Two unusual cases of temporomandibular joint effusion in children are presented. The differential diagnosis, radiographic imaging, treatment, and possible etiologies are described.
Temporomandibular joint (TMJ) effusion is rare in children, but has been reported in association with trauma, infection, and arthritis. Effusions in the TMJ can cause pain, trismus, malocclusion, and jaw deviation. The purpose of this report is to present two unusual cases of TMJ effusion leading to sudden onset malocclusion and discuss the aetiology.
An 11-year-old healthy boy reported that he had developed difficulty chewing, opening his mouth, and a malocclusion 5 days after having a routine maxillary right molar amalgam restoration. He was otherwise well with no constitutional symptoms. There was no history of trauma, recent travel, or exposure to pets or allergens. On clinical examination the patient had facial asymmetry with deviation of the mandible to the right, and mild tenderness and pain in response to palpation of the masseter and medial pterygoid muscles. His maximal incisal opening was 30 mm without pain and his mandibular dental midline was 5 mm to the right of the maxillary dental midline. He had an anterior and a right posterior crossbite ( Fig. 1 ).
There was no obvious abnormality of the TMJ on panoramic radiograph; the condyles were well corticated and seated in the fossa. A computerized tomographic (CT) scan with contrast showed a peripherally enhancing low density collection in the left TMJ without evidence of bony pathology. A magnetic resonance imaging (MRI) study demonstrated a moderate joint effusion in the left TMJ, extending anteriorly into the infratemporal fossa, with synovial thickening ( Fig. 2 ).