- Email: [email protected]
Clinical evaluation of botulinum toxin A in the management of temporomandibular myofascial pain
YBJOM-5849;
No. of Pages 4
ARTICLE IN PRESS Available online at www.sciencedirect.com
ScienceDirect British Journal of Oral and Maxillofacial Surgery xxx (2019) xxx–xxx
Clinical evaluation of botulinum toxin A in the management of temporomandibular myofascial pain Daniel Stonehouse-Smith ∗ , Anne Begley, Martin Dodd Aintree University NHS Foundation Trust, Lower Lane, Liverpool, L9 7AL Accepted 12 November 2019
Abstract We did a clinical service evaluation of patient-reported outcomes for pain and change in interincisal distance in patients treated with botulinum toxin A (BTX-A) for temporomandibular myofascial pain at nurse-led clinics. We retrospectively reviewed the clinical records of 100 patients and the prescribing patterns of two OMFS consultants. The mean starting pain score of 7.54 out of 10 was reduced by a mean (SD) of 2.48 (2.1) points after the intervention (p < 0.001). The most common prescription was for 100 units (n = 59 prescriptions). The change in the mean pain scores did not differ significantly whether 100 or 200 units were prescribed (p = 0.19). Interincisal distance increased by a mean (SD) of 0.5 (5.24) mm after treatment with BTX-A, which was not significant (p = 0.35). In most cases the treatment helped to manage and reduce the symptoms of temporomandibular myofascial pain. Considerable improvement in interincisal distance as a result of this treatment alone, however, is unlikely, but it may have a role in a multifaceted approach, particularly when other conservative methods have failed. The use of a pro forma may allow for more consistent record keeping and the detailed assessment of patient-reported pain scores in the weeks and months after treatment. Development of an electronic patient-reported outcome (ePRO) tool may facilitate this further. © 2019 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved. Keywords: Myofascial pain; TMJ; Botulinum toxin A; Temporomandibular joint dysfunction; Pain
Introduction Botulinum neurotoxin A (BTX-A) is a commercially available preparation derived from the bacterium Clostridium botulinum. On injection into muscle, it produces a semipermanent paresis that has various clinical applications. At the regional oral and maxillofacial unit where this evaluation was done, we use it to treat some patients who have myofascial pain associated with temporomandibular joint dysfunction (TMD), but to our knowledge, evidence to support its efficacy when compared with saline placebo or physiotherapy, is limited.1,2 It has been suggested that ∗
Corresponding author. E-mail addresses: [email protected] (D. Stonehouse-Smith), [email protected] (A. Begley), [email protected] (M. Dodd).
BTX-A produces an improvement that has minimal clinical relevance in these patients,3 but the heterogeneity in the study design, outcome measures, and sample sizes in published papers, mean that consensus on its therapeutic benefit is lacking.4 There has been a call for further trials and research into its use in patients with TMD and myofascial pain.5 A local recommendation for the commissioning of BTX-A has proposed outcome measures that include reductions in both pain (measured with a visual analogue scale) and the use of analgesics, and improvements in sleep and diet scores.6 There may be a positive benefit in these patients when conservative management has failed.7–9 We have therefore evaluated our current service provision to assess the effectiveness and patientreported outcomes of treatment with BTX-A in patients with temporomandibular myofascial pain.
https://doi.org/10.1016/j.bjoms.2019.11.010 0266-4356/© 2019 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.
