Hyperbaric oxygen treatment did not significantly affect radiation injury in the mandibular area of rats

Objective: Hyperbaric oxygen therapy (HBOT) has been used to enhance microcirculation and thereby oxygen tension in tissues. The present study aimed to investigate the effect of HBOT on radiation injury in the mandibular area of rats.

Study design: The left mandibles of rats were irradiated by external radiotherapy (15 Gy every other week for a total of 75 Gy). Four HBOT strategies were used: 2 prophylactic groups receiving HBOT either between each radiation treatment or immediately following terminated radiation treatment, and 2 therapeutic groups receiving HBOT after the latent period of 6 weeks after irradiation either every day (standard HBOT protocol) or 3 days a week for 6 weeks. Tissue samples of the irradiated area were taken from skin, the salivary gland, and the mandible. All tissues were stained with hematoxylin and eosin for morphologic examination. Furthermore, skin samples were stained with CD31 for blood vessel analysis.

Results: There was no change in blood vessel density or morphology between controls and HBOT tissues after radiation. The dentin of 2 of the 5 rats that received HBOT either normalized or was not affected by irradiation.

Conclusions: HBOT did not affect radiation injury of the mandibular area in rats within 12 weeks after irradiation.