Scottish Dental

I feel your pain

A guide to managing common non-dental orofacial pain in primary dental care

01 February, 2016 / clinical
 Emma Finnegan, Alexander Crighton  

The patient presenting with non-dental orofacial pain can be one of the most challenging aspects of primary dental care and appears to be more prevalent than previously thought. Although a small part of everyday dentistry, dentists are often the first point of call for patients with orofacial pain, usually before the GP, and pain consultations can be among the most difficult to manage.

Time constraints and lack of experience in managing non-dental pain disorders are just some of the challenges faced, but a good history, along with a few simple investigations, can improve the consultation outcome, therapeutic options and, where needed, the quality of pain referrals. This article aims to help clarify some of the most common orofacial pain disorders and, where appropriate, give guidance on investigations and treatment that may be carried on in a primary care setting.

Before considering the following diagnoses, other dental and pathological sources of pain must be excluded through appropriate clinical examination and imaging. The more common non-dental orofacial pain conditions that may present to the dentist include:

• TMD
• Burning Mouth Syndrome
• Sinusitis
• Trigeminal neuralgia.

The acronym SOCRATES (Site, Onset, Character, Radiation, Associated Factors, Timing, Exacerbating/Relieving Factors and Severity) is a standardised tool for pain history and assessment endorsed by many medical and dental schools across the UK and provides a thorough and logical approach to history taking. This is as applicable to the dental practice setting as to the specialist pain clinic. Each of these features should be asked about and the response noted. Remember that the ‘absence’ of a finding can be as important as a ‘positive’ response where pain and its associated
features are concerned – both must be recorded in the notes.

Temporomandibular joint dysfunction (TMD)

Background

This is the most frequently seen non-dental pain condition presenting to the dentist. It is also one of the most varied orofacial pain disorders as it can appear in many different ways. Always consider TMD in the differential diagnosis of orofacial pain, even if the symptoms do not seem exactly to fit. This is particularly the case where the pain reported is bilateral. It is easy for the practitioner to treat in primary care and will respond promptly to the correct treatments.

Remember that for TMD:

• Clicking of the jaw in the absence of pain and locking does not require referral or treatment
• Bite splints DO work and should be tried where TMD cannot be excluded. These are now available on the NHS without prior approval. They are not effective alone for every patient, but are used together with other medical and physical therapies to good effect.

Where locking of the TMJ is the main problem, the issue is usually related to the joint itself and these patients should be referred to the local maxillofacial surgery service for assessment.

Aetiology

Parafunctional habits, such as clenching and grinding, are frequently seen in patients with TMD, although many patients also have similar habits without problems. Where pain is present, habits such as chewing gum seem to be an important trigger of pain. Unilateral chewing especially appears to be a risk factor.

Evidence of clenching can be seen from the oral soft tissues with crenulation of the tongue edge and a buccal mucosa occlusal line being common findings. Stress and emotional burden are very often cited, but will not always feature in the history unless specifically asked about by the dentist.

Figure 1

Occlusal factors themselves seem to play a very small role in chronic TMD, although
acute changes may be found after placement of a restoration that disrupts the normal intercuspal position. However, looking at the occlusion for triggers in chronic TMD is rarely helpful and often results in destruction of dental hard tissue unnecessarily. TMD itself may in fact cause occlusal changes, as pain-induced muscle dysfunction around the joint results in altered closing patterns of the mandible and a secondary occlusal change.

There is certainly no link with orthodontics in either the origin or resolution of TMJ dysfunctions. Hypermobility of the joints, however, does show an increased probability of developing problems. This is demonstrated in studies on patients with Ehlers-Danlos syndrome, where all patients in the study experienced TMD and multiple joint dislocations.

Who is affected?

As a condition which affects 5-12 per cent of the population, these patients frequently present in dental practice. More women than men are affected by the disorder (quoted up to 4:15) and unlike other types of orofacial pain, its prevalence is higher in a younger age group, with up to 7 per cent of 12-18 year olds diagnosed with mandibular pain dysfunction. However, children and older adults are also affected, commonly with stressful life events being key precipitators.

Interestingly, women taking oral contraceptives or on supplemental oestrogen are also more likely to both suffer from TMD and to seek treatment for the condition. This is thought to be due to the presence of oestrogen receptors in the TM joints, which modify metabolic activity, affecting ligament laxity and also due to the effects of oestrogen on pain experience. There appears to be no genetic predisposition and no influence from the family environment, although many patients citing ‘stress’ as a trigger have home issues!

Examination

Palpate the muscles of mastication for evidence of pain or hypertrophy. Use forced movements of the mandible against pressure to look for pain in the medial and lateral pterygoid muscles. Palpate the TMJs in static and dynamic movements – this may elicit pain, clicking and crepitus, all of which should be noted. Measure mouth opening inter-incisally – as a single measure, this does not contribute much, but can be measured serially to look for improvements as treatment progresses.

Soft tissue features, including evidence of parafunctional clenching and tooth wear, should also be noted. If neck or shoulder pain is also present, palpate the trapezius and sterno-mastoid muscles, looking for areas of focal tenderness which might indicate referred pain from the neck to the face.

