LAUSR

BACKGROUND Temporomandibular disorders (TMD) primarily affect adolescents and young adults, with potentially distinct risks and clinical outcomes. However, most studies focus on a single age group, and the lack of comparative research hinders clinical decisions regarding optimal intervention timing and treatment strategies. OBJECTIVES This study aims to investigate temporomandibular joint bony structural changes in adolescents and adults with anterior disc displacement with reduction (ADDwR) or without reduction (ADDwoR) using Cone-Beam Computed Tomography (CBCT). METHODS A total of 99 TMD patients (54 adolescents, 45 adults) with no history of TMD treatment were included, all of whom had undergone two CBCT scans with an average follow-up of 11.30 ± 1.68 months. Condylar morphological and positional indicators were measured, and condylar bone changes were evaluated using a scoring system. RESULTS Significant changes were observed in adolescents, with the ADDwR group showing increased condylar volume and surface area but a reduced morphological index, accompanied by bone changes that showed minimal progression during the observation period, while the ADDwoR group showed reductions in most morphological parameters and progressively worsening bone changes. Dynamic shifts in condylar position were also noted in adolescents, with the ADDwR group showing an increase in posterior positioning, while the ADDwoR group shifted towards the central position. In adults, both ADDwR and ADDwoR groups demonstrated condylar morphology and position that remained largely unchanged over the observation period, with a tendency towards relieved bone destruction indicating potential for bone repair. CONCLUSION These findings underscore distinct progression patterns across age groups and ADD subtypes, supporting the need for stratified TMD treatment.