Most of us will experience some form of tooth decay in our lifetime. In fact, a 2017-18 study by the National Study of Adult Oral Health found that fewer than 11% of Australian adults had never experienced dental decay in their adult teeth. Minor forms of tooth decay include cavities, discolouration, and spots. If left untreated, decay can result in infection, tooth rotting and tooth loss. Tooth decay can cause a number of issues outside the mouth, too. Rotting teeth can cause headaches, bite issues, and health problems throughout the body. In this guide, we explain how rotting teeth can cause headaches. We also take a look at what your treatment options are if you’re suffering with dental decay.

What Are Dental Headaches?

Dental headaches can be triggered due to a variety of problems, including face and jaw issues, tooth decay, infection, gum disease, and tooth grinding.

Let’s take a look at some of the most common causes of dental headaches.


Malocclusion means that your teeth are not aligned properly when you bite. In other words, if your teeth do not form a smooth curve when you close your mouth, you have malocclusion.

This can occur because of emerging wisdom teeth, orthodontic work, a misaligned jaw, or previous dental issues.

If you have malocclusion, your jaw muscles overcompensate to make up for the misalignment. This puts strain on the muscles, which can cause pain to spread throughout the head. You may experience headaches as a result.


Temporomandibular Joint Disorder (TMJ) occurs when the jaw and surrounding muscles are not functioning properly.

TMJ can be triggered by whiplash, sporting injuries, or even leaving the mouth open too wide for too long.

TMJ causes the muscles to constrict, which often causes a shooting pain in the area. People suffering from TMJ may also experience clicking of the jaw, or the jaw may pop out of place. Both symptoms can cause intense pain through the face and jaw, which can also refer pain to the head.

Teeth Grinding

Medically known as bruxism, teeth grinding can cause headaches.

Teeth grinding is often caused by stress, and most people who grind their teeth do so without realising it. Teeth grinding puts stress on the jaw and surrounding muscles. This tension can cause headaches.

If you wake up with jaw pain or experience nocturnal headaches, this may be a sign that you’re grinding your teeth while you sleep.

Can Rotting Teeth Cause Headaches?

Rotting teeth and tooth decay can cause headaches.

Tooth decay generally begins with a cavity. Cavities often start as small, pinhole-sized holes in the teeth that quickly open up into much larger holes beneath the surface of the tooth.

While cavities themselves are unlikely to cause headaches, if left untreated they can lead to infections and abcesses, both of which can cause headaches.

When a tooth or the gum lining becomes inflamed or infected, the nerve endings from the tooth root cause pain in the area. This can result in referral pain in other parts of the head, which is why you may experience a headache along with your toothache.

If left to progress, tooth and gum infections may spread to other parts of the body through the bloodstream, which can cause a number of serious health issues.

Link Between Tooth Decay and Migraines

Link Between Tooth Decay and Migraines

Migraines are severe headaches that usually present as a throbbing pain on one side of the head. Migraines are often accompanied by other symptoms such as nausea, vomiting, and sensitivity to light and sound. These headaches typically last between 4 and 72 hours, and can be debilitating. The trigeminal nerve plays a part in forming migraines.

Toothaches have been shown to cause migraines, and the trigeminal nerve is believed to be the linking factor. The trigeminal nerve is responsible for all sensation in the facial area. It’s responsible for sending pain, temperature, and touch signals from the face to the brain.

Because the branches from the trigeminal nerve extend to the jaw, lips, and gums, it’s believed that tooth and gum infections put pressure on the nerve, which therefore triggers a migraine.

What Causes Rotting Teeth?

Our mouths are full of various bacteria that form a film over our teeth. This film is known as dental plaque.

When you consume carbohydrates, particularly sugary foods and beverages, the bacteria in the plaque converts those carbs into energy. This conversion process produces an acidic substance. As plaque builds up, so too does the acidic substance. The acid slowly dissolves the surface of the tooth, and cavities are formed.

When cavities form on the tooth enamel, the dentine (the bone-like matter under the enamel) becomes exposed to plaque and bacteria. Dentine is softer than enamel, so once exposed to bacteria and plaque, the tooth decays quickly.

If the tooth decay isn’t treated at this point, the bacteria enters the pulp. This is the area of the tooth that contains the blood vessels and nerves. Pain occurs when these nerves become exposed to bacteria.

