BURNING MOUTH SYNDROME

[Drsumitra]

Chronic Myogenous Facial Pain/Myofacial Pain

 

Orofacial pain of muscular origin is often referred to as myofacial pain. The current conservative treatment approach includes the use of nonsteroidal anti-inflammatory medications, soft diet, and occlusal splint. Other medications such as muscle relaxants and tricyclic antidepressants have been used. Some clinicians advocate the use of other modalities such as massage therapy, ultrasound therapy, and transcutaneous electric nerve stimulation. More than 80% of patients respond to conservative therapy.¹³

 

For those patients who are refractory to these treatments and continue to suffer significant pain and dysfunction, treatment with BTX has been proposed. As mentioned previously, patients with masseteric hypertrophy and pain often respond well to BTX A administration to the affected muscles. In a randomized, blinded, placebo-controlled study by Von Linden, et al⁷, 90 patients with chronic facial pain were treated (60 BTX A, 30 placebo). Patients received on average 35 units of BTX A to affected muscles (masseter, temporalis, or medial pterygtoid), and 0.9% normal saline was used as a control. The data indicated that 91% of those who received BTX A reported improvement, with a significant mean reduction of approximately 3.2 on the visual analog pain scale (VAS 0 to 10).

 

It is believed that BTX A hinders trigeminal nerve activity not only by preventing the release of acetylcholine but also preventing the release of substance P. Substance P is a potent neurotransmitter that plays a role during neurological inflammation.⁷ Furthermore, BTX A therapy can indirectly alleviate pain of arthrogenic origin. This is achieved with the prolonged “joint-sparing” effect of diminished loading secondary to the decreased ability of the musculature to affect joint loading.⁸

 

A study by Freund, et al⁹ also supports the effectiveness of BTX A in the reduction of myogenic pain associated with the TMJ. Forty-six patients with TMD were treated with a total dose of 150 units of BTX A (50 units per masseter and 25 units per temporalis). During the following 8 weeks these patients had a mean 3-point reduction in the 0 to 10 VAS pain score. There were no controls in this study.⁹

 

A study by Nixdorf, et al10 of 15 patients (10 completed the study) examined the use of BTX A for chronic myogenous orofacial pain. This report did not show a statistically significant improvement in the group that received BTX A versus normal saline. In the discussion, they acknowledged the small number of patients in the study.¹⁰