Why does patient mental health matter? part 5: chronic orofacial pain as a consequence of psychiatric disorders

Case 1: persistent idiopathic orofacial pain

A 56-year-old woman presents to you as a new patient. She reports that over the past 10 years she has been experiencing severe episodes of pain affecting the right side of her face. The pain is sharp and lancinating, but can be throbbing, heavy and aching. She feels this pain inside the mouth ‘near the top right’, but says it can radiate across the whole right-hand side of her face. Nothing alleviates the pain, but it can worsen later in the day, with no other obvious pattern.

Over the years, this pain has resulted in many teeth being removed, multiple surgical explorations of the area, various injections and drug therapies. Some of these have had limited success for brief periods of time. She has seen many specialists and has had numerous scans and radiographs, with no one providing a diagnosis. She has a medical history of gastric ulcers and a previous thyroidectomy and hysterectomy. Her medications include diazepam, ranitidine, and levothyroxine. She has been married for 33 years and has two adult children. She does not work and does not smoke cigarettes, but consumes 4 units of alcohol per week.

On examination, she wears an upper complete denture and is partially dentate on her lower arch. She does not wear her lower denture as it is ‘too painful’. When you ask her to point to the area that causes her chronic pain she identifies the upper right alveolar ridge and buccal mucosa in the area of previously extracted canines and premolars.

What are our initial thoughts?

Several features of the clinical scenario raise concerns about the patient experiencing a somatoform disorder, such as bodily distress disorder (Figure 1).

This somatization of physical symptoms appears to be in the form of persistent idiopathic facial pain and we should consider this in overall patient management.

Could a somatization disorder (such as bodily distress disorder) play a role in this clinical picture?

Bodily distress disorder has a frequency of 17% within primary care services and is common among men and women between the ages of 41 and 65 years.⁷ Patients with bodily distress disorder have self-reported chronic physical illness, often resulting in higher use of all types of medical services.⁷ The patient has had a history of high use of medical services, with repeat interventions and scans for persistent pain. She is also in the most common age range for a presentation of bodily distress disorder, so the possibility somatization is involved in her case is high. The relationship between bodily distress disorder and the patients’ case is explored further in Table 1.

When exploring this diagnostically, it is useful to collect a thorough pain history, including: ‘onset, frequency, duration, characteristics of the pain, provoking factors, site of initiation of pain, exacerbating factors, relieving factors, severity and associated features’.⁸ We should also discuss what the patient perceives the origin of the pain to be and the success and nature of any previously attempted management strategies.⁸

The patient is experiencing a constant, aching, long-lasting pain with no exacerbating or relieving factors, which radiates around the right face and head. No clinical or radiological signs indicate an underlying dental cause, although the potential for denture-related trauma and poorly fitting dentures should be investigated and not dismissed. All previous management attempts have failed and there may be comorbid stress owing to medical and lifestyle factors.

The most likely diagnosis would be persistent idiopathic facial pain (PIFP), previously known as atypical facial pain,⁸ which could originate from a somatization disorder. Patients who have bodily distress disorder often have high rates of comorbid anxiety and depression,⁷ highlighting the relationship between somatization and these conditions.

In our next case, we consider the somatic symptoms of anxiety and depression.⁷

Case 2: temporomandibular joint dysfunction

You have a 21-year-old male patient with a medical history of anxiety, depression, irritable bowel syndrome and chronic fatigue syndrome for which he takes diazepam, sertraline and mebeverine. Over the past 2 years he has experienced pain and clicking near his ears that radiates to his lower jaw and can cause headaches. He describes the pain as throbbing, heavy and aching. The pain has worsened recently and is constant, with very painful episodes intermittently. Exacerbating factors include ‘chewing, talking for long periods or opening wide’ and he reports that his symptoms feel worse in the morning.

He has recently finished his degree in journalism and has started a high-profile stressful job. He smokes 20 cigarettes per day and drinks 16 units of alcohol a week. He reveals that stress can provoke the pain and has been using soft foods, heat pads and massaging the area to relieve symptoms.

On examination, there is palpable tenderness in the pre-auricular region, and on mouth opening. This tenderness extends to the muscles of mastication, trapezius and sternocleidomastoid. There is 40 mm of inter-incisal mouth opening with an audible click.

What are our initial thoughts?

In this scenario the patient is experiencing COFP in the form of temporomandibular joint dysfunction with a background of anxiety, depression and work associated stress (Figure 2).

Somatic symptoms can exist as an extension of other psychiatric conditions such as depression and anxiety.⁵ Given the patient's medical history this element of the presentation should be considered.

What could be the cause of his COFP?

A vast majority of patients with COFP initially present to their general medical practitioner.⁹ In a case of TMD-related COFP this can result in misdiagnoses such as otalgia^10-12 owing to the close proximity of the temporomandibular joints to the ear. Similarly, TMD pain can be mistaken as toothache by dentists and there are numerous differential diagnoses that may be relevant in a case of TMD-associated pain (Table 2).

