- Email: [email protected]
A Preliminary Report on the Efficacy of a Dynamic Jaw Opening Device (Dynasplint Trismus System) as Part of the Multimodal Treatment of Trismus in Patients With Head and Neck Cancer
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ORIGINAL ARTICLE
A Preliminary Report on the Efficacy of a Dynamic Jaw Opening Device (Dynasplint Trismus System) as Part of the Multimodal Treatment of Trismus in Patients With Head and Neck Cancer Michael D. Stubblefield, MD, Laura Manfield, MD, Elyn R. Riedel, MA ABSTRACT. Stubblefield MD, Manfield L, Riedel ER. A preliminary report on the efficacy of a dynamic jaw opening device (Dynasplint Trismus System) as part of the multimodal treatment of trismus in patients with head and neck cancer. Arch Phys Med Rehabil 2010;91:1278-82. Objective: To examine the effectiveness of a dynamic jaw opening device as part of a multimodal treatment strategy for trismus in patients with head and neck cancer. Design: Retrospective cohort study. Setting: Tertiary care cancer center. Participants: Patients with head and neck cancer and trismus (N⫽20). Intervention: All patients underwent assessment by a board-certified physiatrist and were referred to physical therapy for delivery of the DTS and instructed to progress use of the DTS to 30 minutes 3 times a day. Additional modalities for the treatment of trismus including pain medications and botulinum toxin injections were prescribed as clinically indicated. Main Outcome Measures: Change in maximal interincisal distance (MID) as documented in the medical record. Results: The use of the DTS as part of multimodal therapy including physical therapy, pain medications, and botulinum toxin injections as deemed clinically appropriate resulted in an overall improvement of the MID from 16.5mm to 23.5mm (P⬍.001). Patients who could comply with the treatment recommendations for DTS treatment did better than those who could not, with an improvement of the MID from 16mm to 27mm (P⬍.001) versus 17mm to 22mm (P⫽.88). Conclusions: The DTS is a safe and effective component of a multimodal strategy for improving trismus associated with head and neck cancer and its treatment. Further investigation is needed to determine the relative efficacy of the treatment modalities available for trismus including physical therapy and other jaw stretching devices. Key Words: Quality of life; Radiation; Rehabilitation; Trismus. © 2010 by the American Congress of Rehabilitation Medicine
From the Department of Neurology, Rehabilitation Medicine Service (Stubblefield), and the Department of Epidemiology and Biostatistics (Riedel), Memorial Sloan-Kettering Cancer Center; and the Department of Physical Medicine and Rehabilitation, New York-Presbyterian Hospital (Manfield), New York, NY. No commercial party having a direct financial interest in the results of the research supporting this article has or will confer a benefit on the authors or on any organization with which the authors are associated. Reprint requests to Michael D. Stubblefield, MD, Rehabilitation Service, Memorial Sloan-Kettering Cancer Center, 1275 York Ave, New York, NY 10065, e-mail: [email protected]. 0003-9993/10/9108-00299$36.00/0 doi:10.1016/j.apmr.2010.05.010
Arch Phys Med Rehabil Vol 91, August 2010
RISMUS IS DEFINED as inability to open the mouth T fully. Impairment in mouth opening may have a detrimental effect on quality of life as basic functions such as chewing,
swallowing, and pulmonary function may be affected.1,2 Similarly, maintenance of oral health and surveillance of cancer recurrence may be less effective. Normative mouth opening for an adult is reported to range from 23 to 71mm as measured between the incisor teeth.3 Impaired mouth opening is a common complication of head and neck cancer and its treatment, with a prevalence reported to range from 5% to 38%.4 This wide variation in reported incidence reflects the lack of uniform criteria for the definition of trismus.5 Trismus in the head and neck cancer setting can result from local invasion of the primary or metastatic tumor into critical structures of mastication including the masseter and pterygoid muscles, their neural innervation, the temporal mandibular joint, and/or other supportive tissues.6 Similarly, surgery and radiation therapy are well known to cause trismus in this population. Radiation in particular is known to result in trismus in up to 45% of patients who received curative doses of radiation therapy.7 Trismus generally evolves most rapidly 1 to 9 months after completion of radiation therapy.8 Mandibular opening seems to worsen as the dose of radiation delivered to the pterygoid muscles increases.9 The probability of developing trismus is reported to increase 24% for every 10Gy of additional radiation delivered to the pterygoid muscles.10 Noncancer and cancer treatment– related causes of trismus are also common in the cancer setting and include infection, trauma, and osteoradionecrosis of the jaw among other causes.11 Multiple modalities have been used in the treatment of trismus. Physical therapy is generally considered the mainstay of trismus treatment and is often used alone or in combination with other modalities. Despite widespread use, the limited literature on the use of physical therapy to treat trismus in the head and neck cancer population has not demonstrated significant efficacy.12-14 Hyperbaric oxygen and pentoxifylline have shown no and modest efficacy, respectively.15,16 Forced mouth opening under general anesthesia can improve trismus, but the effect is often short-lived and potentially complicated by alveolus fracture and adjacent soft tissue rupture. Surgical coronoidectomy has demonstrated significant efficacy in a noncontrolled study of patients with head and neck cancer who had failed to respond to physical therapy.17 Botulinum toxin injection has been reported to have potential benefit in treating selected complications of the radiation fibrosis syndrome.18 A report on the efficacy of botulinum toxin injection into the
