Hypothyroidism is a common endocrine disorder with systemic effects that extend beyond metabolic regulation. Emerging evidence highlights oxidative stress as a central mechanism in its pathophysiology: impaired thyroid hormone activity reduces antioxidant defenses, leading to excess reactive oxygen species, cellular injury, and tissue dysfunction. These processes not only contribute to oral diseases such as periodontitis but may also accelerate aging pathways. The resulting changes resemble progeroid phenomena, where adults develop premature aging features typically seen decades later in life. This literature review synthesizes current findings on oxidative stress as a missing biological link between hypothyroidism, oral health deterioration, and progeria‑like premature aging. By integrating evidence from clinical, experimental, and molecular studies, it underscores the need for further interdisciplinary research to validate these associations and explore therapeutic strategies targeting oxidative imbalance. Keywords: hypothyroidism, oxidative stress, oral health, periodontitis, progeria, progeroid syndromes, premature aging