Efficacy of Photobiomodulation Therapy Using 980nm Versus 635nm Diode Lasers for Treatment of Myofascial Pain
Phase: NA
Conditions: Myofascial Pain Syndrome
Sponsor: National Institute of Laser Enhanced Sciences

 
 
Efficacy of Photobiomodulation Therapy Using 980nm Versus 635nm Diode 
Lasers in the Management of Myofascial Pain Syndrome (LLLT-
MPS_sEMG) 
 
 
NCT Number: NCT07069764 
 
 
Document Date: 25 March 2024 
 
 
 
 
 
 
 
 
 
 
 

 
 
Introduction 
Temporomandibular disorders (TMDs) are the most  common non dental 
orofacial pain influencing tempomandibular joint (TMJs), orofacial muscles, or 
both.(1) 
 
The Most common symptom is pain, which is generally localized to the 
masticatory muscles,pre_auricular area and temporomandibular joint.(1,2)  
 
The significant clinical signs and symptoms of TMDs are muscle/TMJ pain, TMJ 
sounds, limitation, deviation, or deflection of mandibular movements(3) 
The prevalence of TMDs is higher among people in the 25-45 age range, women 
are more affected, and psychosocial problems cause higher prevalence and 
greater intensity of TMD symptoms.(3) 
Surgical approaches are only indicated in patients without any improvement 
following conservative treatments after at least six months and those with 
severe disability.(3) 
 
IN DENTISTRY,  Low-level laser therapy (LLLT), recently named 
photobiomodulation which has been  
      Photobiomodulation therapy (PBMT) has an anti-inflammatory effect due to 
the light absorption in intracellular photo-acceptors and modulation of cell 
responses. Photo biomodulation therapy emitting infrared spectrum.(4,6) 
Photobiomodulation therapy (PBMT) increases the blood microcirculation, 
vascularization, and proliferation of the fibroblasts cells, ATP production, as well 
as reducing edema and the level of cyclooxygenase-2 (COX2) and prostaglandin 
E2 (PGE2) as a result of increased lymphatic flow.(4,5) 
 
RECENTILY, Evaluation of the effect of photobiomodulation therapy depend on 
pain intensity, maximum mouth opening(MMO), lateral movements(LM), 
protrusive movements(PM), pressure pain threshold, electromyography activity 
and TMJ sounds in patients with TMDS.(3,4,5) 
 

 
 
 
 Photobiomodulation therapy  has been used to relieve pain for 
temporomandibular  disorders in combination with conventional therapies such 
as physiotherapy exercises and occlusal splints. Published outcome data report 
diode lasers with a wavelength of between 650 and 1000 nm, with fluences of 
between 1.5 and 140  J/cm2. Treatments are usually repeated two or three 
times a week until the symptoms have disappeared.(7)  
 
 

 
 
Review of literature 
Nima Farshidfar in 2023 , Effects of PBMT on the alleviation of pain and improvement in Maximum 
mouth opening. Using the infrared diode laser with a wavelength ranging between 780-980 nm, an 
energy density of <100j/cm2, and an output power of  ≤500 mW for at least six sessions of 
treatment seems to be a promising option for treating mentioned TMDs signs and symptoms.(1) 
 
Ahmed Fadhel Al-Quisi in 2023, Both LED light and LASER therapies could efectively relieve pain 
associated with myogenic TMD as there were no important diferences between their outcomes. 
However, the biosafety and lower cost of the LED light device compared to the LASER should also 
be considered.  The LED light device used in the current study had a wavelength of 660 nm (red 
light) with a power of 1.6 Watt, which is equivalent to 1.6 J of work per second. The Diode LASER 
had the following parameters: wavelength = 810 nm, 2.5 Hz, and power = 1 Watt.(23) 
 