List of Abbreviations DTS MID
Dynasplint Trismus System maximal interincisal distance
EFFICACY OF DYNASPLINT IN TRISMUS, Stubblefield
masseters of patients with head and neck cancer and with radiation-induced pain and trismus did not demonstrate significant improvement of trismus but did demonstrate significantly reduced local pain.19 One unusual report details the use of a 14lb sledgehammer tied to the lower jaw by a necktie to markedly improve the patient’s maximum mouth opening from 20 to 38mm.20 A variety of jaw opening devices have been used to treat trismus (fig 1).21 Devices currently in common clinical use include stacked tongue depressors, corkscrew devices, the TheraBite Jaw Motion Rehabilitation System,a and the DTS.b The TheraBite demonstrated efficacy in a small trial (7 patients) when used within 6 weeks of surgery for oropharyngeal carcinoma.22 TheraBite combined with unassisted exercise also demonstrated efficacy in a group of patients who had undergone radiation therapy within the preceding 5 years (most within the preceding year) compared with unassisted exercise and compared with mechanically assisted mandibular mobilization using stacked tongue depressors combined with unassisted exercise.14 The fabrication and/or use of dynamic jaw opening devices to treat both benign and oncologic causes of trismus have been detailed in numerous reports dating back to 1968.23-28 The DTS is a commercially available dynamic jaw opening device that operates on the principle of low-torque, prolonged duration stretch. It has demonstrated efficacy in achieving improved jaw opening in a retrospective evaluation
1279
of 48 patients with trismus from 4 cohort groups including radiation therapy for head and neck cancer, dental treatment, oral surgery, and stroke.29 While the 20 patients in the head and neck cancer cohort improved their maximal interincisal distance by a mean of 13.6mm, little demographic and oncologic information was given save that they all received radiation therapy. The present study is a retrospective examination of the role of the DTS in a cohort of patients with head and neck cancer with both acute and chronic trismus as well as active and metastatic disease. It is intended as a pilot study to explore further the efficacy of the DTS as part of a multimodal treatment strategy for reducing trismus in patients with head and neck cancer. The results of this study will provide insights that will be used to design a larger prospective trial to clarify the optimal treatment of trismus in patients with head and neck cancer. METHODS Twenty consecutive patients with head and neck cancer referred to the rehabilitation medicine service at a large tertiary care cancer center for evaluation and treatment of trismus and deemed appropriate for a trial of the DTS as part of multimodal management were included in this retrospective review. All patients underwent detailed clinical evaluation by a boardcertified physiatrist specializing in the evaluation and treatment
Fig 1. Devices used to treat trismus include (A) stacked tongue depressors, (B) corkscrew devices, (C) the TheraBite Jaw Motion Rehabilitation System, and (D) the DTS. Reprinted with permission from Stubblefield MD, O’Dell MW. Cancer rehabilitation principles and practice. New York: Demos Medical Pub; 2009.
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EFFICACY OF DYNASPLINT IN TRISMUS, Stubblefield
of patients with cancer. All patients were referred to physical therapy by a board-certified physical therapist for delivery and training with the DTS as well as for initiation of manual techniques and physical modalities. Additional physical therapy for cervical dystonia, shoulder dysfunction, and other neuromuscular and musculoskeletal disorders was provided where appropriate. Botulinum toxin injections into the masseter muscles and prescription of pain medications including nerve stabilizing agents, nonsteroidal anti-inflammatory drugs, muscle relaxants, and opioids were prescribed when deemed clinically indicated by the treating physiatrist. Baseline measurements of the patients MID were made prior to initiation of therapy and at completion of therapy. Subsequent measurements were made on follow-up visits to the treating physiatrist. The baseline and best MID recorded in the patient’s medical record are presented. All patients were instructed to progress use of the DTS to 30 minutes 3 times a day. All data were collected and maintained in a registered database, and this study was approved by the hospital’s institutional review board. Pretreatment and posttreatment MID scores and differences in individual pretreatment and posttreatment scores were summarized using median and range. Differences in pretreatment and posttreatment scores were analyzed using the Wilcoxon signed-rank test. P values less than or equal to .05 were considered statistically significant. RESULTS Patient characteristics are presented in table 1. The average age of patients was 54 years (range, 21–78y), and most (60%) had squamous cell carcinoma. Nineteen (95%) had received radiation therapy as part of their initial oncologic treatment with a range of 5760 to 7200cGy to the bulk disease, and 2 (10%) had received a second course of radiation therapy for recurrent disease. Fifteen (75%) of patients underwent surgical resection of the primary tumor, and 11 (55%) underwent cervical lymph node dissection. Fourteen patients (70%) received both radiation therapy and surgery, and 9 patients (45%) had received chemotherapy as part of their initial oncologic treatment. Four patients (20%) had metastatic disease at the time of treatment with DTS. Seven patients (35%) had concurrent radiation-induced cervical dystonia. Four of these patients (20%) received botulinum toxin injections for the cervical dystonia. Five patients (25%) received botulinum toxin injections into 1 or both masseter muscles as part of their multimodal