Most orthodontic treatment is accomplished with fixed braces. Fixed orthodontic appliances include brackets and archwires. Brackets are fixed to the teeth with an adhesive until the end of treatment. The archwire connects the upper and lower brackets to the teeth, and the brackets apply force to the teeth to guide them to move. Nowadays, the brackets commonly used in clinical practice can be divided into metal brackets and ceramic brackets according to the material; labial brackets and lingual brackets according to the location of the bonding. Depending on the ligature, they are divided into self-ligating brackets and non-self-ligating brackets. All different orthodontic appliances have their own advantages and disadvantages. And patients can choose these aligners according to their own situation reasonable choice. Metal straight wire orthodontic appliances are the most widely used fixed orthodontic appliances in clinical practice, and are capable of treating most malocclusions with high efficiency, practicality, low price, and low friction between the brackets and the archwire. It is the first choice of many people. However, the biggest disadvantage of these brackets is that they have a greater impact on aesthetics. Some patients with high aesthetic requirements may not be able to accept them. The advent of ceramic brackets has solved the problems of these patients. As you can see from the picture, ceramic brackets have a similar color to the teeth, which can improve the aesthetics greatly compared to metal brackets. However, since the archwire cannot be completely white or transparent, it may be noticeable at close range. Also, ceramic brackets are very brittle and can be easily broken, and the position of the bond cannot be adjusted. The above two types of brackets can satisfy the majority of patients. But for patients whose appearance is important to their work, such as actors, there is an urgent need for a completely invisible aligner. There are two types of aligners that can do this: lingual aligners and invisible braces (Invisalign). Both of these aligners have their own advantages and disadvantages. Both types of aligners are very expensive. Lingual braces are, as the name implies, bonded to the lingual side. Although they are completely invisible, they make them inconvenient for the doctor to operate and prolong the time of each follow-up visit. Also, since they are on the lingual side, there is some impact on tongue movement as well as pronunciation, which most people can adapt to in a short period of time. Invisible braces are actually a new orthodontic technology that produces a series of personalized clear aligners based on each patient’s specific situation through a system of computationally assisted three-dimensional diagnosis, design and manufacturing, and patients achieve their orthodontic goals by wearing them on time and replacing them regularly. However, its indications are more limited, and can only treat mild to moderate malocclusion. With all this said, the ultimate goal is to give patients a little help in choosing their aligners and choosing the right brackets for them. Self-ligating braces, lingual braces, and invisible braces have certain indications, and not every patient is suitable for use. Generally speaking, there is no significant difference between the orthodontic effect of different aligners, the key is still the operation of the doctor.