Please cite this article in press as: Stonehouse-Smith D, et al. Clinical evaluation of botulinum toxin A in the management of temporomandibular myofascial pain. Br J Oral Maxillofac Surg (2019), https://doi.org/10.1016/j.bjoms.2019.11.010
YBJOM-5849;
No. of Pages 4
2
ARTICLE IN PRESS
D. Stonehouse-Smith et al. / British Journal of Oral and Maxillofacial Surgery xxx (2019) xxx–xxx
Our aims were to find out whether BTX-A improved outcomes (including changes in patient-reported pain scores and maximum interincisal distance), to assess the intervals for treatment within our service, and to develop a standard clinical pro forma for the administration of BTX-A to improve the consistency of prescribing and recording of patient-reported outcomes. Methods We retrospectively reviewed the clinical records of 100 patients and the logbooks for nurse-led applications of BTXA that were prescribed for myofascial pain by two consultant oral and maxillofacial surgeons. Data were collected by a dental core trainee and advanced nurse practitioner, and entered on an electronic data capture sheet. No information that identified patients was included. The review only included patients with myofascial pain associated with TMD who have previously been given other conservative treatment such as advice leaflets and physiotherapy with or without an occlusal appliance. Patients with masseteric hyperthrophy, those who had BTX-A for aesthetic reasons, and those treated with alternative preparations such as Dysport® BTX (Ipsen), were excluded. The site of injection, number of units given, and the interval between treatments were recorded, together with measurements of interincisal distance (mm) and patientreported pain scores out of 10 before and after treatment. When pain scores for each side of the joint were different, the side with the highest score was selected. The same side was then used after the procedure for comparison. We hypothesised that there would be no significant differences in pain scores and measured interincisal distances before and after treatment, and in the change in mean pain score whether prescriptions were for 100 or 200 units of BTX-A.
Results Data were collected between June 2018 and November 2018 to sample the required number of 100 records. A total of 87 patients were female, and the mean (range) age of all the patients was 61 (24-85) years. The number of prescriptions made by the two consultants was similar (n = 52 and 48). Bilateral treatment to both the temporalis and masseter muscles made up 69 of the prescriptions. A total of 26 were unilateral and 9 were isolated to a single muscle group. The most common prescription was for 100 units (n = 59 prescriptions). A total of 28 patients were prescribed 200 units and the remainder were given varying smaller doses with a minimum of 30 units. There were some minor variations between consultants in their prescribing patterns: one prescribed 200 units more often, accounting for 22/28 of these prescriptions. The difference in the recall intervals selected by the consultants was minimal: 52 patients were recalled four-monthly, 44 every six months, and the remainder at no less than two months. The mean (SD) starting pain score (7.54 out of 10) reduced by a mean (SD) of 2.48 (2.1) points after injection of BTX-A (p < 0.001). In 14 patients there was no change in pain score and only two reported an increase. In patients who were given 100 units the pain scores reduced by a mean (range) of 2.28 (0 - 10) points. In those who were given 200 units the mean reduction was 2.89 (0 - 7) points. The null hypothesis, that there was no significant difference in the change in mean pain score between these two most common doses, was retained (p = 0.19). The maximum interincisal distance varied considerably among patients and across treatment intervals. Generally, it increased by a mean (SD) of 0.5 (5.24) mm after treatment, but in 30 patients it did not change and in 28 it reduced. The mean increase was not significant (p = 0.35). Discussion
Statistical analyses All patients were included in the analyses, which were done with the help of IBM SPSS Statistics for Windows version 20.0 (IBM Corp). Both pain scores and interincisal distances looked normally distributed on the histograms. Paired-sample, two-tailed t tests were done to assess the significance of change in either direction for both pain scores and interincisal distance before and after treatment. An independent sample, two-tailed t test was done to test the null hypothesis that there was no difference in the change in mean pain scores between patients who were given 100 or 200 units of BTX-A. Probabilities of less than 0.05 were accepted as significant.