Nahla Mahmoud Awad in 2023, Alaser group showed more improvement in the pain and mouth 
opening measurements infrared lamp therapy. A vicious cycle of pain, muscle spasms, and more 
pain has been said to be broken by enhancing microcirculation through the utilization of laser 
therapy. This could improve the supply of oxygen to the cells in low-oxygen environments and aid 
in getting rid of waste products from cell metabolism. Diode Soft Tissue LASER, , 980 nm, 3.5w 
CW/6.0w) .a 7 W laser beam with a 2.8 cm2 spot size transmitted radiation continuously at an 
intensity of 960 nm. Each application lasted 3 minutes (24 s per application point). For ten days, the 
session was repeated every two days. The laser was applied extra orally to certain points: 
preauricular, mastoid, angle of the mandible, temporal, and zygomatic.(6) 
 
Mohammed Nadershah in 2020,Photobiomodulation therapy proved to be an effective short-term 
therapeutic modality for myofascial TMD pain. It is non-invasive, easy to apply with no systemic 
side effects. Its long-term effect and its effect on different subtypes of TMD need further 
investigation. Patients with unilateral TMJ and masticatory muscles pain during function 
were recruited and divided into two groups: a control group that received a sham laser 
treatment every 48 h for 10 days and a test group that received the same frequency of 
treatment to deliver a dose of 257 J per treatment and a total dose of 1285 J for the entire 
treatment. For the test group, a diode laser was applied using the Ezlase 940 device.A 7 W 
laser beam with a 2.8 cm2 spot size emitting radiation continuously at a wavelength of 
940 nm was applied by the therapist extraorally and at a 2 cm distance from the skin to 5 
points at the temporal (center of Temporalis muscle), zygomatic (origin of Masseter 
muscle), angle of the mandible (insertion of Masseter muscle), pre-auricular, and mastoid 
areas. Each application lasted 2 min (24 s per application point) so that each patient 
received approximately 300 J of energy per treatment .(30) 
 
Sabrina Araújo Pinho COSTA in 2017, treatment of masticatory muscles, The photobiomodulation 
therapy (830 nm) acted effectively on the analgesia of the masticatory muscles in the participants 
with TMD, based on muscular palpation, but was not effective regarding the criteria for mouth 
opening range. Further research is needed to evaluate the long-term effects of PBMT (830nm) on 
the treatment of patients with chronic pain from temporomandibular disorders.(31) 
 

 
 
Aim of the study 
To assess the effect of low level laser therapy (LLLT) to relieve pain in  myofacial pain syndrome 
(MPS), caused by fatigue of temporalis and masseter muscles, by using 980n.m diode laser, and 
compare between diode laser 980n.m and diode laser 635n.m 
 
Materials and methods 
Patient assignment and blinding: 
 
30 PATIENTS. Divided in to 2groups. 
Comparison betweem  two groups , First one, By using diode laser 635n.m(flat top 
handpiece)  
And other group by using diode laser 980n.m 
(flat top handpiece). 
 
 The  hand-pieces fixed at distances of 3 mm and 15 mm from the power meter, only the FT profile 
hand-piece had a constant power output, which was comparable to the contact mode.  
Introusion criteria:-patients with Tmds due to stress,medically free, not to resort to self-medication 
during the study period. 
Extrusion criteria:-patients with bruxisms,erosions,medically free,diabetics 
 
Pico:- 
Population:patients with myofacial pain. 
Intervention:grouo1,using diode laser 635nm 
Comparison:group2,using diode laser 980nm 
Outcome:primary outcome:relief pain 
Secondary outcome: maximum mouth opening(MMO), lateral movements(LM), protrusive 
movements(PM. 
 
The clinical procedure: 
 In all groups, the painful points were determined at each assessment interval. Bilateral muscles 
including masseter (origin, body, and insertion), temporal (anterior, middle, posterior), tendon of 
temporal, and insertion of internal pterygoid as well as temporomandibular joints (TMJs) at rest 
and function were palpated and the painful points were recorded in the patient’s folder.  
 Group 1 (low-level laser therapy): patient received laser treatment with diode laser 635nm with 
flat top hand piece  Applied on the trigger points. 
Group 2(low_level laser therapy):patient received laser treatment with diode laser 980 
nm with flat top hand piece Applied on the trigger points. 
The laser was applied two times a week for 5 weeks.(23,18) 
Both the patient and the operator wore protective goggles during treatment. 
 The patients in all groups were asked not to resort to self-medication during the study period. 
 
