Could this white line on my chin be caused by filler? (Photo)

Given the history, which includes what was injected, the initial bruising, the hardness, etc. it would be reasonable to consider fibrosis (I.e. scar tissue) as a very likely explanation. If this is indeed so, then the matter becomes one of how much this bothers you, since it is largely under your chin. If it disturbs you enough, then you might consider consultation with an experienced, board certified cosmetic dermatologist scar treatment expert to discuss the use of manual, mechanical microneedling (no need for the added expense and risks of RF Microneedling) accompanied by the application of Rx pigment topicals, such as topical tyrosine, to better blend the scar with the surrounding normal skin. Hope this helps and best of luck.

Based on your description, it sounds as though this white line comes and goes after you had a bruise in the area. If that is the case, I am completely uncertain as to what is causing this. If it is in the identical area of the bruise, they are likely related, however, I'm not sure the mechanism of cause and effect in this particular situation. Please consider Consulting with your physician on this. Thank you. Sincerely, Dr Joseph

A white line on the chin appearing intermittently long after filler placement is unlikely to be active filler-related vascular compromise, especially at 20 months post-injection, as most hyaluronic acid fillers like Restylane are metabolized within 6–18 months. However, residual filler, scar tissue, or subtle fibrosis from the initial injection and bruising could cause localized changes in skin texture or color that appear more noticeable under certain conditions (such as skin stretching or temporary changes in blood flow).

Things to Consider:

Scar Tissue/Fibrosis: The hard line you initially noticed may have been due to localized swelling or fibrotic tissue, which can persist even after the filler is gone.

Skin Color Changes: A transient white line can result from blanching (temporary reduced blood flow) if the skin is compressed during sleep.

Filler Longevity: In rare cases, small amounts of filler can persist beyond the typical breakdown time, particularly in areas with less movement, and could slightly alter skin contour.

Summary:
This intermittent white line is more likely due to residual scar tissue or localized changes from your previous treatment rather than an active complication. It is not typically a cause for concern unless it becomes persistent, painful, or changes in appearance.