Facial Prostheses Research Articles

Primary vs secondary zygomatic implant placement in patients with head and neck cancer-A 10-year prospective study.

Zygomatic implants can provide excellent remote anchorage to support the prosthetic rehabilitation of patients treated for maxillary and midfacial tumors. Patients who underwent zygomatic implant placement by the author between 2006 and 2016 as part of their oncology treatment were followed prospectively. Forty-nine consecutively treated patients received 131 zygomatic implants of which 9 failed and were removed from 4 patients; 24 patients (49%) received radiotherapy either before or after implant insertion. The overall 12-month survival estimate was 94% and the 60-month estimate was 92%. The use of zygomatic implants in the management of maxillary and midfacial malignancy is a predictable prosthetic treatment modality to support complex oral and facial prostheses. Their use with or without free tissue transfer can provide effective prosthetic rehabilitation with high implant survival irrespective of the timing of placement or the need for adjuvant radiotherapy. Zygomatic Implants provide an excellent platform for the restoration of the dentition and facial structures affected by maxillary and midfacial malignant disease.

Retention systems used in maxillofacial prostheses: A review.

Defects in the face area caused by trauma, accident, tumor or congenital defects are treated with special facial prostheses. Besides esthetics, the most common problem with these prostheses is the retention of prostheses. In the present article review, the methods used for the retention of prostheses from past to present were researched, and the advantages of adhesives and implants, which are the most commonly used current methods, were evaluated. Current techniques, new materials, treatment options, and implementation procedures are described. The success of maxillofacial prostheses in meeting the expectations of patients and dentist doctors is increasing day by day with the development of adhesive material science, the emergence of technical knowledge, and the development of implant technology. Increasing the retention provides both ease of use and acceptance by the patient. Therefore, the chosen method for retention has great importance in the long-term prognosis of the prosthesis.

Production of Medical Grade Silicone for Facial Prosthesis with Bactericidal Properties from the Inclusion of Poly (Diallyldimethylammonium Chloride): An in Vitro Study

Objective: To evaluate the inclusion capacity and bactericidal efficiency of diallyl dimethyl ammonium chloride (PDADMAC) diluted in tetrahydrofuran (THF) upon inclusion in the medical grade silicone polymer structure. Material and Methods: It was diluted the PDADMAC in THF at the concentration of 4wt%. It was included in the silicon paste during its vulcanization process. The contact angle measurements were performed to evaluate whether the biocide inclusion into the silicon paste was successful. All samples were sterilized with gamma radiation at 25KGy-dosage prior to the microbiological tests. Microbiological testing strictly followed the Antibacterial products - Test for antibacterial activity and efficacy JIS Z 2801: 201010 and the used of specific bacteria, as Staphylococcus aureus ATCC 6538P and Escherichia coli ATCC 8739. Results: The results showed that PDADMAC, when dissolved in THF at 4wt%, displayed good incorporation in medical silicone and a broad-spectrum antibacterial response. The results of the tests using Escherichia coli ATCC 8739 and Staphylococcus aureus ATCC 6538P showed that the silicone with no biocide addition did not present antibacterial activity. In contrast, the experimental group plus 2 mL of PDADMAC would have an ideal antibacterial response. Conclusion: Medical grade silicone can be used as a material with antibacterial properties, since it has been able to keep PDADMAC compound attached to its structure, thus acquiring antimicrobial property.

Proposition of integrated electrical mechanism and facial prosthesis for eyelid motion on prosthetic oculopalpebral rehabilitation: technical note

Proposition of integrated electrical mechanism and facial prosthesis for eyelid motion on prosthetic oculopalpebral rehabilitation: technical note

Antifungal efficiency of chemically and thermally-activated acrylic resins after surface treatment using poly (diallyldimethylammonium chloride)

Acrylic resins are used in the preparation of facial prostheses and may be colonized by fungi. Here, we verified the antifungal efficacy of this material after surface treatment using poly (diallyldimethylammonium chloride). Acrylic resin specimens with and without surface treatment were subjected to tests for fungistatic and fungicidal activities. Standard strains of Candida albicans and Aspergillus niger were used. After surface treatment, the fungistatic and fungicidal efficacies of the resins against C. albicans and fungistatic action against A. niger were verified. The surface treatment was a determinant of the antifungal activity of the material.

