The mouth and the nervous system

The mouth and face is the location for 30-40 per cent of the body’s sensory and motor nerves. It’s the most sensitive part of the body. The nervous system is a key mediator of health and wellbeing.

The nervous system has a voluntary or peripheral nervous system and involuntary or autonomic nervous system. The autonomic nervous system is further divided into parasympathetic and sympathetic functions. When you feel relaxed, the parasympathetic nervous system is dominant and allows your body to function optimally. It helps to digest food, a regular heart beat and allows your immune system to work optimally – ‘rest and digest’.

When you feel stressed, the sympathetic nervous system, or ‘fight or flight’ response kicks in. At this point, the sympathetic nervous system becomes dominant and diverts blood from the digestive system to your leg muscles, enabling you to run from danger. But these days, danger isn’t from a saber-toothed tiger coming after you but the experience of being cut off in traffic or from other emotional stresses.

There’s no physical release after the stressful situation but your body is still flooded with cortisol and adrenaline. Because stress is common in modern life, the body suffers sympathetic overload. Long-term consequences include poor digestion and poor absorption of nutrients, impaired logical thinking, compromised immune system and poorer health. It’s also implicated in chronic musculoskeletal pain, tension headaches, neck aches and jaw ache. Symptoms that seem unrelated are influenced by the relationship between the peripheral and autonomic nervous systems.

Cranial nerves also impact on wellbeing. In addition to the spinal cord, your brain has 12 cranial nerves that regulate sight, balance, smell, taste, swallowing, mucous and saliva secretions. Cranial nerves pass through small holes, or foramen, in the cranial bones and can be compromised by poor posture or muscular strains. The fifth cranial nerve, the trigeminal nerve, has both sensory and motor functions and can impact on other cranial nerves.

If there’s an imbalance in your bite, jaw joints, clenching or grinding, and there are chronic oral infections or inflammation, it can impact on the nervous system in often surprising ways.