BDJ 2012. Letter to Editor. TMJ Dysfunction

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TMJ DYSFUNCTION as a side effect of long-term treatment TRAUMA BY iPAD Sir, the general dental practitioner may with antipsychotic drugs and approxi- Sir, an 11-year-old boy attended the be the first point of contact for patients mately 10% of patients exposed to these emergency clinic at Glasgow Dental Hos- with TMJ problems. Presenting com- will experience a dystonic reaction.4 It pital and School’s paediatric department plaints may include pain, limitation in is important that GDPs are aware of this in March 2012 following a second inci- mouth opening, clicking and disloca- condition for successful management. dent of trauma to his upper right central tion with occlusal changes. There may Such dislocation of the TMJ is usually incisor. The first incident, a skateboard- also be associated tooth wear. Often the unilateral, although reports have shown ing accident in May 2011, resulted in a symptoms may be related to functional that the mechanical energy derived from middle third comminuted root fracture, habits such as bruxism. the oromandibular dystonia can occa- which healed with connective tissue However, various medications may also sionally cause bilateral dislocations. union after a period of splinting and result in TMJ dysfunction, due to side Classic signs of TMJ dislocation the tooth remained vital. The second effects such as bruxism and TMJ disloca- include pain, inability to completely traumatic incident resulted in an oblique tion. There have been several reported close the mouth, deviation of the jaw to crown fracture at the level of the cervi- incidents of iatrogenic bruxism involving the side, forward protrusion of the man- cal margin (see accompanying radio- diurnal bruxism1 thought to be associated dible, difficulty swallowing, drooling graph, Fig. 1). The coronal fragment was with dopaminergic blockade, and noctur- from the mouth, difficulty chewing and subsequently removed, the exposed pulp nal bruxism. Nocturnal bruxism has been difficulty articulating. Treatment of the extirpated and an overdenture provided reported with venlafaxine, a serotonin/ dislocation requires manual manipula- to restore aesthetics in the short term. noradrenaline reuptake inhibitor, which tion of the joint, aided with the use of Ideally, the root will be obturated and responded to gabapentin,2 as well as three analgesics and benzodiazepines. Botuli- retained in order to facilitate placement selective serotonin reuptake inhibitors num toxin A (BTA) injection therapy is of a single osseointegrated implant at an (SSRIs), paroxetine, fluoxetine and setra- indicated where conservative treatment appropriate age. line. In both reports the SSRI-associated has failed, and surgery carries an unac- bruxism was treated with buspirone. ceptable risk. BTA is also beneficial in Nocturnal bruxism may also be second- patients who suffer recurrent disloca- ary to the SSRI citalopram.3 tion of the TMJ as a result of impaired Phenothiazines are widely used for muscle coordination secondary to their antipsychotic, antiemetic and seda- mandibular dystonia, early and late tive properties. They are known to block dyskinesias, epilepsy and brain stem the dopamine receptors in the brain, syndromes of various origins. which may account for their extrapy- K. Bhuva, W. Matthews, ramidal side effects. These side effects L. M. Carter, A. Kanatas cause various movement disorders Leeds including oral bucco-lingual dyskinesia 1. Brown E S, Hong S C. Antidepressant-induced (continual side to side or circular chew- bruxism successfully treated with gabapentin. J Am Dent Assoc 1999; 130: 1467–1469. ing movements of the jaw) and oroman- 2. Ellison J M, Stanziani P. SSRI-associated nocturnal dibular dystonia (OMD). OMD is a focal bruxism in four patients. J Clin Psychiatry 1993; 54: 432–434. dystonia manifested by involuntary 3. Wise M. Citalopram-induced bruxism. Br J Psychia- muscle contractions producing repeti- try 2001; 178: 182. 4. Maestre-Ferrín L, Burguera J A, Peñarrocha-Diago tive, patterned mouth, jaw, and tongue M, Peñarrocha-Diago M. Oromandibular dystonia: movements.4 This is often referred to as a dental approach. Med Oral Pathol Oral Cir Bucal primary (idiopathic) or secondary dysto- 2009; 15: e25–27. Fig. 1 Oblique crown fracture at the cervical margin nia. The latter most commonly develops DOI: 10.1038/sj.bdj.2012.728