Understanding and Managing Dental Patients with Central Sensitivity Syndrome

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Central sensitivity syndrome (CSS) is a term that encompasses multiple disorders, including fibromyalgia, irritable bowel syndrome, chronic headaches, temporomandibular disorder, trigeminal neuralgia, and pelvic pain syndromes. This group of disorders often share common symptoms, and chronic pain is the most prominent feature.1,2

Diseases associated with central sensitivity syndrome are often “invisible” diseases. Invisible diseases are often present in a way that makes them hard to understand and identify. Many of these diseases lack measurable symptoms, yet they are just as debilitating as diseases that do have measurable symptoms.2,3

Currently, the etiology and pathophysiology are not fully understood. Furthermore, treatments are primarily palliative care with modest benefits, leaving patients struggling to manage daily life in many cases.1

As health care professionals, dental hygienists must understand these diseases and the complications often associated with them. Understanding enables hygienists to provide empathy and a better experience for patients with central sensitivity syndrome.

Understanding Central Sensitivity Syndrome

Health care professionals must trust patients, listen to their symptoms, and take them seriously. A huge problem with CSS is that far too often, health care professionals see these patients as “drug seeking” and assume the patient is “faking” symptoms. I cannot stress enough how important it is to understand that invisible symptoms do not mean the symptoms are not real.4

The term “central sensitization” was coined in 1989 after studies in rats indicated that neurons in the spinal cord can become hyperexcitable over time after an injury. This is believed to lead to a heightened state of neural reactivity and contribute to chronic pain. When this occurs, the central nervous system is hyperexcited even in the absence of sensory stimuli.4

The hyperexcitability of the central nervous system is due to structural, functional, and neurochemical changes. These changes can contribute to three different conditions. The patient may experience one or all of these conditions:4

  • Hyperalgesia: Painful stimulus becomes associated with even more pain.
  • Allodynia: Previously nonpainful stimulus now causes pain.
  • Global sensory hyperresponsiveness: Patients become extremely affected by external and internal stimuli, including, for example, sensitivity to bright lights, loud noises, smells, foods, medications, and internal stimuli such as their heartbeat or peristalsis in the GI tract.

As you can imagine, hyperalgesia could contribute to lower pain tolerance during dental treatment. At the same time, allodynia could make something as simple as a light touch on the cheek almost unbearable. Patients experiencing global sensory hyperresponsiveness could quickly be stimulated by the multitude of external stimuli in dental offices, such as bright lights, noises, and smells.4

Studies attempting to understand CSS better have focused on sleep dysregulation as a factor. This is a new area of research, and no clear causal link has been made. However, the theory that glial cell activation and neuroinflammatory changes due to sleep dysregulation has been proposed. Studies are ongoing to understand the mechanism of action better and hopefully find treatment to manage the chronic pain associated with CSS.4

Managing Patients with Central Sensitivity Syndrome

Managing patients with CSS during dental treatment can be complex, considering the multiple triggers that can elicit a pain response. Cognitive behavioral therapy in the form of diaphragm breathing can be helpful for many patients. Guiding patients through box breathing may help relax them and activate the parasympathetic nervous system, which helps with relaxation and reduces pain sensations.5

How to guide patients through box breathing:5

  1. Have the patient breathe out slowly, releasing all the air from their lungs.
  2. Have the patient breathe in through their nose as you slowly count to four. Ensure the air fills the patient’s lungs and not their stomach.
  3. Have the patient hold their breath for another count of four.
  4. Have the patient exhale to another count of four.
  5. Have the patient hold their breath again for a count of four.
  6. Repeat for three to four rounds.

Reducing anxiety and stress also reduces pain sensation. Therefore, in some cases, box breathing alone is enough to help manage patients with CSS by increasing their pain threshold. However, in other cases, this may not be enough to keep the patient comfortable.6

Nitrous oxide has also been shown to significantly improve chronic pain, not only during treatment but also after administration. Studies show it reduces neuropathic pain in an animal model for up to four or five days.7,8

Oral conscious sedation may be an option for patients with CSS. A thorough medical history is vital. Further medical clearance from the patient’s primary care physician is a reasonable precaution to ensure no drug interactions. Oral conscious sedation contraindications include pregnancy, allergy, or drug interaction. Additionally, when considering oral conscious sedation, be aware that a history of illicit drug use may impact the efficacy.9


Understanding that some patients may experience pain sensations differently and may have a lower pain threshold than others is an important aspect of providing complete and comfortable care. Patients are more likely to complete treatment and return for routine visits if their experience is a good one. Patients also appreciate being heard and treated with dignity. So many patients with CSS have struggled to get the care they need from medical professionals due to the difficulty in diagnosing and treating many of the conditions associated with CSS.

Patients may seek help in the dental setting for pain associated with trigeminal neuralgia and temporomandibular disorders. Don’t dismiss a patient’s complaints and concerns about pain, as everyone experiences pain differently. Let’s improve their experience in the dental office by listening, having compassion, and offering patients options to make their experience as positive as possible.

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  1. Adams, L.M., Turk, D.C. Psychosocial Factors and Central Sensitivity Syndromes. Current Rheumatology Reviews. 2015; 11(2): 96-108. https://doi.org/10.2174/1573397111666150619095330
  2. Akerberg, P. (2015, June 5). Invisible Illness: A Blessing or a Burden? Pain News Network. https://www.painnewsnetwork.org/stories/2015/6/1/invisible-illness-a-blessing-or-burden
  3. Dobson, J. (2021, July). Invisible Illness and Measurability. AMA J Ethics. https://journalofethics.ama-assn.org/article/invisible-illness-and-measurability/2021-07
  4. Volcheck, M.M., Graham, S.M., Fleming, K.C., et al. Central Sensitization, Chronic Pain, and Other Symptoms: Better Understanding, Better Management. Cleveland Clinic Journal of Medicine. 2023; 90(4): 245-254. https://www.ccjm.org/content/90/4/245
  5. How Box Breathing Can Help You Destress. (2021, August 17). Cleveland Clinic. https://health.clevelandclinic.org/box-breathing-benefits
  6. Busch, V., Magerl, W., Kern, U., et al. The Effect of Deep and Slow Breathing on Pain Perception, Autonomic Activity, and Mood Processing – An Experimental Study. Pain Medicine. 2012; 13(2): 215-228. https://doi.org/10.1111/j.1526-4637.2011.01243.x
  7. Mattos Júnior, F.M., Mattos, R.V., Teixeira, M.J., et al. Chronic Pain Relief after the Exposure of Nitrous Oxide during Dental Treatment: Longitudinal Retrospective Study. Arquivos de Neuro-psiquiatria. 2015; 73(7): 578-581. https://doi.org/10.1590/0004-282X20150061
  8. Ben Boujema, M., Laboureyras, E., Pype, J., et al. Nitrous Oxide Persistently Alleviates Pain Hypersensitivity in Neuropathic Rats: A Dose-dependent Effect. Pain Research and Management. 2015; 20(6): 309-315. https://doi.org/10.1155/2015/809059
  9. Bean T, Aruede G. Conscious Sedation in Dentistry. (2023 April 23). StatPearls. https://www.ncbi.nlm.nih.gov/books/NBK592406/