Related Experiment Video
Updated: Jun 14, 2026

Assessment of Nerve Injury-Induced Mechanical Hypersensitivity in Rats Using an Orofacial Operant Pain Assay
Published on: July 26, 2022
Differences between orofacial inflammation and cancer pain
1Department of Control of Physical Functions, Kyushu Dental College, 2-6-1 Manazuru, Kokurakitaku, Kitakyushu, Fukuoka, 803-8580, Japan.
Abstract:
Rat models of orofacial cancer exhibit both allodynia and hyperalgesia; however, it is unclear whether cancer-induced pain is secondary to cancer-induced inflammation. To address this question, we compared the effects of an anti-inflammatory drug, indomethacin, on pain and neurochemical changes in the medullary dorsal horn in orofacial inflammation and cancer models. Daily peripheral administration of indomethacin largely suppressed mechanical allodynia and thermal hyperalgesia in the inflammation model. The same procedure suppressed allodynia and hyperalgesia in the cancer model, but the suppression was weak when compared with that in the inflammation model. In the medullary dorsal horn, calcitonin gene-related peptide and substance P levels were significantly increased in the inflammation model, but did not change in the cancer model. These results suggest that pain in the orofacial cancer model is not significantly mediated by cancer-induced peripheral inflammation, although it may have some involvement.
Related Concept Videos
Nociception
Blood and Nerve Supply to the Bones
Nutrient Artery
The nutrient artery is the main blood vessel that enters the diaphysis via the nutrient foramen. While most long bones have only one nutrient foramen, large bones, such as the femur, may have two. This...
Assessment of the Mouth
Mouth Inspection
The inspection begins with visually examining the mouth for symmetry, color, and size.
Pain
Inflammatory Response I: Vascular and Cellular
Acute Inflammation III: Local and Systemic Effects

