Lamina dura thickening in patients on antiresorptive therapy as a radiographic risk indicator of medication-related osteonecrosis of the jaw: a retrospective longitudinal cohort study

Abstract Aims This study investigated whether antiresorptive drug (ARD) therapy is associated with lamina dura (LD) thickening, defined as a radiographic increase in the thickness of the normally thin, radiopaque cortical line surrounding the tooth root. It further evaluated whether LD thickening serves as a radiographic marker and risk indicator for medication-related osteonecrosis of the jaw (MRONJ). Methods Panoramic radiographs from 65 ARD-treated patients (University Hospital Leuven) and 65 age- and sex-matched controls were analyzed. Inclusion criteria were prior oncological diagnosis, high-dose intravenous ARD, and radiographs before and after therapy. Three blinded oral and maxillofacial radiologists categorized LD appearance into 4 grades: (0) not/barely visible, (1) normal, (2) mild thickening, and (3) marked thickening. Group differences and longitudinal changes were evaluated using appropriate non-parametric and time-to-event analyses. Results Among 130 participants, LD thickness remained stable in controls but increased in ARD-treated patients (P  Conclusion Lamina dura thickening is strongly associated with long-term ARD exposure and shows progressive changes. Although not directly associated with MRONJ in this cohort, it may still represent a potential risk indicator, warranting confirmation in further studies.