To begin, it is important to discuss the questions you have regarding your retainers
with the orthodontist
who placed your braces
. He or she knows your teeth the best, and will be able to best decide upon the appropriate post braces method to keep your teeth in alignment. Possible options include removable retainers, such as the ones that you have described, various minimally visible options including retainers glued into the backsides of your teeth.
There are pros and cons to each of these types or retainers and it is important that you discuss the possibilities with your orthodontist as he or she will likely have a plan for how he or she wants to keep your teeth in alignment after the braces. This depends on what your orthodontist uses most frequently, his or her comfort with various retainer options, and what their personal preferences are regarding the various options. Some of the cons of removable retainers include the fact that they are easily lost or broken, they are visible, and they are often quite uncomfortable and are difficult to use while eating. Pros of glued in retainers include that they are invisible, although a con is that they are glued in forever.
Again, please discuss these questions with your orthodontist.