Any Ways to Correct "Dented" Lip Scar? (photo)

This indented scar is likely due to scar retraction and can be corrected with a lip scar reduction procedure and layered closure.

I would not use a filler. Though the picture is not great , this appears to be an indentation that is easily corrected by minor surgery.  A Plastic Surgeon should be able to correct this by local tissue rearrangement  and the correction is permanent the scar is barely visible.

In our practice we do a lot of scar/defect corrections and we use liquid injectable silicone. It is an excellent filler for correcting dents such as yours as it is precise and permanent.  We have corrected many similar scars ("dents") on the lip with silicone and they have all done very well.  I recommend you consult with a board-certified dermatologist or facial plastic surgeon experienced in correcting scars with minimally invasive techniques.  Click on the link below for a few before and after photos of indentations/scars corrected with liquid injectable silicone. 

Thanks for the excellent photos. I would try a filler injected into the "dent" first to see if any improvement ca be attained

Of course an exam would be essential. You did not say if you split the lip and it is difficult to see. if the lip was split, it may be a separation of the  muscle.  If there is no cut, you may use a filler to achieve your goals to fill it out.