treatment of trismus. All patients were referred for physical therapy, but 1 refused to go, so the DTS was delivered directly to the home. The average time form the initial MID measurement to the maximal recorded MID measurement was 118 days (range, 19 –246d). Only 15 (75%) of the 20 patients were able to comply with the treatment recommendations for use of the DTS. The duration of treatment with DTS cannot be meaningfully calculated because some of the patients were unable to tolerate use even though it was delivered to them, and others continue to use the device for maintenance of their trismus. Change in MID before and after treatment with the DTS is presented in table 2. Multimodal treatment that included the DTS was associated with significant improvement of the median MID from 16.5 to 23.5mm (P⬍.001). The patients who were able to be compliant with the DTS improved their median MID from 16 to 27mm (P⬍.001). The patients who could not comply with the treatment recommendations did not demonstrate significant improvement (pretreatment to posttreatment MID, 17–22mm; P⫽.88). Three of the 5 noncompliant patients had metastatic disease, and 1 of these died of progressive disease within weeks of initiation of trismus treatment. The Arch Phys Med Rehabil Vol 91, August 2010
Table 1: Patient Characteristics Characteristic
Male Female Age Mean (y) Range (y) Histology Adenocarcinoma Adenocystic carcinoma Adenosquamous carcinoma Lymphoepithelioma Myoepithelial carcinoma Squamous cell carcinoma Location of primary tumor Base of tongue Cheek Hard palate Nasopharynx Neck Parotid gland Submandibular gland Tonsillar region Tongue Stage IV Treated with primary surgical resection Treated with cervical lymph node dissection Treated with primary RT RT dosage to primary (cGy) Treated with primary surgery and RT Time from RT to DTS Mean (mo) Range (mo) Time from initial MID to maximum MID Mean (d) Range (d) Treated with secondary RT Treated with chemotherapy Concurrent cervical dystonia Treated with botulinum toxin for trismus Treated with botulinum toxin for cervical dystonia Previous use of trismus device Compliant with DTS Noncompliant with DTS
No. of Patients
12 8 54 21 to 78 1 2 2 2 1 12 2 1 2 4 1 3 1 5 1 4 15 11 19 5760 to 7200 14 50 ⫺2 to 274 118 19 to 246 2 9 7 5 4 2 15 5
Abbreviation: cGy, centigray; RT, radiation therapy.
only complication seen during treatment with the DTS was osteomyelitis of the jaw in 1 patient, that was not thought to be related to use of the DTS. DISCUSSION Trismus is a common and potentially functionally devastating complication of head and neck cancer and its treatment. Despite the relative commonness of this complication and its deleterious effect on function and quality of life, there are few published studies concerning its treatment, and no standard of care exits. Physical therapy is considered the mainstay of treatment and likely provides little risk but its overall benefit has not been established in the literature.12-14 Moreover, the specific manual techniques and physical modalities most likely to be of benefit to patients with trismus are unclear and likely vary widely in clinical practice. Medications such as pentoxi-
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EFFICACY OF DYNASPLINT IN TRISMUS, Stubblefield Table 2: Change in MID Before and After Treatment With DTS Patients
No.
Pretreatment Score Median (Range)
Posttreatment Score Median (Range)
Difference in Scores Median (Range)*
P†
All patients Compliant patients Noncompliant patients
20 15 5
16.5 (9 to 41) 16 (11 to 41) 17 (9 to 30)
23.5 (10 to 47) 27 (11 to 47) 22 (10 to 26)
5 (⫺4 to 15) 7 (0 to 15) ⫺1 (⫺4 to 5)
.0003 .0001 .88
*Based on the difference of the preintervention and postintervention values for each individual patient. † P values were calculated for differences in pretreatment and posttreatment scores using the Wilcoxon signed-rank test.
fylline and hyperbaric oxygen are likely ineffective, and botulinum toxin injection into the muscles of mastication, while effective as an analgesic modality, is not effective in improving trismus when used as monotherapy.15,16 Surgical coronoidectomy may be of benefit in select patients but is invasive and carries heightened surgical risks in radiated patients with cancer.17 Jaw stretching devices have demonstrated efficacy in improving trismus in patients with head and neck cancer in 3 small studies.14,22,29 The primary devices in clinical practice today include the TheraBite Jaw Motion Rehabilitation System and the DTS. The TheraBite is a plastic device that is placed in the mouth and actuated with manual force applied in a leveraged fashion via plastic handles. Force is proportional to how hard the device handles are squeezed. Force is usually delivered near maximal patient tolerance for 7 seconds repeated for 7 repetitions 7 times a day. This device uses a high-torque, short duration passive stretch that in our clinical practice often results in painful rebound spasm of the muscles of mastication. The DTS works on the principle of low-torque, prolonged stretch that has been demonstrated to be more effective at improving range of motion in an experimental model involving contracted rat knees than high-torque, short duration stretching.30 This device provides a very low level of dynamic jaw opening and is used for up to 30 minutes 3 times a day. Once the maximal use schedule is tolerated, patients may be instructed progressively to adjust the tension minimally to provide increased stretch so long as no rebound spasm of the muscles of mastication is present. The complexities of rehabilitating trismus in patients with head and neck cancer is related to the unpredictable nature of the cancer as well as the patients’ individual tolerance of the oncologic treatments provided. Multimodal management has become the mainstay of treatment with some success but little clarity on which of the component treatments are most effective and how and when they should be