Dental injury during anaesthesia and surgery (G133)

General anaesthesia is a state of controlled unconsciousness during which a patient will likely require instrumentation of their airway to maintain oxygenation. In so doing, medical equipment is utilised in and around the patient’s mouth and accidental dental trauma may occur. This can occur at any point until recovery of full consciousness is achieved.

Additionally, this guideline supports any surgical team (e.g. ENT, Maxillofacial surgeons and any endoscopy practitioner) operating in and around the mouth, as well as clinicians who may introduce bite blocks and endoscopes into “shared airways” alongside an anaesthetist or as a sole practitioner.

Types of trauma that may occur include minor cuts or bruising to the lips and tongue in about 1 in 20 general anaesthetics¹. These will likely heal quickly without any intervention. Sometimes, native teeth or dental restorations (such as fillings, veneers, crowns, bridges and implant crowns) may be chipped, fractured, mobilised or completely removed. The most frequently involved teeth are the upper anterior teeth^2,3,4. Trauma to a tooth requiring subsequent restoration or removal occurs in around 1 in 4,500 general anaesthetics⁴. Traumatic pressure may occur to nerves supplying the tongue leading to temporary loss of sensation and/ or function but accurate figures do not exist. This is likely to be rare or very rare.

With this guideline, NHS Ayrshire & Arran aims to provide guidance to all care providers in documentation of accurate pre-operative dental assessment, consent process, minimising the risk of dental injury and managing it correctly.

Anaesthetic terms

• Shared airway – The term used to describe procedures where the anaesthetist has to maintain a patient’s airway and ventilation in the same anatomical space as the operator.

Dental terms

• GDP – General Dental Practitioner, i.e. the patient’s own dentist with whom they should be registered.
• Filling – A dental material (tooth-coloured or otherwise) is bonded to the tooth to restore form, function and aesthetics. Commonly in the anterior region these are tooth-coloured and more posteriorly may be metallic in colour.
• Veneer – A thin covering of the front surface of a tooth, usually constructed of tooth-coloured material, used to restore discoloured, damaged, misshapen or misaligned teeth.
• Crown – Also known as a “cap”. An artificial replacement that restores missing tooth structure by surrounding the remaining tooth (goes all the way around tooth as opposed to a veneer). Retained by dental cement and/or shape of underyling tooth. Can also sit on a dental implant.
• Bridge – An artificial replacement for 1 or more missing teeth, cemented to the adjacent teeth. It can be found on implants as well. It is a permanent fixture and cannot be removed temporarily by the patient.
• Implant – A (usually) titanium screw(s) placed in the jaw bone which integrates with the bone and provides the foundation for placement of a crown or bridge to replace a missing tooth/teeth. Cannot be removed by the patient.
• Denture – Also known as “false teeth”. An artificial substitute for some or all of the native teeth. Can be made of acrylic or combination of acrylic and metal. Can be removed by the patient. Can be full or partial.

Dental trauma terms

• Avulsion – Complete displacement of the tooth out of its socket.
• Subluxation – an injury to the tooth supporting structures with increased mobility but without displacement of the tooth.
• Extrusion/intrusion/lateral luxation – displacement of tooth within the socket.
• Uncomplicated fracture – does not involve the pulp (nerve) of the tooth.
• Complicated fracture – involves the pulp (nerve) of the tooth.

Dental nomenclature - permanent (adult) teeth

In general, when documenting a dental injury a descriptive summary will suffice, however some may choose to use established dental nomenclature for the avoidance of doubt.

The dentition is divided into quadrants of the mouth, and always described from the patient’s perspective. The permanent teeth are given numbers 1-8, starting from the midline and working backwards. Identities may be challenging when numerous native teeth are already missing.

• UR - Upper right quadrant: upper right first incisor to upper right wisdom tooth.
• UL - Upper left quadrant: upper left first incisor to upper left wisdom tooth.
• LR - Lower right quadrant: lower right first incisor to lower right wisdom tooth.
• LL - Lower left quadrant: lower left first incisor to lower left wisdom tooth.

Example – if a patient’s top front incisor on their left is damaged, this is UL1.

Dental nomenclature - primary (baby) teeth

Primary teeth are also known as deciduous teeth. A child typically loses their primary teeth gradually between the ages of 6-13. The nomenclature is similar, although letters A-E are used instead of numbers as shown:

Staff working in or around the airway are trained to be aware of the potential for damage to teeth. Recognition and discussion around risk of dental injury specific to the patient and procedure in question should form part of the consent process undertaken by healthcare providers.

Identifying risks associated with dental injury

Patient factors

• Poor dental health.
• Loose tooth/teeth e.g. primary (baby) teeth or teeth with gum disease.
• Previous dental injury.
• Presence of pre-existing restorative dental treatment e.g. fillings, veneers, crowns, bridges and implants.
• Orthodontic appliances (wires, bands, brackets)
• Limited mouth opening.
• Known or predicted difficult intubation.