This clinical service evaluation was limited to treatment given in a nurse-led BTX clinic. We did not review direct treatment by consultants or registrars, and did not investigate that given in theatre. As with most retrospective data, some records were incomplete and some patients had to be excluded when outcome measures could not be compared. Patient-reported outcome measures (PROM) are increasingly being used to assess the quality of care and service delivery within the NHS. Patient-reported pain scores were used for this evaluation, and their inherent subjective nature may detract from the reliability of any conclusions. Scores were taken only at the agreed intervals when BTX-A was given. As there was no short-term follow up and the effects
Please cite this article in press as: Stonehouse-Smith D, et al. Clinical evaluation of botulinum toxin A in the management of temporomandibular myofascial pain. Br J Oral Maxillofac Surg (2019), https://doi.org/10.1016/j.bjoms.2019.11.010
YBJOM-5849;
No. of Pages 4
ARTICLE IN PRESS
D. Stonehouse-Smith et al. / British Journal of Oral and Maxillofacial Surgery xxx (2019) xxx–xxx
of the treatment were often starting to wear off at review appointments, the true reduction in pain score may have been under-reported, apart from a few cases in which a short-term reduction was stated in the case notes. Anecdotally, patients’ reports of mouth opening vary from day to day because of a multitude of factors including pain control and stress, so the 0.5 mm increase in interincisal distance between treatments is unlikely to be clinically relevant. Again, the effects of treatment may have been under-reported for the same reasons. There was also the potential for measurement bias and errors, as no calibration or standard method had been agreed. Myofascial TMD often affects patients with other conditions such as fibromyalgia and Ehlers-Danlos syndrome, and these may have unknown effects on the response to BTXA. As our patients had previously had alternative treatments including physiotherapy or bite-raising appliances, the true effect of BTX-A alone for temporomandibular myofascial pain was difficult to assess within the limits of this service evaluation. There is evidence that could support the confounding physiological effect of injection of symptomatic muscle tissue (so called “dry needling”), which may have a role in the patients’ true or perceived reduction in pain.10 Future investigations could include a multi-arm, randomised controlled trial to compare changes in pain score and interincisal distance after BTX-A, with placebo or conservative management alone. Achieving the best clinical improvement with the lowest effective dose is an important factor to consider not only for the financial implications on services, but also with regards to the possible but rare (less than 0.5%) development of resistance.11 We found no significant difference in the reduction in pain scores for patients prescribed the higher dose, but prescriptions should still be considered within the wider clinical context, and some patients may require a higher dose to manage their symptoms. We recognise that this is a limited conclusion with regards to the statistical power of the small sample, and that data were retrospective and not controlled for baseline characteristics. At a dose of 200 units, the greater mean reduction in pain score may suggest an underlying trend, which supports an association between dose and response and the efficacy of BTX-A in these patients. To capture the short-term effects of treatment in this group, we have sought to develop a pro forma that includes a visual analogue pain score that is reported weekly by patients for up to 16 weeks. It includes a more descriptive assessment of overall satisfaction including Likert scales that compare BTX-A with previous treatments and any alternative therapies they have tried. Pre-existing service pressures mean that shorter-term follow up is unlikely, and alternatives such as nurse-led telephone interviews, come with a high financial burden. An area for future development may include the use of a mobile app for the electronic capture of patient-reported outcomes (ePRO). This technology has benefits over traditional paper-based tools for reasons such as ease of capture,
3
completeness, and accuracy of the contemporaneous or realtime feedback from patients without the need for additional follow up in clinic.12 In conclusion, in most patients, treatment with BTX-A can reduce the symptoms of temporomandibular myofascial pain. A considerable improvement in interincisal opening is unlikely, but BTX-A may have a role as part of a multifaceted approach, particularly when other conservative methods have failed. The dose of BTX-A prescribed must take into consideration patient-specific factors and clinical need. The use of a pro forma may allow for more consistent record keeping and more detailed assessment of patient-reported pain scores after treatment. Development of an ePRO tool may facilitate this further.
Conflict of interest We have no conflicts of interest.
Ethics statement/confirmation of patients’ permission Not applicable. This was a clinical service evaluation.
Acknowledgements We thank Sheila Dodd, advanced nurse practitioner, for her assistance with data collection.
