# Recovery of Post-Traumatic Temporomandibular Joint after
## 3 Rehabilitation of TMJ
### Non-Surgical Treatment
#### 3.1.2 Physical Therapy  
Prolonged immobilization of the jaws during fracture can lead to serious complications as periodontal problems, facial pain, malocclusion, chin deviation, contracture of the mandible, hypomobility, or ankylosis of the temporomandibular joint [6; 17; 38]. The management is aimed to be holistic, most often difficult, long, requiring a lot of patience from both the doctor and the patient. Specialized physical therapy options such as TENS (transcutaneous electrical nerve stimulation), ultrasound, iontophoresis, electotherapy as well as low-level laser therapy have been used in the management of TMDs, despite the lack of evidence to support their use [8; 9; 28; 39]. Transcutaneous Electrical Nerve Stimulation (TENS) TENS represents a non-invasive peripheral stimulation technique used to relieve both chronic and acute pain, but also to relax muscles and improve blood circulation. There are few side effects compared with drug therapy; allergic-type skin reaction is the most common complaint, and this is due to the material of the electrodes or the conductive gel. Although TENS techniques include conventional TENS (low-intensity, high-frequency), acupuncture-like TENS (high-intensity, low-frequency), and intense TENS (high-intensity, high-frequency), conventional TENS is the most frequently used [6; 39; 40]. Conventional TENS parameters are as follows: high-frequency (50-100 Hz), low-intensity, small pulse width (50-200 \(\upmu\)s). The goal of conventional TENS therapy is to stimulate large diameter, low threshold non-noxious afferents (A-beta) in dermatomes related to the pain. TENS can inhibit the activity in second-order nociceptive transmission neurons. Increased TENS pulse amplitude can induce a strong paraesthesia-like sensation. An adverse effect of conventional TENS therapy is high-threshold A-delta afferent activity and a painful paraesthesia beneath the electrodes [40]. Usually, the electrodes are placed bilaterally on the preauricular area and on the masseter muscle, one channel on the right-hand side and the other on the left-hand side [6; 39; 40]. Low Level Laser Therapy (LLLT)  
Among various physical therapy modalities, low-level laser therapy (LLLT) has become a technique of interest due to several advantages: easy application, short treatment time, and minimum contraindications. LLLT is characterized by a wavelength ranging from 600-1100 nm, an output power of 1-500 mW, and an energy density of 0.04-50 J/cm\({}^{2}\)[28; 41; 42; 43]. The main medical applications of LLLT are related to its capacity to reduce pain and inflammation and to accelerate tissue regeneration as LLLT is known to stimulate the proliferation of a variety of cells including fibroblasts, keratinocytes, endothelial cells, and lymphocytes. Recently, LLLT proved efficaciously in dentistry, especially in the management of various soft tissue issues, dental hypersensitivity, bone regeneration, and musculoskeletal pain. Furthermore, it seems that LLLT is also considered for TMDs promoting the improvement of TMJ function and reducing signs and symptoms related to TMDs. However, the clinical efficacy of LLLT for the treatment of TMDs remains controversial. Indeed, there are reports of good results by LLLT application as compared to placebo control groups, while others found no significant differences among patients managed with LLLT [41; 42; 43]. No specific established protocol (energy intensity, power, exposure time, and number of applications) is currently recommended for TMDs. But, due to remarkable analgesic and anti-inflammatory properties. various types of lasers, such as helium-neon (HeNe) and arsenideg gallium-aluminum (GaAlAs), are efficient in patients with TMDs [41; 42]. Known as high-frequency sound waves, ultrasound therapy directed to the TMJ aims to reduce pain and inflammation, promote muscular relaxation, and increase blood flow. The analgesic effect is elicited by increasing the temperature in bone and tendons compared with surrounding tissue [44; 45; 46].