Pre-operative assessment

• Thorough generic airway assessment.
• Ask patient about loose teeth with demonstration of mobility.
• Universal and tailored risk discussion regarding the risk of dental injury.
• Documentation in patient record.

Prevention

• Consider referral of high risk patients to a dentist pre-procedure if appropriate.
• It may be appropriate to intentionally extract a tooth before airway instrumentation, with the patient’s consent, to avoid the risk of a foreign body in the airway.
• Consider use of a bite block on solid back teeth e.g. rolled up swabs.
• Consider avoidance of airway instrumentation if appropriate.
• Consider use of alternate equipment to instrument the airway if appropriate e.g. choice of indirect versus direct laryngoscopy techniques.

Anaesthetic procedure planned

• Supraglottic airway device (LMA/iGel)
• Laryngoscopy/tracheal intubation.
• Yankauer suction.
• Guedel airway.
• Shared airway procedures involving laryngoscopy, retractors, gags, bite blocks, endoscopy etc.
• During insertion of nasogastric tube.

Surgical procedure planned

• Shared airway surgery usually ENT and maxillofacial procedures.
• Endoscopy/bronchoscopy.

Consent

Informed consent regarding dental trauma should occur during pre-assessment.
Explain the incidence of dental injury during anaesthesia (1:4500) and also explain the reason(s) for a higher than background risk likelihood of dental injury in individual circumstances.

Communication

Concerns surrounding risk of dental trauma should be communicated to theatre team members at the time of the WHO brief and airway management planned accordingly. Effective communication at recovery handover will ensure safe removal of any airway equipment in all patients at risk of dental trauma.

Avulsion (whole tooth out of socket)

Primary (baby) tooth

• Do not re-implant.
• Advise conservative advice (soft diet for 1 week, good oral hygiene, analgesics if required) and review with patient’s own General Dental Practitioner (GDP)

Permanent (adult tooth)

• Handle tooth by crown and avoid touching root of tooth.
• Tooth can be re-implanted if safe to do so. It could be considered a potentially loose foreign body in an unconscious patient so judgement is advised.
• If tooth is suitable for re-implantation, this should be done as quickly as possible and definitely within 60 minutes. It can be performed by the local staff recognising the injury. If referring, ensure to convey that tooth has been “avulsed from socket”
• Otherwise submerge tooth in saline (not water)
• Control any active haemorrhage from gum with pressure applied using damp sterile gauze.
• Contact Oral and Maxillofacial Surgery (OMFS) on-call for advice/assessment/treatment as necessary.

Fracture (chipped/broken)

Uncomplicated fracture (pulp is not involved)

• Recover fractured component to ensure not inhaled nor ingested. Give this recovered component away with the patient in a specimen pot as their dentist may be able to utilise this.
• Conservative advice including: soft diet, good oral hygiene in area and avoidance of hot/cold/sweet substances which may cause increased sensitivity.
• See GDP as soon as reasonably possible for assessment, treatment and follow up.

Complicated fracture (pulp is involved)

• Recover fractured component to ensure not inhaled nor ingested. Give this recovered component away with patient in specimen pot as their dentist may be able to utilise this.
• Advise patient of need for urgent dental review with their General Dental Practitioner ASAP as there is a likelihood of pulpal death (nerve of tooth dying), which aside from the pulp exposure itself can lead to pain/infection.
• Conservative advice meantime including: soft diet, good oral hygiene in area, avoidance of hot/cold/sweet substances which may cause increased sensitivity and analgesics.

Lost tooth, tooth fragment or restoration

• Consider possibility of inhalation or ingestion and manage accordingly.
• Once excluded, management as above.

For all instances of accidental dental damage, the following procedure should be considered:

1. Administer appropriate first aid to the injury as outlined above.
2. The patient should be informed and an apology offered in line with duty of candour principles.
3. Document an accurate report of the incident in the patient’s notes/anaesthetic record.
4. Complete a Datix clinical incident form http://xhdatix/datix/live/index.php
5. If a trainee, inform your supervising consultant at an appropriate time

A likely outcome is that an assessment and subsequent repair to the dental injury is required to be undertaken as an outpatient by the patient’s own general dental practitioner (GDP).

Procedure if dental repair is recommended

The patient can be advised that the health board may consider covering reasonable expenses towards a repair following the injury e.g. like-for-like repair of an existing restoration or appropriate NHS based treatment.

In this situation an outpatient review with their GDP will be required to be arranged by the patient at the earliest opportunity. The GDP should seek prior approval before proceeding with treatment. Suggested procedure:

Patient information leaflets from the Royal College of Anaesthetists regarding dental damage are available below: 

Royal College of Anesthetists. Anaesthesia explained. 2021.

Royal College of Anaesthetists. Risks associated with your anaesthetic. Section 4: damage to lips, teeth and tongue. 2019.

Sample letter. Copies to both patient and GDP from Crosshouse site.

Sample letter. Copies to both patient and GDP from Ayr site.