Wrong parameters – no results

By Jan Tunér

Comment on:

de Carli ML, Guerra MB, Nunes TB, di Matteo RC, de Luca CE, Aranha AC, Bolzan MC, Witzel AL. Piroxicam and laser phototherapy in the treatment of TMJ arthralgia: a double-blind randomised controlled trial. J Oral Rehabil. 2013; 40 (3): 171-178.

Abstract

This study aimed to evaluate the efficacy of piroxicam associated with low-level laser therapy compared with single therapies in 32 patients presenting temporomandibular joint arthralgia in a random and double-blind research design. The sample, divided into laser + piroxicam, laser + placebo piroxicam and placebo laser + piroxicam groups, was submitted to the treatment with infrared laser (830 nm, 100 mW, 28 s, 100 J cm2) at 10 temporomandibular joint and muscle points on each side during four sessions concomitant to take one capsule a day of piroxicam 20 mg during 10 days. The treatment was evaluated throughout four sessions and 30 days follow-up through visual analogue scale (VAS), maximum mouth opening and joint and muscle (temporal and masseter) pain on palpation. The results showed that all the study groups had a significant improvement in the VAS scores and there were no significant group differences. Piroxicam was effective in the reduction of joint and muscle pain on palpation and showed the lowest temporal pain at the 30-day follow-up. The combination of low-level laser therapy and piroxicam was not more effective than single therapies in the treatment of temporomandibular joint arthralgia. The use of piroxicam was more effective in the following 30 days.

The outcome of this study is in favour of a NSAID over LPT. Is there a reason? Yes!

The patients were divided into three groups:

1) Group L: active laser and placebo piroxicam (11 patients).

2) Group Pi: placebo laser and piroxicam (10 patients).

3) Group LPi: active laser and piroxicam (11 patients).

In group 1 the patients received daily NSAID, whereas the two laser groups were treated at four sessions during 10 days. This is reasonable, since there is a cumulative effect of LPT, in contrast to the NSAID. 10 points on each side were irradiated with 2.8 J per point, five over the TMJ (14 J), three over the temporalis (8.4 J) and two over the masseter (5.6 J). This gives a total of 56 J per session, both sides counted. What is obvious is that the small and superficial TMJ is overdosed with the 14 J. This energy would be reasonable for acute pain, but not for reduction of inflammation. Quite on the contrary, inflammation is best reduced with low energies and long-time [1]. de Almeida [2] compared 1, 3, 6 or 9 J of energy to reduce inflammation and found that the lowest energy was the most effective one. As for the muscles, the situation is different. Here we have thick tissues containing a lot of blood and with consequent poor penetration. WALT recommendation for 808 nm and TMJ is 4 J [3]. For the masticatory muscles there is no recommendation, but is for similar muscles 8 J per point.

Piroxicam is an NSAID and, as such is a non-selective COX inhibitor, possessing both analgesic and antipyretic properties. The dosage of this pharmaceutical is tested and well known, and a fair short term result is to be anticipated. The long term effect of NSAIDs is, on the other hand also too well known.

It is my conclusion that the comparison between NSAID and LPT in the above study is negative because of the selected parameters.

References

[1] Castano A P, Dai T, Yaroslavsky I, Cohen R, Apruzzese W A, Smotrich M H, Hamblin M R. Low-level laser therapy for zymosan-induced arthritis in rats: Importance of illumination time. Lasers Surg Med. 2007; 39 (6): 543-550.

[2] de Almeida P, Lopes-Martins R A, Tomazoni S S, Albuquerque-Pontes G M, Santos L A, Vanin A A, Frigo L, Vieira R P, Albertini R, de Tarso Camillo de Carvalho P, Leal-Junior E C. Low-Level Laser Therapy and Sodium Diclofenac in Acute Inflammatory Response Induced by Skeletal Muscle Trauma: Effects in Muscle Morphology and mRNA Gene Expression of Inflammatory Markers. Photochem Photobiol. 2012 [Epub ahead of print]

[3] http://waltza.co.za/wp-content/uploads/2012/08/Dose_table_780-860nm_for_Low_Level_Laser_Therapy_WALT-2010.pdf