Purpose: This study aimed to evaluate the effect of a low-level laser therapy (LLLT) on pain, trismus, and swelling of patients whose impacted 3rd molar tooth was extracted compared to placebo or "sham" treatment and measure volumetrically the edema with a three-dimensional (3D) surface imaging device (3dMD face system). Materials and Methods: Forty-five patients over 17 years of age were included in the study. Patients were randomized to three groups; Group 1, the control group, received only routine management (ice application) (n = 15); Group 2, received single-dose LLLT immediately after surgery (n = 15); and Group 3, placebo group, received sham therapy immediately after surgery (n = 15). In this study, a gallium-aluminum-arsenide diode laser device was used. The laser was applied extraorally (0.3 W, 40 s, 4 J/cm(2)). The trismus, pain, and facial swelling were evaluated. A 3D surface imaging device (3dMD Photogrammetric System) was used to evaluate the volumetric changes of the swelling. The 3D morphology of the facial swelling was recorded using this imaging device immediately before surgery, the second day after surgery, and the 7th day after surgery. IBM SPSS statistics 22.0 program was used in the statistical assessment and P < 0.05 was considered statistically significant. Results: There was no statistically significant difference in the edema and trismus between the groups. The pain level in Group 2 was significantly lower than that in Group 3 at all-time points. Furthermore, the pain level in Group 2 was significantly lower than that in Group 1 on day 7. Conclusions: LLLT reduced the intensity of pain following third molar surgery by single dose. The results of this study revealed that LLLT reduced facial swelling, but no significant differences were found among the three groups. In addition, a 3D craniomaxillofacial imaging method provided insight into volume changes after 3rd molar surgery and the evaluation of facial swelling in an objective way.