Your Guide to Better Oral Health

How Braces Work?

Behind the mystery of tooth movement is the union of multitude areas of science, namely physics, chemistry and biology.

“Braces” is no longer a foreign term to the current modern society; it is a word that people associate with a wondrous treatment that straightens the teeth and creates beautiful smiles. Yet much unfamiliar to most people is that not only braces can improve the facial aesthetics and smile of a person, it can also improve the biting functions and even breathing problems. So, what exactly is “braces” and how does it work? 

What are dental braces?

Dental braces, or also known as “orthodontic appliance” by the dentists, are devices that are used to correct the misalignment of teeth and jaw. Dental braces treatment can start as an intervention as early as 7-8 years old if a dentist is able to catch early signs of tendency of jaw misalignment due to adverse habits such as thumb sucking and tongue thrusting, genetic predisposition of the upper and low jaw size discrepancy. It can also be done at an older age group, even for patients up to their 70s or 80s to straighten their teeth as a part of treatment to restore some of the missing teeth, improving the prognosis of the remaining teeth and helping the older patients to eat better. 

What are the different types of braces? How do they differ?

Braces are generally classified into “fixed appliances” and “clear aligners”. Fixed appliances are appliances made up of brackets and wires, whereas clear aligners are customised, thin and transparent removable plastic trays. Fixed appliances are again classified into conventional metal fixed appliances, ceramic fixed appliances, self-ligating fixed appliances and lingual fixed appliances. 

Fixed appliances and clear aligners both serve to move the teeth into its ideal position. They only differ in the type of force applied and the method of teeth engagement for movement. Fixed appliances generally pull teeth, whereas clear aligners push teeth into position. Fixed appliances engage the teeth with wires and brackets that are cemented onto the teeth. On the other hand, clear aligners depend on the surface area in contact with the teeth for engagement. 

How do braces (in general) work?

Perhaps the most fascinating thing about braces is behind how it works. How do braces move the teeth that are hard against the underlying hard and rigid bone? Why and how do the teeth stay firm in the bone and not become loose even when being moved? Behind the mystery of tooth movement is the union of multitude areas of science, namely physics, chemistry and biology. Physics being the force and direction of the tooth movement following push and pull motion exerted by the braces, the chemistry being the chemical mediators released by the body that causes the change in the bone following the force exerted by the braces, and biology being the changes in the bone due to the chemical signals that allow the teeth to move through it. 

Our bones have the ability to change to accommodate our physiological needs under normal or healthy conditions. Tooth movement is a physiologic adaptation of bone to mechanical forces induced by braces resulting in minor reversible injury to the tooth supporting structures. This physiologic adaptation of bone is also known as “bone remodeling”, which is carried out by two simultaneous well-coordinated processes, namely “bone resorption” and “bone deposition”. Bone resorption is carried out by bone-eating cells called “osteoclasts”; and bone deposition by bone-making cells known as “osteoblasts”. 

How long do braces take to start working?

The tooth periodontal ligament space plays an important role in tooth movement. It is a 0.2mm space, composed of dense fibrous connective tissue surrounding the root surfaces, functions to support and hold the tooth in their sockets while withstanding repetitive daily chewing forces. The classic Pressure-Tension Theory proposes that within seconds of force application onto a tooth, the tooth is being shifted within the periodontal ligament space, creating a tension side and an opposing pressure side. Sustained force applied creates changes in blood flow and subsequent oxygen supply, releasing chemical mediators affecting the cellular activities within the bone. The chemical signals released activate the osteoclasts (bone-eating cells) on the pressure side of the bone to remove bone, and osteoblasts (bone-making cells) on the tension side to deposit bone. These two types of bone cells work simultaneously, resulting in bone remodelling, thus allowing the teeth to “move through the bone”. 

It would be natural to think that heavy forces will result in greater and more efficient tooth movement. However, the reality is quite the opposite. Too heavy a force cuts out blood flow completely on the pressure side, resulting in death of the bone-eating cells, or osteoclasts. It then takes a longer time for the pressure side to “recruit” the bone-eating cells, needing 7-14 days to move the teeth. On the contrary, when light forces are being applied, “osteoclasts” are able to function normally, and as a result, it only takes about 2 days for tooth movement to occur. 

