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ePaper created 2018-01-10, 10:45:46 | version 1.38.0
Dental Tribune Africa Sub-Saharan Edition | 1/2017 CLINICAL 05 6 8 7 9 Figure 6: Eyeglass frames (Tomato Glasses, TKAC3) with custom chrome-cobalt nose pad designed to be luted to the acrylic substructure of the prosthesis. Figure 7: Completed facial prosthesis. Note the patent nasal and oral orifices to allow breathing through the prosthesis. Figure 8: Frontal profile of the patient with the facial prosthesis in place. Figure 9: Left lateral profile of the completed prosthesis in situ. The eyeglass frames and brassiere strap link together posterior to the auricle via a discrete hook to provide resistance of the prosthesis to vertical displacement. tongue depressor) incorporated into the impression material. The primary cast was poured in hard dental stone (Wiegelmann Dental, Bondur M yellow), and a light-cured acrylic (Willman and Pein, GmbH Plaque photo) special tray was fabricated based on this impression. At the secondary impression stage, the patient was again instructed on the procedure and breathing exercises were practiced using the high-volume evacuator tip. Cotton wool was again packed into the nasal cavity to prevent material aspiration and petroleum jelly was used as a separator over structures that could be incorporated into the impression, such as eyebrows and eyelashes. Impressions were taken using a polyether impression material (3M ESPE Impregum Penta) in the custom tray, and a master cast was poured in die stone (Velmix, Whip Mix - Resin rock). The advantage of this technique is that all facial landmarks are present on the casts, which enable the ideal sculpting of prosthetic structures in anatomically correct positions without the need for the patient being present for repeated trials. A wax try-in was sculpted in pink modelling wax on the master cast in co-ordination with respective facial landmarks. The initial try-in of the wax-up (Fig. 5) was performed where rapid alterations of the facial contours were made using modelling clay (Staedtler, Noris Club Modelling Clay), which provided good stability while adhering to the wax pattern. The wax try-in was adjusted and a second try in was performed. A satisfactory marginal fit and suitable aesthetic profile were acquired. The skin shade and tone were determined using a colour chart. As the position of the spectacle frame could only be verified at chair-side, a template of the nasal bridge was created using silicone putty (Zhermack, Zetalabor 85 Shore A). With the template, the correct position of the exposed acrylic spots for luting could be determined, by transferring it to the plaster cast. cured limited silicones, A polymethyl methacrylate (PMMA) substructure was constructed in high- impact acrylic (Vertex, Castavaria) to reinforce the silicone and prevent excessive flexure of the prosthesis. As PMMA has adherence chemically and mechanically with platinum the substructure was exposed along the prosthetic nasal bridge to allow for the luting process of the spectacles. Acrylic denture teeth (Ivoclar, Ivostar, shade A2, mould 01) were further luted to the substructure to provide a more aesthetic appearance of the facial prosthesis. Once the substructure was complete, processing of the silicone was initiated. Special care had to be taken not to include any residues of latex (gloves), sulphur (silicone based impression materials), tin (Impression paste catalyst) or acetate (Cyanoacrylate glue) during the multiple treatment stages. This was done to ensure that no contamination of the silicone had occurred during the curing process. intrinsic polychromatic The size of the prosthesis prevented conventional flasking processes, and custom plaster split-moulds were created. The silicone (Technovent, M511 Platinum cured silicone) of the prosthesis was coloured intrinsically, using pigments (Technovent, silicone pigment). Following final fabrication of the prosthesis, the spectacle framework (Tomato Glasses, TKAC3) attached to a custom chrome-cobalt nose pad (Fig. 6) was luted to the exposed sub-structure via using cold cure PMMA. Final extrinsic staining (Technovent, extrinsic pigment) was performed and treated with a sealant. The nasal apertures and mouth were perforated in accordance with the acrylic substructure to allow the patient to breathe through the prosthesis. strap To prevent movement of the inferior border of the prosthesis, a transparent