Comparative histometric analysis of the effects of high-intensity focused ultrasound and radiofrequency on skin.
BACKGROUND
High-intensity focused ultrasound (HIFU) and radiofrequency (RF) are used for non-invasive skin tightening. Neocollagenesis and neoelastogenesis have been reported to have a mechanism of controlled thermal injury.


OBJECTIVE
To compare neocollagenesis and neoelastogenesis in each layer of the dermis after each session of HIFU and monopolar RF.


METHODS
We analyzed the area fraction of collagen and elastic fibers using the Masson's Trichrome and Victoria blue special stains, respectively, before and after 2 months of treatments. Histometric analyses were performed in each layer of the dermis, including the papillary dermis, and upper, mid, and deep reticular dermis.


RESULTS
Monopolar RF led to neocollagenesis in the papillary dermis, and upper, mid, and deep reticular dermis, and neoelastogenesis in the papillary dermis, and upper and mid reticular dermis. HIFU led to neocollagenesis in the mid and deep reticular dermis and neoelastogenesis in the deep reticular dermis. Among these treatment methods, HIFU showed the highest level of neocollagenesis and neoelastogenesis in the deep reticular dermis.


CONCLUSIONS
HIFU affects deep tissues and impacts focal regions. Monopolar RF also affects deep tissues, but impacts diffuse regions. We believe these data provide further insight into effective skin tightening.
a Department of Dermatology , Arumdaun Nara Dermatologic Clinic , Seoul , Korea.
Dong Hye
DH
Suh
Jeong Hwee
JH
Choi
Sang Jun
SJ
Lee
Ki-Heon
KH
Jeong
Kye Yong
KY
Song
Min Kyung
MK
Shin
D000328:Adult; D000368:Aged; D017115:Catheter Ablation / Q000379:methods*; D003094:Collagen / Q000378:metabolism*; D003357:Cosmetic Techniques / Q000295:instrumentation*; D020405:Dermis / Q000166:cytology* / Q000000981:diagnostic imaging / Q000528:radiation effects; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012060:Rejuvenation; D014464:Ultrasonic Therapy / Q000379:methods*; D014463:Ultrasonography
D003094:Collagen
high-intensity focused ultrasound; monopolar radiofrequency; neocollagenesis; neoelastogenesis