While poor oral hygiene contributes to gum recession, it can also happen in people with good oral hygiene due to a number of factors:
Age — Around 88 percent of people 65 years and older have a receding gum in at least one tooth.
Periodontal Diseases — The main cause of gum recession is gum disease. Bacterial gum infections destroy gum tissue and supporting bone that hold your teeth in place.
Aggressive Tooth Brushing — Brushing your teeth too vigorously or with a brush that has hard bristles is a common cause of receding gums. Even when dental hygiene might otherwise be good, over-brushing can cause receding gums.
Genetics — Almost one-third of the population may be predisposed to gum disease due to the position of their teeth and gum thickness.
Smoking — People who use tobacco products face an increased risk of receding gums as a sticky plaque on their teeth is difficult to remove and can cause gum recession.