Purpose: This study aimed to evaluate the skeletal and dentoalveolar changes achieved by combining low-level laser irradiation applied on the condyle area with twin-block therapy in growing class II malocclusion patients. Methods: Fourteen patients (9 males, 5 females; mean age, 11.4±2 years) with skeletal class II mandibular defciency were recruited. They were divided into two groups (G 1: twin-block+low-level laser therapy, G 2: twin-block only). A semiconductor diode laser with a wavelength of 940 nm was applied on the condyle area (100 mW, 2.5 J, 3.9 J/cm2). The laser was applied twice a week in the frst month and once a week in the second and third months, totalizing 16 sessions. Skeletal, dental, and soft-tissue cephalometric parameters were measured and compared at diferent treatment points. Results: Mandibular length (Co-Gn) was signifcantly increased by 3.6 mm in the experiment group (3.16 SD) and 4.3 mm (4.4 SD) in the control group, with no signifcant diference between groups at every time point (P-value 0.949 at T2). Similarly, a statistically signifcant positive efect of treatment was found in both groups on ramus height (Co-Go), upper lip to E-Line, SNA angle, ANB angle, and U1/SN angle with no signifcant diference between groups. Conclusion: Based on the results of this preliminary study, low-level laser irradiation with the used parameters seems to have no synergetic impact on the skeletal and dental outcomes of twin-block therapy over 9 months. However, more studies are needed to investigate the efect of low-level laser therapy on condylar growth during functional orthodontic treatment.