used. Similarly, the effectiveness of the various treatment options in relation to the time of onset of treatment is unclear. While most trismus occurs within 9 months of completion of radiation therapy, many of the patients in our small series had trismus for much longer (average⫽50mo).8 That 1 patient afflicted by trismus for nearly 23 years improved the opening from 22 to 35mm with multimodal therapy is encouraging because chronic trismus is often considered more intractable than acute trismus. Clearly, the patients who were able to comply with our treatment recommendations were more successfully treated than those who could not. The reasons for not being able to tolerate the use of DTS varied but were not surprisingly oncologic for most of the patients. Patients with recurrent or rapidly progressive local disease are likely poor candidates for successful trismus treatment. Study Limitations There are many issues with this small retrospective pilot study that should be addressed in future prospective trials. A
large randomized prospective trial that directly compares DTS with TheraBite and each to physical therapy and a nontreatment group for both acute and chronic trismus patients would be potentially illuminating. The use of pain medications including botulinum toxin injections should be controlled in such a study. It is unlikely that botulinum toxin injection into the masseter and/or pterygoid muscles without the use of physical therapy and/or a jaw stretching device will be effective at improving trismus because only pain and muscular contraction will be affected and not the static and contracted structures contributing to and maintaining trismus. Botulinum toxin injection thought not likely to be a good primary treatment for radiation-induced trismus may have an adjunctive role in reducing the painful muscle spasms that occur with trismus and should be considered for use in patients who have not received adequate relief from nerve stabilizing agents, muscle relaxants, and analgesics. Relief of pain associated with antitrismus therapy has, in our clinical experience, been an instrumental component of multimodal therapy and should be considered as a variable in future trials. CONCLUSIONS The DTS as part of a multimodal treatment strategy in patients with head and neck cancer treated with radiation therapy is safe and effective. Further studies are clearly indicated to clarify the relative effectiveness of the DTS compared with other jaw stretching devices and physical therapy. References 1. Scott B, Butterworth C, Lowe D, Rogers SN. Factors associated with restricted mouth opening and its relationship to health-related quality of life in patients attending a maxillofacial oncology clinic. Oral Oncol 2008;44:430-8. 2. Krennmair G, Ulm CW, Lenglinger F. Effects of reduced mouth opening capacity (trismus) on pulmonary function. Int J Oral Maxillofac Surg 2000;29:351-4. 3. Tveteras K, Kristensen S. The aetiology and pathogenesis of trismus. Clin Otolaryngol Allied Sci 1986;11:383-7. 4. Dijkstra PU, Kalk WW, Roodenburg JL. Trismus in head and neck oncology: a systematic review. Oral Oncol 2004;40:879-89. 5. Dijkstra PU, Huisman PM, Roodenburg JL. Criteria for trismus in head and neck oncology. Int J Oral Maxillofac Surg 2006;35: 337-42. 6. Ichimura K, Tanaka T. Trismus in patients with malignant tumours in the head and neck. J Laryngol Otol 1993;107:1017-20. 7. Louise Kent M, Brennan MT, Noll JL, et al. Radiation-induced trismus in head and neck cancer patients. Support Care Cancer 2008;16:305-9. 8. Wang CJ, Huang EY, Hsu HC, Chen HC, Fang FM, Hsiung CY. The degree and time-course assessment of radiation-induced trismus occurring after radiotherapy for nasopharyngeal cancer. Laryngoscope 2005;115:1458-60. 9. Goldstein M, Maxymiw WG, Cummings BJ, Wood RE. The effects of antitumor irradiation on mandibular opening and moArch Phys Med Rehabil Vol 91, August 2010
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10.
11. 12.
13.
14.
15.
16.
17.
18.
19.
20.
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bility: a prospective study of 58 patients. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 1999;88:365-73. Teguh DN, Levendag PC, Voet P, et al. Trismus in patients with oropharyngeal cancer: relationship with dose in structures of mastication apparatus. Head Neck 2008;30:622-30. Dhanrajani PJ, Jonaidel O. Trismus: aetiology, differential diagnosis and treatment. Dent Update 2002;29:88-92, 4. Dijkstra PU, Sterken MW, Pater R, Spijkervet FK, Roodenburg JL. Exercise therapy for trismus in head and neck cancer. Oral Oncol 2007;43:389-94. Grandi G, Silva ML, Streit C, Wagner JC. A mobilization regimen to prevent mandibular hypomobility in irradiated patients: an analysis and comparison of two techniques. Med Oral Patol Oral Cir Bucal 2007;12:E105-9. Buchbinder D, Currivan RB, Kaplan AJ, Urken ML. Mobilization regimens for the prevention of jaw hypomobility in the radiated patient: a comparison of three techniques. J Oral Maxillofac Surg 1993;51:863-7. King GE, Scheetz J, Jacob RF, Martin JW. Electrotherapy and hyperbaric oxygen: promising treatments for postradiation complications. J Prosthet Dent 1989;62:331-4. Chua DT, Lo C, Yuen J, Foo YC. A pilot study of pentoxifylline in the treatment of radiation-induced trismus. Am J Clin Oncol 2001;24:366-9. Bhrany AD, Izzard M, Wood AJ, Futran ND. Coronoidectomy for the treatment of trismus in head and neck cancer patients. Laryngoscope 2007;117:1952-6. Stubblefield MD, Levine A, Custodio CM, Fitzpatrick T. The role of botulinum toxin type A in the radiation fibrosis syndrome: a preliminary report. Arch Phys Med Rehabil 2008;89:417-21. Hartl DM, Cohen M, Julieron M, Marandas P, Janot F, Bourhis J. Botulinum toxin for radiation-induced facial pain and trismus. Otolaryngol Head Neck Surg 2008;138:459-63. Abdel-Galil K, Anand R, Pratt C, Oeppen B, Brennan P. Trismus: an unconventional approach to treatment. Br J Oral Maxillofac Surg 2007;45:339-40.
