The effect of light-emitting diode and laser on mandibular growth in rats

Abstract

Objective: To evaluate the effect of a light-emitting diode (LED) and/or low-level laser (LLL) with or without the use of anterior bite jumping appliances (also known as functional appliances [FAs]) on mandibular growth in rats.

Materials and methods: Thirty-six 8-week-old male Sprague-Dawley rats weighing 200 g were obtained from Charles River Canada (St. Constant, QC, Canada) and were divided into six groups of six animals each. Groups were as follows: group 1: LLL; group 2: LLL + FA; group 3: LED; group 4: LED + FA; group 5: FA; and group 6: control (no treatment). Mandibular growth was evaluated by histomorphometric and micro computed tomographic (microCT) analyses.

Results: The LED and LED + FA groups showed an increase in all condylar tissue parameters compared with other groups.

Conclusion: The LED-treated groups showed more mandibular growth stimulation compared with the laser groups.

Keywords: Functional appliance; LED; Laser; Mandibular growth.

Figures

Figure 1.

LED and LLL applied to the animals while they are under gas anesthesia.

Figure 2.

Rat mandibular condyle showing condylar cartilaginous layers for histomorphometric analysis. (1) Fibrocartilage layer. (2) Proliferative layer. (3) Hypertrophic layer. (4) Chondrocyte Layer. (5) Subchondral bone.

Figure 3.

Comparison of the total surface area of the layers in the mandibular condyles in all groups as measured by histomorphometric analysis in µm2. * P < .05; ** P < .01; *** P < .001. It can be seen that LED shows a significant increase in the surface area of the condylar layers.

Figure 4.

Comparison of microCT analyses (BV/TV) between groups. * P