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Objective To investigate the effects of intra⁃articular injection of alendronate on the mandibular condyle in ovariectomized rats. Methods Sixty female rats were randomly divided into five groups: ovariectomy with vehicle treat⁃ ment alone, early alendronate treatment at ovariectomy, late alendronate treatment at 4 weeks after ovariectomy, sham⁃ operation with vehicle treatment, and the normal control rats. The changes in subchondral bone were evaluated by micro⁃ computed tomography (Micro⁃CT), tartrate⁃resistant acid phosphatase (TRAP) staining and real⁃time quantitative poly⁃ merase chain reaction (RT⁃PCR). Results Compared with late alendronate treatment, early alendronate treatment im⁃ proved microstructural properties of the subchondral bone, with higher bone volume ratio (46.4 + 2.5 vs 37.5 + 2.1; P= 0.038), increased trabecular thickness (47.3 + 1.7 vs 34.6 + 1.4; P = 0.029), elevated trabecular number (8.5 + 0.6 vs 6.2 + 0.3; P = 0.041) and lower trabecular separation (30.2 + 1.6 vs 37.7 + 2.6; P = 0.034). Fewer TRAP⁃positive cells (4.2 + 0.2 vs 6.8 + 0.4; P = 0.019) and a higher OPG/RANKL ratio (0.38 + 0.01 vs 0.25 + 0.03; P = 0.043) in the sub⁃chondral bone were observed in the animals with early treatment group compared to late treatment or ovariectomy/vehi⁃ cle treatment group. Conclusion Our results suggest the therapeutic potential of intra⁃articular alendronate injection in the treatment of osteoporosis⁃associated temporomandibular disorders.