Orofacial Pain Diagnosis for Clinicians

Getting the diagnosis correct to maximise success of managing the patient

• Is the pain health acute pain (nociceptive or inflammatory)? see more on acute pain
• Is the pain chronic (neuropathic or dysfunctional)? see more on chronic pain
• What biological, psychological and social factors are driving this patient’s behaviour and suffering?
• What are the patients expectations?

Chronic orofacial pain can be classified pragmantically as;

Table 1 illustrating a suggested classification for chronic orofacial pain modified from Woda et al

Often patients with OFP will be seen by a clinician who has experience in one aspect of orofacial pain. Dentists will explore dental pain, ENT surgeon will assess for sinus and ear related pain etc. Consulting a patient in pain requires specific skills and excellent communication. The patients are often anxious visiting the dentist without pain. Whilst in pain their anxiety levels are increased potentially related imminent treatment necessary to treat the cause of their pain.

Communication is key to eliciting an appropriate history from your patient and the clinician must be a good listener. The patient must also be able to communicate clearly and this is often not the case (children, intellectual disability in general population 2.5%, Cerebral palsy, Dementia in 8% of people over 65 years, Brain damage:  5 – 1.9 million head injuries per year with 10% of these being serious).[12] These people are all vulnerable to pain even more so because of their inability to communicate it.

In order to provide each patient with the most suitable treatment plan to address individual needs it is essential to discover as much information as possible about each patient’s experience, expectations, health and quality of existing dentures.

Ideally a multi-disciplinary team should assess complex chronic pain patients including: dentists, neurologists, clinical psychologists, psychiatrists, neurosurgeons and pain management consultants.

Patient presentation with persistent pain is often complex and may be driven by many factors. The patient may be fit and well or have significant co-morbidity including psychological, medical history complexities or have difficulty managing their anxiety and fear. Fear and anxiety will increase the pain experience and may require adjunctive therapy including behavioural and medical techniques. As pain is multi-dimensional many aspects of the impact of pain on the patient must be assessed. The biopsychosocial model illustrates the many environmental, phenotypic and psychological factors (Figure 1.1)

These factors must be taken into account when consulting the pain patient. The attentive, listening clinician will build a rapport with their patient rapidly and the ensuing trust will allow the patient to confide in the attending clinician providing invaluable information about their on-going complaint. Managing patient’s expectations is paramount and often a cure is not possible but management is. Providing the patient with clear understanding of what is taking place with realistic goals is essential.

Communication skills underpin a successful consultation for chronic pain. Pain is invisible thus diagnosis is based upon what the patient can communicate to their clinician.

• The patient must be heard
• Careful listening and confirmation of what the patient is trying to convey will elucidate important features and facts about the patients experience

Often a careful history is suffice in making a diagnosisThe cornerstones of assessment and establishing a diagnosis and treatment planning are:

• Thorough history (Social, dental and medical)
  • Pain history (Table 2)
  • Previous medications and their effect on the reported pain
  • Previous consultations and with whom
  • Previous investigations
  • Previous interventions and ensuing effect on the pain
• Careful examination  (Table 3)
• Appropriate special tests (Table 4)
  • Radiographic- dental radiographs may be indicated if not recently performed
  • MRI- useful for patients with recent onset protracted pain and to exclude;
    • Space occupying lesions (intra-cranial and extra-cranial)
    • Vascular compromise (for patients with Trigeminal neuralgia)
    • Exclude demyelination (+/-Gadolinium enhancement)
  • Psychometrics  (Table 5)
  • Haematological  (Table 6) to exclude systemic medical conditions that may contribute to the development or exacerbation of orofacial pain (Table 6).
  • Histological investigations may be indicated if a pathological lesion is discovered. Neurologists routinely biopsy tissues to quantify peripheral nerve density in patients presenting with neuropathy, usually form lower limbs for Diabetic patients. This routine practice is more of a challenge for patients with orofacial pain as sampling facial skin will leave a scar.
  • Adjunctive neurological tests may include quantitative sensory assessment, nerve conduction tests and somatosensory evoked potentials
  • Functional, neurological, psychological assessment ideally undertaken by a multi-disciplinary team

For pain diagnosis the standard history and examination should be augmented with specific questions relating to the history (see Table 2) and specific examination of the mouth and special tests (see Table 3).

