Impact of Hypoxia on Dental Bone Formation During Orthodontic Treatment in Rats

Recent research conducted by scientists from the Institute of Science Tokyo has shed light on how low oxygen levels, or hypoxia, influence the process of orthodontic tooth movement (OTM) in rats. Using a model where orthodontic force was applied via a nickel-titanium spring between molars and incisors, the researchers housed rats in a chamber with only 10% oxygen to mimic hypoxic conditions. Their findings demonstrated that hypoxia accelerates tooth movement but simultaneously reduces alveolar bone levels, suggesting enhanced bone resorption.

Histological analysis revealed increased activity of osteoclasts—cells responsible for bone breakdown—on the compression side of the tooth, while bone-forming osteoblasts, which are typically active on the tension side, showed decreased presence. Molecular examinations further indicated that key factors involved in bone formation, namely RUNX2 and VEGF, were suppressed under hypoxic conditions, especially on the tension side.

These results suggest that hypoxia influences the cellular and molecular mechanisms underlying bone remodeling during orthodontic treatment. The increased osteoclast activity alongside diminished osteoblast function under low oxygen levels can lead to accelerated tooth movement but may also compromise bone integrity. Understanding these effects is vital, particularly for patients with conditions that cause hypoxemia, as this could affect orthodontic outcomes. The study underscores the importance of oxygen availability in managing and optimizing orthodontic therapies.

Published in Scientific Reports on July 1, 2025, this pioneering research highlights the need for considering oxygen levels in orthodontic treatment planning and provides a foundation for further investigations into bone remodeling under hypoxic stress.

Source: https://medicalxpress.com/news/2025-08-hypoxia-dental-bone-formation-orthodontic.html