The sight of a baby sucking their thumb or contentedly holding a pacifier in their mouth is incredibly common. These are natural reflexes that bring comfort to a child. However, many parents wonder: are these habits safe for bite and speech development? Which one is potentially more harmful? And when should you intervene? Dr. Izabela Cwalina-Sidor, an orthodontic specialist with a Master of Science in Orthodontics, who works with patients both young and old in offices in Łomża and Białystok, answered these questions.

Why Do Children Suck Their Thumbs? Understanding the Need for Soothing

Before assessing the potential consequences, it's important to understand why children reach for their thumbs, pacifiers, or other objects. As Dr. Izabela Cwalina-Sidor explains, sucking is a natural, instinctive way for infants and young children toemotional self-regulation and calming down.

"Children most often start sucking their thumbs for emotional reasons," says the expert. When faced with stress, fatigue, or an overload of stimuli, a toddler seeks solace in a familiar reflex. This might be sucking on their mother's breast, a pacifier, their own thumb, or sometimes even a piece of a diaper or a toy. It's their way of coping with difficult feelings.

Thumb vs. Pacifier: The Expert's Verdict

While both habits can affect oral development, the expert clearly indicates which one is more risky: thumb sucking.

"If we focus and narrow it down to these two things, then a pacifier is better," says the orthodontist. "Because a thumb can really wreak havoc on a child's facial development."

Why is the thumb more dangerous?

1. Size and hardness: The thumb is large and relatively hard compared to the soft nipple of the pacifier. It exerts greater pressure on the structures of the oral cavity.
2. Fatal effect on tongue position: This is the most important argument. The thumb in the mouth pushes the tongue to the floor of the mouth. Normally, the tongue should rest against the roof of the mouth. "The worst part is that the child's mouth is actually half-open (...) and the tongue is pushed very firmly to the floor of the mouth," explains Dr. Izabela Cwalina-Sidor, MD.
3. Risk of malocclusion: A persistent, low tongue position is a major cause of malocclusion, including the difficult-to-treat open bite (lack of contact between the front teeth). Pressing the tongue against the teeth during swallowing can also lead to protrusion. Thumb sucking can also disrupt the proper development of the maxilla and mandible.

How does thumb sucking affect oral development?

Whether it's a thumb or a poorly fitted pacifier, prolonged sucking (especially after infancy) can lead to:

• Incorrect resting position of the tongue: Instead of resting on the palate, it lies flat on the floor of the mouth.
• Immature swallowing type: The tongue pushes between the teeth instead of pushing the food back.
• Malocclusion: Most often an open bite, but also a crossbite or underbite.
• Jaw constrictions: The upper dental arch becomes too narrow.
• Pronunciation problems: Improper tongue function makes it difficult to articulate some sounds.
• Mouth breathing: Perpetuation of the abnormal respiratory pattern.

Choosing a pacifier matters: what to pay attention to?

If a pacifier is the lesser of two evils, which one should you choose? The design of a pacifier has a significant impact on its impact on the oral cavity:

• Teat shape: Avoid round ("ball") or symmetrical, biconvex teats. Despite marketing claims, they don't mimic the action of the breast. Worse still, "the tongue takes up a lot of space in the mouth," which contributes to its low position. Anatomical (orthodontic) teats are better, flattened on the tongue side, giving the tongue more room to position itself correctly.
• The "neck" of the pacifier: Although a very thin neck is often touted as a way to avoid an open bite, Dr. Izabela Cwalina-Sidor emphasizes that the main cause of this defect is poor tongue position, not the thickness of the space between the teeth. However, a neck that is too thick can further complicate proper lip closure.
• Pacifier Shield: It must be lightweight so as not to strain the muscles, have ventilation holes that allow the skin to breathe, and an appropriate cutout for the nose.
• Material: Medical-grade silicone is preferred – it's durable, tasteless, and odorless, and easier to sterilize. Rubber (latex) wears out more quickly, can swell, and absorb odors.

Hygiene and pacifier replacement

Remember that a pacifier is an object that comes into constant contact with a baby's mouth. It should be washed and sterilized regularly. For hygiene reasons and to prevent wear and tear (risk of chewing by emerging teeth), pacifiers should be replaced approximately every 1.5 months, or even sooner if any damage is noticed.

When to Say Goodbye to the Pacifier? A Key Developmental Moment

Saying goodbye to a pacifier is often a challenge for the entire family. When is the best time?

"According to the textbook, the pacifier should be weaned when a child is transitioning from infant to adult swallowing," advises Dr. Izabela Cwalina-Sidor. This usually happens between 14 and 18 months of age. By this time, the tongue should naturally rest on the palate during swallowing, and a pacifier can hinder this process.
Remember, however, that every child is different. It's important to wean gradually and calmly, without pressure or embarrassment. Reduce pacifier use to only necessary situations (sleep, high stress), until it's finally eliminated completely.

An appeal to parents: knowledge and prudence instead of stress

Dear parents, remember that sucking is a child's natural way of coping with emotions. Although a pacifier is considered less harmful than a thumb, choosing the right pacifier (shaped like a rubber band, a lightweight shield with ventilation) and using it consciously are crucial. Striving for a correct resting position of the tongue (on the palate) is paramount. It's worth trying to wean the pacifier at the appropriate developmental stage (around 14-18 months of age), approaching this process calmly and with understanding of the child's needs. If you have any doubts or problems, it's always worth consulting a speech therapist/neurologist or orthodontist. A conscious approach, based on knowledge and understanding of their needs, will allow you to support your child's proper development without unnecessary stress.

The article is based on an interview with Dr. Izabela Cwalina-Sidor, a specialist in orthodontics, conducted as part of the Healthy Kids CLUUb.