Wisdom tooth (third molar) – causes of pain. When is wisdom tooth extraction recommended?

The wisdom tooth (wisdom molar) is one of the most controversial elements of the dentition. Although it forms part of the natural dentition, many people come to know it not for its functional role, but for the pain and complications it causes. 

They emerge late, usually between the ages of 17 and 25, and, ideally, wisdom teeth should align correctly with the other teeth, erupt fully and aid in chewing. In reality, however, wisdom teeth often cause problems, particularly when there is insufficient space in the dental arch. The result? Discomfort, inflammation, infections and, ultimately, the need for extraction. 

From an evolutionary perspective, wisdom teeth played an important functional role. In the distant past, humans had a tough, unprocessed diet (roots, raw meat, seeds), which required a greater chewing capacity. Wisdom teeth (third molars) therefore played a significant role in breaking down food.

Nowadays, the role of the wisdom tooth is almost non-existent; the modern diet, consisting of soft, well-processed foods, no longer requires intense chewing. Evolutionarily speaking, the human jaw has shrunk in size, and the space available for wisdom teeth has diminished. Consequently, the wisdom tooth does not play a significant role in chewing, and brushing this third molar is difficult due to its position in the dental arch. 

Pain caused by wisdom teeth can have several causes, and a visit to the dentist is needed to determine the cause and take appropriate action. 

Impacted wisdom teeth

There are situations where a wisdom tooth remains completely or partially impacted within the bone or beneath the gum due to a lack of space. The pressure exerted by these teeth on neighbouring teeth can cause severe pain and discomfort.

In many cases, dentists recommend the prophylactic extraction of impacted or partially impacted wisdom teeth. This recommendation is based on the following arguments:

Prevention of infections – Partially impacted molars can become a constant source of infection and inflammation. Once pericoronitis has developed, the risk of recurrence is high.

Preventing tooth displacement – A wisdom tooth erupting into a space that is too small can lead to crowding of the front teeth, affecting the aesthetics and function of the bite.

Risk of tooth decay – Due to their tight and hard-to-reach position, wisdom teeth are difficult to clean. This promotes the development of tooth decay, both on the wisdom tooth itself and on the neighbouring tooth.

Orthodontic complications – During or after orthodontic treatment, the presence of an impacted wisdom tooth can compromise the results due to the pressure it exerts on the other teeth.

Risk of cysts or tumours – Although rare, an impacted wisdom tooth can lead to the formation of follicular cysts, which destroy the jawbone and may require complex surgical procedures.

Gum inflammation (pericoronitis) caused by wisdom teeth

In the case of partially erupted (semi-impacted) molars, the gum covering them becomes an area vulnerable to infection. Food debris and bacteria can accumulate beneath this gum flap, leading to inflammation, swelling, localised pain and even a fever.

Gum inflammation (pericoronitis) is one of the most common causes of pain in the wisdom tooth area. Symptoms include:

• Localised pain, which is worse when chewing or opening the mouth;
• Swelling of the cheek;
• An unpleasant taste or halitosis (bad breath);
• Mild fever;
• Difficulty swallowing or speaking.

In some cases, the infection may spread to neighbouring soft tissues, leading to dental abscesses or facial cellulitis, complications which require urgent treatment with antibiotics or even surgery.

Temporary treatment of the inflammation includes thorough cleaning of the area, rinsing with antiseptic mouthwash or saline solutions, and taking anti-inflammatories or antibiotics. However, the definitive solution remains the extraction of the problematic molar, especially if the episodes recur.

Pressure on neighbouring teeth  

Wisdom teeth can erupt and grow at an incorrect angle, exerting constant pressure on the second molar. This pressure, combined with the narrow space created between the teeth, leads to the build-up of bacterial plaque and food debris, which are difficult or even impossible to clean by brushing.

Over time, this promotes the development of interdental caries and periodontal disease in the neighbouring tooth. Furthermore, the continuous pressure can affect the roots of the second molar, leading to chronic pain and even the need for root canal treatment or, in severe cases, the extraction of both teeth. This situation highlights the importance of early diagnosis of problems caused by wisdom teeth.

The formation of cysts or abscesses

Sometimes, dental cysts can form around an impacted wisdom tooth. These are fluid-filled cavities that develop slowly but surely within the jawbone.  