Bacteria can also cause abscesses and infection to form in the pulp, which can spread to the bone and into the bloodstream.

Signs of Rotting Teeth

The signs and symptoms of rotting teeth include:

  • Discolouration or spots on the teeth
  • Gum changes (pain, bleeding, pus). These are signs of gum disease. Gingivitis is the milder form of gum disease, which often presents as redness, soreness and bleeding of the gums. Periodontal disease is more severe form of gum disease that develops when gingivitis isn’t treated. It can lead to tooth and bone loss.
  • Cavities
  • Tooth pain that is persistent, sharp, or keeps you awake at night
  • Bad breath
  • An unpleasant taste in the mouth
  • Tooth sensitivity

Can Sensitive Teeth Cause Headaches?

Tooth sensitivity can occur due to decayed enamel, exposed tooth roots, cracked teeth, cavities, gum disease, or worn fillings.

If you’ve ever felt a sharp pain through your tooth when consuming very hot, cold, or sugary foods or drinks — that’s tooth sensitivity. The pain is often at the root of the teeth, and feels like a shooting sensation going up through the tooth.

While sensitive teeth don’t necessarily cause headaches, the issues causing the sensitivity — such as decay and infection — may lead to headaches.

If you have rotting teeth, you may end up dealing with headaches, tooth or gum pain, and tooth sensitivity all at once.

Luckily, there are a number of treatments available to address these issues and eliminate your pain.

Treatment for Tooth Decay

Treatment for Tooth Decay

Treatment options will vary depending on the extent of the tooth decay.

Minor Decay

For minor signs of decay, including discolouration and early stage wear-down of tooth enamel, your dentist will likely discuss dietary changes to prevent the decay from progressing.

They may also apply a fluoride gel, paste, or varnish to the affected area. Fluoride strengthens tooth enamel and is plaque-resistent, so these coatings will help to protect your teeth from future damage.


If your teeth have formed cavities, you may require a filling or a crown depending on the extent of the cavity.

Both treatments will begin with a local anaesthetic to numb the area. If you need a filling, the dentist will remove the decay with a drill, then seal the area with a filling. The filling is usually made from porcelain, amalgam, composit resin, or gold. This procedure can be completed in one dental visit.

The crown procedure often requires two dental visits. Your dentist will first remove a layer from the tooth’s outer surface, and then create a mould of the tooth. You will be fitted with a temporary crown while your permanent crown is made. It will be crafted to match the colour of your other teeth. Then, the permanent crown will be fixed in place using adhesive or dental cement.

Advanced Tooth Decay

If the tooth decay has progressed and spread to the pulp in the centre of the tooth, you will likely require a root canal treatment.

This procedure is more invasive, as it involves removing the pulp and replacing the damaged tooth root with a root filling. Once your dentist determines that you require a root canal, they will work to relieve your pain and stabilise your tooth in the lead up to the procedure.

On your second visit, the affected area will be numbed, and if necessary, sedation can be administered. Any decay or infection will be removed from the area. Then, your dentist will shape the canals within the tooth root into hollow tunnels. This will prevent bacteria from building up in the area. This step may need to be repeated a few times to effectively clear stubborn bacteria.

After the canals are prepared, they will be filled and sealed with a barrier material. This will prevent bacteria from re-entering the space. To make the tooth functional again, a large and well-sealed restoration will be fixed onto the tooth.

The root canal procedure is usually completed over a two-week period.

Irreparable Decay

If your dentist determines that the decay is irreparable and the tooth cannot be restored, your tooth will likely be removed and replaced with an implant.

Dental implants are permanent replacements for missing teeth, unlike dentures which can be removed.

There are two types of dental implants: traditional implants and All On 4 implants. Traditional implants can be used to replace a single missing tooth or multiple teeth, while All On 4 treatment replaces all of your teeth with porcelain or resin implants.

Visit our dedicated article for a deep dive into dental implants.

A Final Word

If left untreated, rotting teeth can cause headaches, functional issues, infection, and tooth loss. Receiving the right treatment will eliminate your pain and prevent further health issues from developing as a result of tooth decay.

At Kew Dentistry, we offer all treatments mentioned in this article. If you suspect your headaches may be a sign of tooth decay, get in touch with us today. Our expert dentists will be able to assess your concerns and discuss treatment options with you.

Kew Dentistry