THE ROLE OF DIGITAL TREATMENT PLANNING IN MAXILLOFACIAL PROSTHETICS

Advances in treatment planning have changed patients’ expectations of the functional and aesthetic outcomes of maxillofacial prosthetic treatments. This case report describes and discusses the role of digital technology in the treatment planning of a facial prosthesis for a patient with complex maxillofacial prosthetic needs. A 75-year-old man was diagnosed with squamous cell carcinoma of the left maxillary sinus. The tumor was surgically resected and resulted in extensive tissue loss. The four key elements of visualization, design, manufacture, and evaluation were considered in digital treatment planning of the facial prosthesis; the first two are discussed in this report. The defect areas were three-dimensionally digitized using computed tomography and stereophotogrammetry. The scanned data were saved as a standard tessellation language file. From these data, virtual three-dimensional models were created for treatment planning options. With the aid of computer-aided design software, two types of facial prostheses were designed: an open-eyeprosthesis and a closed-eye prosthesis. These designs were discussed with the patient to determine the one most suitable to meet his aesthetic expectations. Patients’ expectations of treatment options can be improved through the virtual visualization and design offered by digital treatment planning. This case report confirms the applicability of digital treatment planning in managing patients with complex maxillofacial prosthetic needs.

Direct 3D Printing of Flexible Nasal Prosthesis: Optimized Digital Workflow from Scan to Fit.

A maxillofacial prosthesis is a successful treatment modality to restore missing facial parts. Digital technologies and 3D printing are employed in constructing facial prostheses such as ears; however, their application is still partial, and final prostheses are usually manufactured conventionally using stone molds. This report aims to introduce a complete digital workflow to construct a nasal prosthesis and compare it to the conventional workflow of a patient requiring a nasal prosthesis. A computer tomography scan showing the defect was exported to specialized software to create 3D reconstructions of the patient's face and underlying bone. The nose was digitally designed restoring facial esthetics, anatomy, shape, and skin color. Different skin tones were digitally matched to skin tissues adjacent to the defect area using the Spectromatch system. The design was 3D printed in flexible and colorful material at 16 μm resolution using a 3D printer. External color pigmentations were applied to the nose for optimum esthetics, and the prosthetic nose was sealed in silicone and left to heat polymerize for 15 minutes. The prosthetic nose was retained in place using biomedical adhesive, and the patient was pleased with it. This report proposes a complete digital workflow to directly design and fabricate a prosthetic nose of acceptable esthetics. Such a workflow can lead to enhanced prosthesis reproducibility and acceptability and may become an effective treatment option for treatment of patients with facial defects.

Maxillofacial prosthetic rehabilitation: A survey on the quality of life

Statement of problemMaxillofacial prostheses, especially those supported by endosseous implants, are regarded as a viable, secure treatment for the reconstruction of facial defects to restore quality of life. The long-term quality of life of patients treated with facial prostheses with different retentive systems is unclear. PurposeThe purpose of this clinical study was to assess the long-term quality of life of patients treated with facial prostheses with different retentive systems over a 14-year period at a Dutch oral and maxillofacial surgery unit. Material and methodsA total of 66 patients with facial prostheses were inventoried and categorized based on anatomic location and type of retention. A 62-item questionnaire was designed to survey the daily prosthetic use, care, quality, durability, longevity, and reliability of retention. Furthermore, issues relating to general satisfaction, self-image, and socialization frequency were addressed. ResultsCompleted validated questionnaires were returned by 52 patients. Of the prosthetic replacements, 23% (n=12) were orbital, 33% (n=17) nasal, and 44% (n=23) auricular prostheses. The survey showed that a prosthetic reconstruction led to high satisfaction scores with regard to wearing comfort, anatomic fit, color, and anatomic form. A significant difference was shown for implant-retained facial prostheses, which provided enhanced retention and increased ease of placement and removal (Fisher exact test P=.01 and P=.04). Patients with nasal prostheses were less satisfied with the junction of their prostheses to the surrounding soft tissue and more aware of others noticing their prosthetic rehabilitation. Patients with auricular defects were less embarrassed (P=.01) by their prostheses. Although auricular prostheses were less frequently cleaned (P=.01), no significant difference was found in minor soft tissue complications between different anatomic locations and the various retentive systems. ConclusionsImplant-retained prostheses have advantages over adhesive-retained prostheses in terms of ease of handling. However, improvements in prosthetic material properties, including color stability and durability, are needed to increase the longevity of facial prostheses.

