Nasolabial folds are creases in the skin that mark the edge of the upper lip, starting from the nose. They can be more or less pronounced, and this is an inherited facial feature. The position of the teeth affects how far forward the upper and lower lips sit. If the teeth sit further forward, the lips are pushed forward too and the nasolabial folds are smoothed out. If the orthodontic treatment plan involves moving the patient's teeth backwards, the nasolabial folds can be expected to deepen and become more noticeable.
This answer is for general information. Your own case needs an examination by an orthodontist.