Can filler be injected in bunny lines?

Thank you for your questions. Yes, in our practice we use fillers to successfully treat bunny lines. We prefer to use a combination of Botox and fillers. 
Bunny lines are caused by the contraction of the alaeque nasi muscle. Botox safely relaxes this muscle and smooths out the wrinkles. Dermal fillers can restore volume to superficial lines that can still be seen even when the face is relaxed. 

Bunny lines are the result of multiple muscles surrounding the nose, but most importantly, the Nasalis muscle.  Treatment of these lines are best treated with Botox, as this will flatten and smooth the area, and with time and repeat administration of Botox, atrophy of the muscle will continue to improve the area.  Fillers are best used for deep folds that are present even when your not animating your face/nose.  Hope this helps!

Bunny lines are formed when there is ongoing use of the frown/nose muscles near the bridge of the nose which causes eventually some loss of volume in that area as one ages.  Typically, Botox or Dysport is used to slow down the muscles.  There are some patients who may need an additional amount of filler to help with the volume loss.  I would recommend that you go to an experienced cosmetic surgeon to see what is best for you.  Good luck!