After the completion of the human microbiome project, and recent advances in genome wide association studies, there is greater appreciation that virtually all human disease results from the interaction of genetic susceptibility factors and modifiable environmental factors. The broadly defined modifiable environmental factors include infectious, chemical, physical, nutritional, and behavioral factors. Genetic variations do not cause disease but rather influence a person’s susceptibility to environmental factors. Evaluation of single nucleotide polymorphisms may aid in the complete evaluation of the patient. A homozygous MTHFR polymorphism may be associated with poor methylation patterns and increase a patients risk to develop anxiety, stress, and possibly cancer. Environmental factors such as a poor gut microbiome, or low vitamin D status or omega 3 deficiencies may influence a patient’s genes and predispose to disease. When a patient displays daytime bruxism, it is often due to an imbalance of excitatory and inhibitory signals in the brain. Learn to target the microbiome or the neurotransmitter imbalances that have led to the manifestation of stress, instead of using muscle relaxants and night guards. Information presented in the lecture will rely on information published within the last 5 years.