What filler(s) would help this boxcar scar?

At-home microneedling (see link) can be used to jumpstart the skin's natural healing process. The tiny needles puncture the skin to create micro-wounds. Professional-grade serums can be used in combination for maximum results. I suggest you seek out a board-certified dermatologist to discuss your best treatment options. Best, Dr. Emer

Subcision, a quick, inexpensive technique for elevating and smoothing boxcar scars (and most kinds of indented scars) that has a nearly three decade track record of safety and efficacy, would be my first choice. Bellafill is a permanent filler, and while the sound of permanent is enticing, permanent fillers are well known for their potential for the development of adverse reactions, such as lumps, bumps, nodules and granulomas, that can occur not only shortly after treatment, but even five, ten or twenty or more years later (especially after manipulation of the area, such as following dental work in the region). And these complications can be extremely difficult to sometimes impossible to treat without leaving disfigurement. Subcision, on the other hand, which depends upon the person making his/her own new collagen and elastic fibers in response to the treatment, accordingly gives rise to long-lasting to permanent results without the concern for the aformentioned complications. Make sure that you consult with an experienced, board certified cosmetic dermatologist with scar treatment experience. Best of luck.

a filler should improve the appearance of this scar.. I like bellafill but would probably use a hyaluronic acid filler first.