Treatment

Conservative management remains the most successful treatment for TMD and should always be tried in primary care before considering a referral. Patients must be aware of the self-limiting nature of the condition and they must understand that their role in the treatment is paramount. The success of treatment will depend upon the patient following a standardised regime:

• Medications: NSAIDs (TDS for first two weeks and as needed thereafter)
• Soft diet (liquid for first two weeks and avoidance of hard/chewy foods after)
• Localised heat (apply to affected side for five minutes TDS in evening with five minute breaks intermittent between for two weeks and as needed thereafter)
• Yawning support/avoid wide opening
• Avoidance of chewing gum/habits (e.g. nail/pen biting) and playing wind instruments.

If these simple measures fail to produce an improvement within a month, a Bite Raising Appliance (BRA) should be made and fitted. There is evidence to support the use of both soft and hard BRAs, but neither is clearly better. A soft appliance may be useful in the first instance, as is more comfortable to wear and easier to construct and fit. Some patients will find these encourage clenching; however, this does not seem to affect the success. The patient should be advised to expect this at the beginning of treatment and even some initial increase in discomfort.

Most patients will have seen a good improvement in two months of night use of a splint. In acute cases, a small dose of diazepam (2-5mg up to TDS) can be useful in conjunction with the treatments suggested above remembering to assess the impact this may have on the patient’s life and warning the patient about drowsiness and sedation from the treatment.

If there is no good improvement in this time, a referral for specialist assessment should be arranged.

Specialist referral

Onward referral to oral medicine should be made if symptoms are not improving or the symptoms are increasing despite conservative management AND provision of a BRA.

Investigations and treatment that can be carried out in specialist centre, include ultrasounds and MRI scanning to give evidence of disc displacement and Cone Beam CT to demonstrate joint degeneration. Medication, commonly a tricyclic antidepressant such as Nortriptyline, can be used at night to help with sleep, relaxation and improve pain in conjunction with conservative measures. SSRIs often exacerbate TMD pain and where patients present taking these, discussion with the GP with a view to changing the SSRI to an alternative antidepressant therapy can help treatment.

Burning Mouth Syndrome (BMS)

Background

This name encompasses a number of disorders, which include burning/pain (often of the tongue, lips and buccal mucosa) in the absence of soft tissue abnormalities, as well as a bad taste (dysgeusia), perceived dry mouth (xerostomia) with plenty of saliva present, or a feeling of paraesthesia. For this reason, the term oral dysaesthesia is often preferred. Glossodynia is another term for the same condition.

BMS is a diagnosis of exclusion and true BMS has no identifiable cause. It is a neuropathic pain in which there is either a disturbance in the way in which information is passed from the oropharynx to the brain, or the understanding of that information by the brain.

Aetiology

This is unknown. In some cases it behaves like a neuropathic pain and in others as an abnormal perception. In some patients, testing of vitamin B12, folate or iron reveals deficiencies; others have diabetes as an undiagnosed cause of dryness or neuropathy and in a few candida has been shown to be responsible for the burning. The most common finding in patients with BMS or other forms of dysaesthesia is a generalised tendency to anxiety.

Who is affected?

It is a condition which affects between 1-15 per cent of the population at some point and occurs more commonly in females particularly of peri-menopausal (as high as 40 per cent of this group), but these figures seem higher than seen in clinical practice in Scotland. Although any age can be affected, it occurs rarely in women below 30 years and men below 40 years.

Investigations

It is important to exclude lichen planus, haematinic deficiencies, diabetes and invasive candidiasis before concluding that there is an oral dysaesthesia. Gastro-oesophageal Reflux Disease (GORD) has been suggested as a trigger where taste is involved and a trial of a proton pump inhibitor is often given. Referral to the GP for exclusion of nutritional deficiencies and diabetes is sensible and, where oral dryness is the main complaint, a review of the patient’s medication to see if any medicines with antimuscarinic side effects can be eliminated.

Treatment

A lower soft acrylic bite splint can be helpful to avoid irritation from teeth if a parafuctional habit is present. This is particularly the case where the symptoms are predominantly present around the edge of the tongue. Chewing gum is a useful distraction from symptoms and Gelclair or similar products can be helpful to soothe and distract from the sensation. Alphalipoic acid has shown to be helpful to some patients- this can be purchased at health food shops.

Relaxation/stress reduction exercises and hypnotherapy can be useful where patients are not keen for medication but the use of a tricyclic antidepressant such as Nortriptyline for up to six months can give a good reduction in symptoms. Sometimes patients seek reassurance of the absence of pathology and have comfort in knowing their diagnosis and require no further treatment. Many have suspected that they have cancer and the dentist should always make clear to the patient that this is not the case.

Specialist referral

In many circumstances the patient can be managed in primary care by the dentist and the doctor, but where there is doubt as to the diagnosis or the patient’s symptoms fail to respond to the treatments outlined above, referral to an oral medicine specialist is needed.

Figure 2

Maxillary sinusitis

Background

Acute maxillary sinusitis produces unilateral midface pain which can be very similar in character to pulpal or periapical pain in the upper molar teeth. It should be suspected where a dental cause does not seem likely after clinical and radiographic examination of the teeth and sensibility testing. It can also be confused with TMD pain.

