Changes in temporomandibular joint sounds after botulinum toxin injection into masticatory muscles

Abstract

Temporomandibular joint (TMJ) sounds such as clicking/popping or crepitus that are not associated with any pain and do not affect the movement of joint do not need to be treated. And conservative treatments are not successful in reducing the sounds generally. However, some patients find such joint sounds themselves to be very distressing.

This study looked at patients who received botulinum toxin (BoNT) injection into their masseter and/or temporalis muscles for treatment of myofascial pain, bruxism, clenching, or chronic migraine. To identify the related factors underlying changes in production of TMJ sounds, patients who ceased producing TMJ sounds were compared to those who continued producing TMJ sounds following BoNT injection.

This study found that only the degree of cheek ridging differed significantly between the groups. This suggests that weakening the intensity of masticatory muscle contraction by BoNT injection could be responsible for reducing TMJ sounds by decreasing the joint loading or microtrauma. BoNT injection into the masseter and/or temporalis muscles may reduce distressing TMJ sounds and serve as an alternative treatment for patients who have moderate to severe cheek ridging. However, since this study was subject to several limitations, the results need to be confirmed in future well-controlled prospective studies.