Alar retraction can be congenital, traumatic, or iatrogenic, with the latter of these being the most common. Overresection or malpositioning of the LLCs can cause the alar rim to retract, increasing columellar show. A hanging columella may also increase columellar show, so it is important to assess whether this is also a contributing factor. Filler can be placed along the alar rim, achieving some of the same effects as a rim graft.
The filler is introduced laterally with a 29-gauge needle, slowly and with frequent aspiration. Particular care should be taken in patients who have undergone prior rhinoplasty, because the normal marginal arterial flow may already be compromised. When in the proper plane, the needle moves forward relatively effortlessly. Overall, this is a somewhat risky area of placement, so it should only be performed by experienced injectors with proper precautions.