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21. Lund TW, Cohen JI. Trismus appliances and indications for use. Quintessence Int 1993;24:275-9. 22. Cohen EG, Deschler DG, Walsh K, Hayden RE. Early use of a mechanical stretching device to improve mandibular mobility after composite resection: a pilot study. Arch Phys Med Rehabil 2005;86:1416-9. 23. Lubit EC. The trismus exerciser: an oral dynamic bite opener. N Y State Dent J 1968;34:489-93. 24. Brown KE. Dynamic opening device for mandibular trismus. J Prosthet Dent 1968;20:438-42. 25. Kouyoumdjian JH, Chalian VA, Hutton C. An intraoral positivepressure device for treatment of trismus. Oral Surg Oral Med Oral Pathol 1986;61:456-8. 26. Dijkstra PU, Kropmans TJ, Tamminga RY. Modified use of a dynamic bite opener—treatment and prevention of trismus in a child with head and neck cancer: a case report. Cranio 1992;10: 327-9. 27. Brunello DL, Mandikos MN. The use of a dynamic opening device in the treatment of radiation induced trismus. Aust Prosthodont J 1995;9:45-8. 28. Lo LJ, Lin CL, Chen YR. A device for temporomandibular joint exercise and trismus correction: design and clinical application. J Plast Reconstr Aesthet Surg 2008;61:297-301. 29. Shulman DH, Shipman B, Willis FB. Treating trismus with dynamic splinting: a cohort, case series. Adv Ther 2008;25:9-16. 30. Usuba M, Akai M, Shirasaki Y, Miyakawa S. Experimental joint contracture correction with low torque—long duration repeated stretching. Clin Orthop Relat Res 2007;456:70-8. Suppliers a. Atos Medical Inc, 11390 W Theodore Trecker Way, West Allis, WI 53214-1135. b. Dynasplint Systems Inc, River Reach, Ste W21, 770 Ritchie Highway, Severna Park, MD 21146.
ORIGINAL ARTICLE
A Preliminary Report on the Efficacy of a Dynamic Jaw Opening Device (Dynasplint Trismus System) as Part of the Multimodal Treatment of Trismus in Patients With Head and Neck Cancer Michael D. Stubblefield, MD, Laura Manfield, MD, Elyn R. Riedel, MA ABSTRACT. Stubblefield MD, Manfield L, Riedel ER. A preliminary report on the efficacy of a dynamic jaw opening device (Dynasplint Trismus System) as part of the multimodal treatment of trismus in patients with head and neck cancer. Arch Phys Med Rehabil 2010;91:1278-82. Objective: To examine the effectiveness of a dynamic jaw opening device as part of a multimodal treatment strategy for trismus in patients with head and neck cancer. Design: Retrospective cohort study. Setting: Tertiary care cancer center. Participants: Patients with head and neck cancer and trismus (N⫽20). Intervention: All patients underwent assessment by a board-certified physiatrist and were referred to physical therapy for delivery of the DTS and instructed to progress use of the DTS to 30 minutes 3 times a day. Additional modalities for the treatment of trismus including pain medications and botulinum toxin injections were prescribed as clinically indicated. Main Outcome Measures: Change in maximal interincisal distance (MID) as documented in the medical record. Results: The use of the DTS as part of multimodal therapy including physical therapy, pain medications, and botulinum toxin injections as deemed clinically appropriate resulted in an overall improvement of the MID from 16.5mm to 23.5mm (P⬍.001). Patients who could comply with the treatment recommendations for DTS treatment did better than those who could not, with an improvement of the MID from 16mm to 27mm (P⬍.001) versus 17mm to 22mm (P⫽.88). Conclusions: The DTS is a safe and effective component of a multimodal strategy for improving trismus associated with head and neck cancer and its treatment. Further investigation is needed to determine the relative efficacy of the treatment modalities available for trismus including physical therapy and other jaw stretching devices. Key Words: Quality of life; Radiation; Rehabilitation; Trismus. © 2010 by the American Congress of Rehabilitation Medicine
From the Department of Neurology, Rehabilitation Medicine Service (Stubblefield), and the Department of Epidemiology and Biostatistics (Riedel), Memorial Sloan-Kettering Cancer Center; and the Department of Physical Medicine and Rehabilitation, New York-Presbyterian Hospital (Manfield), New York, NY. No commercial party having a direct financial interest in the results of the research supporting this article has or will confer a benefit on the authors or on any organization with which the authors are associated. Reprint requests to Michael D. Stubblefield, MD, Rehabilitation Service, Memorial Sloan-Kettering Cancer Center, 1275 York Ave, New York, NY 10065, e-mail: [email protected]. 0003-9993/10/9108-00299$36.00/0 doi:10.1016/j.apmr.2010.05.010
Arch Phys Med Rehabil Vol 91, August 2010
RISMUS IS DEFINED as inability to open the mouth T fully. Impairment in mouth opening may have a detrimental effect on quality of life as basic functions such as chewing,
