Gum recession happens when the gum tissue that hugs your teeth gradually pulls back or wears away, exposing more of the tooth or even the root beneath it. The causes range from brushing too hard to bacterial infection to genetics you can’t control. Nearly half of U.S. adults over 30 have some form of gum disease, and that number climbs past 70% for adults over 65, making recession one of the most common dental problems people face as they age.
Understanding what’s actually driving your gums to recede is the first step toward slowing or stopping the process. Most people have more than one factor at work.
Gum Disease Is the Leading Cause
The most common reason gums recede is periodontal disease, a bacterial infection that quietly destroys the tissue and bone supporting your teeth. It starts with plaque, the sticky film of bacteria that builds up along the gumline. When plaque isn’t removed, certain bacteria trigger your immune system to mount an inflammatory response. That inflammation is supposed to be protective, but when it becomes chronic, it turns destructive.
The bacteria involved in advanced gum disease produce proteins that ramp up your body’s production of enzymes designed to break down connective tissue. These enzymes chew through the collagen fibers that anchor your gums to your teeth and the underlying bone. Over time, the gum attachment loosens, pockets form between the tooth and gum, and the gum margin creeps downward. The tricky part is that this process is often painless for years. Many people don’t realize anything is wrong until they notice a tooth looks longer than it used to or feels sensitive near the gumline.
Brushing Too Hard Wears Gums Away
Aggressive brushing is one of the most preventable causes of recession, and it’s surprisingly common. Studies measuring brushing force found that the average person brushes at about 2.3 newtons of force. That’s within a safe range for most people, but forces above 3 newtons are where damage starts. People who brush at around 3.8 newtons of force show severe recession, while those brushing at 2.1 newtons or below tend to have none.
The type of brush matters just as much as how hard you press. Hard-bristled toothbrushes (bristle diameter of 0.20 to 0.30 mm) produce significantly more tissue and tooth surface loss than soft bristles at the same force level. Systematic reviews have concluded that soft and extra-soft bristles are safe, while medium-hard bristles can create small tears in the gum tissue. Soft bristles are also more flexible, which means they actually reach more tooth surface and maintain better contact with toothpaste than stiff bristles do.
Brushing technique plays a role too. The horizontal scrub method, where you move the brush back and forth across the teeth, is the most commonly used technique and the one most associated with gum wear. The repetitive side-to-side motion drags bristles across the gum margin over and over, gradually pushing it down.
Your Gum Thickness Is Genetic
Not everyone’s gums are built the same. Gum biotype, the natural thickness of your gum tissue and the bone underneath, is a genetically determined trait. People fall broadly into two categories: thick biotype and thin biotype.
Thick gums are dense, resilient, and better at withstanding both physical trauma and inflammatory damage. Thin gums are delicate, sometimes nearly translucent, with a narrow band of firm attached tissue and minimal underlying bone. They’re significantly more prone to recession from any cause. One study of sites with recession found that nearly 74% had a thin biotype. If you’ve noticed recession even though you brush gently and don’t have obvious gum disease, your tissue thickness may be the main factor.
Teeth Grinding and Clenching
Chronic teeth grinding (bruxism) and clenching place enormous lateral forces on teeth. Over time, these forces cause the tooth to flex slightly at the point where it meets the gumline. That repeated micro-flexing can create wedge-shaped notches in the tooth surface called abfractions, and the gums in those areas tend to recede along with the structural damage. As gums pull back, root surfaces become exposed, often causing sharp sensitivity to cold or pressure.
Bite misalignment creates a similar problem. When teeth don’t come together evenly, certain teeth absorb more force than they’re designed to handle, concentrating stress at the gumline.
Orthodontic Treatment
Braces and aligners move teeth by remodeling the bone around them, and if a tooth is pushed outside the boundaries of its bone housing, the gum tissue on that side can follow and recede. The risk depends on the direction the tooth is being moved and how much tissue surrounds it. Patients with a thin gum biotype are more likely to see gum margin changes during orthodontic treatment regardless of what type of movement is involved.
Other localized factors that increase recession risk during orthodontics include a narrow band of attached gum tissue, high frenal attachments (where the small fold of tissue connecting the lip to the gum sits too close to the tooth), and poor oral hygiene during treatment.
Smoking and Nicotine Products
Smoking accelerates gum recession through a mechanism that also makes it harder to detect. Nicotine triggers the release of adrenaline and noradrenaline, which cause the smooth muscle around blood vessels to contract. This narrows the blood vessels in the gums, reducing blood flow to the surrounding tissue. With less blood supply, the gums receive fewer nutrients and fewer immune cells, weakening their ability to fight infection and repair damage.
The reduced blood flow also creates a masking effect. The classic warning signs of gum disease, such as redness, swelling, and bleeding, are all driven by increased blood flow during inflammation. When blood vessels are chronically constricted, those signs get suppressed. Smokers often have gum disease that’s more advanced than it appears because the tissue looks deceptively pale and firm even as the underlying support structures are deteriorating.
Hormonal Changes Across a Lifetime
Shifts in estrogen and progesterone levels make gum tissue more reactive to the bacteria already present in your mouth. Higher hormone levels increase blood flow to the gums, making them more sensitive and more likely to overreact to even small amounts of plaque. This means the same level of oral hygiene that keeps gums healthy at one point in life may not be enough during hormonal shifts.
During puberty, surging hormones can cause gums to become red, swollen, and prone to bleeding. Pregnancy brings a similar effect, sometimes called pregnancy gingivitis, where gums become tender and sore even with good brushing habits. Menopause works differently. The drop in estrogen that accompanies menopause increases the risk of bone density loss throughout the body, including in the jaw. When jawbone density decreases, gums often recede as the structural support beneath them shrinks. Receding gums during or after menopause can expose more of the tooth surface, increasing the risk of root decay and sensitivity.
How Recession Is Classified
Dentists and periodontists grade recession using a system that helps predict how treatable it is. The key factor is how much tissue and bone remain between the teeth.
- Class I: The gum has pulled back, but not past the boundary where firm attached gum transitions to looser tissue. No bone or tissue loss exists between the teeth. Full coverage of the exposed root is expected with treatment.
- Class II: The recession extends further, past that firm-tissue boundary, but the bone and tissue between the teeth are still intact. Full root coverage is still achievable.
- Class III: Bone or tissue between the teeth has been lost, or the tooth is significantly out of position. Only partial root coverage is possible.
- Class IV: Severe bone and tissue loss between the teeth. Root coverage through grafting is not expected to succeed.
The practical takeaway: earlier-stage recession (Class I and II) responds well to treatment because the supporting structures between teeth are still intact. Once that bone is lost, the options narrow considerably.
What Treatment Looks Like
For mild recession, the first step is usually addressing whatever caused it. Switching to a soft-bristled brush, correcting brushing technique, treating gum disease, or managing grinding with a nightguard can stop the progression without surgery.
When recession is more advanced and root surfaces are exposed, a gum graft is the standard treatment. A periodontist takes a small piece of tissue, often from the roof of your mouth, and attaches it over the exposed area. The goal is to rebuild the band of firm, attached tissue that protects the tooth. Healthy gums can generally function with as little as 1 to 2 mm of attached tissue, but if restorative dental work is planned, about 5 mm of firm tissue is considered ideal to maintain long-term stability.
Recovery from grafting typically involves a week or two of soreness and dietary restrictions while the tissue heals and integrates. The success rate for Class I and II recession is high, with complete root coverage expected in most cases. For Class III recession, partial coverage is realistic, meaning the gum will be higher than before surgery but may not fully return to its original position.