Craig-Hallum analyst Alexander Nowak says Sientra has gained 6% after the company gained FDA approval for four new styles of round breast implants, adding that he has not seen the product codes before, but they could be for Sientra's new line of extra-large, ultra-high profile breast implants. Nowak says FDA approval for these new implants -- two types of smooth implants and two types of textured implants -- could be viewed as more of a positive than normally, as there has been discussion if textured implants would be removed from the market and says the market may read into this that FDA is comfortable with Sientra's safety data. He maintains a Buy rating and $23 price target.