ANESTHESIA INDUCED BY LOCAL REFRIGERATION OF THE JAWS

¹ Naval Medical Research Institute, National Naval Medical Center, Bethesda, Md.

1. Temperature measurements were taken in dogs from areas of mandibles cooled by applicators through which a refrigerant at 0° to 1°C. was circulated. The lowest temperature attained in the area of the inferior alveolar nerve was 11.5°C.; between the bone and periosteum, 7.5°C.; and the lowest registered at the surface of the mucous membrane in contact with the applicator was 2.8°C.

2. Histologic investigation of nerves from canine mandibles subjected to continuous local refrigeration at 0° to 1°C. for 2-hour periods did not disclose evidence of injury to either the inferior alveolar nerves, or to the nerves of the mucous membrane and periosteum.

3. Fifty-two cavities were prepared for filling under local refrigeration at 1° to 2°C. in the teeth of 33 members of the naval service. In 34 instances (63%), complete anesthesia was obtained; in thirteen (25%,) very mild to moderate pain was experienced; and in five (10%), there was little or no anesthesia.