soft thermoplastic polyurethane brassiere (MRP, SKU1702710001001) was threaded through the chin cup anteriorly and connected to the spectacle strap posteriorly, as seen in figures 7 and 8. Adequate retention was achieved and a satisfactory seal was established on the prosthesis boundary (Fig. 8 and 9). for alterations Rapid facial growth is expected over the years to follow and regular maintenance visits will be required. The brassiere straps and spectacle elastics were selected their adjustable nature and can allow interim between replacements. This is expected to be done at 2-year intervals until the patient is old enough to receive an implant retained prosthesis. Regular follow up will entail exploring improvement of the patient’s mouth opening and the further possibility of restoring and masticatory function. dentition his Discussion Due to the gross amount of extraoral scarring, the patient’s mouth opening was limited to 1mm and masticatory efforts were accomplished using pressure of the patient’s tongue against his palate. It was deduced that minimal mobility of the extraoral tissue would be present and that a full- facial prosthesis may be constructed to restore aesthetics to the patient. The primary concern during the process of treatment planning however, was retention. Typically, eyeglass frames used in maxillofacial prosthetics rely on the presence of ears and a nose- bridge for support. However, this effect is compromised, and in some cases, negated in patients having undergone surgical removal of either of these anatomical structures.5 Furthermore, this form of support suspends the prosthesis from the supero-lateral aspects, providing resistance in the vertical plane from these two points only.4 In these instances, clinicians consequently make use of adhesives to retain parts of the prosthesis albeit to a less effective result. The weight and span of the prosthesis in this specific patient rendered the use of adhesives inadequate. Alternative methods or retention were therefore approached until the child is of the age to receive an implant retained prosthesis, as skeletal growth is a less-understood variable when implants are used in children.7 The procedure described exhibits an effective alternative means of retaining a large facial prosthesis where retention would otherwise be severely compromised. The incorporation of the brassiere straps effectively reduced movement of the inferior aspect and provided even load distribution along the support structures incorporated into the prosthesis. The tension on the prosthesis can also be attuned via the adjustable straps to maintain close approximation to the tissues as the child grows. In the South African context, a holistic view needs to be taken and factors such as finance, distance to reach treatment centres, and maintenance of prostheses need to be factored into a treatment plan. It is a multidisciplinary team approach is needed to ensure appropriate care is given. reason that this for a Conclusion The crucial role of facial features in daily interpersonal relationships is easily appreciated. In most societies, personal attractiveness plays an integral role in a patient’s self-esteem.2 With extra-oral prosthesis retained by glasses and a facial strap, the patient’s appearance early was rehabilitation allowing psychosocial reintegration until a more rigid, implant based prosthesis becomes a viable treatment option. enabling and rudimentary enhanced, References 1. Goiato MC. Patient satisfaction prosthesis. with maxillofacial Literature review. J Plast Reconstr Aesthet Surg. 2009;62:175-80 2. Hatamleh MM, Watson J, Srinivasan D. Closed-eye orbital prosthesis: A clinical report. J Prosthet Dent. 2015;113:246 - 9. 3. Fonseca EPF. The Importance of form, characterization and retention in facial prosthesis. J Prosthet Dent. 1966;16:338 - 43. 4. Tautin FS, Schoemann D. Retaining a large facial prosthesis. J Prosthet Dent. 1975;34:342 - 5. 5. Parr RP. Accessory retention for a facial prosthesis. J Prosthet Dent. 1979;41:546 - 7 6. Ajay O, Gilsa KV, Nidhin R. Nasal Prosthesis - A case report. J Med Dent Sci. 2014;13:113 - 6. 7. Percinoto C, de Mello Vieira AE, Barbieri CM, Melhado FL, Moreira KS. Use of dental implants in children: A literature review. Quintessence Int. 2001;32:381 – 3 Acknowledgements The authors thank Henk du Plessis (Dura Art Dental Laboratory) for their materials and Mrs Celisha Singh (Vision Hub Optometry) for sponsorship of spectacles.