Effect of low-intensity laser treatment on sensorineural recovery after split ramus osteotomy of the mandible

Abstract

Patients with significant dental and skeletal deformities require, as a form of treatment, the association of orthodontics and orthognathic surgery in order to optimize facial aesthetics and occlusal stability in the long term. However, when the sagittal osteotomy of the mandibular ramus is performed, the risk of long-term postsurgical sensory abnormalities must be consider, resulting from lesions to the inferior alveolar nerve. One of the forms of treatment for these changes is the low-level LASER with therapeutic purpose. Thus, the purpose of this research will be to evaluate the effectiveness of low-intensity LASER on the sensorineural recovery after split ramus osteotomy of the mandible. The sample will consist of 20 patients who underwent mandibular advancement surgery, which will be divided into two groups (1 and 2): Group 1: patients with short postoperative (15 days), Group 2: patients with late postoperative period (6 months to 1 year) and persistent sensory abnormalities. All patients will receive low intensity LASER on one side of the jaw (experimental), while the opposite side will receive the equivalent placebo treatment (control), randomly. Each patient will receive 5 sessions of LASER/placebo at intervals of 3-4 weeks. The experimental side of each patient will receive application of low intensity LASER (infrared), in assisted mode, in the option of paresthesia 157.5 J/cm2 at 780 nm and 90 seconds of irradiation per point, which will follow the path of the lower alveolar nerve in the following areas: extrabuccal (from the mandible ramus and in all directions of the lower alveolar nerve to the region of the chin, forming one quadrante 1 cm away from each point) and a single intraoral point (in the region of the foramen mentale). The control side will receive concurrent placebo treatment in equivalent areas. The neurosensory determination will be performed through the Semmes-Weinstein sensory test. In this perspective, the project aims to assess the efficacy of the low intensity LASER therapy in the treatment of neurosensory changes, as well as find the appropriate time (immediately or later) to start the treatment.