Assessment of the Quality Of Life and Patients’ Satisfaction in Egyptian Patients Wearing Facial Prostheses

Objectives: The aim of this study was to assess patients’ satisfaction and Quality of Life withfacial prostheses through a special designed questionnaire.Material and Methods: 120 patients using facial prostheses retained either by chemicaladhesives or bone anchorage implant for at least 6 months were asked to answer a twenty questionsquestionnaire through a cross-sectional survey. This questionnaire covered the appearance,retention means and effectiveness, awareness, self-confidence, difficulty of placement and removal,cleaning, restriction of social actions, pain and inflammation of tissues, and advice of the methodto other patients. Visual analogue scale (VA S) was used to show patient response. The mean of theanswers was converted into a percentage to symbolize the satisfaction index.Results: Wearing facial prostheses made most of patients happy (mean (SD) 9.4 (1.54)). Themost satisfied patients was those who had facial prosthesis retained by implants (p = 0.025), andadditional self-awareness was experienced in those retained by adhesives (p = 0.012). 72% ofpatients experienced no pain or troubles with the prosthesis during function. Both implant andadhesive retained prostheses have noticeable advantages without the presence of statisticallyconsiderable differences between them.Conclusions: The results showed that use of extraoral prostheses retained by adhesive or bybone anchorage implant provided a high level of satisfaction among patients.

Risk factors for periimplantitis and implant loss in orbital implants

BackgroundAfter orbital exenteration a facial prosthesis is a viable option for rehabilitation. The aim of this study was to evaluate implant loss and peri-implantitis of solitary orbital implants with regard to risk factors. Patients and methodsImplant loss (primary outcome) and periimplantitis (secondary outcome) were reviewed retrospectively in patients who received orbital implants between 2006 and 2015 with a minimum follow-up time of 12 months. Potential risk factors were analyzed using univariate and multivariate statistics. Results94 patients were included with 371 inserted implants and 326 implants remaining for final analysis. At the time of last follow-up 18.1% (59/326) of the implants were lost and 3.4% showed signs of periimplantitis but were still stable in situ. Daily smoking (p = 0.016, OR = 2.1), irradiation (p < 0.001, OR = 2.8) and daily alcohol abuse (p = 0.028, OR = 3.1) had a significant effect on periimplantitis and implant loss. Combining smoking and irradiation, implant failure was 46.9% versus 15.0% in patients without these risk factors (p < 0.001, OR = 5.0). Age, tumor entity, ASA Score, anticoagulation, chemotherapy, diabetes and implant position did not show a significant correlation for implant loss or – except for age – periimplantitis. Younger patients showed a higher risk of developing periimplantitis (p = 0.011). ConclusionOrbital prostheses retained by solitary implants provide a solid option to reconstruct facial defects. Whereas in general high implant survival can be expected, they should be carefully considered in patients with the risk factors irradiation, smoking and alcohol abuse.

Development of three-dimensional facial expression models using morphing methods for fabricating facial prostheses

PurposeIt is essential to fabricate a best-fit three-dimensional (3D) facial prosthesis model capable of facial expressions. In order for the facial prosthesis to remain in position, especially around marginal areas subject to movement, a new method of making 3D facial expression models using time-series data allowing changes in facial expression by morphing technique was developed. MethodsSeven normal subjects and seven patients with nasal defects or nasal deformities participated in this study. Three distinct facial expressions (i.e., a neutral expression, smiled, and open mouthed) were digitally acquired with a facial scanner. Prepared template models were transformed to homologous models, which can represent the form as shape data with the same number of point cloud data of the same topology referring to the scanning data. Finally, 3D facial expression models were completed by generating a morphing image based on two sets of homologous models, and the accuracy of the homologous models of all subjects was evaluated. Results3D facial expression models of both normal subjects and patients with nasal defects were successfully generated. No significant differences in shape between the scanned models and homologous models were shown. ConclusionsThe high accuracy of this 3D facial expression model in both normal subjects and patients suggests its use for fabricating facial prostheses.

