Inflammatory and cancer-related orofacial pain mechanisms: Insights from human experimental studies

For our understanding of biological processes, such as pain, the use of animal models is essential. However, animal pain models cannot be directly translated to humans, given that pain is a complex phenomenon that requires a conscious mind to be perceived. Animal pain models assess behavioral responses to nociceptive stimuli that are interpreted as being equivalent to pain. To bridge the gap between animal and clinical pain research, human experimental pain models are necessary. A standardized model of pain reduces the number of subjects needed in clinical trials and provides fast and reliable information on dose-efficacy relationships in drug trials. It is important for the pain model to have similar characteristics to the clinical pain condition it is supposed to mimic. It should also target the same anatomical region, because potential regional differences could affect the results. This chapter will review knowledge about orofacial inflammatory and cancer-related pain mechanisms gained from human experimental pain models, with a focus on cutaneous, oral mucosal, and dental tissues. Chapter 22 provides analogous coverage of mechanisms in human musculoskeletal inflammatory pain states in the orofacial region.