## 4 Discussion
In the research carried out by [PERSON] et al., the impact of photobiomodulation on the recuperation of the sensory function in the lip and chin following bilateral sagittal split osteotomy (BSSO) was examined [26]. The procedure involved the utilization of a GaAs diode laser emitting continuous waves at a wavelength of 980 nm, generating a power output of 100 mW, and delivering an energy density of 12 J/cm\({}^{2}\). Substantial enhancements were noted in the scores recorded on the visual analogue scales (VAS) for general sensitivity, discrimination of pain, recognition of direction, and discrimination of two points, both after a span of 30 days and once more after 60 days [26]. [PERSON] et al. [27] considered patients with nerve injury due to odontectomy of the third molars or related practices such as anesthetic injection wounds. They used photobiomodulation with a diode laser 830 nm continuous wave, administrated in 20 applications over 3 months for each patient. Instrumental tests such as VAS or 2-point discriminations did not show any significant improvement in sensibility repair compared to the control group. However, the limitation of this study is considered by the authors themselves to be the fact that they did not categorize the patients according to the degree of severity of the nerve damage, which could have influenced the significance of the statistics [27]. [PERSON] et al. [28], [PERSON] et al. [29], [PERSON] et al. [30], [PERSON] et al. [32], [PERSON] et al. [33], and [PERSON] et al. [34] used the GaAlAs laser in their trials with wavelengths between 789 and 880 nm; according to their studies, their photobiomodulation protocol could significantly improve healing and sensibility could be regained after nerve injury, based on an improvement on pain scales and mechanical test results. [PERSON] et al. [30], however, show that there is no statistical difference between the control group and the treatment group in regards to thermal sensitivity in all the periods examined, while all three authors agree that during the follow-up, the mechanical tests have better results [28; 29; 30; 32; 33; 34; 35; 36; 37]. The diode laser was used respectively by [PERSON] et al. [27], [PERSON] et al. [31], [PERSON] et al. [38], [PERSON] et al. [39], [PERSON] et al. [36], and [PERSON] et al. [35]. Except for the trial conducted by [PERSON] et al., the diode laser could be considered as effective as the GaAlAs laser; in fact, in all of the studies, there is a significance in the improvement of pain relief, quality of life, and faster healing. Diode laser wavelengths were used between 632 and 880 nm, in a continuous mode and with the scanning method [27; 31; 35; 36; 38; 39]. The articles examined in our review are all clinical trials. Peripheral nerve lesions are mainly caused by osteotomies involving the maxillofacial area and, to a lesser extent, nerve lesions following the extraction of the third molars. In the clinical trials examined, the evaluation of nerve sensitivity and the sensation of paraesthesia were evaluated through different tests: mechanosensory tests for routine assessment of surgical trigeminal nerve injuries, such as the brush stroke test, the 2-points discrimination test, and Semmes-Weinsten monofilament test and thermal sensitivity test to evaluate the neurological response to temperature change. Regarding the disturbance the patient perceived, a VAS scale is administered in almost all studies [26; 27; 28; 29; 30]. As far as photobiomodulation is concerned, the authors mostly used diode lasers or GaAs or GaAlAs lasers, and only in one case, a LED laser is used. The wavelengths used vary from a range from 632 to 910 nm for an application time of at least 10 sessions. Most of the treatments were administrated with a continuous wave. All of the authors report, because of the experimentation, an objective and subjective improvement of the symptoms without side effects, although in some cases, it was a matter of very long therapeutic plans in terms of time.