Complications of Tooth Extraction

It is important to know the complications of tooth extraction that could occur in order to correctly consent a patient. Without properly knowing these, informed consent cannot be obtained and you cannot prepare your patient for the potential complications. This post will focus on the common complications that should be considered and potentially consented for if appropriate.

*This post is a comprehensive summary of the complications of tooth extraction – individual detailed posts are linked for complications where applicable.

Classifying Complications

There are multiple ways complications can be divided. We can divide them in to:

• Pre-operative – issues relating to medical conditions or anatomy
• Intra-operative – those that occur during the procedure
• Post-operative – those that occur following the procedure

Alternatively, complications could be divided based on location (local or distant), severity (minor or major) and type (general extraction complication or specific to a certain tooth).

Pre-extraction Complications of Tooth Extraction

1) Difficulty in achieving anaesthesia

It may not be feasible to achieve sufficient anaesthesia to extract a tooth. This could be due to varied nerve supply, extensive infection or failure to deliver the anaesthetic in the correct location. Consideration should be given to delivering anaesthetic using alternative measures e.g. intra-ligamental injections.

There may also be issues with pain during anaesthetic delivery, which could be caused by excessively speed/pressure of injection, penetration of a nerve or subperiosteal injection.

2) Poor co-operation

A lack of patient co-operation will be a barrier to effective extractions. Prior to commencing the extraction, a discussion and judgement should be made to determine whether the patient will likely tolerate the procedure.

3) Complications associated with medical conditions

There are a whole host of medical conditions/medications that may introduce new complications or alter the risk of existing ones. There are too many to discuss here, but a careful assessment of a patient’s medical history should be completed. Common medications that may impact complications include steroids, antiplatelets/anticoagulants and bisphosphonates.

4) Difficulty in access

A limited opening, trismus, may be an obstacle to safe extraction. This may due to intra-articular factors (abnormalities with the joint) or extra-articular factors (scars, such as with radiotherapy, or swellings, such as with an infection). If there is acute infection, a patient may require a course of antibiotics before extraction can be attempted.

Alternatively, patients may suffer from a reduced mouth aperture, microstomia, which may be due to scarring or a congenital malformation. Teeth may be poorly positioned or crowded, which may necessitate a surgical approach.

Intra-operative Complications of Tooth Extraction

1) Failure to complete extraction/Fracture of Tooth

Failure of extraction is often something that may be anticipated. Examples of situations to consider include:

• • A previous history of difficult extractions
  • Root-filled teeth that are likely to be brittle and fracture
  • Age/size of the patient – is there a risk of longer roots or ankylosed teeth?
  • Bruxists are likely to have ankylosed teeth
  • Extensive caries or restoration may lead to fracture

Proper clinical and radiographic assessment will allow for identification of abnormal anatomy or ankylosis. This will allow you to plan and determine if you should embark on the extraction or not.

Often, in the above situations, there is a resistance to movement which leads to a fracture of the crown/root. At this point, alternative techniques must be considered including surgical removal.

As well as the above reasons, it is is vital to determine if poor surgical technique has led to fracture. Ensure correct forceps with appropriate apical application and force are used, otherwise fractures become more likely.

Ideally the fractured portion should be retrieved. However, if retrieval of the fragment may increase the risk of damage to adjacent structures, then a conscious decision may be made to leave it. However, the fragment should be no greater than 1/3rd of the root, it should not have been displaced, have any signs of apical infection and should not pose a long-term risk to the patient. A common situation this may be carried out is in third molar removals where there is a significant risk to the inferior alveolar nerve. A fully informed discussion should occur with the patient.

2) Damage to other teeth

Extraction of the wrong tooth is indefensible and should not occur. Prior to extraction, patient identification should be confirmed and the tooth for extraction should be confirmed with the nurse. It is also useful to have the annotation on the wall for everyone to see and confirm the correct tooth is being extracted. If this does happen, the patient must be informed and a decision must be made whether to reimplant the tooth.

More commonly, damage may occur to adjacent teeth. These may include dislodging of restorations or fracture/mobilisation of teeth. Correct application of instruments will minimise this – particularly with elevators to ensure force is not being applied to adjacent teeth. If a restoration is dislodged, ensure it is accounted for and advise the patient. Temporise the tooth if possible.

When extracting primary teeth, it may be worth mentioning damage to underlying developing teeth during the extraction, as surgical instruments may cause damage.

3) Loss of tooth or roots

When extracting, care must be taken to ensure any teeth or fragments are properly retrieved otherwise they can be lost in various locations. Common locations are other areas of the mouth e.g. underneath the tongue or in to adjacent sockets, or in to the suction. The three main areas to be aware of, however, are loss in to the airway, in to bone cavities (particularly the maxillary sinus) and under the mucoperiosteum.

Teeth or roots can be swallowed or inhaled. Adequate airway protection should be maintained wherever possible. If this occurs, the procedure should be stopped and a chest x-ray should be carried out to check. Teeth will commonly go down the right bronchus as it is straighter and larger than the left. No major concern should occur if it is confirmed that the patient has swallowed it.