How long do I have to wear braces?

One of the first questions patients planning to get braces will ask is “how long will my treatment take?” The average treatment time ranges from 1 year to 3 years. Unfortunately, there is no one definite answer for everyone to this question without taking into consideration the variables. 

One of the utmost important factors that will affect the treatment period is patients’ compliance. As mentioned above, sustained force is needed for tooth movement to occur. In clear aligners especially, patients must be compliant to wear the appliance for at least 22 hours a day for satisfactory movement to occur. Missed appointments and frequent need for brackets/bands replacements for fixed appliances cases will prolong the treatment duration as well. Much unknown to the patients, their oral hygiene maintenance plays an imperative role in the treatment duration. Orthodontic tooth movement may be more efficient with less gum inflammation, which is part of the supporting structures of the teeth. 

Generally, patients in their teens tend to have better tooth movement compared to their adult counterparts. Nevertheless, at the end of the day, the treatment duration still boils down to the complexity of their treatment and the amount of tooth movement needed. Bone density is also a known influence of tooth movement, in that teeth move easier in the upper jaw with more porous bone as compared to lower jaw which has denser bone.

What type of braces work the fastest?

The magnitude of force exerted on the teeth affects the rate of the tooth movement. Self-ligating appliances generally require lighter force to work as compared to the conventional metal appliances, hence teeth tend to move better with self-ligating fixed appliances. Compared to the conventional metal brackets, self-ligating appliances and clear aligners both allow multiple mechanics of tooth movements to occur at once, making them one of the efficient choices of braces appliances. 

Over the years, continuous medical and technological research has been carried out on surgical, physical and biochemical methods to shorten the braces treatment time. There is, however, no one fastest braces or method for every patient but the most suitable braces for the individual patient. Clear aligners are a popular choice due to its invisible design, allowing the teeth to be aligned in the most inconspicuous way. Since they are usually best suited to treat mild to moderate cases, the treatment duration can be less than a year. Hence, it is always a good option to seek professional opinion regarding the best appliance for your condition. 

Braces pain – is it real? Do braces hurt?

“Do braces hurt?” is perhaps most, if not all, of the patients’ concern when they are considering whether to take up braces treatment. Pain, or the lack thereof, is a subjective experience that is influenced by emotional, cognitive and environmental factors such as age, gender and culture[6]. Emotional factors such as patient’s fear towards dental treatment, and cognitive factors like patient’s motivation directly or indirectly affects patient’s perception of pain during the orthodontic treatment. Hence, descriptions of patients’ experience range from just sensation of pressure and tension, to pain and soreness of teeth. 

The choice of appliances is also one of the variables affecting the experience of braces patients. Based on few comparison studies carried out, clear aligners are generally deemed to be the most comfortable appliance, followed by self-ligating appliances, conventional metal appliances and conventional ceramic appliances. 

Why do braces cause discomfort? As force is being applied on the teeth, changes in blood flow and subsequent inflammatory reactions occur in the pulp and the surrounding tissues, causing chemical mediators to be released, giving rise to the discomfort feeling. Pain or discomfort do not usually occur right after placement of new wires or change of new set of aligners, but instead, the discomfort commences within 4 hours after the activation and tends to increase in its intensity up to 24 hours before it gradually decreases back to normal during the next 7 days. 

Although there could be some discomfort or pain during the braces treatment, painkillers are known to be very effective in pain control. It has been proposed that taking one dose of painkillers before and then at least 2 doses after the braces activation result in complete pain control after the procedure. Having soft, cold food after the procedure will also help to lessen the discomfort. 

Fixed appliances, at times, may cause irritation to the gums and mouth, but that can be taken care of with orthodontic relief wax. Placing a small amount on the appliances will keep the appliances from rubbing the inside of the mouth. This issue does not usually happen with clear aligners. 

With the suitable choice of appliances, good compliance and oral hygiene maintenance, braces treatment can be an efficient and pain-free treatment. While pondering the question of “Do braces hurt?” It is beneficial knowing that in our daily lives, be it working out our bodies or pursuing our studies and careers, we only see changes and improvements when we push ourselves out of our comfort zone. Similarly, when it comes to braces treatment, the slight discomfort that we experience will be worth the while when we see the final result. 


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