Guideline 43: Management of Unerupted and Impacted Third Molar Teeth

Management of Unerupted and Impacted Third Molar Teeth
Section 5: Clinical management

Every effort should be made at the time of the operation to minimise or avoid complications and side effects of the operative procedures.

5.1 Preoperative management

Preoperative management requires, as a minimum, the taking of a detailed history plus clinical and radiological assessment (see section 4). A decision is made with regard to which third molars should be removed (see sections 2 and 3) and, once fitness for surgery is established, informed consent must be obtained (see section 5.8).⁷²

After referral but prior to surgery, interim measures may include systemic antibiotic administration, chlorhexidine mouth rinses, operculectomy, local dressing and lavage.⁷

Referring practitioners should contact the surgeon to expedite treatment if a patient on a waiting list experiences recurrent bouts of infection.

5.2 Anaesthesia

Methods of anaesthesia include local anaesthesia, local anaesthesia with intravenous sedation, and general anaesthesia. It is common practice to use local anaesthesia in general anaesthesia cases to improve field of vision and cardioprotection. In general dental practice, the former two methods are considered appropriate, but still require suitable facilities to be available.⁷³ General anaesthesia may be needed for complex and lengthy procedures but it must be recognised that local anaesthesia carries less risk.⁷² Recent General Dental Council guidance emphasises that general anaesthesia is a procedure which is never without risk and that 'in assessing the needs of an individual patient, due regard should be given to all aspects of behavioural management and anxiety control before deciding to prescribe or to proceed with treatment under general anaesthesia'. ⁷⁴ Evidence level IV

5.3 Surgical procedure

The procedure is variable and is influenced by the type of impaction and surrounding structures, for example proximity of the inferior alveolar and lingual nerves. Generally surgery involves the raising and protection of soft tissue flaps and bone removal with either chisel or bur with water cooling irrigation. There is conflicting evidence as to the most appropriate form of protection for the lingual nerve.^{75,
76}

The whole tooth should be removed and wound toilet completed. Any suspected pathological material should be sent for a histopathology report.

Resorbable sutures may be used at any time but particularly where no review is planned.

Occasionally a decision to leave a small fragment of apical root of a vital tooth may be made if its removal carries a greater risk of complications than retention.⁷⁷ The patient should be informed and such events recorded in the notes.⁷⁸

5.4 Other procedures

Other, rarely performed procedures include surgical periodontics, which can be considered in carefully selected cases with the proviso that subsequent removal of the tooth may be required. In selected cases, surgical exposure can be carried out. Surgical reimplantation/transplantation may be appropriate treatment in selected cases. The advice of an experienced orthodontist is helpful in these cases.

5.5 Perioperative drug therapy

5.5.1 ANTIBIOTICS

Where there is significant bone removal, prolonged operation time, or the patient is at increased risk of infection, it is common practice to prescribe antibiotics.^{79,
80} However, the limited evidence available is insufficient to make a recommendation on the routine use of antibiotics for third molar removal. Evidence level IV

In severe cases, where there is acute infection at the time of operation, significant bone removal, or prolonged operation, antibiotics should not be withheld.

5.5.2 ANALGESIA

Normal practice is to prescribe or advise oral analgesics such as paracetamol or ibuprofen for outpatients.⁸¹ For inpatients a number of options including non-steroidal anti-inflammatory agents and opiates are commonly prescribed. Pre-emptive analgesia may be considered. Evidence level IIb

5.5.3 STEROIDS

Where there is a risk of significant postoperative swelling, pre- or peri-operative administration of dexamethasone or methyl prednisolone has been shown to reduce swelling and discomfort.^{82,
83, 84} Evidence level Ib

Preoperative steroids should be considered (unless contraindicated) where there is a risk of significant postoperative swelling.

5.6 Complications associated with treatment

As noted earlier, removal of third molars is a common surgical procedure and - as with all surgical procedures - there is a risk of operative and postoperative complications. The rate of complications and their severity varies,¹² but the management of common and more serious complications is described below.

5.6.1 COMMON COMPLICATIONS

(a) Haemorrhage

Haemorrhage must be controlled at the time of surgery. Soft tissue bleeding may require haemostatic agents, bipolar diathermy and/or sutures. Occasionally a small amount of bone wax is necessary to control bleeding from bone, but this must be used with caution. Haematoma formation outwith the socket can occur and may require drainage.

(b) Ecchymosis

Patients should be informed that bruising is common and self-limiting and will usually resolve within two weeks of surgery.

(c) Infection

Infection of the soft tissues may result in secondary haemorrhage, cellulitis or, rarely, abscess formation.⁸⁵ Evidence level III

Where signs of systemic involvement are present (pyrexia, regional lymphadenopathy) antibiotics should always be prescribed.

Alveolar osteitis (dry socket) may occur in c. 20% of patients, particularly in those who smoke.⁸⁶ Irrigation with saline (or chlorhexidine 0.2%) and/or placement of an obtundent, such as proprietary iodoform based medication, usually reduces the pain.⁸⁷ Evidence level III

Rarely, osteomyelitis may occur which requires long term antibiotic therapy and/or further surgery in a hospital environment.

(d) Retention of root fragment

When a retained root fragment gives rise to symptoms it should be removed.⁷³

Any infection should be controlled prior to surgical exploration.

(e) Displacement of tooth

A lower third molar or tooth fragment may be displaced into the lingual tissues, whilst an upper third molar may pass into the infratemporal fossa.