Metamerism of Three Different Pigments for Facial Prostheses and a Method to Improve Shade Evaluation.

To assess the illuminant metamerism of three different pigments used for maxillofacial prostheses under three different illumination sources and to standardize subjective shade-matching and observation protocols. Nine silicone shade tabs were constructed for three volunteers who had light, medium, and dark skin tones using make-up, oil paint, or silicone pigments (three shade tabs per volunteer). A shade recipe was recorded during session one, and further tabs were constructed by following the recipe at two subsequent sessions. Using an observation protocol, expert examiners rated the shade match under three different illuminants. The intra-rater and inter-rater reliability revealed acceptable reliability (ICC > 0.6). Two-way analysis of variance revealed significant differences (P < .05) for pigments and illuminants and for the interaction of pigments with illuminant on the raters' scores. Illuminant metamerism affected the appearance of the silicone shade tabs. Oil paint with fluorescent or incandescent illumination had the worst effect. It was found possible to construct a consistent shade guide and to recommend an observation protocol, which should be repeatable if similarly experienced examiners are used.

Double Investment Technique of Hollow Bulb Denture Obturator Fabrication in a Completely Edentulous Patient

Introduction: Prosthodontic management of palatal defects has been employed for many years. Palatal defects of any extent cause multiple problems in speech, mastication and aesthetics. Obturator prosthesis for an edentulous patient is more critical in terms of its movements as there is no mechanical retention available. Obturators and facial prostheses are important not only for rehabilitation and aesthetics, but also in patient resocialisation. Maxillary defects are created by surgical treatments of benign or malignant neoplasms and by trauma, in which case, denture is supported only by the underlying residual ridge and the defect. This clinical report describes the rehabilitation of a maxillary resected patient with a single piece hollow bulb denture obturator fabricated by double investment technique. Materials & Methods: In this double investment technique of hollow bulb denture obturator fabrication two same size transposable flasks were used for flasking and curing of the prosthesis. Results: Hollow bulb denture obturator was obtained by this double investment technique. Conclusion: Decreased weight of prosthesis positively affects retention leading to improved physiologic function, and it also does not cause excessive atrophy in muscle balance.

Perceptibility and acceptability thresholds of simulated facial skin color differences

PurposeThis study investigates the perceptibility and acceptability thresholds (PT, AT) of observers for L*, a* and b* facial skin differences, very important for the fabrication of a maxillofacial prosthesis. MethodsOne image (10×13.3cm/300dpi), simulating standard facial skin color, and 27 smaller images (4.9×6.0cm/300dpi), simulating shades with different RGB values from the standard were made, using Adobe-Photoshop CS3. The RGB values, were based on 9 stepped increases in L*, a* and b*. Images were shown in the middle of a computer screen with the standard image in the background. 90 persons with normal color vision and optical acuity were selected and instructed to evaluate 81 (27×3) randomly shown images for a perceptible or an acceptable (48h later) mismatch, between central and background image. Using best fitting regression curves 50 % PT and 50 % AT for all parameters were estimated along with their 95 %CI. ResultsObservers’ reliability found high (0.807–0.945) while the cubic and exponential were the best fitted curves to the data. Overall 50 % ATs were smaller than 50 % PTs (p<0.01) and overall ΔL* parameter showed the lowest thresholds (0.119PT/0.864AT), significantly smaller (p<0.05) than Δa* (0.993PT/2.037AT), Δb* (1.147PT/2.517AT), and ΔEab*(1.497PT/1.808AT). No differences were found between sex or age groups in 50 % ATs for Δa* and Δb* parameters, but 50 % PT for Δa* was smaller in females and in older people with the opposite for Δb*. ConclusionsChanges in L* were more perceptible and less acceptable than changes in a* and b*. For this reason ΔL* parameter needs attention equally to ΔE*ab when fabricating a facial prosthesis.