swallowing, and pulmonary function may be affected.1,2 Similarly, maintenance of oral health and surveillance of cancer recurrence may be less effective. Normative mouth opening for an adult is reported to range from 23 to 71mm as measured between the incisor teeth.3 Impaired mouth opening is a common complication of head and neck cancer and its treatment, with a prevalence reported to range from 5% to 38%.4 This wide variation in reported incidence reflects the lack of uniform criteria for the definition of trismus.5 Trismus in the head and neck cancer setting can result from local invasion of the primary or metastatic tumor into critical structures of mastication including the masseter and pterygoid muscles, their neural innervation, the temporal mandibular joint, and/or other supportive tissues.6 Similarly, surgery and radiation therapy are well known to cause trismus in this population. Radiation in particular is known to result in trismus in up to 45% of patients who received curative doses of radiation therapy.7 Trismus generally evolves most rapidly 1 to 9 months after completion of radiation therapy.8 Mandibular opening seems to worsen as the dose of radiation delivered to the pterygoid muscles increases.9 The probability of developing trismus is reported to increase 24% for every 10Gy of additional radiation delivered to the pterygoid muscles.10 Noncancer and cancer treatment– related causes of trismus are also common in the cancer setting and include infection, trauma, and osteoradionecrosis of the jaw among other causes.11 Multiple modalities have been used in the treatment of trismus. Physical therapy is generally considered the mainstay of trismus treatment and is often used alone or in combination with other modalities. Despite widespread use, the limited literature on the use of physical therapy to treat trismus in the head and neck cancer population has not demonstrated significant efficacy.12-14 Hyperbaric oxygen and pentoxifylline have shown no and modest efficacy, respectively.15,16 Forced mouth opening under general anesthesia can improve trismus, but the effect is often short-lived and potentially complicated by alveolus fracture and adjacent soft tissue rupture. Surgical coronoidectomy has demonstrated significant efficacy in a noncontrolled study of patients with head and neck cancer who had failed to respond to physical therapy.17 Botulinum toxin injection has been reported to have potential benefit in treating selected complications of the radiation fibrosis syndrome.18 A report on the efficacy of botulinum toxin injection into the
List of Abbreviations DTS MID
Dynasplint Trismus System maximal interincisal distance
EFFICACY OF DYNASPLINT IN TRISMUS, Stubblefield
masseters of patients with head and neck cancer and with radiation-induced pain and trismus did not demonstrate significant improvement of trismus but did demonstrate significantly reduced local pain.19 One unusual report details the use of a 14lb sledgehammer tied to the lower jaw by a necktie to markedly improve the patient’s maximum mouth opening from 20 to 38mm.20 A variety of jaw opening devices have been used to treat trismus (fig 1).21 Devices currently in common clinical use include stacked tongue depressors, corkscrew devices, the TheraBite Jaw Motion Rehabilitation System,a and the DTS.b The TheraBite demonstrated efficacy in a small trial (7 patients) when used within 6 weeks of surgery for oropharyngeal carcinoma.22 TheraBite combined with unassisted exercise also demonstrated efficacy in a group of patients who had undergone radiation therapy within the preceding 5 years (most within the preceding year) compared with unassisted exercise and compared with mechanically assisted mandibular mobilization using stacked tongue depressors combined with unassisted exercise.14 The fabrication and/or use of dynamic jaw opening devices to treat both benign and oncologic causes of trismus have been detailed in numerous reports dating back to 1968.23-28 The DTS is a commercially available dynamic jaw opening device that operates on the principle of low-torque, prolonged duration stretch. It has demonstrated efficacy in achieving improved jaw opening in a retrospective evaluation
1279
of 48 patients with trismus from 4 cohort groups including radiation therapy for head and neck cancer, dental treatment, oral surgery, and stroke.29 While the 20 patients in the head and neck cancer cohort improved their maximal interincisal distance by a mean of 13.6mm, little demographic and oncologic information was given save that they all received radiation therapy. The present study is a retrospective examination of the role of the DTS in a cohort of patients with head and neck cancer with both acute and chronic trismus as well as active and metastatic disease. It is intended as a pilot study to explore further the efficacy of the DTS as part of a multimodal treatment strategy for reducing trismus in patients with head and neck cancer. The results of this study will provide insights that will be used to design a larger prospective trial to clarify the optimal treatment of trismus in patients with head and neck cancer. METHODS Twenty consecutive patients with head and neck cancer referred to the rehabilitation medicine service at a large tertiary care cancer center for evaluation and treatment of trismus and deemed appropriate for a trial of the DTS as part of multimodal management were included in this retrospective review. All patients underwent detailed clinical evaluation by a boardcertified physiatrist specializing in the evaluation and treatment
Fig 1. Devices used to treat trismus include (A) stacked tongue depressors, (B) corkscrew devices, (C) the TheraBite Jaw Motion Rehabilitation System, and (D) the DTS. Reprinted with permission from Stubblefield MD, O’Dell MW. Cancer rehabilitation principles and practice. New York: Demos Medical Pub; 2009.
