INTRODUCTION
Age-dependent modification is at the forefront of dermatological
research and cosmetic science.1,2 Besides
topical active ingredients and minimally invasive treatments,
eg, botulinum toxin or hyaluronic acid, laser devices
have expanded into numerous applications to treat a wide array
of skin conditions.2-4 Lasers direct a high-energy beam of a
single wavelength of coherent light into specific tissues, varying
in strength and the type of tissue they target.5,6 Corresponding
to its chronological development, two main laser classifications
have been established in the past regarding the degree
of ablation and recovery.7 Ablative laser systems, eg, CO2 and
erbium-doped yttrium aluminium garnet (Er:YAG) lasers, were
among the first resurfacing devices that were proven successful.
5,6 Although highly effective for rejuvenating photoaged
skin, the demand for less ablative treatments became evident
because of the high risk of unwanted side effects, eg, scarring,
infections, edema, or prolonged erythema, combined with a
long recovery period and painful treatment sessions.4 Based on
the concept of selective photothermolysis, presented by Anderson
and Parrish in the early 1980s, a second, less invasive treatment
modality was developed, promising good results while
preserving the epidermis.6,8 This nonablative technique was based on the principle of absorption of light and the different
chromophores in the skin, such as water, melanin, or hemoglobin,
resulting in selected damage limited to the target.4,6,8
In 2004, fractional photothermolysis was introduced which
treats only a fraction of the skin, unlike conventional ablative
and nonablative lasers.9 The prototype fractional, nonablative
device, a fractional 1,550-nm Er:YAG laser resulted in a combination
of epidermal coagulation for a resurfacing effect and
dermal denaturation for deeper remodeling repopulated by
fibroblast activity of neocollagenesis.4,5 A new generation of
fractional lasers followed, featuring high-power and fractionated
beams for nonablative skin remodeling and rejuvenation.10
Since microscopic columns of thermally denatured epidermis
and dermis are created and intervening zones of normal skin facilitate
wound rapid healing, fractional, nonablative treatments
have been associated with some perioperative discomfort and
a 2- to 3-day recovery period with erythema and mild edema.
A novel fractional, nonablative Q-switched neodymium-doped
YAG (Nd:YAG) 1,064-nm laser technology is presented here, which
combines the benefit of a nonablative and a fractional laser de-
