# Acceleration Techniques for Teeth Movements in Extractive Orthodontic Therapy
## 4 Discussion
### Low-Level Laser Therapy (LLLT)
Immediately following the spring installation on the experimental side, LLLT irradiation was used. A continuous, uninterrupted beam of light at a wavelength of 940 nm from a GaAlAs diode laser was used. [PERSON] al. claimed that LLLT during routine orthodontic appointments spaced three weeks apart accelerates OTM and considerably lessens pain [51; 79]. The combined impact of corticotomy and LLLT on the speed of OTM was examined by [PERSON] et al. [36]. The premolar extractions were performed on the same day a surgical corticotomy was conducted. The laser was applied at the beginning of the four-month study period or on the first day of full canine retraction, as well as one week, two weeks, three weeks, and every two weeks after that. According to [PERSON] et al., corticotomy and LLLT alone could not increase the rate of canine retraction above that of the gold-standard corticotomy approach [36]. [PERSON] et al. evaluate whether the LLLT can accelerate OTM during en-masse retraction [28]. The experimental side was subjected to biostimulation by using a GaAlAs diode laser with a wavelength of 810 nm. Each site received ten irradiations for 10 s, five on the palatal side and ten on the buccal side of the tooth. With a three-week interval between appointments, the total energy density at each application was 10 J. It was found that the rate of extraction space closing can be accelerated via biostimulation using an 810 nm diode laser. As a result, it can accelerate tooth mobility during orthodontic treatment [28]. [PERSON] et al. examined if LLLT might hasten the migration of crowded maxillary incisors during orthodontic treatment [40]. Patients in the laser group obtained an LLLT dosage from a GaAlAs laser device with an energy of 2 J/point at an 830 nm wavelength just after the first archwire was inserted. Due to a statistically significant difference in total TT between the two groups, [PERSON] et al. asserted that LLLT is a valuable technique for quickening OTM [40]. In 2020, [PERSON] et al. used a split-mouth RCT to assess the efficacy of photo-biomodulation therapy in accelerating OTM [41]. Following the extraction of the first premolar, canine retraction movement was monitored. Linear measurements of the canine's anteroposterior position were obtained at the onset of treatment and one month later, and these values were contrasted with those from the non-irradiated side to determine the pace of orthodontic therapy. GaAlAs PBM was administered four times to the experimental segment. The results indicated a statistically significant disparity and a 32% acceleration in OTM attributable to the biostimulatory agent [41]. [PERSON] et al. 's work (2004) also utilised LLLT to assess the speed difference between the irradiated and C Sides of OTM [14]. The authors emphasised a notable acceleration of OTM on the side that had been exposed to radiation, and they specifically demonstrated that the laser group always experienced faster displacement with each spring activation. The authors claimed that LLLT in that region increased the region's receptivity to biochemical alterations that help OTM [14]. [PERSON] et al. (2020) monthly applied LLLT in both the upper and lower arch [56]. The LLLT technique for the upper arch varied depending on whether the side was buccal or palatal; the latter side required a larger dosage since the canine root was further from the laser application site due to the greater bony thickness of the palate. However, they discovered in their research that the LLLT procedure proved only helpful in the upper arch in the first stages of canine retraction, with speed around the same as on the C Side. The effectiveness of LLLT is correlated with both the dosage and frequency of laser application, according to scientists, who speculated that variations in bone density between the maxilla and mandible may have had differing effects on laser light absorption [56].