Table 2.

General characteristics of included studies.

S.No	Author/Year	Study Subjects	Number of Teeth	Mean Age and Gender	Study Groups	Study Design	Study Duration	Method of Evaluation
1	Goymen et al. 201927	30	30 teeth	14 males; 16 females Mean age 16.27 ± 0.87 years	Group 1–10 teeth LLLT and OIRR; Group 2–10 teeth LED and OIRR; Group 3–10 teeth Placebo and OIRR	Randomized controlled trial	4 weeks	Micro-computed tomography (micro-CT) 3D Quantitative
2	Fernandes et al. 201926	30	30 teeth	Age range- 35–65 years.	G1 Control (n = 10) - Without orthodontic movement and without premature contact; G2 (n = 10) - Orthodontic movement only; G3 (n = 10) - Orthodontic movement plus laser irradiation (LLLT)	Randomized clinical trial (?)	90 days	Conventional computed tomography 3D Quantitative
3	Khaw et al. 201825	20	40 teeth	8 males; 12 females Mean age – 15 years 9 months	Group 1–20 teeth LLLT and OIRR; Group 2 - 20 teeth Sham and OIRR	Double blind, split mouth randomized controlled trial	6 weeks	Micro-computed tomography (micro-CT).
4	Okla et al. 201824	Initial – 38 Dropouts – 12 Final sample – 26	52 teeth	Mean age: Experimental group- 16.7 ± 6.75 years. Control group-13.2 ± 0.99 years.	Experimental group (n-12) – LLLT (Orthopulse) and OIRR; Control Group (n-11) - Placebo and OIRR	Randomized controlled trial (?)	6 months	Digital periapical radiographs, 2D Quantitative
5	Ng et al. 201723	20	40 teeth	10 males - 16.4 ± 1.3years 10 females - 16.7 ± 1.1 years	Group 1–20 teeth LLLT and OIRR; Group 2 - 20 teeth Placebo and OIRR	Double blind, split mouth randomized controlled trial	28 days	Micro-computed tomography, 3D Quantitative
6	Sousa et al. 200721	10	26 teeth	6 female and 4 male patients Mean age of 13.1 years	Laser Group (LG) - 13 teeth LLLT and OTM with OIRR; Control Group (CG) – 13 teeth Placebo and OTM with OIRR	Randomized controlled trial (?)	4 months	Periapical radiographs, 2D Quantitative