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of patients with cancer. All patients were referred to physical therapy by a board-certified physical therapist for delivery and training with the DTS as well as for initiation of manual techniques and physical modalities. Additional physical therapy for cervical dystonia, shoulder dysfunction, and other neuromuscular and musculoskeletal disorders was provided where appropriate. Botulinum toxin injections into the masseter muscles and prescription of pain medications including nerve stabilizing agents, nonsteroidal anti-inflammatory drugs, muscle relaxants, and opioids were prescribed when deemed clinically indicated by the treating physiatrist. Baseline measurements of the patients MID were made prior to initiation of therapy and at completion of therapy. Subsequent measurements were made on follow-up visits to the treating physiatrist. The baseline and best MID recorded in the patient’s medical record are presented. All patients were instructed to progress use of the DTS to 30 minutes 3 times a day. All data were collected and maintained in a registered database, and this study was approved by the hospital’s institutional review board. Pretreatment and posttreatment MID scores and differences in individual pretreatment and posttreatment scores were summarized using median and range. Differences in pretreatment and posttreatment scores were analyzed using the Wilcoxon signed-rank test. P values less than or equal to .05 were considered statistically significant. RESULTS Patient characteristics are presented in table 1. The average age of patients was 54 years (range, 21–78y), and most (60%) had squamous cell carcinoma. Nineteen (95%) had received radiation therapy as part of their initial oncologic treatment with a range of 5760 to 7200cGy to the bulk disease, and 2 (10%) had received a second course of radiation therapy for recurrent disease. Fifteen (75%) of patients underwent surgical resection of the primary tumor, and 11 (55%) underwent cervical lymph node dissection. Fourteen patients (70%) received both radiation therapy and surgery, and 9 patients (45%) had received chemotherapy as part of their initial oncologic treatment. Four patients (20%) had metastatic disease at the time of treatment with DTS. Seven patients (35%) had concurrent radiation-induced cervical dystonia. Four of these patients (20%) received botulinum toxin injections for the cervical dystonia. Five patients (25%) received botulinum toxin injections into 1 or both masseter muscles as part of their multimodal treatment of trismus. All patients were referred for physical therapy, but 1 refused to go, so the DTS was delivered directly to the home. The average time form the initial MID measurement to the maximal recorded MID measurement was 118 days (range, 19 –246d). Only 15 (75%) of the 20 patients were able to comply with the treatment recommendations for use of the DTS. The duration of treatment with DTS cannot be meaningfully calculated because some of the patients were unable to tolerate use even though it was delivered to them, and others continue to use the device for maintenance of their trismus. Change in MID before and after treatment with the DTS is presented in table 2. Multimodal treatment that included the DTS was associated with significant improvement of the median MID from 16.5 to 23.5mm (P⬍.001). The patients who were able to be compliant with the DTS improved their median MID from 16 to 27mm (P⬍.001). The patients who could not comply with the treatment recommendations did not demonstrate significant improvement (pretreatment to posttreatment MID, 17–22mm; P⫽.88). Three of the 5 noncompliant patients had metastatic disease, and 1 of these died of progressive disease within weeks of initiation of trismus treatment. The Arch Phys Med Rehabil Vol 91, August 2010
Table 1: Patient Characteristics Characteristic
Male Female Age Mean (y) Range (y) Histology Adenocarcinoma Adenocystic carcinoma Adenosquamous carcinoma Lymphoepithelioma Myoepithelial carcinoma Squamous cell carcinoma Location of primary tumor Base of tongue Cheek Hard palate Nasopharynx Neck Parotid gland Submandibular gland Tonsillar region Tongue Stage IV Treated with primary surgical resection Treated with cervical lymph node dissection Treated with primary RT RT dosage to primary (cGy) Treated with primary surgery and RT Time from RT to DTS Mean (mo) Range (mo) Time from initial MID to maximum MID Mean (d) Range (d) Treated with secondary RT Treated with chemotherapy Concurrent cervical dystonia Treated with botulinum toxin for trismus Treated with botulinum toxin for cervical dystonia Previous use of trismus device Compliant with DTS Noncompliant with DTS
No. of Patients
12 8 54 21 to 78 1 2 2 2 1 12 2 1 2 4 1 3 1 5 1 4 15 11 19 5760 to 7200 14 50 ⫺2 to 274 118 19 to 246 2 9 7 5 4 2 15 5
Abbreviation: cGy, centigray; RT, radiation therapy.
only complication seen during treatment with the DTS was osteomyelitis of the jaw in 1 patient, that was not thought to be related to use of the DTS. DISCUSSION Trismus is a common and potentially functionally devastating complication of head and neck cancer and its treatment. Despite the relative commonness of this complication and its deleterious effect on function and quality of life, there are few published studies concerning its treatment, and no standard of care exits. Physical therapy is considered the mainstay of treatment and likely provides little risk but its overall benefit has not been established in the literature.12-14 Moreover, the specific manual techniques and physical modalities most likely to be of benefit to patients with trismus are unclear and likely vary widely in clinical practice. Medications such as pentoxi-
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EFFICACY OF DYNASPLINT IN TRISMUS, Stubblefield Table 2: Change in MID Before and After Treatment With DTS Patients
No.