Suitability of a Mobile Phone Colorimeter Application for Use as an Objective Aid when Matching Skin Color during the Fabrication of a Maxillofacial Prosthesis.

Color matching a facial prosthesis to human skin is very challenging. Colorimeters aid this process by adding objectivity to what is an otherwise subjective procedure. Mobile phone colorimeter applications offer a less expensive and widely available alternative to dedicated colorimeter devices for color measurement. There is a lack of evidence in the literature regarding the suitability of mobile phone colorimeter applications for the development of silicone shades for facial prosthetics. The purpose of this study is to determine the suitability of a mobile phone colorimeter application for matching natural skin colors during the fabrication of maxillofacial prostheses. Ten pigmented maxillofacial silicone elastomer swatches were fabricated to mimic a range of human skin tones. Color measurements of these swatches were recorded using a test instrument-the mobile phone colorimeter application (RGB Colorimeter) and a reference instrument-the commercially available skin color measurement device e-skin spectrocolorimeter. Comparisons in trueness and precision of the color measurements were made using previously described methods. Data analysis was performed on the recorded results for each of the parameters at three distances (25, 30, and 35 mm) of the test instrument from the target against both a black and a white background. The trueness of the mobile phone colorimeter application relative to the colorimeter device varied depending on the distance from the target and the background color. The relative trueness of the color difference measurements fell just within the documented upper threshold of acceptable limits of color difference (∆E 3.0 - 4.4). The calculated precision of the CIE L*a*b* and ∆E measurements of the mobile phone colorimeter application was good, with the latter being well within the documented acceptable limits. A mobile phone colorimeter application would be a suitable aid in objectifying the process of color matching a silicone maxillofacial prosthesis. Further investigation into image calibration to improve trueness and the control of variables such as background noise, uniformity of illumination, and measuring distance is required.

Evaluation of shear bond strength between maxillofacial silicone and fiber-reinforced composite resin after various surface treatments

Statement of problemThe most common reason for remaking a facial prosthesis is the debonding of maxillofacial silicone from the substructure. Improved bonding would help overcome this problem. PurposeThe purpose of this in vitro study was to evaluate the shear bond strength between maxillofacial silicone and fiber-reinforced composite resin after various surface treatments. Material and methodsAcrylic resin specimens were prepared with a dimension of 14.4 mm in diameter and 25 mm in height with a depression of 5 mm in depth and 8 mm in diameter, according to International Organization for Standardization technical specification (ISO/TE) 11405:1994. Fiber-reinforced composite resin was dispensed and packed into the depressed part of acrylic resin and allowed to polymerize. A total of 120 specimens were fabricated, and primer was then applied over the specimens. They were washed with acetone and subjected to various surface treatments, including airborne-particle abrasion, silicon carbide paper abrasion, and laser etching. The maxillofacial silicone was mixed according to the manufacturer’s instructions and packed into the cylindrical die with dimensions of 3 mm in thickness and 8 mm in diameter. The shear bond strength test on the specimens was carried out in a universal testing machine at a 5-mm/min crosshead speed, at 24 hours after fabrication and 200 hours after accelerated aging. The values were statistically analyzed using 1-way ANOVA and the Tukey honest significant difference (HSD) post hoc test. ResultsThe mean shear bond strength values of the control group was 24.7 ±2.1 MPa, 26.9 ±1.8 MPa for the airborne-particle abraded group, 28.4 ±1.9 MPa for the silicon carbide abraded group SiCp, and 33.4 ±1.8 MPa for the laser-treated specimens at 24 hours after fabrication and 34.2 MPa at 200 hours after accelerated aging. ConclusionsThe shear bond strength between the maxillofacial silicone and the fiber-reinforced composite resin was increased after laser surface treatment compared with airborne-particle abrasion and silicon carbide paper abrasion 200 hours after accelerated aging.

