Objective: To investigate the incidence and radiographic characteristics of mandibular deviation in patients with unilateral anterior disc displacement without reduction (anterior disc displacement without reduction，ADDWoR) of the temporomandibular joint, and to analyze the related factors influencing mandibular deviation. Methods: This retrospective study enrolled 210 patients (210 affected sides) with unilateral anterior disc displacement without reduction (ADDWoR) who visited the Department of Oral and Maxillofacial Surgery, Affiliated Stomatological Hospital of Nanjing Medical University between April 2020 and December 2023. Cone-beam computed tomography (CBCT) was used to analyze mandibular morphology and positional characteristics, while magnetic resonance imaging (MRI) assessed disc features. Multivariate logistic regression analysis was employed to identify factors associated with mandibular deviation. Results: Among the 210 patients, 104 were assigned to the deviation group (mean age 27.8±17.5 years) and 106 to the control group (mean age 34.0±19.2 years). The deviation group demonstrated significantly reduced ramus height and body length on the affected side compared to the unaffected side, with the entire mandible exhibiting posterior-superior rotation toward the affected side. This rotation pattern manifested as increased anterior joint space on the affected side, increased posterior/lateral/superior spaces on the unaffected side, while showing decreased posterior/lateral spaces on the affected side and reduced anterior space on the unaffected side. The articular disc in the deviation group was shorter in length and positioned farther from the condylar apex. In adolescent patients with deviation, besides mandibular morphological and positional changes, significant alterations in disc position were observed, whereas adult patients showed no remarkable changes in disc morphology or position. Multivariate logistic regression analysis revealed that mandibular positional parameters (including the ratio of anterior to posterior space on the affected side, lateral space on the affected side, the ratio of anterior to posterior space on the unaffected side, and superior space on the unaffected side) and mandibular morphological characteristics (ramus height discrepancy and mandibular body length discrepancy) were independent influencing factors for mandibular deviation (P < 0.05). Conclusion: The mandibular deviation associated with unilateral ADDWoR is closely related to changes in mandibular morphology and position. Sagittal shortening of the affected side and posterior-superior rotation of the entire mandible toward the affected side may be the primary contributing factors to mandibular deviation. Adolescent patients with ADDWoR are more prone to significant alterations in mandibular morphology, positional relationship, and disc status.