Orofacial pain and dysfunction

Pain and functional jaw disorders are an inadequately recognized problem in Denmark, despite the
fact that they affect 10% of the Danish population. For some the pain is so debilitating that they are
ultimately declared medically unfit to work.,

One ambition for the Department of Dentistry and its unit for clinical oral physiology is to help relieve severe pain of this nature. Our research therefore revolves around finding
better diagnostic and therapeutic methods to treat patients suffering from oral and jaw pain.

The unit has a particularly high level of competence in the field of Quantitative Sensory Testing (QST) and orofacial pain. We are world leaders in the technical aspects of QST and have developed a special device – a palpometer – which, by “feeling” the muscles, can standardize pressure, thereby
reducing the variation in the clinical examination of different muscles and joints. This small device gives greater certainty in the diagnostic process and thus benefits patient treatment. The palpometer is patented, and commercial production has begun.

Another specialized skills area is our work with a wide variety of techniques used to measure motor function. In this context we measure reflexes and evoked potentials, as well as other biological muscle reactions. Combined with various brain-scan techniques this gives us a new way of looking at the brain of patients suffering from severe pain. An added advantage is that we can look not only at the teeth, but more broadly at the patient as a whole.

An international partner
Within our professional area we collaborate with many other groups based in the fields of neurology, rheumatology, psychology, and anaesthesiology. However, we are also strong on international partnerships, uniting our efforts with researchers and units in Europe, Japan, and Canada. In Nanjing, China, we co-founded the Sino-Denmark Orofacial Pain & TMD Research Center in 2011.

As an active participant in the international research community, we help to create a consensus about what topics are most relevant for research in our field. Here, our unit at AU Health is one of the international heavyweights measured, for instance, in terms of research output, but also by virtue of the emphasis our voice carries in international bodies and discussions. We play a very active role in special interest groups for facial pain, and we hold the chairmanship in an international forum on temporomandibular disorder pain.


  1. Motor learning/cortical plasticity. This heading covers a series of projects in which repeated jaw or tongue movement is practiced to obtain a high degree of accuracy in execution, and in which precision can be measured simultaneously with the brain’s altered control of the muscles in question. This is an important part of relearning functions, for example for people learning to swallow again after a stroke, or for those internalizing jaw exercises in connection with physical therapy.
  2. Illustration of ambulatory recording of jaw muscle activity with the use of Grindcare (Medotech A/S) and standardized assessment of jaw muscle pain sensitivity with a so-called palpometer.QST and orofacial pain. Quantitative Sensory Testing is a “window” that can reveal many things about the pain-related nervous system: By systematically describing the function of various sensory nerves, we are able to form an impression of the background of orofacial pain. Therefore QST can also be used to document damage to the nervous system and form a prognosis on how orofacial pain will develop.
  3. Bruxism – causes and effects. Toothgrinding and clenching – bruxism – is a frequently occurring phenomenon. It can not only wear down teeth, but can also result in headaches or pain and tenderness in the jaws. Working with commercial firms, we have developed EMG measuring apparatuses and therapeutic devices for diagnosing and treating bruxism. This equipment can also be used to investigate basic circumstances relating to the condition.
  4. Autonomous reactions to orofacial pain. Leading a stressful life can aggravate orofacial pain. This project employs several physiological, psychological, and genetic measurements of pain sensitivity to assess the autonomous nervous system’s significance for orofacial pain.
  5. Brain scans. We are collaborating with the university’s Center of Functionally Integrative Neuroscience (CFIN) and the Danish Pain Research Centre to conduct several studies that explore the interaction between pain, brain activity, and emotions. We expect to identify critical areas in the brain that give rise to an intensified feeling of pain, as well as areas that can alleviate pain.


Our goal is to make high-profile contributions to the internationally recognized literature on orofacial pain and functional disorders. Furthermore, our ambition is to continue to obtain research funding from Danish and foreign sources, and to attract visiting researchers from abroad.

Development, patenting, and validation of the new palpometer
(Futarmal S. J Dent Res. 2011;90:918–22)

Guidelines and recommendations for assessment of somatosensory function in orofacial pain conditions
(Svensson P. J Oral Rehabil. 2011;38:366–94)

Demonstration of lower levels of pain perception during hypnosis
(Abrahamsen R. Pain. 2010;151:825–33)


The research done on pain and functional jaw problems involve techniques for systematically assessing sensory functions – as this gives us a window to understanding how the pain system works. For this purpose we use Quantitative Sensory Testing (QST). Our research unit at Health has drawn up guidelines for the use of QST on orofacial areas. 

We also employ a variety of other scientific methods, including:

  • Electrophysiology (EMG, reflex, EEG)
  • Autonomous measurements (EKG variability)
  • Brain scans (fMRI)
  • Experimental pain investigations – models for pain in, for instance, muscles or joints
  • Standardized clinical functional assessments (Research Diagnostic Criteria for Temporomandibular Disorders)
  • Assessment of bruxism (tooth-grinding) using Grindcare

Sections and departments working within the research area


Peter Svensson

Phone: +4587168132

Lene Baad-Hansen
!!Lektor, Viceinstitutleder for forskning og talent

Phone: +4587168123

Eduardo Castrillon
Associate professor

Phone: +4587152657