Open bite

What causes it

• Habits in childhood. Prolonged thumb sucking or dummy use past the age at which the permanent teeth arrive holds the front teeth apart mechanically.
• Tongue posture and swallowing pattern. A tongue resting forward between the teeth applies light force for many hours a day, which is more than enough to hold an opening.
• Skeletal pattern. Some faces grow with a downward and backward rotation of the lower jaw, producing an open bite that is structural rather than habitual.
• Airway and nasal obstruction. Where a child cannot breathe comfortably through the nose, an open-mouth posture is often adopted, and posture over years influences how the jaws develop. The relationship is real and is specific to the individual, so it is assessed rather than assumed. Anything in this territory is examined properly rather than treated as a slogan.

Why it is difficult

The correction is achievable; holding it is the challenge. If the cause was a habit or a tongue pattern and that pattern has not changed, the same force that opened the bite reapplies itself the day the appliances come off. Open bite cases have among the highest relapse rates in orthodontics, and honest treatment planning says so at the outset.

How it is corrected

• Habit interruption first in children, usually with a simple appliance and a conversation rather than a fight.
• Fixed braces with vertical or box elastics to settle the front teeth together.
• TADs to intrude the back teeth, which rotates the jaw closed at the front. This changed what is achievable non-surgically in adults.
• Orthognathic surgery for severe skeletal open bites in adults, planned jointly with a surgeon.
• Myofunctional therapy alongside orthodontics where the tongue pattern is a contributor.

Retention

Longer and more deliberate than in most cases, and the underlying cause has to have been addressed rather than overpowered. Where breathing is part of the picture, that is worth pursuing in its own right — see mapleridgeorthodontist.com.