Habit/Crib Appliances

The Merriam Webster dictionary defines the tongue as “the soft, movable part in the mouth that is used for tasting and eating food and in human beings for speaking”.  While this is true, what the definition leaves out is the fact that the tongue is made up mostly of muscle.  This explains why it is so effective in moving food through the oral cavity, and why when one receives lidocaine (‘novocaine’) during a dental procedure, your tongue feels like it’s paralyzed.

Mouth with openbite (before surgery)

One of the clearest examples of the power of the tongue is in individuals who have enlarged tongues, hyper-active tongues or a condition known as tongue thrust.  Over time, as the tongue pushes on the teeth (mostly the front teeth), the teeth are displaced, and are gradually moved forward and tipped out, resulting in a malocculsion known as an ‘open bite’. If the tongue thrust habit persists, the open bite can become quite significant, making it a challenge to correct even with braces.

Mouth with openbite (after)

When we identify a patient with a tongue thrust, we typically recommend placement of a habit appliance.  This appliance, called a crib appliance, affectionately described as a ‘hockey mask’ by our patients, is cemented onto a patient’s back molars.  The ‘crib’ portion of the appliance is made up of a smooth cage like attachment which prevents the tongue from pushing directly against the palate and the backsides of the upper front teeth,thereby eliminating the undesired pressure contributing to the open bite.  And since the lips are a muscle in and of themselves, over time, lip and cheek pressure can reduce the open bite, and improve a patient’s bite.

The crib appliance is typically kept in the mouth for a year to break the tongue thrust habit. After an initial short period of adjustment to the appliance, most patients adapt easily, and have no problems whatsoever with eating and speech.  And despite it’s cage-like appearance, most patients are not put off by it’s look.

Photo of crib placement

In some cases where patients are also sucking their thumb, spurs are added to the appliance which act as a deterrent for thumb placement.

Diagram of crib placement

While the crib appliance is effective in stopping the tongue thrust habit, oftentimes one will need full braces to close the bite and improve one’s smile completely.  However, if left untreated for too long, even braces may not correct one’s bite completely.  Hence, early intervention is recommended.