Patients presenting similarly to Case 2 should have their temporomandibular joints assessed and managed according to the diagnostic criteria for TMD.¹⁴ A brief TMD checklist is shown in Figure 3, with an accompanying referenced video¹⁵ to help clinicians make this assessment. It outlines a systematic approach to assessing and diagnosing patients with TMD. Such a checklist can be implemented throughout primary care, to minimize the potential for misdiagnosis of TMD as nonspecific otalgia, which ultimately results in mismanagement.

For this patient, the clinical features suggest a likely diagnosis of an internal derangement (disc displacement with reduction), and myofascial pain, given the pain radiates beyond the muscles of mastication. Symptoms of depression and anxiety are known risk factors for chronic temporomandibular disorders¹⁷ and stress can result in clenching and grinding, which exacerbate muscle tension and physical symptoms of pain.¹⁸ The patient has a known history of anxiety, depression and currently reports high stress levels, so there is significant potential for clenching and grinding as a cause for his myofascial pain.

Chronic orofacial pain: what should I do in such scenarios?

Even if a case of COFP is considered a medically unexplained symptom with roots in somatization, the pain is still very real and often debilitating. In these cases, it is important to take the patient's pain seriously; treat anything that can be treated and then focus on supportive management and improving functionality.¹⁹ For example, in our first case, the patient has complained about difficulties with her dentures alongside her chronic pain – it would be sensible to review the dentures and make adjustments while also supporting her with her persistent idiopathic facial pain.

To provide reassurance, we should provide a definitive diagnosis; one of persistent idiopathic facial pain and one of TMD. These should be clearly communicated to the patient using an explanation of pain pathways (so-called pain science education) and explanation of mechanisms by which the vicious pain-anxiety-muscle tension cycle is exacerbated. In the case of persistent idiopathic facial pain, the patient should be reassured of the fact that pain can occur in the absence of underlying pathology. Patients can feel unsupported or confused in cases of persistent pain without organic pathology, which can lead to unproductive or extensive investigations. This can be redirected with reassurance and continuous input on how these symptoms can present, deliberately moving away from the misconception that the pain ‘is all in the patient's head,’ which is often how the patient feels.

Supported self-management using a biopsychosocial approach,^20,21,22 has been shown to reduce long-term pain and depression in patients with COFP. In addition to offering a plausible explanation for symptoms, we can identify the impact the pain has on daily life, eg restrictions in household activities, work, relationships, personal and social activities. With an awareness of the impact on their quality of life, we can set goals to help break the vicious cycle that exacerbates pain symptoms. With cases of chronic pain, vicious cycles often arise from the interrelationship between the autonomic physical symptoms and the behavioural and cognitive response. This cycle produces negative thoughts about the symptoms, which results in avoidance of activities and consequent symptom amplification (Figure 4).

Aside from reassurance and explanation, the psychosocial approach focuses on cognitive restructuring and behavioural activation. Here, we should challenge negative thoughts about the pain, making a plan to balance routine, necessary and pleasurable activities to prevent pain from becoming the focus. Our actions can be summarized in Table 3.

In the case of TMD there is chronic myofascial pain that may be exacerbated by his underlying psychiatric conditions and stress. Here, we can discuss the exacerbating factors of his medical conditions and stress levels, which are resulting in oral parafunctional habits and increased alcohol intake. There should also be a focus on reversing habits that exacerbate symptoms. The patient should be advised on posture control (eg sleeping on his back) to limit night-time parafunction, heat application, soft diet and massaging his masseter and temporalis muscles.²³ Overall, this can help to reduce muscle tension and myofascial pain.

The effectiveness of splints for TMD is questionable.²⁴ If we decide to provide a splint, there should be regular review to monitor symptoms. If they worsen, splint usage should be stopped. There can also be liaison with the GMP or the patient's psychiatrist (if he is already part of psychiatric services) to determine medical management of stress and limiting alcohol intake.

In the medium term, we should monitor pain intensity and the impact on activities of daily living. There may be a need to refer to secondary care for multidisciplinary team management by oral surgery with continued psychiatric input. Onward referral to OMFS or an oral surgery team is indicated if there are any red flag signs and symptoms (Table 4).

Those living with chronic pain may express suicidal thoughts or ideations. Up to 50% of patients living with chronic pain have had serious thoughts about committing suicide.²⁵ As discussed, primary care practitioners will have a continuous relationship with patients living with chronic pain. Any expression of such thoughts should be explored, for example: are they experiencing feelings of hopelessness or significant stressors, do they have any plans to act on these thoughts and whether there have been any previous self-harm or suicide attempts. With patient consent, such a conversation would prompt communication with the GMP, psychiatric services or local crisis teams.

When managing cases of COFP we must not lose sight of the three most important steps: make a definitive diagnosis, provide a clear explanation and guide patients through supported self-management.³ If these steps are taken, many may not require an onward referral.³