Retainers


 When the braces have been removed at the completion of active treatment, there may be considerable rebound with the teeth tending to move out of alignment. Retainers are designed to hold the teeth in their correct positions and are removable or fixed.

There are several pre-treatment features that are highly prone to relapse or movement following the removal of the braces:
  1. Rotations of teeth.
  2. Spaces between teeth.
  3. Where the upper teeth have to be expanded to match the bottom teeth.

We recommend that the fixed retainers (flexi-wires) which are bonded behind the upper and lower teeth stay in place very long-term. The removable retainers are worn full-time for several months and then at night only for an indefinite period. Sometimes we ask our patients to wear their retainers once or twice a week long-term.
 

Removable Retainers

Hawley Retainers

The most usual removable retainer is a “Hawley retainer” or a variation of this. It is a simple appliance that clasps the upper first molars and has a wire running around the outside of all the upper teeth. It is worn full-time for some months following the removal of the braces and then for a variable time at nights only. Some adults and those patients who have had their upper teeth expanded may be required to wear this retainer part-time (say, two nights per week), long-term.

Although these retainers will hold the upper front teeth straight, they will allow the side teeth to settle in with the lower teeth, giving a natural and comfortable bite.

    

Vacuum-formed or Essix retainers

These retainers are like mouth guards made of a thin, clear and more rigid plastic which covers all the teeth and none of the roof of the mouth. It may be worn full-time or at night only and it is important to not eat anything or drink hot fluids while wearing it. The disadvantage of this retainer is that it does not allow settling of the back teeth.


Bonded or fixed retainers

Lower front teeth are highly prone to moving and crowding with age. This is a natural process and occurs in a high proportion of the population. Post-treatment relapse of an original problem is very disappointing and even the natural irregularity of lower front teeth is undesirable if one has had braces. To prevent or at least reduce this movement, a fine braided wire (made of several very fine wires woven together) is bonded on behind the six lower front teeth. In this practice, we also bond a wire behind the upper four or upper six front teeth. These wires are not visible from the front and patients get completely used to them and forget they are in place except when they are brushing and flossing their teeth.

We recommend to our patients that they keep these wires intact for many years, if not forever! The gums never forget!

    

In Summary

After the braces have been removed, the teeth are subject to many influences from their surrounding bone, gums, tongue, lips and cheeks. The retainers are designed to allow settling of the bite and to resist adverse or unsightly movement or relapse towards the original problem.  It is not possible to guarantee that your teeth will remain in a perfect position for the rest of your life.   Every part of the body changes with growth and ageing and the teeth are no exception.

 

当固定矫正器摘下以后,牙齿会移动到治疗前 的位置。固位器会把您的牙齿固定在准确的位
置。我们可以把它粘在您前牙后面或给您戴活
动性的固位器。

有一些病例是比较容易返回到治疗前的位置:
  1. 牙齿旋转
  2. 齿间空隙大
  3. 上牙弓扩大的治疗
我们建议病人戴固定固位器(flexi-wires)。这种固位器
是粘在上下前牙的舌侧,长期戴着。活动固位器是每天每
晚戴几个月,然后只有晚上戴一段时间。有时候,我们会
建议病人每星期全天戴一到二天。

活动固位器

Hawley 固位器

最常见的活动固位器是叫“Hawley 固位器”。它是通过钢丝
扣着第一上磨牙固定在牙弓上,上前牙上还有一根钢丝用
来固定前牙的位置。通常全天戴几个月然后晚上戴一段时
间。成年病人和一些上牙弓扩张的病人可能需长时间戴活
动固位器一周两个晚上 。

虽然这固位器能够保持前牙整齐,它们也会让后牙咬合吻
合。

    

透明固位器(Vacuum-formed 或Essix 固位器)

这种固位器就象牙齿保护器一样,细而透明的塑料做成的
保住所有的牙齿。您可能需要全天或晚上戴。吃东西或喝
热饮料是必须摘下。它的缺点是后牙不能咬住。

固定固位器

通常下前牙随着年龄的增长会移动的比例很高。虽然这是

正常的生理现象,但您还是不希望做完矫正后牙齿移动。
防止移动的最好方法是在下面六个前牙后面粘上固定钢丝。
在我们诊所,我们也会在上面四或者六个前牙后面粘上固
定钢丝。钢丝是看不见的。病人也会很快习惯不觉得它的
存在。

我们希望病人长年戴着钢丝或者永久性戴着以免移动。

    

总结

当摘下矫正器以后,牙齿通常由于牙槽骨,牙龈,舌头,
嘴唇等都会引起牙齿移动。固位器就是用来固定牙齿咬合
防止它们移到原来的位置。但是并不能保持您的牙齿终身
都在完美的位置。身体的每个部位一直都在变化,牙齿也
一样