Effect on orofacial pain in patients with chronic pain participating in a multimodal rehabilitation programme – a pilot study

Study population

Patients aged 18–65 years with chronic pain who participated in an MMRP at the Pain Rehabilitation Clinic, Umeå University Hospital, Sweden, from August 2016 to March 2018 were eligible for inclusion. Patients who completed the MMRP and filled in questionnaires before and after the MMRP were included in the study.

The multimodal pain rehabilitation programme

The MMRP is a team-based goal-oriented programme run by a multidisciplinary team over the course of four consecutive weeks. The timetabled activities include both group sessions and individual sessions based on a biopsychosocial perspective. The multidisciplinary team consists of a physiotherapist, occupational therapist, physician, social worker and a psychologist. The teamwork is integrated using an interdisciplinary approach and the patient is encouraged to take an active part in their rehabilitation process. The MMR programme included physical and occupational therapy, information and training in coping strategies, information about bodily and psychological reactions to chronic pain, relaxation and body-awareness training. All patients also had an individual schedule. No specific treatment targeting the orofacial area in specific was given. At the end of the programme, contacts were established with external collaborating partners such as the workplace, and the patient’s general practitioner.

Procedure

Before(baseline) and after participating in MMRP (follow-up), the patients filled in the questionnaires commonly used for the Swedish Quality Registry for Pain Rehabilitation (SQRP). Orofacial pain was assessed by two screening questions on frequent orofacial pain from the 3Q/TMD [21, 22]:

1. Do you have pain in your temple, face, jaw or jaw joint once a week or more?

2. Do you have pain once a week or more when you open your mouth or chew?

Each question is answered with a “yes” and a “no”. Orofacial pain was categorized as positive in the case of an affirmative answer to any of the two questions.

The number of pain sites was registered using 36 pre-defined anatomical areas. The patient reported the number of sites with pain on the left side of the body (n=18) and on the right side of the body (n=18), a total of 36 locations. These pain sites were: (1) head/face, (2) neck, (3) shoulder, (4) upper arm, (5) elbow, (6) forearm, (7) hand, (8) anterior aspect of chest, (9) lateral aspect of chest, (10) belly, (11) sexual organs, (12) upper back, (13) lower back, (14) hip/gluteal area, (15) thigh, (16) knee, (17) shank, and (18) foot. The total score ranges between 1–36.

Patient-reported outcome measures (PROM)

Orofacial pain was regarded as being present when a participant answered affirmatively for at least one of the two screening questions. Pain intensity was assessed using the West Haven-Yale Multidimensional Pain Inventory (WHYMPI), the Swedish version (MPI-S) of on a 7-point numerical rating scale (range 0–6) [23]. Higher scores indicate higher pain intensity.

To evaluate the impact on quality of life, the Short Form Health Survey (SF-36) [24] and the EuroQol 5 Dimensions (EQ-5D) [25] were used. SF-36 intends to represent conditions and limitations in daily life including well-being and personal evaluations of health. The instrument consists of 36 questions comprising eight dimensions reported in a scale 0–100. Higher scores reflect better self-reported health status. This study used the dimensions: physical functioning, role physical, general health, vitality, social functioning, role emotional and mental health. The EQ-5D consists of 2 parts: the EQ-5D (3-L) and the EQ-VAS. This study used the EQ-5D (3-L) that contains 5 dimensions: mobility, self-care, usual activities, pain/discomfort, and anxiety/depression. Each dimension has 3 levels: no problems, some problems, and extreme problems. The answers on the 5 dimensions are converted into a single EQ-5D index ranging from −0.594 to 1, where 1 indicates optimal health.

Statistical analysis

Descriptive statistics were used to present patient characteristics before and after the MMRP, using median scores with interquartile range (IQR) and means with standard deviations (SD). For categorical variables, numbers and percentages were presented. Wilcoxon signed-ranked test was used for the study of paired observations and Mann Whitney U test for comparison between groups. Questionnaires with separate missed items in SQRP questionnaires were accepted, and no imputations were made for missing values. An exact McNemar’s test was used to evaluate difference in proportion of participants with orofacial pain before and after intervention. A p-value <0.05 was considered statistically significant.

