Sir, we would like to report a case of temporomandibular joint (TMJ) dislocation which occurred during administration of an inferior alveolar nerve block.

A 28-year-old male patient was being administered inferior alveolar nerve block by his dentist for a class II filling in the 36, when the patient felt a click in the right TMJ, with associated pain and inability to close his mouth. A diagnosis of unilateral TMJ dislocation was made, however, no attempt was made to reduce the dislocation and the patient was referred to the Accident and Emergency department.

The dislocation was spontaneous. The patient did not have any previous history of clicking, subluxation, trauma or dislocation of the TMJ.

An orthopantogram was performed (Fig. 1) and the patient was referred on to the maxillofacial team. Clinical history and examination was not suggestive of connective tissue disorders like Ehler danlos or Marfan's syndrome. The patient was in considerable pain. There was a palpable deformity and the TMJ was low on the same side.

Figure 1
figure 1

Dislocated right condyle

Full size image

Two millilitres of local anaesthetic was infiltrated around the right TMJ and the dislocation was reduced with considerable effort using a combined intraoral and extra oral technique. No sedation was required. The patient was advised not to open his mouth wide and to support his jaw. He was subsequently discharged with an analgesic prescription and warned about further risk of dislocations.

Non-traumatic dislocations of the TMJ occur most commonly while yawning, eating, dental treatment, endoscopy1 and oral intubation.2 Most dental treatments require the patient to open his or her mouth wide for a long period of time, which makes it likely for the dislocation to occur in the dental surgery. The risk of dislocation can be minimised by asking the patient to bite on a mouth prop and ensuring adequate rest during prolonged treatment.

In this particular patient, four hours had elapsed since the dislocation during which time the patient had been in a lot of discomfort. Spasm of the masseter and pterygoid muscles worsens as time progresses, rendering reduction difficult. In addition, complications of reduction such as fracture of the condyle and the articular eminence are rare if reduction is achieved early using the correct techniques.

All the tools that are required to reduce a non-traumatic dislocation which occurs in the dental surgery are within easy reach of a general dental practitioners ie local anaesthetic, panorex and if necessary sedation. It is far easier to relocate it immediately and the morbidity is much reduced if the dislocation is reduced as soon as possible. If needed, the patient may then be referred on to a maxillofacial unit.

Reduction of dislocated TMJ is being taught as a mandatory skill for physicians working in the emergency department. During dental school, the theoretical management of TMJ dislocation is covered in the curriculum. However, no attempt is made to train using mannequins or simulators to teach practical skills at reduction.

We would like to emphasise the need to include teaching practical techniques in undergraduate dental education.