While some malocclusions are genetic, others are caused by bad oral habits.
For teeth and jaws to develop normally and grow straight, the balance of tension between bones and muscles should not be disturbed. We may not consciously notice it, but our lips and our tongue are constantly pressing against our teeth. The pressure is usually not too strong, not too weak and in the right places.
An altered tension relationship in the oral cavity can affect the growth of the jaw and teeth. Our tongue pushes the teeth forward and to the sides, while closed lips have the exact opposite effect. The habit of sucking or pressing the lips causes the pressure of the lips to be greater than the pressure exerted by the tongue muscles. This can lead to tipped front teeth.
Many people know that thumb sucking in babies and toddlers is bad for the position of their teeth. However, this is not the only cause. There are also many adults who influence their dental alignment with certain habits. These include lip biting, lip sucking, lip pressing, nail biting, tongue pressing and mouth breathing.
But let's start by explaining the negative effects of thumb sucking, chewing on blankets or stuffed animals. If foreign objects are regularly inserted into the mouth, the jaw cannot develop properly, which can lead to an open bite. In this case, the upper incisors tilt forward and the back incisors tilt inward. In addition, the upper incisors are pushed into the jaw. As a result, the upper and lower incisors no longer meet when biting. Children should stop sucking their thumb or other objects from the age of three. However, if they continue doing it after the age of 6, very severe tooth and jaw malformations can develop.
Contrary to what many people believe, dental misalignments due to bad habits is a phenomenon that also affects adults. In the case of adults, mouth breathing may be a problem. If the nasal airway is obstructed, natural breathing through the nose is more difficult and mouth breathing becomes more frequent. This results in a lowering of the lower jaw and encourages the tongue to be placed on the floor of the mouth. Possible consequences are an open bite, altered size of the front teeth and a narrowing of the upper jaw. We highly recommend visiting an ENT physician in addition to the dentist to have the nasal airway treated.
Compulsive and frequent nail biting can cause damage to teeth and gums at any age. Similarly to what happens with thumb sucking, the fingers, as foreign objects, push against the teeth, causing them to shift over time. In addition, the fingernail splinters can injure the gums and inflammation may occur. Reasons for nail biting include stress, nervousness and behaviour disorder.
Incorrect lip functions include sucking in the lips, pressing the lower lip against the lower front teeth and lip biting. These oral habits, as described above, can alter the tension balance between lips and tongue. Regular lip biting can affect the jaw muscles and the temporomandibular joint and cause misaligned teeth. Sucking in the lip(s) increases pressure behind the upper incisors, causing them to tilt forward while the lower teeth tilt inward. Lip pressing should not be confused with jaw clenching and teeth grinding. We have dedicated a separate article to this topic: Bruxism – Teeth grinding at night.
When in resting position, the tongue lies gently on the roof of the mouth with its apex on the palatine spot. In the case of frontal, lateral and circular tongue pressing, however, the tongue is positioned between the upper and lower jaw. This gives the tongue more space and the rows of teeth move away from each other. If the tongue constantly presses forward or sideways against the teeth, the result may be a permanently open mouth. This so-called dyskinesia can be treated with speech therapy, psychotherapy, myofunctional therapy or orthodontics.