The persistent habit of licking the gums or lips can be directly related to the development of dental alignment issues, known as malocclusion. While a single instance is harmless, the sustained, repetitive action applies a subtle but powerful force against the teeth and surrounding structures. This abnormal pressure affects the development and position of the teeth, particularly the front teeth. The habit is frequently linked to tongue thrusting, where the tongue pushes forward during swallowing or while at rest.
Understanding How Oral Habits Impact Alignment
The position of teeth is maintained by a delicate balance of forces from the lips, cheeks, and tongue. When this balance is disrupted by a persistent oral habit, the teeth can begin to shift over time. This misalignment, or malocclusion, is the improper meeting of the upper and lower teeth when the mouth is closed. Malocclusion affects appearance, chewing, speech, and overall oral health.
Teeth are moved by light, continuous pressure, a principle that forms the basis of all orthodontic treatment. The prolonged, low-level force exerted by a recurring habit is particularly effective at causing teeth to move and the jaw structure to adapt. A habit that occurs for many hours a day, even with minimal intensity, can gradually overcome the natural resistance of the bone and ligaments holding the teeth in place.
The Specific Mechanism of Licking and Tongue Pressure
The physical act of habitually licking the gums or lips is often associated with or causes an abnormal swallowing pattern known as tongue thrusting. Instead of the tongue resting against the roof of the mouth during swallowing, it pushes forward against the back of the front teeth. Since an individual swallows hundreds of times a day, this repeated forward pressure acts like a constant, low-grade orthodontic appliance.
This persistent outward force on the upper front teeth, or incisors, often results in two specific types of malocclusion. One common result is incisor protrusion, where the front teeth tilt forward unnaturally. The other frequent outcome is an anterior open bite, where a noticeable gap exists between the upper and lower front teeth even when the back teeth are biting down. The tongue fills this open space, which reinforces the abnormal tongue posture and perpetuates the problem.
Other Common Childhood Habits That Affect Tooth Position
While tongue pressure is a major concern, several other common habits can similarly alter dental alignment by applying unbalanced forces to the teeth and jaws. Prolonged thumb or finger sucking is one of the most recognized, causing a combination of an open bite and an excessive horizontal overlap of the front teeth. The constant presence of the digit physically prevents the front teeth from meeting and pushes the upper arch outward.
Extended pacifier use, particularly past the age of three, is strongly linked to malocclusion. This habit often results in a posterior crossbite, where the upper back teeth fit inside the lower back teeth, alongside an anterior open bite.
Chronic mouth breathing, often caused by allergies or nasal obstruction, changes the resting posture of the tongue, causing it to sit low in the mouth. This lack of pressure against the roof of the mouth can lead to a narrower upper dental arch and subsequent crowding.
Identifying When Intervention Is Necessary
Most oral habits in children, including some forms of tongue thrusting, are considered normal in infants and toddlers and often resolve spontaneously. Intervention is usually not recommended unless the habit persists past the age of four to six years, especially once the permanent front teeth begin to erupt. Continuing the habit into the mixed dentition stage increases the likelihood of permanent changes to the jaw structure and tooth position.
Parents should look for clear warning signs that indicate the habit has become problematic and requires a consultation with a dentist or orthodontist. These signs include a visible gap between the front upper and lower teeth (a hallmark of an open bite) or a noticeable forward protrusion of the upper front teeth. A lisp or other speech impediments are also often associated with incorrect tongue placement. Early intervention can involve simple behavioral modification techniques or the use of habit-breaking appliances to physically deter the action and retrain the tongue muscles.