A (recent) report[13] on the differential diagnosis of orofacial pain (OFP) highlights some important strategies to help distinguish between orofacial pain (OFP) conditions and comes to a diagnosis or differential diagnoses. History taking remains of paramount importance in facilitating the diagnostic process. There are specific guidelines for the assessment and diagnosis of neuropathic pain. [14-15] Several recent studies have made further recommendations regarding neurological assessment of patients presenting with orofacial pain.[16-17]. However, it remains a challenge to fully assess these often complex patients and a multidisciplinary team is essential.[18]

There are many systemic conditions that can and must be excluded in order to make diagnoses for example Burning Mouth Syndrome is a diagnosis by exclusion. Neoplasia can occasionally mimic or masquerade as orofacial pain though rare this must always be excluded and fear of cancer is likely to be a prominent reason for the patient seeking care.[19] Risk factors or RED Flags for occult neoplasia include:

• Age over 50yrs
• Sudden recent onset and intense pain, motor or sensory neuropathy
• Painless persistent lymphadenopathy
• Painless trismus,
• Worsening trismus despite therapy
• Developing spontaneous Asymmetry
• Trigeminal neuralgia in patients under 50 years suspect Multiple Sclerosis Conversely some Orofacial pain conditions may masquerade or be misdiagnosed or misinterpreted as toothache for example Trigeminal neuralgia.

Measuring pain

Measuring pain is near impossible.  The pain experience is an entirely individual response.  No other person can derive your own experience of pain because you alone experience it; and due to its complexity, conveying your total pain experience to others is impossible.  Unless your clinician is equipped with Dr Spock’s (from Starship Enterprise not paediatrics) ability to key into your experience using bi-temporal palpation, sharing your pain experience will depend upon your clinician’s talent for listening and empathising that may, in part, allow him/her to begin to understand your pain.  We attempt to gain an idea of the affective component of your pain experience using questionnaires for psychometrics and we use questionnaires to assess your functionality, disability and behaviour.  Scoring pain using a Lickhert scale is standard but it massively over simplifies the complex pain experience.

A pain diary may provide both clinician and patient an extremely useful adjunct to the initial pain history. Particularly clarifying response of the pain to various medications, avoidance strategies taken by the patient and identifying factors that exacerbate the pain. Daily changes in the pain are important for example:

• Does the patient wake up night with the pain? This is very rare for neuropathic pain disorders (Trigeminal neuralgia).
• Is the pain worst in the morning? This may be an indication of nocturnal bruxism precipitating TMJ pain.
• Is the pain worse with stress or anxiety (symptomatic of neuropathic pain)? Does the pain respond to anti-inflammatories (including paracetamol and ibuprofen)? If the pain does NOT respond it is likely to be neuropathic rather than inflammatory pain

Psychological assessment of the pain patient (Table 5)

In the introductory section to this series it is highlighted the significant component of the affective and emotional role in pain perception, behaviour and suffering (Figure 4). As pragmatic clinicians we tend to focus on ‘mechanical/medical’ interventions to prevent the nociceptive pain and forget the ‘holistic’ management of pain. With simple acute inflammatory conditions that can be simply managed with a swift and effective surgical intervention less understanding of the affective burden is required. However in chronic pain the emotional components of persistent pain, its social, functional and resultant psychological sequeale cannot be underestimated[20, 29]. The biopsychosocial model of pain (Figure 5) emphasises the complexity of managing pain patients. Many authors have made recommendations regarding the preferred psychological assessment of the pain patient.[30-35] Our local orofacial pain team, which includes, liaison psychiatrist, clinical psychologist, health psychologist, dental clinicians, neurosurgeon, neurologist and pain management consultant use the questionnaires in Table 5.Using these questionnaires we are able to elicit anxiety and depression that may be contributory to the patient’s pain condition. We can identify their ability to cope and how impactful the pain is in relation to their daily function. Red flags including self-harming tendency and suicidal ideation can also be identified early on, precipitating an expeditious referral to the psychiatrist. Overall the patients are extremely cooperative with completing these questionnaires and the data collected is undoubtedly facilitating the development of tailored cognitive behavioural techniques for specific orofacial pain conditions.

