**Core Concept**
Evaluation of the temporomandibular joint (TMJ) involves assessing the articular disc, condyle, and surrounding structures. A discrepancy in the articular disc suggests a potential pathology, such as disc displacement or degenerative joint disease. Imaging modalities play a crucial role in diagnosing these conditions.

**Why the Correct Answer is Right**
Magnetic Resonance Imaging (MRI) is the preferred modality for evaluating the TMJ, particularly when assessing the articular disc. MRI provides high-resolution images of soft tissues, including the disc, ligaments, and tendons. It can detect subtle changes in the disc, such as displacement, degeneration, or perforation. The use of specific MRI sequences, like T2-weighted and T1-weighted images, allows for detailed evaluation of the disc and surrounding structures.

**Why Each Wrong Option is Incorrect**
**Option A:** Transpharyngeal projection is an outdated radiographic technique that provides limited information about the TMJ. It is not suitable for evaluating the articular disc.

**Option C:** Arthrography involves injecting a contrast agent into the joint space to visualize the articular disc and surrounding structures. While it can provide useful information, it is not as sensitive as MRI in detecting subtle changes in the disc.

**Option D:** Arthroplasty is a surgical procedure that involves replacing or repairing the damaged joint. It is not a diagnostic tool and is not used to evaluate discrepancies in the articular disc.

**Clinical Pearl / High-Yield Fact**
When evaluating the TMJ, it's essential to consider the patient's symptoms and clinical findings in conjunction with imaging results. A discrepancy in the articular disc may be associated with symptoms like jaw pain, limited mouth opening, or clicking sounds.

**✓ Correct Answer: B. MRI. Magnetic Resonance Imaging is the best way to evaluate discrepancy in articular disc of TMJ.**