Why does it hurt after a brace is fitted?

April 29, 2018by Mahesh Patel

Pain is to do with evolution and species survival:

Pain is an evolutionary mechanism for protection of species to avoid situations that can be harmful. Unfortunately, not all evolutionary processes are immediately beneficial. For example after a brace is fitted!

Pain is a complex subject. Our understanding is getting better with gene markers and may indicate why we all react differently to pain. Some patients do not feel a thing after a brace is fitted and wonder it is working! Others can have very sensitive mechanisms and the discomfort can last up to a week.

So why does it hurt after a brace is fitted?

The wires on the brace exerts a light pressure on the periodontal ligament (PDL for short) around the tooth. Even though the pressure is light, it initiates a physiological process in the PDL where cells produce chemicals which tell the bone to change shape. By changing the shape of the bone, the teeth move! However, some of the chemicals cause inflammation which stimulates nerve fibres in the PDL. The nerve fibres sends a pain signal to the brain to let it know something is going in the PDL that is not normal!  This pain process is an evolutionary mechanism that tells us we need to check this out. In time the body accommodates to the signal by producing a negative feedback loop once it understands the process is not harmful and everything settles in about a week at the most.


How is the pain managed during orthodontics?

Initially, it can be controlled by 6 hourly cycles of mild pain killers – we will issue guide notes on pain management. Once the movement of the teeth is commenced, subsequent changes of wires rarely cause the same degree of discomfort as the body controls the pain management.

Why has evolution designed the PDL to be painful on pressure?

To appreciate this, one must look at how joints of the body respond; fundamentally, the PDL is a joint:


Nature has designed joints to allow movement within a limit. These zones are highly innervated to send neural messages by way of pain signals to the brain if the joint is performing outside its design parameters. In the case of teeth, the PDL is a joint and loads placed on teeth from a brace will express itself with increased pain/sensitivity. In virtually all patients there is an increase in discomfort when a tooth moves followed by a graduate reduction in pain. So think of it this way: orthodontics is moving a tiny joint in our body beyond its functional parameter and it should be of no surprise it hurts most individuals. By being gentle with the initial activation of the appliance the discomfort is bearable.

One thing bearing in mind:

Of the 30,000 plus cases we have commenced, non have been stopped due to discomfort. That speaks volumes that one should not worry too much about discomfort and orthodontics.