 
Patient assessment: 

 
 
 The patients were evaluated before treatment ,after laser applications ,at the end of treatment , and 
1 month after the laser applications.(18) 
Evaluation of the patient is determined by pain intensity, maximum mouth opening(MMO), lateral 
movements(LM), protrusive movements(PM), pressure pain threshold, electromyography activity and 
TMJ sounds in patients with TMDS.(1,3,4,5) 
At each assessment interval, the amount of mouth opening and the range of protrusive and lateral 
excursive movements of the jaw were measured and recorded. To measure mouth opening, the 
patient was asked to open the mouth at both “maximum pain-free” and “maximum possible” 
conditions. 
 
The vertical interincisal distance was then measured with a digital caliper and recorded in millimeters 
in patient’s folder.  
The right and left lateral jaw movement was measured in millimeters by detecting the horizontal 
distance between the midpoints of the upper and lower central incisors.  
A visual analog scale (VAS) was used for calculating pain grade right before our therapy. Patients were 
asked to describe the degree of discomfort/pain from zero to ten, the pain scale read "no pain" and 
"the greatest pain possible. 
Refernces: 
 
1. Nima Farshidfar1# ID , Golnoush Farzinnia2# ID , Nazafarin Samiraninezhad3# ID , Sahar 
Assar4# ID , Parsa Firoozi5 ID , Fahimeh Rezazadeh6* ID , Neda Hakimiha7* ID. doi 
10.34172/jlms.2023.24 
2. Madani A, Ahrari F, Fallahrastegar A, Daghestani N. A randomized clinical trial comparing 
the efficacy of low-level laser therapy (LLLT) and laser acupuncture therapy (LAT) in 
patients with temporomandibular disorders. Lasers Med Sci. 2020;35(1):181-92. doi: 
10.1007/s10103-019-02837-x 
3. Barbero M, Schneebeli A, Koetsier E, Maino P. Myofascial pain syndrome and trigger 
points: evaluation and treatment in patients with musculoskeletal pain. Curr Opin 
Support Palliat Care. 2019;13(3):270-6 
4. Ayyildiz S, Emir F, Sahin C. Evaluation of low-level laser therapy in TMD patients. Case 
Rep Dent. 2015;2015:424213. doi: 10.1155/2015/424213.  
5. Pereira TS, Flecha OD, Guimarães RC, de Oliveira D, Botelho AM, Ramos Glória JC, et al. 
Efficacy of red and infrared lasers in treatment of temporomandibular disorders--a 
double-blind, randomized, parallel clinical trial. Cranio. 2014;32(1):51-6. doi: 
10.1179/0886963413z.0000000005. 
6. Nahla Mahmoud Awad1 , Arwa Ibrahim Mousa2 , Mohamed Kadry Nasr1, 
Clinical Efficacy of Low-Laser Therapy in the Treatment of Fascial Trigger Points: A Randomized 
Prospective Clinical Study, (2023). 

 
 
