Stimulation of morphofunctional repair of the facial nerve with photobiomodulation, using the end-to-side technique or a new heterologous fibrin sealant

Abstract

This research evaluated the influence of Photobiomodulation Therapy (PBMT) on lesions of the facial nerve repaired with the end-to-side technique or coaptation with a new heterologous fibrin sealant. Thirty-two Wistar rats were separated into 5 groups: Control group (CG), where the buccal branch of the facial nerve was collected; Experimental Suture Group (ESG) and Experimental Fibrin Group (EFG), in which the buccal branch was end-to-side sutured to the zygomatic branch on the right side of the face or coaptated with fibrin sealant on the left side; Experimental Suture Laser Group (ESLG) and Experimental Fibrin Laser Group (EFLG), in which the same procedures were performed as the ESG and EFG, associated with PBMT (wavelength of 830nm, energy density 6.2J/cm, power output 30mW, beam area of 0.116cm, power density 0.26W/cm, total energy per session 2.16J, cumulative dose of 34.56J). The laser was applied for 24s/site at 3 points on the skin's surface, for a total application time of 72s, performed immediately after surgery and 3 times a week for 5weeks. A statistically significant difference was observed in the fiber nerve area between the EFG and EFLG (57.49±3.13 and 62.52±3.56μm, respectively). For the area of the axon, fiber diameter, axon diameter, myelin sheath area and myelin sheath thickness no statistically significant differences were found (p<0.05). The functional recovery of whisker movement occurred faster in the ESLG and EFLG, which were associated with PBMT, with results closer to the CG. Therefore, PBMT accelerated morphological and functional nerve repair in both techniques.

Photobiomodulation Therapy (PBMT) in Peripheral Nerve Regeneration: A Systematic Review

“…With the evolution of the technology in the health field and the evolution of the adjunct methods for rehabilitation and functional restoration of injured nerves [3,6,7,8,9], the PBMT has shown a wide range of benefits with clinical relevance. Thus, the aim of this research was to carry out a review of the scientific papers published in the last 10 years in order to verify the relation of PBMT in the regeneration of injured peripheral nerves.…”

“…The functional analysis evidenced the evolution of functional recovery associated with PBMT [6,7,34,38,39]. Marcolino et al [40] found a functional recovery with both 40 J/cm 2 and 80 J/cm 2 (830 nm), Akgul; Gulsoy; Gulcur [41] also scored improvement in functionality with late application PBMT (650 nm) (7 days after injury), as well as Medalha et al [35] at 660 nm at 50 J/cm 2 .…”

“…The effects of PBMT on nerve damage were verified in the sciatic nerve in 17 articles [19,30,31,32,33,34,35,36,38,39,41,42,43,44,46,47,49], facial nerve in 3 [3,6,7], fibular nerve in 2 articles [40,48], and vagus nerve [2], accessory nerve [29], alveolar nerve [45], and dorsal root [37] in one article each. Of the 26 articles inserted in this review, it was observed that 14 [19,31,32,37,38,39,40,41,42,44,45,46,48,49] presented compression as nerve damage (crushing) and 11 [2,3,6,7,30,33,34,35,36,43,47] articles evaluated the effects of PBMT on neurotmeses, which is the worst type of nerve injury.…”

“…Its effects are related to tissue biostimulation, presenting therapeutic responses from photoelectric, photoenergetic, and photochemical reactions [1]. Scientific research has shown the application of PBMT in bone tissue and peripheral nerves with good results whether or not it is associated with other supporting methods in tissue repair [2,3,4,5,6,7]. …”

“…Its beneficial effects are independent of the repair technique, neurorrhaphy techniques, and the use of fibrin sealants [3,6,7,21]. …”