Teeth and roots are sometimes lost in to bone cavities, particularly the maxillary sinus. Pre-extraction radiographic assessment should identify any potential risk of this occurring. Care should be taken to avoid excessive apical force, particularly on retained roots, to minimise the risk of pushing the root in to the sinus. If this occurs, it may be possible to retrieve the root if visible and appropriate instruments are present. However, in most situations, this will require a referral to a specialist. A specialist may decide to leave the root if it is small and minimal risk to the patient. Alternatively, they may choose to retrieve this using either a transalveolar approach or a Caldwell-Luc approach. These will be covered in more detail in a separate post.

Teeth or roots can be lost under the mucoperiosteum as well, for example where flaps are raised for upper and lower posterior teeth.

4) Oroantral Communication (OAC)

The maxillary sinuses sit above the upper posterior teeth, and therefore when extracting these teeth there is a risk of creating a communication between the mouth and the sinus. Again, effective clinical and radiographic assessment will help identify this risk e.g. chronic infection may erode the sinus floor and increase the risk of an OAC. An OAC may be identified during the procedure or as a later complication.

Signs and symptoms of an OAC include:

• • Air passing from the nose into the mouth
  • Bubbling within the socket
  • Fluid may pass from the mouth to the nose and leak out
  • Inability to achieve an oral seal
  • Sinus lining may be visible through the socket
  • An eggshell of bone may be present on the apex of the extracted tooth

If an OAC is identified immediately, if it is small it may be feasible to close the wound by bringing the gingival tissue together with sutures or alternatively a decision may be made to leave and monitor the healing. Antibiotic therapy and decongestants may be considered.

If a true OAC develops then patients may experience more significant symptoms than those above including a purulent discharge and bad taste. Management of this may be carried out with a buccal advancement flap or a palatal rotation flap to close over the wound.

Over time, without treatment, this communication may epithelialise leading to formation of an oroantral fistula (OAF).

5) Soft tissue trauma

Soft tissue trauma usually occurs due to poor operator control. Burns can occur along the buccal tissues or lips from a surgical handpiece with lack of soft tissue protection. Instruments can slip and damage unprotected tissues e.g. floor of mouth or palatal tissues. Gingival tissues can also be ripped from poor forceps application.

6) Damage to nerves

Nerves can be damaged from the injections or from the extraction procedure itself. The inferior alveolar nerve should always be considered when extracting lower teeth, particularly if extracting a lower wisdom tooth. Patients should be warned about an altered sensation to the lower lip +/- tongue +/- lower teeth +/- chin +/- gums (which may be permanent). This is a significant risk from removal of lower teeth. The mental nerve should be consented for in a similar manner when extracting lower premolars.

7) Fracture of alveolus or mandible

Commonly fractures may occur of the lingual or buccal walls when extracting a tooth. This may be particularly if the tooth is ankylosed or forceps have not been applied correctly. If the fractured bone is still attached to the mass of alveolar bone, then it should be gently repositioned and secured. If the bone is separate and loose, however, then this should be removed to prevent healing complications.

Extractions can cause more significant fractures, including fractures of the maxillary tuberosity or the mandible. Tuberosity fractures have a higher risk of occurring in older patients, with long-standing upper molars that are heavily restored. Other factors such as a large maxillary sinus and abnormal tooth anatomy can also increase the risk. The signs that this has occurred include tearing of the palatal mucosa and the mass movement of multiple teeth in a block. The procedure should be stopped at this point. The fragment should be splinted for four weeks and then returned to for completion of treatment. A surgical approach may be considered to minimise the risk of repeated fracture.

Fractured mandibles are rare during extraction but may occur due to general weaknesses in the mandible. These may be due to systemic conditions such as osteopetrosis, pathology such as cysts or tumours or abnormal tooth position/anatomy. Care must be taken to minimise force in these extractions.

8) Dislocation of temporomandibular joint (TMJ)

This usually occurs during extraction of lower teeth under general anaesthetic, when the joint is lax. It can also commonly occur in children for a similar reason. Correct support should be provided to the mandible to reduce this risk and a mouth prop may be used to minimise this risk. If the jaw dislocates, then it should be relocated as soon as possible to prevent muscle spasm.

9) Broken instruments

Instruments may break due to wear or improper use. Care must be taken with use but to also ensure any broken pieces are fully retrieved.

Post-operative Complications of Tooth Extraction

1) Haemorrhage

Prolonged haemorrhage is extremely common following extractions. Haemorrhage may be primary, reactionary or secondary.

• • Primary – occurs immediately following the extraction
  • Reactionary – occurs within 48 hours following the procedure
  • Secondary – occurs typically 7 days following the procedure. This is usually a sign of a developing infection

Medical conditions causing increased bleeding and antiplatelets/anticoagulants may cause haemorrhage at any of these points, though primary and reactionary are most likely.

Management should involve identifying the cause, local measures and escalating to systemic if necessary. Local measures can include packing and pressure of the socket, along with sutures or use of a tranexamic acid (TXA) mouthwash. In more significant haemorrhage, systemic management with TXA or reversal agents for medication may be necessary.

