A 74-year-old woman was seen at the Postgraduate Rehabilitation and Maxillofacial Prosthesis Department of the University of Barcelona to replace her oculo-palpebral prosthesis.
After a thorough examination of the facial defect, the support zones were evaluated to see the possibilities of obtaining stability, as well as the form of retention of the prosthesis4.
The latter presented a firm, stable, skin-covered surface, in the form of a fully communicated consistency with the temporal fossa through a hole of approximately 5 mm as a result of implant failure. An osteitis gap of 5 mm
For the elaboration of the flexible oculo-palpebral prosthesis, an impression must be obtained that faithfully reproduces the remaining tissues.
For this purpose, a delimitation was made of the extension of the prosthesis because its margins must be supported on stable surfaces.
The aim is to obtain a model of work and study in plaster stone or extradoor plaster.
Facial and temporal zones were individualized to impress by capturing the orifice created by the loss of the implant with Utility wax, so that at the time of impression it did not block its removal.
Vaseline was applied in regions that can retrace impression material such as cephalea or hair. Fluid silicones, aggregate, poly2.5*ether material or algina* may also be used as impression material
In this case alginate was used, which must be very fluid so as not to deform the integuments and it begins to be placed in the deeper areas of the defect, to avoid bubble formation.
Then, a gauze was placed over the alginate to avoid its draining and it also served as a union to the plasterboard layer of quick setting plaster placed on the impression material2,6.
It is important to keep the patient's airway free, telling her to breathe through her mouth and talk to her during the procedure, comfort her and inform her2.
The ocular prosthesis was then manufactured, imitating the remaining eye.
Due to its individual characteristics, some authors call it «almendra»3*.
Its size will correspond to the width between the inner and outer corner of the healthy eye.
The external face is totally convex and covered with transparent acrylic to obtain better aesthetic results.
Its internal face will be flat and will be supported on the posterior wall of the oculo-palpebral3* prosthesis.
For this patient, a silicone mold was used, which had been made of an immobilized patient.
Many waxes may be used, which are hard and weigh little.
Here, a hard consistency brown wax was used.
The iris must be previously characterized, so many techniques have been described.
In this case graphite discs were used because they are very resistant, they retain painting better and have several sizes.
The graphite disk is selected according to the size of the iris of the patient.
The iris diameter varies between 11.5-12 mm, and the pupil diameter varies between 2.5-3 mm5.
This precise characterization of a monomer (liquid) mixture with acrylic powder and oil, making it as smooth as possible5*.
The base colors were placed on a palette7.
The fixation of the disc to a pinch facilitates its painting in a radial way 4,5*.
There are several techniques for better color disposition.
The one that was used began with lighter colors and continues to subside from the center towards the periphery.
Thus, a better perspective of depth is achieved.
This step depends on 50% of the technique and another 50% of art3*,5*,8.
The color of an object is nothing else than the property it has of absorbing a certain amount of light radiation and emitting others.
Therefore, it is important to use the same type of light when examining the iris colour.
The presence of the patient is advisable for a better reproduction of the colors of the healthy eye3*,5*,8.
There are several ways to make the pupil.
Preformed corneal shapers incorporating it may also be acquired to adhere to the disc where the iris is painted.
These shapers make it possible to check in wax the focus of the eye on the patient.
After adapting the iris-pupilla set to the wax model, the building site was built to obtain the acrylic protuberance.
White resin matrix was loaded, including pigments that resemble sclerotic as much as possible and polymerized in boiling water for 30 minutes.
After cooling, the excess of resin on the surface of the iris was worn out, leaving it concave, to give a greater appearance of depth; the same was done with the space corresponding to the depth.
Sclerotic characterization was performed by mimicking blood vessels with wool or silk threads cut and stuck in the sclera longitudinally, starting from the angles of intensity when there is closer concentration*9.
The same paintings used for the iris are used.
Once the external pigmentation of the prosthesis has been removed, it has become established in the matrix and is loaded with a transparent acrylic layer which has the function of protecting and rendering the prosthesis transparent.
After polishing, both resins have to be bonded perfectly, without irregularities.
