Low-level laser effect in patients with neurosensory impairment of mandibular nerve after sagittal split ramus osteotomy. Randomized clinical trial, controlled by placebo

Abstract

Objectives: Evaluate the effect on the application of low level laser therapy, in patients that have been previously intervened with a sagittal ramus split osteotomy and present neurosensory impairment due to this surgery, compared with placebo. Study Design: This preliminary study is a randomized clinical trial, with an experimental group (n=17) which received laser light and a control group (n=14), placebo. All participants received laser applications, divided after surgery in days 1, 2, 3, 5, 10, 14, 21 and 28. Neurosensory impairment was evaluated clinically with 5 tests; visual analog scale (VAS) for pain and sensitivity, directional and 2 point discrimination, thermal discrimination, each one of them performed before and after surgery on day 1, and 1, 2 and 6 months. Participants and results evaluator were blinded to intervention. Variables were described with absolute frequencies, percentages and medians. Ordinal and dichotomous variables were compared with Mann Whitney’s and Fisher’s test respectively. Results: Results demonstrate clinical improvement in time, as well as in magnitude of neurosensory return for laser group; VAS for sensitivity reached 5 (normal), 10 participants recovered initial values for 2 point discrimination (62,5%) and 87,5% recovered directional discrimination at 6 months after surgery. General VAS for sensitivity showed 68,75% for laser group, compared with placebo 21,43% (p-value = (0.0095). Left side sensitivity (VAS) showed 3.25 and 4 medians for placebo and laser at 2 months, respectively (p-value = (0.004). Conclusions: Low-level laser therapy was beneficial for this group of patients on recovery of neurosensory impairment of mandibular nerve, compared to a placebo. Key words:Laser Therapy, low-level, LLLP, osteotomy, sagittal split ramus, paresthesia, mandibular nerve.

Is Low-Level Laser Therapy Effective on Sensorineural Recovery After Bilateral Sagittal Split Osteotomy? Randomized Trial

“…It should be pointed out that laser treatment is not indicated for nerve transections; the only effective treatment for nerve discontinuity defects or total lack of impulse transmission is microsurgical repair. 22 Although there are different treatment options for paresthesia after orthognathic surgery, LLLT is used largely to restore neuronal function. The main effects of LLLT irradiation are an increase in b-endorphin production and neurotransmission, pain relief, and increased blood flow, thus allowing for drainage of substances from inflammation and its consequent regulation, in addition to accelerated tissue repair, bone regeneration, and re-establishment of neural function.…”

Uso de laserterapia em pós-operatório de osteotomias sagitais bilaterais do ramo mandibular: revisão de literatura

“…Gasperini et al, em 2014 mostra que houve uma melhora na sensibilidade do lábio inferior e do mento em todos os pacientes, ambos os lados irradiados e não-irradiados, porém o lado irradiado se recuperou mais rapidamente e quase completamente no período de 60 dias pós-cirúrgio. Já Führer-Valdivia et al, (2014) relataram diferença entre os pacientes irradiados e não-irradiados, o resultado mais expressivo foi a sensibilidade geral avaliada pela Escala Visual Analógica (VAS) que demonstrou a recuperação normal alcançada por um grande número de pacientes do grupo que recebeu a terapia com laser (68,75%) contra apenas um pequeno número de pacientes tratados apenas com placebo (21,43%) seis meses após a cirurgia. Isso sugere que o tratamento com laser de baixa potência é eficaz na aceleração do reparo neurossensorial do nervo alveolar inferior devido aos estresses mecânicos causados pela osteotomia sagital do ramo mandibular.…”

Photobiomodulation in Oral Surgery: A Review

“…46 Neurosensory recovery. Neurosensory recovery was assessed in nine studies; six studies after mandibular ramus osteotomy, [47][48][49][50][51][52] and three of them after various oral surgeries [53][54][55] (Table 2). Six studies represented a wide range of effective PBM parameters for nerve recovery after mandibular ramus osteotomy (wavelength: 632-830 nm; power: 20-100 mW; energy density: 2-32 J/cm 2 ).…”

“…Six studies represented a wide range of effective PBM parameters for nerve recovery after mandibular ramus osteotomy (wavelength: 632-830 nm; power: 20-100 mW; energy density: 2-32 J/cm 2 ). [47][48][49][50][51][52] In addition, three other studies showed positive impact of PBM on inferior alveolar nerve (IAN) paresthesia after various oral surgeries such as orthognathic surgery. [53][54][55] de Oliveira et al, 54 in a 3year retrospective study, reported that gallium, aluminum, arsenide (GaAlAs) diode 808 nm at 100 mW and 100 J/cm 2 was more effective than placebo in treating IAN paresthesia.…”