Lost at follow up

Out of 72 individuals with information on orofacial pain status at baseline, there were 13 (of which 11 women, 84.6 %) who were lost at follow-up (Figure 1). Of those, five individuals (38.5 %) reported orofacial pain at baseline, compared with 50/72 (69.4 %) for the whole group. The mean age was 42.5 (SD 11.6) and 43.8 (SD 9.5) for participants with and without orofacial pain, respectively. There were no significant differences in self-reported level of depression, anxiety nor impact on quality of life among the individuals lost at follow up when compared with the study sample (p=0.3, p=0.4 and p=0.9, respectively).

Figure 1:

Flow chart of participants process through the multimodal rehabilitation programme.

Study sample

The final study sample consisted of 59 participants (of which 48 women, 81.9 %) (Table 1). The mean age was 42.9 years (SD 10.9). The median number of pain sites was 16 of 36 (IQR 12). The median pain intensity before MMRP was 4.0 (IQR 1) and after the MMRP 3.5 (IQR 1.5) with a significant decrease over time (Wilcoxon signed ranks test, p=0.005).

The frequency of orofacial pain before and after MMRP was n=50 (69.4 %) and n=40 (67.8 %), respectively. There was no significant difference in frequency of orofacial pain from before to after MMRP (McNemar’s test p=0.228).

Among individuals with orofacial pain, there was a significant decrease in the level of indicated self-reported possible depression from before (baseline) to after MMRP (follow-up) (p=0.004) (Figure 2). Apart from this decrease, there was no difference in self-reported level of possible anxiety nor quality of life between individuals with or without orofacial pain, nor between before and after MMRP.

Figure 2:

Level of possible depression among individuals with and without orofacial pain respectively, and level of possible depression before and after the multimodal rehabilitation programme.

Frequency of orofacial pain before and after MMRP

With an overlap between widespread pain and orofacial pain of about 70 %, our findings are well in line with previous reports on overlap pain [29, 30].

At pain rehabilitation clinics, the professionals working in MMRP have experience of meeting patients suffering from different types of chronic pain conditions. The majority of the interventions in the MMRP are conducted in group sessions based on cognitive-behavioural principles. The programme consists of physical exercises including relaxation and body awareness training, adopting coping strategies according to cognitive-behavioural therapy approaches, and pain education together with education in pain management [31]. When needed, the patients were given individually tailored sessions with different members of the team, for example, individually designed meetings with an occupational therapist, physiotherapist, or psychologist. However, the team members are probably not used to paying attention to functional jaw disorders including orofacial pain, since the two conditions are commonly treated separately today. In clinical practice, it is essential to use methods that are efficient when identifying patients in need of treatment. The present study shows that the 3Q/TMD questionnaire could easily be introduced at pain specialist healthcare clinics, together with an initial clinical assessment by the physician to identify individuals with comorbidity that may need further examination or dental care treatment.

The non-significant decrease in frequency of orofacial pain after completing the programme suggests that the multimodal interventions included in the MMRP may have significant impact on pain intensity but not on frequent orofacial pain alone. When local orofacial pain complaints are related to oral behaviours such as teeth clenching and grinding, a majority of these individuals benefit from information targeting jaw relaxation or the provision of occlusal appliances [32]. The results from this pilot study suggest that in settings like ours, additional screening procedures may be needed to specifically target orofacial pain complaints. In addition, the inclusion of specific information on the jaw system in the MMRP could be both cost-effective and useful for these individuals with orofacial pain.

Psychosocial comorbidities are a well-established clinical challenge among patients with chronic pain, not least since such factors have a negative effect on prognosis. In a previous study of 320 patients with orofacial pain, significant associations between more severe depression and higher pain intensity as well as higher pain-related disability were found [33]. Even though the MMRP did not affect the frequency of orofacial pain, there was a decrease in level of symptoms indicating depression after participation in the programme. This finding reinforces the importance of holistic management of all patients with chronic pain, including orofacial pain. Since this is often not the case in clinical practice today, improvements in collaboration between healthcare and public dental care services are warranted to offer patients who require a proper examination and treatment with the vision of a life with less pain interference in daily life and consequently with increased quality of life. Further studies, using larger samples, are needed to verify the findings of this pilot study.