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Chow, et al.
scar control for optimum treatment efficacy. Apart typically used to treat burn victims by providing a
from that, Unkovskiy et al. also developed a continuous pressure of about 25 mmHg to inhibit
[3]
silicone facial prosthesis for rehabilitation treatment the growth of HS and encourage its maturation
based on the direct digital manufacturing (DDM) through pressure garments, face masks, casts,
technique which uses additive manufacturing splints, or conformers [22-26] . However, the human
technologies. DDM is characterized by flexible body has a complex geometry, which means that
and lean production process which do not require the pressure exerted onto certain anatomical parts
injection and mold making process [4,5] . It is evident with a concave surface cannot properly inhibits the
that personalized products can be more readily growth of HS . Therefore, a variety of different
[27]
produced with the use of additive manufacturing materials such as thermal plastic, silicone sheets,
to cater to each individual patient based on his/her or hydrogels are inserted between the skin and
conditions and needs. the pressure garment to exert adequate pressure
HS is considered to be the greatest unmet onto different body parts and in the case of HS,
challenge in wound and burn rehabilitation. HS is induce extra pressure onto the scar for effective
an abnormality in which the epidermis is greatly treatment [17,28] . However, these additional inserted
thickened and collagen is irregularly deposited . materials like silicone sheets are usually larger in
[6]
As a result, the injured area is thickened, size than the HS . The unnecessary pressure and
[17]
raised, and erythematous in appearance which coverage will cause excessive sweating, pruritus
tremendously affect the quality of life . Apart or even contact dermatitis of the healthy skin
[7]
from cosmetic impairment, functional sequelae next to the HS [17,29] . Another limitation of pressure
can also occur . HS tissue has less elasticity than therapy is material deterioration with gradual loss
[8]
normal skin tissue, and subsequently, the range of pressure with use. During the application of
of motion of the joints can be limited . The skin pressure therapy, repeated joint movements stretch
[9]
is the primary interface between humans and the pressure therapy garment which reduces the
the environment, and therefore is more prone to elasticity of the fabric . As a result, the pressure
[30]
injury. The most frequent sites for burns in human therapy garment has to be replaced or adjusted
body part are hand, and when the skin of the after a period of time to ensure adequate pressure
hand receives a burn injury and an HS is formed, performance and effectively treat HS to facilitate
the range of motion of the fingers decreases . recovery. To improve the treatment process,
[10]
Although the mechanism of treatment process different types of therapies can be collectively
for scars is not well understood, some of the most applied at the same time . Li-Tsang et al.
[31]
[32]
common rehabilitation treatments for HS in the concluded that the integration of pressure and
past decade are the use of pressure therapy and silicone gel sheeting therapy has a positive and
silicone gel sheets [11,12] . Silicone (polysiloxane) is better effect in reducing scar thickness than the
the representative material used for treating HS conventional use of pressure garments.
and has a flexible structure of a backbone chain In this study, we propose an innovative and
with alternating oxygen and silicon atoms . customized fabrication approach with the use of 3D
[13]
Back in early 1980s, Perkins and Davey first scanning and DDM of silicone technology. Medical-
[14]
suggested the potential of using silicone sheets for grade silicone is extruded through a nozzle directly
treating burn scars. A few years later, silicone in onto the fabric based on 3D scanned data to provide
scar treatment was adopted and tested by different an accurately sized insertion material which would
researchers [15,16] . The mechanisms of silicone optimize the pressure delivery. Hence, adequate
therapy in scars treatment have been suggested by pressure is induced onto the HS by the printed
different researchers and the possible suggested silicone gel with the benefit of silicone treatment
effects of silicone include increased skin while the individual variations of the anatomical
temperature, hydration of scars, and polarization features are also taken into consideration. This
of scar tissue [17-21] . In practice, pressure therapy is combined therapy which integrates pressure and

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