To evaluate the effectiveness of the low-level laser therapy (LLLT) in accelerating the early treatment of the skeletal anterior open bite (AOB) and to evaluate the associated skeletal and dentoalveolar changes.

A three-arm, parallel-group, randomized controlled trial was conducted on 42 patients aged 8–10 years with skeletal AOB. Patients were randomly allocated to three groups: the fixed posterior bite block+low-level laser therapy (FPBB+LLLT) group; the fixed posterior bite block (FPBB) group; and the untreated control group (UCG) in a 1:1:1 allocation ratio. The LLLT dose in the FPBB+LLLT group was applied using 808-nm wavelength Ga-Al-As semiconductor laser device with the energy of 4-joules/point and irradiation time of 16 seconds/point. LLLT was applied in the first visit; then, it was applied on day 3, 7 and 14 of the first month. Afterwards, it was applied every 15 days until the end of the treatment. Lateral cephalometric images were taken at the beginning of the treatment (T0) and at the end of the active phase (T1). The primary outcome measures were the overall time needed to correct the AOB and the skeletal and dentoalveolar changes.

The correction of the AOB required significantly less mean time in the FPBB+LLLT group compared to the FPBB group (x̅=7.07, x̅=9.42 months, respectively; P=0.001). The mean upper first molar intrusion in the FPBB+LLLT group was 1.21mm and significantly greater than that of the FPBB group (0.82mm; P=0.018). However, there was a slight mean extrusion of the upper first molar in the UCG (0.32mm).

The overall time needed to correct the AOB was shorter in the FPBB+LLLT group. The LLLT appeared to be effective in accelerating orthodontic tooth movement. FPBB alone or LLLT were effective in the early treatment of anterior open bite (AOB). The two interventional groups produced similar dentoalveolar and skeletal changes; most of which were dentoalveolar in the correction of the anterior open bite.