Patients will receive low-level laser therapy on the temporomandibular joint disc

Using Helkimo Anamnestic Index that includes 5 items, each having 3 possible answers scored 0, 1 or 5. The 1st item assesses limitations in range of jaw movement & is divided to 4 sections: maximum mouth opening, protrusion & lateral shift. For mouth opening , value of >40mm scores 0, 30-39mm scores 1 & <30mm scores 5. Protrusion & lateral shifts score 0 if the measurement is ≥7mm, 1 if ranging between 4-6mm and 5 if it is <4mm. These sections are added together to get a total that scores 0 if the sum of the 4 sections is 0, 1 if the subtotal is between 1-4 & 5 if the subtotal is >4. The 2nd item evaluates joint alterations that produce deviations, sounds and joint locks. The 3rd item evaluates pain when performing movements. The 4th item evaluates masticatory muscles pain. The 5th item evaluates pain on palpation in the prearticular area of TMJ. The 5 items are added and scored; 0: no TMJ involvement, 1-9: mild involvement, 10-19: moderate involvement & 20-25: severe involvement

This will be assessed using the visual analogue scale (VAS) with score ranges from 0 (lowest) to 10 (highest). Higher scores indicate greater pain levels.

Magnetic Resonance Imaging (MRI) will be performed for all patients using a 3 Tesla MRI scanner with a head coil. Gradient T2 (T2*) and proton-density (PD) weighted spin echo (SE) sequences will be carried out in closed and open mouth positions in the oblique sagittal plane. MRI is considered the gold standard (objective) in imaging the soft tissue components of the TMJ.