Summary

Most importantly the clinician must keep a broad perspective of the patient’s presentation and complaint. Systemic diseases, psychological and environmental factors all play a potential role in the patient’s pain experience and thus must be considered in order to provide effective pain alleviation and education. The subsequent papers provide and update on the management of acute and specific chronic trigeminal pain conditions. Pain management procedures including Local anaesthesia and the management of anxiolysis (Behavioural techniques and medical techniques –Sedation) are not included in this series.

Table 2  Pain history taking is often taught as using SOCRATES

• Site – Where is the pain? Or the maximal site of the pain.
• Onset – When did the pain start, and was it sudden or gradual? Include also whether if it is progressive or regressive.
• Character – What is the pain like? An ache? Stabbing?
• Radiation – Does the pain radiate anywhere?
• Associations – Any other signs or symptoms associated with the pain?
• Time course – Does the pain follow any pattern?
• Exacerbating/Relieving factors – Does anything change the pain?
• Severity – How bad is the pain?

Table 3 The clinical evaluation of the patient presenting with orofacial pain

• Inspection of the head and neck, skin, topographic anatomy, and swelling or other orofacial asymmetry
• Palpation of the temporomandibular joint and masticatory muscles, tests for strength and provocation. With assessment and measurement of the range of mandibular movement
• Palpation of soft tissue (including lymph nodes)
• Palpation of cervical muscles and assessment of cervical range of motion
• Cranial nerve examination (usually excluding cranial nerve 1 (olfactory) and VII (vestibule cochlear) and include examination of C2 and C3 as cervico genic referred pain is not uncommon
• General inspection of the ears, nose, and oropharyngeal areas
• Examination and palpation of intraoral soft tissue
• Examination of the teeth and periodontium (including occlusion)

Table 4 Examination with reference to pain and apecial tests required for pain patients

Table 5 Commonly used Psychometric evaluation for patients with chronic OFP

• McGill Pain questionnaire short version (Dworkin et al. (2009) developed the SF-MPQ-2) [20]
• Chronic Pain Acceptance Questionnaire (CPAQ-8).[21]
• HADS Hospital Anxiety depression score.[22]
• Pain catastrophising score.[23]
• OHIP 14 Health Impact Profile (also known as the OHIP–14 questionnaire), which asks about the frequency of 14 functional and psychosocial impacts that people have oral functional problems.[24]
• Pain detect & question survey to detect neuropathic pain versus inflammatory pain.[25]
• EuroQOL  EQ-5D™ is a standardised instrument for use as a measure of health outcome.[26]
• PCS score Pain Catastrophising Scale Scoring Information Sullivan, Bishop & Pivik, 1995.[27]
• PCL (Brief version) post-traumatic stress disorder assessment.[28]
• PSEQ PAIN SELF EFFICACY QUESTIONNAIRE M.K.Nicholas (1989).[29]

Table 6 Haematological tests to exclude systemic conditions that may contribute to the development or facilitate  chronic OFP

Links to useful assessment documents

AAOP guideline assessment diagnosis and management of OFP
BDJ Pain Tables – Some useful tables for classification and diagnosis of OFP
Classification_DD_TR et al.pdf
DD Tables TR et al.pdf
Perils of diagnosis of orofacial pain