The photo appears to show some missing enamel at the gumline as well as the gum tissue has what is called a clefting defect. This happens when the bite is too forceful in the wrong direction against the lower front teeth. Many docs will place a filling here but the real problem is the incorrect bite force on the teeth. Fillings in the area will address the color but you may consider invisalign if you are a candidate to correct the bad bite issues.