References 1. The International Centre for Allied Health Evidence, New Zealand. Available from URL: https://www.acc.co.nz/assets/research/843bedb8b9/ Botox-injections-for-myofascial-pain-systematic-review.pdf (last accessed 6 November 2019) Systematic review of literature. The effectiveness of injection of botulinum neurotoxin for myofascial pain as a form of interventional pain management: technical report. Prepared for the Accident Compensation Corporation; 2017. 2. Khawaja SN, Crow H, Holmlund T, et al. Botulinum toxin type A for the management of masticatory muscle pain in temporomandibular disorders: a systematic review. J Dent Health Oral Disord Ther 2017;7:00266. 3. Ernberg M, Hedenberg-Magnusson B, List T, et al. Efficacy of botulinum toxin type A for treatment of persistent myofascial TMD pain: a randomized, controlled, double-blind multicenter study. Pain 2011;152:1988–96. 4. Chen YW, Chiu YW, Chen CY, et al. Botulinum toxin therapy for temporomandibular joint disorders: a systematic review of randomized controlled trials. Int J Oral Maxillofac Surg 2015;44:1018–26. 5. Sunil Dutt C, Ramnani P, Thakur D, et al. Botulinum toxin in the treatment of muscle specific oro-facial pain: a literature review. J Maxillofac Oral Surg 2015;14:171–5. 6. South East London Area Prescribing Committee Formulary recommendation, Available from URL: http://www.lambethccg.nhs.uk/news-andpublications/meeting-papers/south-east-london-area-prescribingcommittee/Documents/New%20Medicine%20Recommendations/ Recommendation%20051%20Botulinum%20toxin%20in%20T emporomandibular%20jaw%20September%202016.pdf (last accessed 6 November 2019) Botulinum toxin type A injection for the treatment
Please cite this article in press as: Stonehouse-Smith D, et al. Clinical evaluation of botulinum toxin A in the management of temporomandibular myofascial pain. Br J Oral Maxillofac Surg (2019), https://doi.org/10.1016/j.bjoms.2019.11.010
YBJOM-5849; 4
No. of Pages 4
ARTICLE IN PRESS
D. Stonehouse-Smith et al. / British Journal of Oral and Maxillofacial Surgery xxx (2019) xxx–xxx
of myofascial pain syndrome associated with temporomandibular jaw dysfunction (TMJD) Reference 051; 2016. 7. Sidebottom AJ, Patel AA, Amin J. Botulinum injection for the management of myofascial pain in the masticatory muscles. A prospective outcome study. Br J Oral Maxillofac Surg 2013;51:199–205. 8. Kahn A, Bertin H, Corre P, et al. Assessing the effectiveness of botulinum toxin injections into masticatory muscles in the treatment of temporomandibular disorders. J Oral Med Oral Surg 2018;24:107–11. 9. Gupta A, Aggarwal A, Aggarwal A. Effect of botulinum toxin-A in myofascial pain in temporomandibular disorders: a randomized, doubleblinded, placebo-controlled study. Indian J. Pain 2016;30:166–70.
10. Machado E, Machado P, Wandscher VF, et al. A systematic review of different substance injection and dry needling for treatment of temporomandibular myofascial pain. Int J Oral Maxillofac Surg 2018;47:1420–32. 11. Naumann M, Carruthers A, Carruthers J, et al. Meta-analysis of neutralizing antibody conversion with onabotulinumtoxinA (BOTOX® ) across multiple indications. Mov Disord 2010;25:2211–8. 12. Coons SJ, Eremenco S, Lundy JJ, et al. Capturing patient-reported outcome (PRO) data electronically: the past, present, and promise of ePRO measurement in clinical trials. Patient 2015;8:301–9.
