Braces are appliances that are put on the teeth to align them. They are composed of three main components; bands, brackets and archwire.
Bands are ring-shaped metallic components bonded to four first molars in the mouth. It has a central tube that provides support to the archwire.
Brackets are square or rectangular-shaped components that are bonded to the upper and lower teeth. They have slots that provide attachment to the active components of the braces such as archwire and power chain and deliver force from the active component to the teeth.
The archwire is a u-shape metalic wire made of different materials (stainless steel or nickle-titanium) and varying thicknesses that transfers force to the teeth through brackets. It is changed every month and moves the teeth to the desired position.
The procedure of braces placement is described in detail here.
There are different varieties of brackets or braces available and the choice of brackets depends on the patient’s affordability and individual case requirements.
Edgewise or traditional brackets
Edgewise or traditional brackets are the commonest and the most affordable type of brackets available. They were introduced in 1928 and are used ever since with several modifications.
They have a horizontal slot that houses the archwire. The archwire is held in the slot by an elastic tie called an o-ring. O-rings are available in different colours. Young patients love to select their colour and wish to get a new colour every time.
They are made of stainless steel and are often a concern for the patients due to poor aesthetics. They are also initially uncomfortable for the patients and can leave indentations on the inner surface of cheeks and lips.
They are less expensive and can be sterilized and reused if they come off (debond).
Due to their hardness, they resist deformation and fracture. They exhibit the least friction at the wire bracket interface and therfore prolongs the treatment duration. Furthermore, they can corrode and cause staining of teeth.
They were introduced in 1980. The bracket has a door mechanism that is opened and closed to hold the archwires. They don’t require an elastic tie to hold the wire as compared to the traditional brackets.
They have enhanced efficiency and are simple to use. They offer reduced friction at the bracket and wire interface and thus reduce the overall treatment time. They efficiently align the severely irregular teeth and also gives better plaque control.
They are also less uncomfortable for the patients and reduce the risk of dentist and patient injury such as puncture wounds because of their smooth, curved outer surfaces.
They are made up of stainless. Yet, they aren’t aesthetically pleasing and the patient tends to have a metallic smile. They are costly in comparison to the standard edgewise brackets.
Because of their low friction design, some practitioners feel they need trouble expressing the minor tooth movements necessary to end cases.
The more contact between the archwire and bracket slots (the greater the friction) is required for precise movements for finishing a case.
They were introduced in 1996 by Dr Dwight Damon. They are self-ligating brackets but offer the least frictional resistance to the archwire of all the brackets available. They have the following advantages over the other types.
- They tend to expand the arches and reduce the need for tooth removal to align the teeth.
- It reduces the overall duration of treatment by up to 7 months and also decreases the number of appointments.
- Reduced pain is experienced by the patients as the force applied to the teeth is kept minimal throughout the treatment.
- Less chair-side time due to locking door system and no use of elastic ligatures.
Plastic brackets were first introduced in the 1970s. They are made from polycarbonate or a modified sort of polycarbonate. They were developed to improve the aesthetics of the appliances.
Plastic brackets are available in tooth-coloured or transparent forms, however, they discolour particularly in patients who smoke or drink coffee.
Another drawback of these brackets over the stainless steel edgewise is the distortion of their slots because of the poor dimensional stability of the material.
Lastly, the friction between plastic brackets and the metal archwire is higher than metal and therefore require a little longer for the treatment to complete.
Ceramic brackets began in practice in the late 1980s. They are composed of either polycrystalline or monocrystalline alumina based on their distinct method of fabrication.
The primary ceramic brackets were monocrystalline which were milled from single crystals of sapphire using dimensional tools. Later polycrystalline zirconium or zirconium are introduced to alumina ceramic brackets.
They have improved esthetics and enamel-like translucency and resist staining better than plastic brackets. Moreover, they are more resistant to wear and deformation and are less prone to plaque build-up than stainless steel brackets.
These brackets are known for their hardness. They are harder than the tooth enamel and can damage it if brought in contact with it. It is important to keep in mind that your lower bracket shall not touch the enamel of your upper teeth when you chew or make contact with your back teeth. It can occur in patients who have deep bite.
Regardless, they offer greater frictional resistance between the bracket slot and archwire and can diminish the pace of tooth movement.
Ceramic brackets can not be reused and need a new replacement. This can cost you a new bracket every time you debond your bracket. It is important to know that manufacturers instruct to recycle a ceramic bracket once it’s used. However, some clinics use some laboratory techniques to reuse them.
Another shortcoming of Ceramic brackets is their lack of flexibility. In other words, rigid ceramic and enamel have little ability to disperse debracketing forces applied by pliers at the end of treatment or if it is required to reposition the bracket. Thus, there are chances of bracket fracture or enamel damage if proper care and technique (laser, electrothermal or ultrasonic) are not used.
This system consists of specially designed brackets which are placed on the surface of teeth facing the roof of the mouth. This appliance is used in selective cases.
These braces are custom-made for your teeth. Your orthodontist takes an accurate impression or digital scan of your teeth, which is then used to create customised wires and brackets that will snugly fit along the line of your teeth and help to gradually move them into the desired position.
The brackets are not visible and thus are highly aesthetic. People whose primary concern to have no show brackets such as people in media industry, it’s an ideal option for them. However, these brackets are very expensive.
They cause no damage to the outer surface of teeth. On the contrary, they can cause difficulty in eating and speech. Because of their inside placement, you need to avoid hard foods and eat the ones that are soft, nutritious and low in sugar. Maintenance of oral hygiene is critical as plaque deposition can lead to gum inflammation (gingivitis).
Furthermore, they take longer time to place because of the difficulty of placement on the inner surface of teeth. The brackets are made of soft precious metal such as gold and possesses a very smooth surface to avoid any injury to the tongue. However, any sharp edge of wire can hurt the tongue.
The article summarizes the types and the functions of orthodontic brackets. As technology advances new brackets are replacing the older ones that are more aesthetic and efficient. Regardless, every type has their own pros and cons and its their selection is based on the individual case requirement and affordability of the patient.