Who is affected?

Sinusitis rarely affects children below the age of nine years as the maxillary sinuses do not develop properly until puberty. Elderly people are at higher risk due to both a more compromised immune system and also a combination of anatomical and physiological factors such as dry nasal mucosa, weaker cartilage causing airflow changes and a diminished cough/weakened gag reflex.
Atopic individuals show a particular high risk for developing chronic sinusitis.

Aetiology

Most are viral infections. Chronic sinusitis is not painful, only acute exacerbations. There may be local nasal and sinus abnormalities contributing to the aetiology, such as polyps in the nose or sinus, septal deviation or obstruction to the meatus of the sinus in the nose. There may have been a precipitating event such as an upper molar extraction where the roots have been close to the sinus floor.

Character

Constant throbbing pain which may vary in intensity.

Associated features

There will often be a history of sinusitis and frequently an awareness of a bad taste or halitosis. This is often worse in the morning and due to pus running into the oropharynx from the nasal floor (post nasal drip). Many patients get tenderness to pressure of the cheek over the affected sinus and discomfort on pressure on the alveolar ridge between the roots of the first and second premolar teeth. The patient may report the pain as being more severe on bending forward or
lying down.

Management

If maxillary sinusitis is suspected, the patient should be referred to their GP for appropriate treatment. If the dentist wishes to give temporary supportive therapy, this can be with spray or drop nasal decongestants and not antibiotics, which are ineffective in viral infections.

Trigeminal neuralgia (TN)

Background

TN is usually a straightforward diagnosis due to the character of the pain experienced. The sudden intense and short duration of the pain means that the dental pains which can be confused with TN are acute dentine sensitivity and cracked cusp syndrome. Both of these can give similar histories in some patients where the trigger for trigeminal neuralgia is intraoral. The dentist should look carefully for evidence of these, trying agents to reduce sensitivity, testing the cusps of the premolar and molar teeth in the area of the pain.

Aetiology

The cause of TN is often unknown. Demyelination of the trigeminal nerve is a common factor, however, and this may be due to pressure from an adjacent blood vessel, or, less commonly, a tumour or other intracranial mass (2 per cent of patients) or multiple sclerosis. Diagnosis is by clinical assessment and exclusion of other causes of pain.

Who is affected?

Trigeminal neuralgia is a rare condition traditionally affecting an older age group, typically individuals over 50. However, many more patients now are seen in a younger age group and the diagnosis should be considered in any patient
with the characteristic pain history. More women are affected than men and the overall prevalence varies in the literature, but has been quoted at between 0.16 per cent and 0.3 per cent.

Character

The key feature of trigeminal neuralgia is the short intense pain experienced on one branch of the trigeminal nerve. This may be triggered by touch, washing, eating or a change in ambient temperature. The patient often describes the pain as being “like an electric shock” and stops them in their tracks.

However, between these, the patient is pain free, although some describe a burning feeling in the trigger area. Trigeminal neuralgia often first presents in the autumn and is frequently worse over the winter months.

Associated features

Rarely, patients will report swelling and redness in the area of their trigger.

Management

Trigeminal neuralgia requires specialist assessment and management at the beginning. Once the treatment is stabilised, the care can be continued in primary care. Primarily, this should be through the GP. A dentist suspecting TN should liaise with the patient’s GP for a referral to oral medicine or neurology and to start the patient on an appropriate medicine, usually carbamazepine whist the referral process progresses.

Although this drug is in the dental formulary, it should only be started by a dentist on the instruction of a specialist, particularly because the patient needs to have blood tests before and during treatment with this drug.

Conclusions

Although many of the pain conditions covered in this article would traditionally be referred to a specialist unit, a good history, careful examination and appropriate investigation can help establish an accurate diagnosis, which can facilitate initial management in a practice setting. This can be much more convenient for the patient and allow a much quicker start to treatment and relief of symptoms.

The simple strategies outlined above are frequently effective, making for a happy
patient and dentist. They are often the first things tried by a specialist and having this initiated in primary care means that patients subsequently passed to a specialist get quickly on to the more complex treatments where needed. Patients often have to travel significant distances for specialist care, especially in oral medicine and are often grateful for management locally. Additionally, limiting the pressures on tertiary care centres allows the patients needing this level of care to be seen more promptly.

Always try to have the same methodical process for pain history taking using SOCRATES – this will help form a logical thought process for forming a diagnosis. Employ all means of investigation prior to referral. Radiographs in particular are critical to eliminating dental sources of pain. Liaison between dentists and general medical practitioners is underutilised and is of immense benefit for complete patient care, from simple investigations to appropriate prescribing or onward referral to specialist medical services.

About the authors

Emma Finnegan graduated in Dentistry from the University of Glasgow and has a special interest in oral medicine. She currently working as a core trainee in Glasgow Dental Hospital and School.

Dr Alexander Crighton is a consultant in oral medicine and honorary senior lecturer in medicine in relation to dentistry at Glasgow Dental Hospital and School.

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