Please cite this article in press as: Stonehouse-Smith D, et al. Clinical evaluation of botulinum toxin A in the management of temporomandibular myofascial pain. Br J Oral Maxillofac Surg (2019), https://doi.org/10.1016/j.bjoms.2019.11.010
No. of Pages 4
ARTICLE IN PRESS Available online at www.sciencedirect.com
ScienceDirect British Journal of Oral and Maxillofacial Surgery xxx (2019) xxx–xxx
Clinical evaluation of botulinum toxin A in the management of temporomandibular myofascial pain Daniel Stonehouse-Smith ∗ , Anne Begley, Martin Dodd Aintree University NHS Foundation Trust, Lower Lane, Liverpool, L9 7AL Accepted 12 November 2019
Abstract We did a clinical service evaluation of patient-reported outcomes for pain and change in interincisal distance in patients treated with botulinum toxin A (BTX-A) for temporomandibular myofascial pain at nurse-led clinics. We retrospectively reviewed the clinical records of 100 patients and the prescribing patterns of two OMFS consultants. The mean starting pain score of 7.54 out of 10 was reduced by a mean (SD) of 2.48 (2.1) points after the intervention (p < 0.001). The most common prescription was for 100 units (n = 59 prescriptions). The change in the mean pain scores did not differ significantly whether 100 or 200 units were prescribed (p = 0.19). Interincisal distance increased by a mean (SD) of 0.5 (5.24) mm after treatment with BTX-A, which was not significant (p = 0.35). In most cases the treatment helped to manage and reduce the symptoms of temporomandibular myofascial pain. Considerable improvement in interincisal distance as a result of this treatment alone, however, is unlikely, but it may have a role in a multifaceted approach, particularly when other conservative methods have failed. The use of a pro forma may allow for more consistent record keeping and the detailed assessment of patient-reported pain scores in the weeks and months after treatment. Development of an electronic patient-reported outcome (ePRO) tool may facilitate this further. © 2019 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved. Keywords: Myofascial pain; TMJ; Botulinum toxin A; Temporomandibular joint dysfunction; Pain
Introduction Botulinum neurotoxin A (BTX-A) is a commercially available preparation derived from the bacterium Clostridium botulinum. On injection into muscle, it produces a semipermanent paresis that has various clinical applications. At the regional oral and maxillofacial unit where this evaluation was done, we use it to treat some patients who have myofascial pain associated with temporomandibular joint dysfunction (TMD), but to our knowledge, evidence to support its efficacy when compared with saline placebo or physiotherapy, is limited.1,2 It has been suggested that ∗
Corresponding author. E-mail addresses: [email protected] (D. Stonehouse-Smith), [email protected] (A. Begley), [email protected] (M. Dodd).
BTX-A produces an improvement that has minimal clinical relevance in these patients,3 but the heterogeneity in the study design, outcome measures, and sample sizes in published papers, mean that consensus on its therapeutic benefit is lacking.4 There has been a call for further trials and research into its use in patients with TMD and myofascial pain.5 A local recommendation for the commissioning of BTX-A has proposed outcome measures that include reductions in both pain (measured with a visual analogue scale) and the use of analgesics, and improvements in sleep and diet scores.6 There may be a positive benefit in these patients when conservative management has failed.7–9 We have therefore evaluated our current service provision to assess the effectiveness and patientreported outcomes of treatment with BTX-A in patients with temporomandibular myofascial pain.
https://doi.org/10.1016/j.bjoms.2019.11.010 0266-4356/© 2019 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.
