Teeth hurt when they are straightened because the force placed upon the teeth actually stops circulation in the area under pressure. When the blood supply to the area stops, lactic acid builds up and you effectively get a little "Charlie Horse" or cramp next to that tooth. The teeth respond this way whether the force comes from metal or clear braces or Invisalign (clear plastic aligners). The teeth can't tell from where the force originates. Discomfort is inevitable any time teeth are moved. Luckily it only lasts for a couple of days after each adjustment.
Anytime a consistent force is applied to a tooth, that tooth will move. Whether the force is light or heavy, the body/teeth react to the force by starting a biologic reaction that causes the teeth to move, but also causes the teeth to be sore. In addition, the chemical mediators released by the body to help the teeth move may also cause the teeth to become sensitive to hot and cold. Some patients may think that they have a cavity. This sensitivity will usually dissipate over time.
Usually, the soreness created by moving the teeth with Invisalign can be controlled with ibuprofen, or any of the over-the-counter pain medications. In addition, I recommend eating a soft diet during these 2-3 days of soreness. Most patients will experience the soreness most when chewing.
Continue Learning about Orthodontics
Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.