7. Dompe C, Moncrieff L, Matys J, Grzech-Leśniak K, Kocherova I, Bryja A, et al. 
Photobiomodulation-underlying mechanism and clinical applications. J Clin Med. 
2020;9(6):1724. doi: 10.3390/jcm9061724. 
8. Donald J. Coluzzi Steven P. A. Parker, laser in Dentistry. 
9. Hanna, R.; Agas, D.; Benedicenti, S.; Ferrando, S.; Laus, F.; Cuteri, V.; Lacava, G.; Sabbieti, 
M.G.; Amaroli, A. A Comparative Study between the Effectiveness of 980 nm 
Photobiomodulation delivered by hand-piece with gaussian vs. flat-top profiles on 
osteoblasts maturation. Front. Endocrinol. 2019, 20, 92. [CrossRef] [PubMed] 
10. Rodrigues CA, Melchior MO, Valencise Magri L, Mazzetto MO (2018) Can the severity of 
orofacial myofunctional conditions interfere with the response of analgesia promoted by 
active or placebo low-level laser therapy? Cranio:1–8. https://doi.org/10.1080/ 
08869634.2018.1520950 
11. ) \ Bayani S, Rostami S, Ahrari F, Saeedipouya I (2016) A randomized clinical trial 
comparing the efficacy of bite wafer and low level laser therapy in reducing pain 
following initial arch wire placement. Laser Ther 25(2):121–129. 
https://doi.org/10.5978/islsm.16-OR-10  
12. Eshghpour M, Ahrari F, Takallu M (2016) Is low-level laser therapy effective in the 
management of pain and swelling after mandibular third molar surgery? J Oral Maxillofac 
Surg 74(7):1322.e1321– 1322.e1328. https://doi.org/10.1016/j.joms.2016.02.030 
13. Sardari F, Ahrari F (2016) The effect of low-level helium-neon laser on oral wound 
healing. Dent Res J (Isfahan) 13(1):24–29. https:// doi.org/10.4103/1735-3327.174693 
14.  Heravi F, Moradi A, Ahrari F (2014) The effect of low level laser therapy on the rate of 
tooth movement and pain perception during canine retraction. Oral Health Dent Manag 
13(2):183–188 
15.  Ahrari F, Madani AS, Ghafouri ZS, Tuner J (2014) The efficacy of low-level laser therapy 
for the treatment of myogenous temporomandibular joint disorder. Lasers Med Sci 
29(2):551–557. https:// doi.org/10.1007/s10103-012-1253-6 
16.  10. Moosavi H, Maleknejad F, Sharifi M, Ahrari F (2015) A randomized clinical trial of the 
effect of low-level laser therapy before composite placement on postoperative sensitivity 
in class V restorations. Lasers Med Sci 30(4):1245–1249. https://doi.org/10.1007/ 
s10103-014-1565-9  
17. Moosavi H, Arjmand N, Ahrari F, Zakeri M, Maleknejad F (2016) Effect of low-level laser 
therapy on tooth sensitivity induced by in office bleaching. Lasers Med Sci 31(4):713–719. 
https://doi.org/10. 1007/s10103-016-1913-z. 
18. Seifi M, Ebadifar A, Kabiri S, Badiee MR, Abdolazimi Z, Amdjadi P (2017) Comparative 
effectiveness of low level laser therapy and transcutaneous electric nerve stimulation on 
temporomandibular joint disorders. J Lasers Med Sci 8(Suppl 1):S27–s31. https://doi. 
org/10.1007/s10103-017-2406-410.15171/jlms.2017.s6 
Firoozi P, Amiri MA, Soghli N, Farshidfar N, Hakimiha N, Fekrazad R. The role of 
photobiomodulation on dentalderived mesenchymal stem cells in regenerative dentistry: 
19. Azamsadat Madani1 & Farzaneh Ahrari1 & Amir Fallahrastegar1 & Naeemeh 
Daghestani2. A randomized clinical trial comparing the efficacy of low-level laser therapy 
(LLLT) and laser acupuncture therapy (LAT) in patients with temporomandibular 
disorders. 
Feb;35(1):181-192. https://doi.org/10.1007/s10103-019-02837-x 
 

 
 