Please cite this article in press as: Stonehouse-Smith D, et al. Clinical evaluation of botulinum toxin A in the management of temporomandibular myofascial pain. Br J Oral Maxillofac Surg (2019), https://doi.org/10.1016/j.bjoms.2019.11.010
YBJOM-5849;
No. of Pages 4
2
ARTICLE IN PRESS
D. Stonehouse-Smith et al. / British Journal of Oral and Maxillofacial Surgery xxx (2019) xxx–xxx
Our aims were to find out whether BTX-A improved outcomes (including changes in patient-reported pain scores and maximum interincisal distance), to assess the intervals for treatment within our service, and to develop a standard clinical pro forma for the administration of BTX-A to improve the consistency of prescribing and recording of patient-reported outcomes. Methods We retrospectively reviewed the clinical records of 100 patients and the logbooks for nurse-led applications of BTXA that were prescribed for myofascial pain by two consultant oral and maxillofacial surgeons. Data were collected by a dental core trainee and advanced nurse practitioner, and entered on an electronic data capture sheet. No information that identified patients was included. The review only included patients with myofascial pain associated with TMD who have previously been given other conservative treatment such as advice leaflets and physiotherapy with or without an occlusal appliance. Patients with masseteric hyperthrophy, those who had BTX-A for aesthetic reasons, and those treated with alternative preparations such as Dysport® BTX (Ipsen), were excluded. The site of injection, number of units given, and the interval between treatments were recorded, together with measurements of interincisal distance (mm) and patientreported pain scores out of 10 before and after treatment. When pain scores for each side of the joint were different, the side with the highest score was selected. The same side was then used after the procedure for comparison. We hypothesised that there would be no significant differences in pain scores and measured interincisal distances before and after treatment, and in the change in mean pain score whether prescriptions were for 100 or 200 units of BTX-A.
Results Data were collected between June 2018 and November 2018 to sample the required number of 100 records. A total of 87 patients were female, and the mean (range) age of all the patients was 61 (24-85) years. The number of prescriptions made by the two consultants was similar (n = 52 and 48). Bilateral treatment to both the temporalis and masseter muscles made up 69 of the prescriptions. A total of 26 were unilateral and 9 were isolated to a single muscle group. The most common prescription was for 100 units (n = 59 prescriptions). A total of 28 patients were prescribed 200 units and the remainder were given varying smaller doses with a minimum of 30 units. There were some minor variations between consultants in their prescribing patterns: one prescribed 200 units more often, accounting for 22/28 of these prescriptions. The difference in the recall intervals selected by the consultants was minimal: 52 patients were recalled four-monthly, 44 every six months, and the remainder at no less than two months. The mean (SD) starting pain score (7.54 out of 10) reduced by a mean (SD) of 2.48 (2.1) points after injection of BTX-A (p < 0.001). In 14 patients there was no change in pain score and only two reported an increase. In patients who were given 100 units the pain scores reduced by a mean (range) of 2.28 (0 - 10) points. In those who were given 200 units the mean reduction was 2.89 (0 - 7) points. The null hypothesis, that there was no significant difference in the change in mean pain score between these two most common doses, was retained (p = 0.19). The maximum interincisal distance varied considerably among patients and across treatment intervals. Generally, it increased by a mean (SD) of 0.5 (5.24) mm after treatment, but in 30 patients it did not change and in 28 it reduced. The mean increase was not significant (p = 0.35). Discussion
Statistical analyses All patients were included in the analyses, which were done with the help of IBM SPSS Statistics for Windows version 20.0 (IBM Corp). Both pain scores and interincisal distances looked normally distributed on the histograms. Paired-sample, two-tailed t tests were done to assess the significance of change in either direction for both pain scores and interincisal distance before and after treatment. An independent sample, two-tailed t test was done to test the null hypothesis that there was no difference in the change in mean pain scores between patients who were given 100 or 200 units of BTX-A. Probabilities of less than 0.05 were accepted as significant.
