Objective: The objectives of this study were to quantitatively measure temporomandibular joint (TMJ) disk stiffness in adolescents with bruxism using shear wave elastography (SWE) and to examine the relationship between elastography values, patient age, and duration of bruxism. Study Design: This prospective study evaluated 120 TMJ disks of 60 adolescents (30 patients with bruxism and 30 controls). The stiffness of the anterior, intermediate, and posterior parts of the disk was measured. The patient and control groups’ respective quantitative SWE values of elasticity (kilopascals [kPa]) and velocity (meters/second [m/s]) were compared. Results: The elasticity and velocity values of the anterior and intermediate parts were significantly higher in the patients than in the controls (P ≤ .013), with no significant difference in the size of the joint space (P = .886). A receiver operating characteristic analysis resulted in sensitivity for the anterior part of 0.80 for kPa and 0.83 for m/s, with specificity of 0.57 (kPa) and 0.60 (m/s). For the intermediate part, the sensitivity was 0.80 for kPa and 0.86 for m/s, with specificity of 0.64 (kPa) and 0.57 (m/s). No correlations were found between the SWE values and patient age (P ≥ .098) or duration of bruxism (P ≥ .134). Conclusions: SWE may be useful in the evaluation of TMJ disk stiffness in patients with bruxism.