Computer-aided design of facial prostheses by means of 3D-data acquisition and following symmetry analysis

The aim of this study was to investigate whether a method of designing digital models of facial prostheses was suitable for patients with orbital defects. 32 patients were included in a retrospective study. 23 of them already had a facial prosthesis. 3D-data of the faces were acquired optically using fringe projection technique without and with (if available) the facial prosthesis in place. The healthy side of the surface models was mirrored to reconstruct the defect area. By generating a NURBS-model, the edges of the virtual prostheses were adapted to the defect region. The CAD models were stored in STL format as templates for facial prostheses. Using an automatically calculated asymmetry index (AI), four situations of the digitized facial surface were analysed for symmetry: 1. with defect area excluded, 2. with mirrored healthy surface, 3. with digital CAD template, and 4. with manually produced facial prosthesis inserted (if available). Mean AI values were 6.05 ± 3.26 (situation 1), 4.79 ± 2.51 (situation 2), 5.12 ± 2.61 (situation), and 6.74 ± 2.77 (situation 4). Additionally, the CAD templates were rated by three anaplastologists. Ratings did not differ significantly. They partially agreed with the three statements “The CAD prosthesis fits harmoniously within the face”, “The CAD prosthesis could be used for a wax pattern during conventional fabrication” and “The CAD prosthesis and the wax pattern reduce workload”. The results indicate that the presented technique has the potential to increase facial symmetry and facilitate the technical procedure. However, symmetry alone is not a sufficient criterion for design of a facial prosthesis.

Augmented patient-specific facial prosthesis production using medical imaging modelling and 3D printing technologies for improved patient outcomes

ABSTRACT Facial prosthetic offer patients a low risk and high impact treatment option to address underlying facial defects. Such devices are generally handmade, requiring several labour-intensive manufacturing phases and numerous patient consultations to develop the final device. Therefore, production is a time-consuming and costly process with significant inconvenience to the patient and highly dependent on the skills of the prosthetists, making the whole process highly subjective. We investigate the potential of medical imaging, 3D design modelling and high-resolution 3D printing to augment the production of an auricular prosthesis for a patient who was previously using a handmade prosthesis. We reproduce the patient’s uncompromised anatomy from CT scan data, before printing a mirrored template to use in the casting process for a silicone prosthesis. This technique realises a superior end prosthesis with a realistic look on the patient while streamlining the current production methodology.

Availability of cosmetic treatment using novel cosmetics-based material on patients with craniofacial concavity

PurposePatients treated with maxillofacial prosthetics often experience emotional problems because of the remaining facial skin concavity such as a surgical scar. In such cases, cosmetic treatment can potentially correct their skin tone imperfections and deformities. This study aimed to evaluate the clinical availability of novel cosmetics-based material for craniofacial small concavity by initiating a cosmetic treatment in a preliminary case. MethodsEighteen patients with aesthetic problems such as craniofacial deformities, small defects, and concavities on their faces underwent cosmetic treatment that was performed by makeup practitioners. Data were collected from the patient’s charts and a survey questionnaire. A visual analog scale was used to conduct a survey regarding the satisfaction levels of the patients following cosmetic treatment with a novel cosmetics-based material. The cosmetic treatment was performed for a concavity on the left midface of a 67-year-old woman with partial maxillectomy. The novel cosmetics-based material was manufactured from a semi-translucent oil base. ResultsThe satisfaction level of the patient increased after undergoing the cosmetic treatment. Regarding clinical applications, the novel cosmetics-based material can help reduce their cosmetic disturbance and restore the small deformity. ConclusionsThese results suggest that the cosmetic treatment with the novel cosmetics-based material can be used as a subsidiary method for facial prostheses or an independent new method for correcting patients’ small craniofacial concavity and for reducing visible deformity.

Digital design of patient-specific abutments for the retention of implant-retained facial prostheses

The present report describes the digital design of patient-specific milled abutments for the retention of osseointegrated facial prostheses by using digital technology. Patient imaging including surface scans of the patient’s head, scans of the patient’s definitive cast, and digitally designed prosthesis prototypes were combined to create a digital simulation of the patient. Using this simulation, patient-specific abutments were digitally designed, printed in 3-dimensions (3D), and finally copy-milled in titanium. This process provided the patient with an optimal abutment design for prosthetic retention, hygiene control, and skin emergence profile.