Evaluation of low-level laser therapy in the treatment of masticatory muscles spasticity in children with cerebral palsy

J Biomed Opt. 2016 Feb;21(2):28001. doi: 10.1117/1.JBO.21.2.028001.


Spasticity is a motor disorder frequently present in individuals with cerebral palsy (CP). This study aimed to evaluate the effect of low-level laser therapy (LLLT) on the spasticity of the masseter and anterior temporal muscle fibers in children with CP over three weeks of intermittent laser exposures. The bite force (BF) of the masticatory muscles and the amplitude of mouth opening were evaluated before and after laser irradiation in 30 children with CP. Both sides of the masseter and temporalis muscles were irradiated with low-intensity diode laser pulses of 808-nm wavelength six times over three consecutive weeks. During the subsequent three weeks of postlaser exposures, although no laser treatment was applied, the evaluation parameters were measured and recorded. A significant improvement in the amplitude of mouth opening and a decrease in the BF were observed in the weeks following LLLT (P<0.05 ). However, by the sixth week post-LLLT, the BF and the amplitude of mouth opening reverted to values equivalent to those obtained before the first application of LLLT. Our investigation revealed low-level energy exposures from a 808-nm diode laser to be an effective short-term therapeutic tool. This method increased the amplitude of mouth opening and decreased the muscle tonus of children with spastic CP over a time course of three weeks of intermittent laser applications.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Bite Force
  • Cerebral Palsy / complications*
  • Child
  • Female
  • Humans
  • Longitudinal Studies
  • Low-Level Light Therapy*
  • Male
  • Masticatory Muscles / physiopathology*
  • Muscle Spasticity / etiology
  • Muscle Spasticity / physiopathology
  • Muscle Spasticity / radiotherapy*
  • Range of Motion, Articular