Causes of Toothache

When you experience a toothache, there can be various causes. The first thing that a dentist would do when you go to him with a toothache is to identify the underlying cause, because the treatment will then be based on that. Here are some of the possible reasons:

1. Caries and pulp disease

This is the most common cause of toothache. Caries start in the enamel, and slowly works its way into the deeper dentine layer, and ultimately, the pulp. This bacterial infection results in pulpitis, which can manifest as a sharp stabbing pain or a dull throbbing pain depending on the nature of the pulpitis. Left untreated, the bacterial infection can spread, leading to formation of cyst, pulp granuloma, or pulpal abscess at the tip of the root. Treatment is by draining the abscess, root canal treatment, or extraction.

Caries-induced pulpitis and pulp abscess

 2. Fracture/cracked tooth syndrome.

Sometimes a crack line can be present on a tooth without being visible to the naked eye. You will feel sensitivity when you bite on that tooth. If the crack line progresses into the pulp of the tooth, bacteria can easily gain access and infect the pulp and cause pulpitis. Furthermore, the tooth is susceptible to fracture when you bite hard food.

 3. Exposed root or tooth surface.

Exposed tooth surface can cause sensitivity. It can be due to:

i)                  Abrasion: over-zealous tooth brushing technique, especially if the tooth is already subjected to gum diseases like gum recession and bone loss.

ii)                 Attrition: bruxism/tooth grinding habit.

iii)                Erosion: acidic food and drinks, eating disorder such as bulimia nervosa, gastric reflux

Dental erosion due to chronic induced vomiting(bulemia)

 4. Impacted or erupting teeth

When a tooth does not have enough space to grow out into the mouth, its growth becomes impeded, or impacted. They can hit against other teeth, leading to inflammation and infection, which causes pain. This is most commonly seen in wisdom teeth, as they are the last tooth to come out in the mouth, and having the least amount of space into which it can erupt, are the most prone to impaction. Sometimes the eruption of a tooth itself can cause pain, as seen in children when they are teething, because eruption of a tooth can be accompanied by inflammation of the surrounding gums.

5. Diseases of tooth-supporting tissues (periodontal diseases)

Gum diseases (gingivitis) and its more severe form (periodontitis) usually do not cause pain. However, if an abscess is present, be it gingival abscess (an abscess in the gums) or a periodontal abscess (an abscess within bone adjacent to a tooth), can be painful. Infection of these supporting tissues can also spread to the tip of the root of the tooth and gain access to the pulp, leading to infection of the tooth, and hence, pain. This is called a “perio-endo lesion”.

 6. Barodontalgia

“Barodontalgia” is derived from the word “baro” which means pressure, and “odontalgia” which means toothache. So barodontalgia is toothache caused by a change in atmospheric pressure. This can happen when the patient has an existing cyst (a pathological fluid-filled cavity with an epithelial lining) at the root of a tooth or within his jawbone. When the atmospheric pressure decreases, as in travelling in an airplane, the cyst expands and applies pressure to the surrounding tooth or structures, thus causing pain.

7. Referred pain.

Referred pain means that the tooth itself is normal and not the cause of the pain. It is important to identify when the pain is referred to avoid extracting a perfectly normal tooth. Examples:

  • Infection of the maxillary sinus (sinusitis) can be easily mistaken for a toothache because of the close proximity of the sinus with the roots of the upper teeth, where the nerve fibres of the tooth emerge. 
  • Angina (chest pain) can cause referred pain to your lower jaw and sometimes even your teeth. 
  • Trigeminal neuralgia is a neurological disease in which the tissues supplied by branches of the trigeminal nerve (the 5th cranial nerve) experiences extreme excruciating pain when triggered by light touch. Only one side of the face will be affected. Of the 3 branches of trigeminal nerve, the mandibular branch, which gives nerve supplies to the lower teeth, is most commonly affected. Treatment should be by prescribing anticonvulsants instead of extracting the affected teeth.

3 branches of trigeminal nerve and what they supply

8. Atypical facial pain

Sometimes toothache can have a psychogenic etiology. Atypical facial pain is a persistent facial pain that does not have the characteristics of the cranial neuralgias classified (eg. trigeminal neuralgia) and is not associated with physical signs or a demonstrable cause. These patients are usually victims of depression or hypochondria, and keeps complaining of toothache or facial pain no matter what treatment has been attempted.