Expert Q&A with Dr. Cate Quas

My son is six years old and still sucks his thumb. We are working on helping him lose the habit, but it hasn’t been easy.

Q: Will my son’s thumb sucking hurt his teeth long term?

A: The short answer is: it depends on how long and with what intensity the habit has persisted and continues.
Thumb sucking is one of the most natural self-soothing behaviors a child can develop. It often begins in the womb and, for many children, serves a genuine neurological purpose. Research suggests that the rhythmic sucking motion stimulates the release of dopamine and serotonin, producing a calming effect on the nervous system. There is also the effect of cranial pumping on the system—the idea that the subtle pressure and rhythm of sucking may stimulate cerebrospinal fluid movement, contributing to that sense of calm and balance. In other words, your son isn’t just being stubborn. His brain is getting something meaningful from this habit.

Q: What happens to the bite- specifically the jaws and teeth?

A: The mouth is a system of balanced forces. When a thumb occupies that space regularly, it disrupts the balance. The continuous sideways pressure against the inside of the upper jaw causes it to narrow over time, creating a shape that is more V-like than the rounded U it should be. This narrowing also raises the palate—the roof of the mouth—higher than normal.

The thumb itself typically rests behind the upper front teeth, pushing them forward and outward (what parents often describe as “buck teeth”). Meanwhile, the lower front teeth respond to the thumb’s position and the altered mechanics of the bite, often tipping inward toward the mouth. The result is an open bite—where the upper and lower front teeth don’t meet even when the back teeth are closed together—combined with a narrowed upper arch.

These changes compound any orthodontic tendency your child may already have. Genetics load the gun; habits like thumb sucking can pull the trigger.

The good news about timing:

Before the permanent teeth come in—generally between ages six and twelve—the bones of the face and jaw are remarkably adaptable. Some changes caused by thumb sucking in a child who quits before the permanent teeth erupt will self-correct, particularly mild open bites. The longer and or stronger the habit persists into the permanent dentition, the more intervention may eventually be needed.

At six years old, your son is right at the threshold. This is genuinely a good time to resolve it.

Quitting the habit:

One of the most important reframes I offer parents is this: focus on replacing the habit rather than simply stopping it. Abrupt cessation, especially with shame or punishment, rarely works because it removes the coping mechanism without offering anything in its place. Think about what triggers the thumb sucking—fatigue, transitions, screen time, stress? Identifying the trigger lets you introduce a substitute: a fidget tool, a soft toy, a consistent breathing routine or even just a conversation about what’s bothering him.

Physical reminders—a bandage on the thumb, a sock at night—can help break the automatic nature of the behavior, especially during sleep, but these work best alongside positive reinforcement, not as a replacement for it.

Another tool worth exploring is body work such as craniosacral therapy. This gentle form of bodywork addresses subtle restrictions in fluid flow and muscle coordination that may be working against your child’s ability to release the habit—often without either of you knowing those restrictions exist.

If the habit is proving particularly resistant, ask your dentist about a palatal appliance designed specifically for this purpose. It doesn’t hurt and removes the physical reward of the behavior—which is often enough to resolve it within a few weeks.

The bottom line:

Your son’s teeth are telling a story right now, but that story isn’t finished. Catching this at six, working on habit replacement rather than just cessation, and staying in close contact with your pediatric dentist gives you every reason to be optimistic about what his smile looks like at sixteen.

There is so much information online about preventing cavities naturally. I feel like I need an expert opinion.

Q: What is the recommended protocol for giving kids their best shot at healthy teeth?

A: Two lines of defense:

Cavities form through a two-part process: harmful bacteria in the mouth produce acid, and when those bacteria are allowed to linger on teeth, that acid slowly erodes the enamel. Preventing cavities, then, comes down to two lines of defense—starving the bacteria so they can’t produce much acid, and physically disrupting them so they can’t settle in one place.

Line 1: Feed your child, not the bacteria

The bacteria responsible for cavities thrive on sugar and highly processed carbohydrates. Foods like sugary drinks, fruit snacks, and even seemingly innocent snacks like goldfish crackers give these bacteria exactly what they need to ramp up acid production.

On the other hand, diets rich in protein and healthy fats do double duty. Bacteria can’t break down protein to produce acid—and protein also helps raise the pH of saliva, which naturally buffers and neutralizes any acid that is produced. Foods like cheese, meat, eggs, vegetables and fruit are genuinely protective for teeth.

One natural tool worth knowing about is xylitol, a sugar substitute derived from plants. Unlike regular sugar, xylitol cannot be fermented by cavity-causing bacteria, so it doesn’t fuel acid production. Studies have shown that using xylitol mints or gum after meals or snacks can meaningfully reduce the normal acid spike that follows eating. Xylitol gum or mints are widely available and a great option for children and adults. Xylitol drops and sprays are also available for toddlers.

Diet at a Glance:

Better choices

Cheese
Meat, eggs, legumes
Vegetables
Whole fruit
Water
Xylitol gum or mints

Limit when possible

Sugary drinks & juice
Fruit snacks & gummies
Crackers & puffed snacks
Sticky or chewy candy
Soda and sports drinks

Line 2: Keep bacteria on the move

Even a great diet isn’t enough on its own—bacteria need to be physically removed from tooth surfaces before they can cause damage. Brushing and flossing remain the gold standard here, because they mechanically dislodge bacterial colonies before they can settle and produce sustained acid.

Beyond brushing and flossing, some additional tools worth knowing about are oral antiseptics which have been shown to reduce the population of cavity causing bacteria in the mouth. Examples include povidone iodine and essential oils (e.g.: menthol and eugenol). Oral antiseptics are used topically as a rinse and are not to be ingested. It is important to consult your dentist on application recommendations

When it comes to toothpaste, two ingredients—fluoride and hydroxyapatite—come up often. Fluoride works by strengthening and hardening enamel, making the tooth surface more resistant to acid attack in the first place. Nano-hydroxyapatite, a naturally occurring mineral, works differently—it helps to remineralize and repair enamel that has already been lightly damaged by acid, essentially patching the tooth’s surface.

Hygiene toolkit

Brushing & flossing: The foundation—twice daily brushing, once daily flossing
Antiseptic rinses: Reduces bacterial load; ask your dentist if appropriate
Fluoride toothpaste: Hardens enamel to resist acid erosion
Nano-hydroxyapatite toothpaste: Remineralize and repair early acid damage to enamel

The bottom line

Protecting your child’s teeth doesn’t require perfection—it requires consistency. A diet that limits the bacteria’s fuel source, paired with regular brushing and flossing, will take you a very long way. Add in a few of the extra tools described here as it makes sense for your family, and you’re building a strong foundation for lifelong dental health.

When in doubt, your child’s dentist is always your best resource for personalized guidance—because every mouth is a little different.

This article appears in Bend Nest Summer 2026.