For this purpose, diamond freak, cones, loose paper, and always at low speed can be used.
The polishing was done with water, powder-stone and cotton5,10.
The globe wax starts from a pink wax sheet well adapted to the work model, filling spaces and sculpting the limits and protrusions of the prosthesis, which are defined and adapted 102,611.
The location of the proband constitutes an extremely critical step for which the presence of the patient is recommended8*,11.
The «almendra» should be able to achieve the correct position in the three planes of space
Different alignment techniques are used; all of them aim to achieve the correct position in the wax foil.
Parameters such as Vernier's rule and pupillometers are used to help locate the eye prosthesis within the orbit.
Vernier's rule measures the interpupilary distance that is normally 60 mm, approximately2.3*, 10.
Once the «almond» is located, the sculpture begins, making a larger eye that allows greater adaptation to the cavity.
Sculpture tries to copy all lines of expression and skin irregularities in wax.
Eyelids are created and the eyelid opening is established, always comparing them with the patient's healthy eye.
The plaster marks seen in the photo correspond to the midline of the face and the bipupilary line.
The limits of the prosthesis must be differentiated according to the wishes of the patient.
The experiesis test on the patient allows checking the alignment of both eyes.
The patient is asked to imitate the action of reading a journal.
When everything is correct, it includes the edge of the epitesis in the mesh, where the inner side of the sculpture corresponds to the cavity of the defect.
This type of prosthesis is the only one that allows retention zones cavitary.
Matrix supporters should have guidelines to ensure proper placement and, therefore, a retention in the eye is performed, which allows its location in the matrix.
It is very important that wax margins are on a polished plaster base to be well defined.
Silicone was the material of choice to make the experiesis.
It comes with a hardener or “crosslinker”, a catalyst and a skin coloring base in different shades, to facilitate mixing and to find the appropriate colors in each case.
In this study, a silicone coated with silicone (Epi) was used, manufactured by Dr. Catasyl, which is already pre-colored.
Some brandy silicones are clear from other commercial houses.
If one or other silicone is used, it is necessary to add pigments, which can be mineral or organic13.
Here organic pigments were used, which are already mixed with silicone oil.
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On the other hand, local fragmentation must be natural to avoid errors.
The patient should be present at the time of silicone characterization.
Pruritus determines the base color of the skin by mixing vulcanization silicones with pressure.
After pressing the patient's skin with his finger for a few seconds, it shows a color without blood flow.
This is when color should be compared.
Then try to get to the outside skin color.
The different colors are separated and pigments are mixed until the regions of the upper and lower eyelids and surrounding areas are imitated.
Different colors can be added with a pincel directly to the different areas of the mestizo.
Once the eye was placed on the silicone, it was loaded with a corresponding skin color base.
The mesh was fixed and pressed until metal edges contacted.
This done, it is placed in water and is boiled for 2 hours until the material polymerizes or the manufacturer's instructions are followed.
Once silicone vulcanization is verified, care is opened because silicone can tear at the edges and rush the work.
With the epithesis in hand, the margins were rectified.
Washing remains that may have been left.
The eye is also removed for a new polish and the hole made is filled to place the eye.
With a hypodermic needle, bend your eyebrows and eyelashes with hair.
The color should be as close as possible to the patient's hair, so it is ideal to use the patient's own hair3*.
The prosthesis is placed and margins are checked.
The use of glasses is recommended because it helps protect the natural eye and protect the prosthesis14.
It is essential to explain to each patient the proper handling of its oculo-palpebral epithesis, its placement, cleaning and medical adhesive more appropriate8*.
The adhesives used are based on medical silicone (external unleaded silicates).
Normally the time of effectiveness of cutaneous adhesives is 48 hours, but it depends on the weather.
After this time, the patient must remove the prosthesis, clean it correctly, also cleaning the area where it is located.
This almost daily task should be very careful because the thin edges of the prosthesis should not receive the adhesive, thus avoiding deterioration thereof3*.
Patients should also be advised to protect their prostheses from abrasive, solvent or volatile cleaners, perfumes, colonies and sprays.
Only warm water, mild soap, or detergent should be used to clean the prosthesis.
