January 23rd, 2018
Retainers in Orthodontics:
“How long do I have to wear these things?!”
by Jeff Wing DDS MS
Perhaps the question I get asked most often (other than “when do I get my braces off?” and “why do you ride a hoverboard around your office?”), is…”how long do I have to wear my retainers?” There is nothing more frustrating than going through 18-24 months of braces, only to wake up one morning and see a lower incisor going rogue and breaking away from the nicely aligned team. This phenomenon is called “orthodontic relapse,” and it is one of the most common reasons that adults and older teens come into our office seeking treatment. Before I answer the question of how long retainers need to be worn, let’s first take a look at why teeth want to move after the braces come off in the first place.
Reasons for Orthodontic Relapse:
- Contraction of Periodontal Ligament As teeth are moved with braces, the fibers of the periodontal ligament are stretched (these ligaments attach the roots of the teeth to the bony tooth sockets…basically they’re what hold the teeth in the jaw). When braces are removed, these fibers can act like little rubber bands, springing back to their original position and bringing the tooth with them.
- Late Growth of Jaw - As with every other physical feature of the human body, some people are luckier than others when it comes to the genetics of their teeth and jaws. The unlucky ones have genes that tell the lower jaw to continue to grow well past the normal age of growth completion. This can gradually turn a perfect bite into…well, a less than perfect bite (such as an underbite).
- Newly Remodeled Bone Not Fully Calcified - As the roots of the teeth are moving, the bone surrounding these roots remodels to accommodate for the new position of the root. If this bone hasn’t had a chance to fully calcify, it can’t stabilize the root well enough to keep the tooth from moving.
- Facial Muscles or Tongue - The forces from facial muscles and any habits with the cheeks or lips can put pressure on the teeth and cause them to move. The habit I see cause the most unwanted movement of teeth is the dreaded tongue thrust. Instead of swallowing with the tongue pressing against the roof of the mouth, it pushes forward against the back of the teeth. This can lead to flared front teeth (“buck teeth”) and the vertical separation of the upper and lower teeth (“open bite”).
- Wisdom teeth - These infamous teeth commonly grow in at a forward angle, which puts pressure on the teeth in front of them and causes the front teeth to shift out of alignment. Normal 6-year and 12-year molars also have a tendency of drifting forward with time, but this is usually a slower and less drastic effect than wisdom teeth.
So…as you can see, retainers after braces are critical! Now, back to the original question…”how long do I have to endure the shame and embarrassment of taking these things out in a restaurant with a string of saliva hanging from my mouth?”
Full time wear (22 hours/day) is necessary for a certain amount of time after the braces are removed. This recommended time varies among orthodontists from 6 weeks to 6 months. After this initial period of full time wear, it is then recommended that the retainers are worn only while sleeping. And if you happen to be a major party animal or Netflix binge watcher who only sleeps for 3-4 hours, this doesn’t cut it — we’re looking for more like 7-8 hours each night.
After a year (give or take) of wearing the retainers each night, patients can then test the tooth stability waters by dropping down to wearing them every other night. At this point, it is recommended that personal best judgment is used — if the retainers feel unusually tight after not wearing them for 48 hours, it would be wise to stick with the "every night” routine for a while longer. If they slide right in with minimal pressure, you might be one of the lucky ones who only needs to wear them long term for 1-2 nights per week.
The moral of this slobbery retainer story is that the best answer to the question of “how long do I have to wear my retainers?” is…as long as you want your teeth to stay straight!