2) Pain

Pain can occur due to a traumatic or incomplete extraction, soft tissue trauma, exposed bone, infections or nerve damage. Management is through identification and correction of the cause and analgesics.

3) Swelling

This is a typical inflammatory response to an operative procedure and can occur at varying degrees. Poor surgical technique can lead to greater inflammation such as poor tissue handling.

4) Dry Socket

Dry sockets develop as a result of premature loss of the blood clot. Patients will typically report severe pain (often not controlled by regular analgesia) and bad taste/smell. A true dry socket is not an infection and therefore pus would not be present.

The aetiology is variable and not completely understood. Some factors known to increase the risk include smoking, failure to comply with post-operative instructions and certain medications.

Management would involve irrigation of the socket and packing with a material with sedative combined with antiseptic, such as Alvogyl. Repeated treatments may be necessary.

Read further details here.

5) Infection

This may occur due to numerous reasons including an immunocompromised patient or debris left within the socket. Patients would present with standard signs of infection – swelling, pus and lymphadenopathy. Treatment will be carried out depending on severity but may include drainage or antibiotics.

May develop from a dry socket. If infections continue, progress or are severe enough, they may spread to the bone, osteomyelitis. This is more likely in a patient who is immunocompromised or has other underlying medical problems.

6) Osteoradionecrosis (ORN)

This is specific to patients who have undergone radiotherapy to the head and neck region. With reduced vascularity to the bones, the patient’s capacity to heal is considerably reduced. As a result, they may not be able to recover from the trauma of an extraction and non-vital bone remains. They may develop secondary infections.

Prevention is best in these patients. Prior to their radiotherapy, any poor prognosis teeth should be extracted. Once they have had the radiotherapy, conservative methods should be used to treat any teeth and extractions should be avoided where possible. If extractions are required, these should be as atraumatic as possible and the patient should be reviewed.

It is not possible to cure someone with ORN and there is great reliance on their body healing itself. Hyperbaric oxygen has been trialled as a way to manage ORN. If left over time, it may continue to spread through the jaw and can lead to fractures.

7) Medication-related Osteonecrosis of the jaw (MRONJ)

Historically, this was caused by bisphosphonate medications (medications that reduce bone turnover – antiresorptive). These are commonly given in conditions such as osteoporosis, Paget’s disease and prevention of bone metastasis. They could be given orally or intravenously. Intravenous delivery carries a higher risk of MRONJ. More recently, it has been discovered that other medications may also cause the same problems with healing, such as antiangiogenics, so care must be taken when assessing a patient’s medical history.

MRONJ refers to an area of exposed or necrotic bone in the maxillofacial region that has not healed within 8 weeks, in a patient who has been exposed to an antiresorpative or antiangiogenic medication and has not had any radiotherapy to the head and neck region (AAOMS).

Patients may experience pain, discomfort, mobile teeth, exposure of dead bone or altered sensation. They may develop secondary infections in these areas. Similar to ORN, prevention is vital and patients should be dentally fit prior to commencing therapy. The risk of the patient should be judged, commonly by whether it is oral or IV therapy.

Ideally, extractions should be avoided at all costs. If an extraction is necessary then it should be as atraumatic as possible and a specialist may be better placed for this.

Again, like ORN, MRONJ cannot be treated and you are relying on the patient’s body to heal up. This is a significant risk that patients must be warned of prior to an extraction.

8) Trismus

Trismus may occur due to oedema and swelling, and may be associated with infection. It may also occur due to trauma to the TMJ as a result of force during the extraction or due to haematoma formation following an inferior alveolar nerve block. The cause of trismus should be identified and managed as necessary. Trismus will generally gradually resolve and jaw exercises may be given.

9) Surgical emphysema

Surgical emphysema refers to a collection of air that is forced in the tissue spaces. It may occur intra-operatively due to inappropriate use of a handpiece. It can occur post-operatively due any increase in air pressure, such as blowing up a balloon. Patients will often report a sudden, alarming swelling and when palpated it has a eggshell sound. This will gradually self-resolve over time as the air is absorbed.

Summary

• The complications of tooth extraction are vast and can be divided in to pre-operative, intra-operative and post-operative.
• Pre-operative complications include: difficulty in achieving anaesthesia, poor patient co-operation and difficulty in access.
• Intra-operative complications include: failure to complete an extraction/fracture of the tooth, damage to other teeth, loss of tooth/roots, OACs, soft tissue trauma, damage to nerves, fractures of the alveolus/mandible and dislocation of the TMJ.
• Post-operative complications include: haemorrhage, pain, swelling, dry socket, infection, ORN, MRONJ, trismus and surgical emphysema.
• Good technique and comprehensive clinical and radiographic assessment will minimise many of these complications.
• Management may often involve referral to a specialist.

Quiz

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Recommended Reading

• Essentials of Oral and Maxillofacial Surgery
• Master Dentistry: Volume 1: Oral and Maxillofacial Surgery, Radiology, Pathology and Oral Medicine, 3e