Efficacy of low level laser in treating anterior open bite

36 eligible patients with open Anterior bite in 8-10 years old children will be randomly divided into 3 groups: Posterior bite block with low-level laser, arm 1 Posterior bite block, arm 2 Untreated controlled group, arm 3 The nature of the treatment and the study were explained to the parents, and signed consent was obtained. Each participant will be assigned to one treatment group. Cephalometric radiographs were obtained before (T1) and immediately after appliance removal (T2). In treatment groups, the bite-blocks ( small clear acrylic (plastic) blocks) will be cemented to the teeth until at least an overbite of 1mm was reached and will be followed for 9 months. The untreated controlled group will be followed for 9 months. The application of posterior bite block and low-level laser will be done by an experienced investigator and the intervention will be delivered in the faculty of dentistry at Damascus University. Patients in the laser group received a LLL dose from an 830-nm wavelength Ga-Al-As semiconductor laser device with energy of 4 J/point. A visual examination will be performed every month after the treatment to identify and assess the anterior open bite.