Difference between revisions of "Trigeminal Nervous System Segmentation"

====Laser Evoked Potentials and Masseteric Laser Silent Period====

To evoke motor responses from the masticatory muscles or potential laser evenings, we employ a laser stimulator CO₂ (Neurolas, Florence, Italy) capable of generating a radiant caloria (10.6 mm; intensity 1.5–15 W; duration of 10–15 ms; diameter of the 2.5 mm spot) in the area of the skin in upper and lower upper and lower region (trigeminal terrain V2 and V3). The subjects must sit comfortably in the dental chair and wear protective goggles (<translate>Figure</translate> 9). To avoid the habit to the nociceptive stimuli and the overheating of the skin, the irradiated points have been shifted after each stimulation.   

[[File:Laser_Evoked_Potentials_-_Blink_reflex_-_Masseter_Silent_Period.jpg|left|thumb|'''<translate>Figure</translate> 9:'''  <translate>Laser stimulation that evoke a Blink reflex (BR), a Masseter Inhibitor Reflex (MIR) and Evoked Potentials Laser</translate> (LEPs)]]

For LSPs, the same parameters were used as described above, but the recording is performed on masseter muscles. The area was subtracted from the 100-ms curve prior to adjusted and mediated laser stimulus (pre-analysis). The duration of the registered EMG activity is 400 ms, of which 100 ms corresponds to pre-stimulus and 300 ms in the post-stimulus period. The EMG signals are amplified, filtered (20 Hz–1 kHz), and sampled at 4 kHz. Subjects are asked to tighten their teeth with the maximum muscular strength to determine the EMG activity corresponding to the Maximum Volunteer Contraction (MVC: Maximum Voluntary Contraction) of masseter muscles and at different levels (15–25%), (35–45%), (55-65%), and (75–85%) of MVC. Subjects receive visual feedback with markers on the computer screen, which clearly indicates when the default level is reached. As one can see in Figure 19, the results of the following work are schematized in accordance with the type of test performed. With a laser stimulation in the skin region corresponding to the emergence of the supraorbital nerve (V1), we can have a Blink Reflex as a reflected response (BR) and notice the perfect symmetry of the responses on sides R1 and R2. Stimulation in the perioral region will result in a reflex response from the masseterini muscles called Laser Silent Period (LSP: Laser Silent Period). We might note that, in this test, a slight asymmetry of the track—mainly caused by the different degree of motoneural recruitment in the maximum intercuspidation. The registration on the scalp determines the potential laser summers of the trigeminal somatosensory area (LEPs) and measure the negative and positive spikes (N and P). Here, too, we witness a high level of symmetry.