The increase in acquired facial defects resulting from cancer surgeries, automobile accidents leading to facial trauma and congenital facial defects, has led to an increased demand for maxillofacial prostheses. The materials used in the fabrication of these prostheses can be silicones that are tinted externally and internally to match the color of the surrounding structures. The value and success of well-fitting and anatomically correct prostheses are compromised if the color does not match the adjoining tissue. Hence, a prosthesis that is given a solid flat color is unrealistic and will appear artificial.
The major source of color in human skin are specialized melanin-bearing organelles, the melanosomes present within the epidermis. Gross human skin color derives from the visual impact of the the sum of the melanin pigmentation of the numerous epidermal melanin units. Melanin occurs in two types: 1) black to brown eumelanin and 2) yellow to reddish pheolmelanin. Melanosomes in keratinocytes of light skin are membrane-bound clusters, whereas melanosomes in keratinocytes of dark skin tend to be larger and distributed individually. It has been shown that melanosomes within keratinocytes of Asian skin are distributed as a combination of individual (62.6%) and clustered (37.4%) melanosomes. It has been concluded that the melanosome distribution in keratinocytes of Asian skin is intermediate between light Caucasian and dark African. Hence, yellowish brown is the predominant color for Indian skin.
Color matching of facial prostheses to human skin has long been a challenge to the clinician. Many different materials and methods have been documented. Earlier extrinsic coloring was done to achieve a desired skin tone.Barnhart achieved a more natural, deeper, and long-lasting skin tone by intrinsically coloring silicone rubber with commercially available, colored methymethacrylate powders. The technique involved an easily reproducible specific color whenever required.
Color reproduction in facial prostheses was tried by adding inorganic pigment powders to clear methylmethacrylate powder and then applying these intrinsically to a medical-grade silicone rubber. Inorganic pigments were directly added to silicone rubber. A tattooing machine and an artist’s spray gun were used to apply pigments. Godoy et al, developed an acrylic resin shade guide by mixing different dry earth pigmens with a roch wax carver and a Hue-Friedy cleoid discoid carver, which carried loads of up to an average of 0.0158 g and 0.0024 g, respectively. There are many studies explaining the different techniques of color reproduction but the literature is scanty with respect to the studies concerning silicone color matching that of Indian skin. Hence, the purpose of this study was to develop a simplified silicone shade guide which matches the Indian skin color.
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