20. Firoozi P, Amiri MA, Soghli N, Farshidfar N, Hakimiha N, Fekrazad R. The role of 
photobiomodulation on dentalderived mesenchymal stem cells in regenerative dentistry: 
acomprehensive systematic review. Curr Stem Cell Res Ther. 2022. doi: 
10.2174/1574888x17666220810141411. 
21. Shobha R, Narayanan VS, Jagadish Pai BS, Jaishankar HP, Jijin MJ. Low-level laser therapy: a 
novel therapeutic approach to temporomandibular disorder - a randomized, double-blinded, 
placebo-controlled trial. Indian J Dent Res. 2017;28(4):380-7. doi: 10.4103/ijdr.IJDR_345_15. 
22. . Monteiro L, Ferreira R, Resende T, Pacheco JJ, Salazar F. Effectiveness of photobiomodulation 
in temporomandibular disorder-related pain using a 635nm diode laser: a randomized, blinded, 
and placebo-controlled clinical trial. Photobiomodul Photomed Laser Surg. 2020;38(5):280-8. 
doi: 10.1089/photob.2019.4730. 
23. Ahmed Fadhel Al-Quisi1 , Firas A. Jamil1*, Baseem Natheer Abdulhadi2 and Salah Jassim 
Muhsen1. The reliability of using light therapy compared with LASER in pain reduction 
of temporomandibular disorders: a randomized controlled trial.2023, 
https://doi.org/10.1186/s12903-023-02784-8 
24. Mariana Karina Tasca , Vanessa Ganascini , Maria Luiza Serradourada Wutzke , Márcia 
Rosângela Buzanello Azevedo , Gladson Ricardo Flor Bertolini. Photobiomodulation in the 
treatment of chronic non-specific neck pain. A randomized clinical trial doi: 
https://doi.org/10.5114/pq.2023.120427. 
25. Panhoca VH, de Fatima Zanirato Lizarelli R, Nunez SC, de Andrade Pizzo RC, Grecco C, Paolillo 
FR, et al. Comparative clinical study of light analgesic effect on temporomandibular disorder 
(TMD) using red and infrared led therapy. Lasers Med Sci. 2015;30(2):815–822; doi: 
10.1007/s10103-013-1444-9 
26. Alayat MSM, Battecha KH, Elsodany AM, Alzahrani OA, Alqurashi AKA, Jawa AT, Alharthi YS. 
Effectiveness of Photobiomodulation Therapy in the Treatment of Myofascial Pain Syndrome of 
the Upper Trapezius Muscle: A Systematic Review and Meta-Analysis. Photobiomodul 
Photomed Laser Surg 2022;40(10):661-674 
27. . Valesan, L.F.; Da-Cas, C.D.; Réus, J.C.; Denardin, A.C.S.; Garanhani, R.R.; Bonotto, D.; Januzzi, 
E.; de Souza, B.D.M. Prevalence of temporomandibular joint disorders: A systematic review and 
meta-analysis. Clin. Oral. Investig. 2021, 25, 441–453.  
28.  Ginszt, M.; Szkutnik, J.; Zieli ´nski, G.; Bakalczuk, M.; Stodółkiewicz, M.; Litko-Rola, M.; Ginszt, 
A.; Rahnama, M.; Majcher, P. Cervical Myofascial Pain Is Associated with an Imbalance of 
Masticatory Muscle Activity. Int. J. Environ. Res. Public Health 2022, 19, 1577. [CrossRef] 
29. Vieira, L.S.; Pestana, P.R.M.; Miranda, J.P.; Soares, L.A.; Silva, F.; Alcantara, M.A.; Oliveira, V.C. 
The Efficacy of Manual Therapy Approaches on Pain, Maximum Mouth Opening and Disability 
in Temporomandibular Disorders: A Systematic Review of Randomised Controlled Trials. Life 
2023, 13, 292. [CrossRef] [PubMed]. 
30. Mohammed Nadershah 1, Hala M Abdel-Alim 1 2, Amr M Bayoumi 1 2, Ahmed M Jan 1, Ali 
Elatrouni 3, Fatima M Jadu 4  , Photobiostimulation Therapy for myofacial pain in Temporomandibular 
joint  Dysfunction:ADouble  Randomized Blinded clinical Trial,2020mar, doi: 10.1007/s12663-019-
01222-z 
31. Sabrina Araújo Pinho Costa 1, Giovanna Piacenza Florezi 1, Gisele Ebling Artes 1, Jessica 
Ribeiro da Costa 1, Rosane Tronchin Gallo 1, Patricia Moreira de Freitas 2, Andrea 
Lusvarghi Witzel 1