4 material types with or without additives) of 10 specimens each were assigned to each site. L*, a*, b* readings were obtained before and after weathering from a spectrocolorimeter. Nonpigmented elastomers served as the control. Three-factor ANOVA was conducted to examine interaction effects between weathering sites, specimen type, and the presence of additive (alpha=.05). Overall color change (Delta E) and change in color coordinates (Delta L*, Delta a*, Delta b*) of specimen groups with and without additive were analyzed with independent sample t tests. RESULTS: In specimen groups with the additives (UVA and HALS), color change decreased significantly (P<.05) in burnt sienna and hansa yellow in Phoenix and in the control and hansa yellow in Miami. Additives did not affect color change in the alizarin red group. CONCLUSION: UVA and HALS were shown to be effective in retarding color change in some circumstances.

Absorption↗
PubMed1998

Implant reconstruction following removal of tumors of the head and neck.

Functional maxillofacial rehabilitation following tumor ablation depends on many variables. These include the magnitude of hard or soft tissue defects, the use of adjunctive chemotherapy or radiation therapy, and the presence of underlying systemic disease. The physiologic effects of tumor ablation and radiation therapy on local tissues and grafted bone are discussed in this article in relation to the ultimate use of implant supported prostheses. Cases are presented to illustrate a variety of clinical situations.

Bone Transplantation↗
PubMed2004

Orthodontic treatment for patients with clefts.

Orthodontic strategies continue to evolve as new methods and treatment concepts more directly address the specific problems of patients who have clefts. By continual review of treatment outcomes and comparing outcomes with patients' problem lists and treatment objectives, clinicians will identify areas of treatment needing improvement and formulate hypotheses for future research.

Adolescent↗
PubMed2004

Prosthetic habilitation of patients with clefts.

Through clinical experience and research, treatment of cleft lip and palate has changed and im-proved dramatically. The team concept remains the key to success in the care of these patients. Prosthodontists remain integral members of this team because of the wide range of patient care services that they provide.

Cleft Lip↗
PubMed2004

Nasoalveolar molding for infants born with clefts of the lip, alveolus, and palate.

The principle objective of presurgical nasoalveolar molding (NAM) is to reduce the severity of the initial cleft deformity. This enables the surgeon and the patient to enjoy the benefits associated with a repair of a cleft deformity that is of minimal severity. Retraction of the premaxilla, presurgical elongation of the columella, correction of the nasal cartilage deformity, alignment of the cleft alveolar segments, increase in the surface area of the nasal mucosal lining, up-righting of the columella, and achieving close approximation of the cleft lip segments at rest result from gentle application of forces through the NAM appliance. Preservation of these presurgical changes is achieved through the coordinated and modified surgical technique of the primary cleft repair.

Child, Preschool↗
PubMed2002

New organosilicon maxillofacial prosthetic materials.

OBJECTIVES: The silicone elastomer A-2186 is a widely used maxillofacial prosthetic material. It is a pourable two-component silicone rubber cured by a platinum catalyst. Used as a prosthetic material, A-2186 has short working time and because of its hydrophobic nature, poor adhesion to non-silicone based adhesives. The purpose of this study is to evaluate the physical properties of new prosthetic materials based on methacryloxypropyl-terminated polydimethylsiloxane (MPDS-MF), and to compare the properties with those of A-2186. METHODS: Hardness, tensile strength, ultimate elongation, tear strength and adhesive bonding strength of MPDS-MF and A-2186 with and without additives were determined and compared. The bonding strengths of the extrinsic colorant carrier with the prosthetic materials were also determined. Statistical analyses were done using a two-way analysis of variance (ANOVA). For significant effects, post-hoc tests were done using the Bonferroni correction. RESULTS: The hardness of MPDS-MF is similar to A-2186. However, tensile strength, tear strength, ultimate elongation, and adhesive bonding strength of MPDS-MF are higher than those of A-2186. SIGNIFICANCE: MPDS-MF is cured by free radical thermal polymerization and crosslinking. The working time of MPDS-MF, unlike A-2186, is long. The presence of methacrylate groups in MPDS-MF enhances its adhesion to non-silicone based adhesive. Based on the present study, it appears that MPDS-MF is suitable for use in fabricating of clinical prostheses.

Adhesives↗