This clinical service evaluation was limited to treatment given in a nurse-led BTX clinic. We did not review direct treatment by consultants or registrars, and did not investigate that given in theatre. As with most retrospective data, some records were incomplete and some patients had to be excluded when outcome measures could not be compared. Patient-reported outcome measures (PROM) are increasingly being used to assess the quality of care and service delivery within the NHS. Patient-reported pain scores were used for this evaluation, and their inherent subjective nature may detract from the reliability of any conclusions. Scores were taken only at the agreed intervals when BTX-A was given. As there was no short-term follow up and the effects
Please cite this article in press as: Stonehouse-Smith D, et al. Clinical evaluation of botulinum toxin A in the management of temporomandibular myofascial pain. Br J Oral Maxillofac Surg (2019), https://doi.org/10.1016/j.bjoms.2019.11.010
YBJOM-5849;
No. of Pages 4
ARTICLE IN PRESS
D. Stonehouse-Smith et al. / British Journal of Oral and Maxillofacial Surgery xxx (2019) xxx–xxx
of the treatment were often starting to wear off at review appointments, the true reduction in pain score may have been under-reported, apart from a few cases in which a short-term reduction was stated in the case notes. Anecdotally, patients’ reports of mouth opening vary from day to day because of a multitude of factors including pain control and stress, so the 0.5 mm increase in interincisal distance between treatments is unlikely to be clinically relevant. Again, the effects of treatment may have been under-reported for the same reasons. There was also the potential for measurement bias and errors, as no calibration or standard method had been agreed. Myofascial TMD often affects patients with other conditions such as fibromyalgia and Ehlers-Danlos syndrome, and these may have unknown effects on the response to BTXA. As our patients had previously had alternative treatments including physiotherapy or bite-raising appliances, the true effect of BTX-A alone for temporomandibular myofascial pain was difficult to assess within the limits of this service evaluation. There is evidence that could support the confounding physiological effect of injection of symptomatic muscle tissue (so called “dry needling”), which may have a role in the patients’ true or perceived reduction in pain.10 Future investigations could include a multi-arm, randomised controlled trial to compare changes in pain score and interincisal distance after BTX-A, with placebo or conservative management alone. Achieving the best clinical improvement with the lowest effective dose is an important factor to consider not only for the financial implications on services, but also with regards to the possible but rare (less than 0.5%) development of resistance.11 We found no significant difference in the reduction in pain scores for patients prescribed the higher dose, but prescriptions should still be considered within the wider clinical context, and some patients may require a higher dose to manage their symptoms. We recognise that this is a limited conclusion with regards to the statistical power of the small sample, and that data were retrospective and not controlled for baseline characteristics. At a dose of 200 units, the greater mean reduction in pain score may suggest an underlying trend, which supports an association between dose and response and the efficacy of BTX-A in these patients. To capture the short-term effects of treatment in this group, we have sought to develop a pro forma that includes a visual analogue pain score that is reported weekly by patients for up to 16 weeks. It includes a more descriptive assessment of overall satisfaction including Likert scales that compare BTX-A with previous treatments and any alternative therapies they have tried. Pre-existing service pressures mean that shorter-term follow up is unlikely, and alternatives such as nurse-led telephone interviews, come with a high financial burden. An area for future development may include the use of a mobile app for the electronic capture of patient-reported outcomes (ePRO). This technology has benefits over traditional paper-based tools for reasons such as ease of capture,
3
completeness, and accuracy of the contemporaneous or realtime feedback from patients without the need for additional follow up in clinic.12 In conclusion, in most patients, treatment with BTX-A can reduce the symptoms of temporomandibular myofascial pain. A considerable improvement in interincisal opening is unlikely, but BTX-A may have a role as part of a multifaceted approach, particularly when other conservative methods have failed. The dose of BTX-A prescribed must take into consideration patient-specific factors and clinical need. The use of a pro forma may allow for more consistent record keeping and more detailed assessment of patient-reported pain scores after treatment. Development of an ePRO tool may facilitate this further.
Conflict of interest We have no conflicts of interest.
Ethics statement/confirmation of patients’ permission Not applicable. This was a clinical service evaluation.
Acknowledgements We thank Sheila Dodd, advanced nurse practitioner, for her assistance with data collection.