Cysts can grow in size, putting pressure on the roots of neighbouring teeth and destroying the surrounding bone, thereby jeopardising the stability of the entire dental arch.

It is important to note that, in most cases, cysts can develop without any noticeable symptoms for a long period of time. This is why regular visits to the dentist are essential. Using X-rays, the dentist can identify these problems before they become a serious threat to oral health, preventing the development of an abscess or other major complications.

Referred pain or neuralgia  

The discomfort caused by a wisdom tooth is not limited to the area around the tooth itself. This pain can radiate – that is, spread – towards the ear, neck or jaw. Patients may experience a sensation of pressure or a constant, dull ache in these areas, which is often mistaken for other conditions, such as an ear infection or facial neuralgia.

This confusion complicates an accurate diagnosis and, consequently, delays appropriate treatment, allowing the underlying problem to worsen. That is why it is essential to consult a specialist dentist when you experience such pain. Only a thorough examination, including an X-ray, can accurately determine whether the wisdom tooth is the actual source of the discomfort and guide the specialist towards the best course of treatment. 

Extraction of a wisdom tooth should be considered in the following cases:

• The molar is impacted or semi-impacted and is causing discomfort;
• There are repeated signs of pericoronitis;
• There is caries that is difficult or impossible to treat due to limited access;
• The tooth is partially destroyed, fractured or loose;
• It interferes with orthodontic treatment;
• A cyst is visible on the X-ray.

Surgical extraction of the wisdom tooth is carried out under local anaesthesia, so that the patient feels no discomfort during the procedure. An incision is made in the gum to expose the crown of the tooth; the bone blocking the proper eruption of the molar is removed; the tooth is extracted; the post-extraction socket is cleaned; and the gum is sutured.

The duration of wisdom tooth extraction varies depending on the position and degree of impaction of the tooth:

• Fully erupted molar, favourable position: 20 minutes
• Partially impacted molar (partially covered by gum or bone): 20–40 minutes
• Fully impacted molar, in a difficult position (e.g. horizontal): 40–90 minutes or more
• Complicated cases (close to the nerve, curved roots): up to 2 hours

Post-operatively, the following may occur:

• Pain and discomfort, manageable with painkillers;
• Local inflammation and swelling, particularly in the first 48–72 hours;
• Minor bleeding in the first few hours;
• Limited ability to open the mouth (temporary trismus);
• Possible bruising around the cheek area.

It is essential that the patient strictly follows the doctor’s instructions:

• Apply ice during the first few hours;
• A semi-solid, semi-liquid diet at room temperature
• Avoid smoking and hard or hot foods;
• Thorough oral hygiene, avoiding brushing the treated area for the first 24 hours;
• Use of an antiseptic mouthwash (as recommended by the doctor);
• Follow-up appointment after 7 days to have the sutures removed (if they are not absorbable). 

How long does it take to have a wisdom tooth removed?  

The duration varies depending on the complexity of the case, but a simple extraction usually takes between 20 and 30 minutes. For impacted wisdom teeth (those that have not erupted), the procedure can take up to several hours.

Is anaesthesia used?  

Yes, the extraction is carried out under local anaesthetic, so you won’t feel any pain during the procedure.

Do you need to take any medication?  

The dentist will most likely prescribe anti-inflammatory medication or painkillers to manage pain and swelling after the procedure. You may also need an antibiotic to prevent any potential infection.

What can you eat after a wisdom tooth extraction?  

In the first few days, it is recommended that you eat soft, liquid or semi-liquid foods (yoghurt, soups, purées, smoothies) and avoid hard, crunchy or hot foods, which could irritate the area.

In conclusion, regular dental check-ups and dental X-rays are essential for the early detection of wisdom teeth that are likely to cause complications. In most cases, prophylactic extraction is a safe and effective measure to prevent discomfort and protect long-term dental health. 

1. The Influence of Oral Hygiene and Smoking on Pain and Swelling following the Surgical Extraction of Impacted Lower Third Molars, 2010

2. Risk indicators of postoperative complications following surgical extraction of lower third molars, 2011

3. Factors predictive of the difficulty of mandibular third molar surgery, 2001

4. An evaluation of third molar eruption for the assessment of chronological age: A panoramic study, 2012

5. Surgical extraction of lower third molars: diagnostic tests and surgical technique for the prevention of inferior alveolar nerve injury, 2008