Appropriate instruments should be in place prior to elevation to help minimise the occurrence of displacement. Where this occurs, every effort should be made at the time of surgery to recover the displaced tooth, but referral to a specialist centre may be required.

(f) Wound dehiscence

Where wound dehiscence occurs without the development of pain and infection, patients should be advised to continue wound toilet, e.g. hot salty mouthwashes and socket syringing.

(g) Damage to adjacent teeth

Patients should be told about damage to adjacent teeth at the time of surgery or, if under sedation or general anaesthetic, when they are fully conscious. The consequences of this damage should be explained to the patient and recorded in the patient's notes. If repair is required, the operator should arrange appropriate management.

(h) Periodontal health

The periodontium distal to the mandibular second molar may be affected by removal of an impacted third molar. Early removal of mesio-angular horizontal impacted third molars is associated with better periodontal health.⁴¹ Evidence level III

5.6.2 SERIOUS COMPLICATIONS

The following complications carry significant risk of morbidity and may require immediate referral. The patient should be informed, and a record entered in the patient's notes. Evidence level III

(a) Fracture of the mandible

Fractures should be noted at the time of surgery and repaired if necessary. If the operator is unable to do this, he/she must arrange immediate referral.

(b) Fracture of the maxilla

Tuberosity fractures may occur and should be treated at the time of surgery. If the operator is unable to do this, he/she must arrange an immediate referral.

(c) Oro-antral communication

Oro-antral communication is probably a more frequent occurrence than is realised and thus probably often heals spontaneously.

Any such defect identified at the time of surgery should be repaired, usually with a buccal advancement flap. Antibiotic therapy is advisable and the patient should avoid nose blowing.

(d) Retained foreign body

Any broken instrument should be removed at the time of the operation. If not retrievable, the patient should be told and this recorded in the notes.

(e) Nerve damage

Complete transection of the lingual or inferior dental nerves requires immediate nerve repair by an experienced surgeon. Where there is partial damage, gentle debridement and the maintenance of good apposition of the ends is normally undertaken. The patient should be informed of the situation.

One recent study has shown that significant improvement in nerve function can be achieved by specialist surgical investigation and repair.⁸⁸ Evidence level III

Late recognition of nerve damage may require further surgical exploration.

5.7 Outcomes of unerupted third molar management

Outcomes in response to surgical or non-surgical management of third molar teeth may be successful or unsuccessful. Outcomes must be defined and quantified to enable audit to establish best practice. The success or otherwise of the procedure ideally should be viewed from the perspective of the patient.

A review appointment is required: ⁸⁹

when non-resorbable sutures have been placed
when complications arise
at the patient's or surgeon's request.

5.7.1 SUCCESSFUL OUTCOME

This is achieved when the presenting symptoms and signs of disease associated with a third molar tooth have been eliminated and the tissues have fully healed with no residual functional deficit.

During normal healing it is usual for the patient to experience some discomfort, swelling and trismus over the first three postoperative days. Symptoms should gradually resolve over the next two weeks.

5.7.2 UNSUCCESSFUL OUTCOME

This indicates that complications associated with treatment have occurred and are persistent. These long term complications may include:

Persistent pathology
Severe infection, for example osteomyelitis, requires long term antibiotic therapy and probably further surgery.

Sensory nerve damage
Damage to the lingual nerve leading to sensory disturbances usually improves with time. However, persistence of symptoms beyond three months indicates that a return to normal function is unlikely and that consideration should be given to nerve repair.⁸⁸
Damage to the inferior alveolar nerve, leading to persistent hypoaesthesia/dysaesthesia in its sensory distribution, is less amenable to surgical repair. The prognosis for spontaneous nerve regeneration after six months is poor.¹²

Oro-antral fistula
This requires surgical repair as outlined earlier (see section 5.6.2).
Temporal mandibular joint dysfunction
Appropriate jaw exercises, soft diet, analgesia and oral appliances may be helpful.
Psychological complications
Such complications are rare. It is best practice to refer the patient to their GMP as there may be other underlying contributing factors.
Damage to adjacent teeth.

An audit trail should be set up to enable outcome to be monitored, both clinically and from the patient's viewpoint.

5.8 Patient information

It is recognised that good communication is central to the clinician-patient relationship and to good clinical care. Patients require information about the options available for management of their third molars, together with an explanation of the operation/procedure itself.

At the preoperative appointment, the potential outcome of any chosen course of action - adverse or otherwise - should be explained to the patient in terms that they can easily understand. Details should be noted in the patient's records and should include aspects relating to the patient's quality of life.^{90,
91} In addition, care should be taken to explain to the patient the consequences of not having the tooth removed and other treatment options which may be required in this event.

The information provided should be sufficient to enable the patient or their carer to make a valid informed decision and give consent.⁷² The US National Institutes of Health recommend that patients should be informed of potential surgical risks including any transitory condition that occurs with an incidence >5% and any permanent condition with an incidence >0.5%.³¹

At the time of surgery, the patient should be reminded of the possible complications and side-effects of the operation. The operator should ensure that consent has been obtained, that the patient still wants to go ahead with the procedure, and a note should be made in the patient's records.

At the time of the operation, the patient should know:

How to contact the surgeon in case of emergency
How to look after their mouth postoperatively
Possible complications and side effects of the operation in general and any problems specific to the operation undertaken
Any drug therapy required
Whether a review appointment is required and if so, when
That postoperatively the referring practitioner will receive a letter detailing the treatment undertaken.

Key messages for patients from this guideline are noted in Annex 2.