Silicone breast prostheses were created in 1963, inspired by the plastic bags used in blood transfusions that resemble a breast when carried. Silicone prostheses are materials filled with gel-like silicone, surrounded by a more solid silicone sheath, and can be produced in a round or oval shape. The consistency of the gel is very similar to that of an adult female breast and they are not noticeable on the body.
Silicon is one of the most common elements on earth. The combination of silicon with other elements creates a family of silicons with different structures. Depending on the properties of the joint, silicones can be found in solid, gel or liquid form (Figure 1). The most important difference between silicones used in industry and daily life and those used in breast prostheses is that medical silicones are pure and compatible with the body. Apart from breast prostheses, medical silicones are widely used in areas ranging from catheters to joint prostheses, heart valves and penile prostheses.
Figure 1. As the chains around the silicones lengthen and bond together, their consistency hardens
There are also silicone breast prostheses filled with water, not silicone gel. However, an implant filled with water is not preferred because it is harder in consistency. There is also the possibility of leakage and leakage in water-filled prostheses.
Types of Silicone Prostheses
Types of Implants by Shape:
Silicone prostheses are produced in drops and round forms. Drop prostheses are also called anatomical prostheses because their downward-expanding structure resembles the side view of the breast when viewed from the side (Figure 1).
Figure 1. Anatomical prostheses (top) and round prostheses (bottom)
Types of Implants According to the Consistency of the Gel It Contains:
Silicone prostheses are also divided into two according to the consistency of the gel they contain: soft gel and cohesive gel prostheses that keep their shape. Although soft gel implants are more suitable for the natural consistency of the breast, they are slightly displaced by gravity in their sheath. Cohesive gels, on the other hand, maintain their shape in any case and can not only enlarge the breast in volume, but also shape it into a certain shape. However, the breasts on which these prostheses are placed feel harder to the hand. In the last few years, slightly softer versions of Cohesive silicones have also been introduced as an option (Allergan® SoftTouch, etc.).
Most gel-containing dentures today use a form of gel that does not flow out when burst or cut (Fig. 2). This feature is a precaution to reduce the problems in leakages that may occur due to wear or accident.
Figure 2. An implant containing a cohesive gel does not flow out when burst or cut
If an implant containing a cohesive gel is used, the shape of the chosen silicone prosthesis will affect the shape of the enlarged breast. Which prosthesis to choose depends on what kind of breast shape you like. In general, women’s preferences about breasts can be divided into two (Figure 3):
● Rounded breasts that fill the décolleté and look like they’ve been pushed up with a bra
● Drop-shaped breasts that come with a flat slope down the décolleté and take a round form after the nipple
Figure 3. Which breast shape do you like more? It can be thought that those who prefer the two breast silhouettes on the left like drops, those who prefer the two silhouettes on the left like the round breast shape.
Although it is not a general rule, anatomical prostheses are preferred to achieve the drop shape, and round prostheses are preferred to achieve the round shape.
Other reasons for choosing anatomical prostheses are:
● In very thin patients with no breasts, a cohesive and rounded prosthesis can create a sudden and unnatural transition in the upper part. In such patients, using submuscular and anatomical prosthesis is a better option.
● In patients with slightly drooping nipples, the need for breast augmentation surgery can be reduced by using an anatomical prosthesis to raise the nipple.
The situations in which round prostheses are preferred are as follows:
● Patients who do intense sports such as tennis and swimming and who will be implanted under the muscle: If an anatomical prosthesis is used in these patients, the possibility of the prosthesis turning outward with muscle movements may create asymmetry. Even if round prostheses rotate, this may not produce a noticeable result.
● To fill the gap in the upper part of patients who will be augmented with breast augmentation.
The latest development in silicone technology is the implants containing gel in two different consistencies in the same sheath. Aiming for a more natural look, this technology is available in Polytech 4inTwo Series and Allergan’s 510 series. The part of the drop prosthesis that rests on the chest wall contains a softer silicone and the part under the nipple contains a harder silicone (Figure 4). Thus, the transition line created by the top part of the silicone, especially in the side profile, is eliminated and the projection of the nipple is increased.
Figure 4. Polytech® 4inTwo prostheses with two different densities of silicone
Implant Types According to Sheath Properties:
While the surface of the silicone sheath was flat and smooth in the first periods, textured forms were adopted later on (Figure 5). The sleeves of silicones are also technologically advanced and have become more sealed by adding several layers. The purpose of these changes is to reduce the event called capsular contracture. One of the rough forms is polyurethane coated prostheses. Once the silicone enters the body, this coating begins to melt and thus creates an intermediate zone that will reduce the formation of capsular contracture. It is especially preferred in patients who develop capsule contracture and whose prosthesis will be replaced.
Figure 5. Silicone prostheses with different sheath properties: Top left – formerly flat-surfaced transparent prostheses; Top right – polyurethane coated prosthesis; Bottom row – dentures with rough surface
Every woman’s breast is as unique as her fingerprint. The structure of the rib cage, its angle, the thickness and flexibility of the skin, the posture, the shape and width of the area where the mammary gland begins (footprint) are different in every woman and lead to the development of a personalized breast structure. The silicone prostheses produced, on the other hand, come in certain molds because they are fabricated. A manufacturer’s silicone variety is between 250-300. The most important step of breast augmentation surgery is to choose the most suitable prosthesis among them.
How to choose the most suitable prosthesis for you? In this regard, the first step is to decide what size you want. Psychological studies show that women do not dare to express the dimension they actually want. Another mistake made in this regard, especially in Turkish patients, is to confuse the size of the bra, such as 80-90, with breast size. The best expression of breast size is the “cup sizes” that go as A, B, C, D DD.
The next step is to choose the breast shape. You can do this by bringing photos of the breasts you like. At this stage, it becomes somewhat clear whether a round or drop-shaped prosthesis will be chosen.
Of course, you will also need to have a chest structure in which what you want can be applied. For this, your doctor takes detailed measurements of your breasts. These are listed as width, height, projection, amount of stretching, distance between neck and nipple, skin thickness, etc. The most critical of these measurements is the width of the breast. The limiting step in determining the size of the prosthesis is the width of the breast base. Because if you go sideways, more armpits will be entered, so it cannot be exceeded.
Then, your doctor chooses a few prostheses that are most suitable for you from the catalogs of companies that produce various silicone prostheses according to the measurements they take. There are two methods to pre-determine which of these will yield results: Your pre-operative photographs can be uploaded to the simulation system, and how the results will be obtained with the selected prostheses can be simulated. Crisalix® is one of these systems. By looking at this simulation, a sketch is formed that you can discuss with your doctor about what size or shape you want in general, although it is not exactly one-to-one. But the real live trial is done by placing the prostheses selected during the surgery on your chest and watching how you sit at the table while you sleep. Usually, several types of prostheses and trial pairs are brought in sizes close to the measurements made for the surgery.