References 1. The International Centre for Allied Health Evidence, New Zealand. Available from URL: https://www.acc.co.nz/assets/research/843bedb8b9/ Botox-injections-for-myofascial-pain-systematic-review.pdf (last accessed 6 November 2019) Systematic review of literature. The effectiveness of injection of botulinum neurotoxin for myofascial pain as a form of interventional pain management: technical report. Prepared for the Accident Compensation Corporation; 2017. 2. Khawaja SN, Crow H, Holmlund T, et al. Botulinum toxin type A for the management of masticatory muscle pain in temporomandibular disorders: a systematic review. J Dent Health Oral Disord Ther 2017;7:00266. 3. Ernberg M, Hedenberg-Magnusson B, List T, et al. Efficacy of botulinum toxin type A for treatment of persistent myofascial TMD pain: a randomized, controlled, double-blind multicenter study. Pain 2011;152:1988–96. 4. Chen YW, Chiu YW, Chen CY, et al. Botulinum toxin therapy for temporomandibular joint disorders: a systematic review of randomized controlled trials. Int J Oral Maxillofac Surg 2015;44:1018–26. 5. Sunil Dutt C, Ramnani P, Thakur D, et al. Botulinum toxin in the treatment of muscle specific oro-facial pain: a literature review. J Maxillofac Oral Surg 2015;14:171–5. 6. South East London Area Prescribing Committee Formulary recommendation, Available from URL: http://www.lambethccg.nhs.uk/news-andpublications/meeting-papers/south-east-london-area-prescribingcommittee/Documents/New%20Medicine%20Recommendations/ Recommendation%20051%20Botulinum%20toxin%20in%20T emporomandibular%20jaw%20September%202016.pdf (last accessed 6 November 2019) Botulinum toxin type A injection for the treatment
Please cite this article in press as: Stonehouse-Smith D, et al. Clinical evaluation of botulinum toxin A in the management of temporomandibular myofascial pain. Br J Oral Maxillofac Surg (2019), https://doi.org/10.1016/j.bjoms.2019.11.010
YBJOM-5849; 4
No. of Pages 4
ARTICLE IN PRESS
D. Stonehouse-Smith et al. / British Journal of Oral and Maxillofacial Surgery xxx (2019) xxx–xxx
of myofascial pain syndrome associated with temporomandibular jaw dysfunction (TMJD) Reference 051; 2016. 7. Sidebottom AJ, Patel AA, Amin J. Botulinum injection for the management of myofascial pain in the masticatory muscles. A prospective outcome study. Br J Oral Maxillofac Surg 2013;51:199–205. 8. Kahn A, Bertin H, Corre P, et al. Assessing the effectiveness of botulinum toxin injections into masticatory muscles in the treatment of temporomandibular disorders. J Oral Med Oral Surg 2018;24:107–11. 9. Gupta A, Aggarwal A, Aggarwal A. Effect of botulinum toxin-A in myofascial pain in temporomandibular disorders: a randomized, doubleblinded, placebo-controlled study. Indian J. Pain 2016;30:166–70.
10. Machado E, Machado P, Wandscher VF, et al. A systematic review of different substance injection and dry needling for treatment of temporomandibular myofascial pain. Int J Oral Maxillofac Surg 2018;47:1420–32. 11. Naumann M, Carruthers A, Carruthers J, et al. Meta-analysis of neutralizing antibody conversion with onabotulinumtoxinA (BOTOX® ) across multiple indications. Mov Disord 2010;25:2211–8. 12. Coons SJ, Eremenco S, Lundy JJ, et al. Capturing patient-reported outcome (PRO) data electronically: the past, present, and promise of ePRO measurement in clinical trials. Patient 2015;8:301–9.
Please cite this article in press as: Stonehouse-Smith D, et al. Clinical evaluation of botulinum toxin A in the management of temporomandibular myofascial pain. Br J Oral Maxillofac Surg (2019), https://doi.org/10.1016/j.bjoms.2019.11.010