Pretreatment Score Median (Range)
Posttreatment Score Median (Range)
Difference in Scores Median (Range)*
P†
All patients Compliant patients Noncompliant patients
20 15 5
16.5 (9 to 41) 16 (11 to 41) 17 (9 to 30)
23.5 (10 to 47) 27 (11 to 47) 22 (10 to 26)
5 (⫺4 to 15) 7 (0 to 15) ⫺1 (⫺4 to 5)
.0003 .0001 .88
*Based on the difference of the preintervention and postintervention values for each individual patient. † P values were calculated for differences in pretreatment and posttreatment scores using the Wilcoxon signed-rank test.
fylline and hyperbaric oxygen are likely ineffective, and botulinum toxin injection into the muscles of mastication, while effective as an analgesic modality, is not effective in improving trismus when used as monotherapy.15,16 Surgical coronoidectomy may be of benefit in select patients but is invasive and carries heightened surgical risks in radiated patients with cancer.17 Jaw stretching devices have demonstrated efficacy in improving trismus in patients with head and neck cancer in 3 small studies.14,22,29 The primary devices in clinical practice today include the TheraBite Jaw Motion Rehabilitation System and the DTS. The TheraBite is a plastic device that is placed in the mouth and actuated with manual force applied in a leveraged fashion via plastic handles. Force is proportional to how hard the device handles are squeezed. Force is usually delivered near maximal patient tolerance for 7 seconds repeated for 7 repetitions 7 times a day. This device uses a high-torque, short duration passive stretch that in our clinical practice often results in painful rebound spasm of the muscles of mastication. The DTS works on the principle of low-torque, prolonged stretch that has been demonstrated to be more effective at improving range of motion in an experimental model involving contracted rat knees than high-torque, short duration stretching.30 This device provides a very low level of dynamic jaw opening and is used for up to 30 minutes 3 times a day. Once the maximal use schedule is tolerated, patients may be instructed progressively to adjust the tension minimally to provide increased stretch so long as no rebound spasm of the muscles of mastication is present. The complexities of rehabilitating trismus in patients with head and neck cancer is related to the unpredictable nature of the cancer as well as the patients’ individual tolerance of the oncologic treatments provided. Multimodal management has become the mainstay of treatment with some success but little clarity on which of the component treatments are most effective and how and when they should be used. Similarly, the effectiveness of the various treatment options in relation to the time of onset of treatment is unclear. While most trismus occurs within 9 months of completion of radiation therapy, many of the patients in our small series had trismus for much longer (average⫽50mo).8 That 1 patient afflicted by trismus for nearly 23 years improved the opening from 22 to 35mm with multimodal therapy is encouraging because chronic trismus is often considered more intractable than acute trismus. Clearly, the patients who were able to comply with our treatment recommendations were more successfully treated than those who could not. The reasons for not being able to tolerate the use of DTS varied but were not surprisingly oncologic for most of the patients. Patients with recurrent or rapidly progressive local disease are likely poor candidates for successful trismus treatment. Study Limitations There are many issues with this small retrospective pilot study that should be addressed in future prospective trials. A
large randomized prospective trial that directly compares DTS with TheraBite and each to physical therapy and a nontreatment group for both acute and chronic trismus patients would be potentially illuminating. The use of pain medications including botulinum toxin injections should be controlled in such a study. It is unlikely that botulinum toxin injection into the masseter and/or pterygoid muscles without the use of physical therapy and/or a jaw stretching device will be effective at improving trismus because only pain and muscular contraction will be affected and not the static and contracted structures contributing to and maintaining trismus. Botulinum toxin injection thought not likely to be a good primary treatment for radiation-induced trismus may have an adjunctive role in reducing the painful muscle spasms that occur with trismus and should be considered for use in patients who have not received adequate relief from nerve stabilizing agents, muscle relaxants, and analgesics. Relief of pain associated with antitrismus therapy has, in our clinical experience, been an instrumental component of multimodal therapy and should be considered as a variable in future trials. CONCLUSIONS The DTS as part of a multimodal treatment strategy in patients with head and neck cancer treated with radiation therapy is safe and effective. Further studies are clearly indicated to clarify the relative effectiveness of the DTS compared with other jaw stretching devices and physical therapy. References 1. Scott B, Butterworth C, Lowe D, Rogers SN. Factors associated with restricted mouth opening and its relationship to health-related quality of life in patients attending a maxillofacial oncology clinic. Oral Oncol 2008;44:430-8. 2. Krennmair G, Ulm CW, Lenglinger F. Effects of reduced mouth opening capacity (trismus) on pulmonary function. Int J Oral Maxillofac Surg 2000;29:351-4. 3. Tveteras K, Kristensen S. The aetiology and pathogenesis of trismus. Clin Otolaryngol Allied Sci 1986;11:383-7. 4. Dijkstra PU, Kalk WW, Roodenburg JL. Trismus in head and neck oncology: a systematic review. Oral Oncol 2004;40:879-89. 5. Dijkstra PU, Huisman PM, Roodenburg JL. Criteria for trismus in head and neck oncology. Int J Oral Maxillofac Surg 2006;35: 337-42. 6. Ichimura K, Tanaka T. Trismus in patients with malignant tumours in the head and neck. J Laryngol Otol 1993;107:1017-20. 7. Louise Kent M, Brennan MT, Noll JL, et al. Radiation-induced trismus in head and neck cancer patients. Support Care Cancer 2008;16:305-9. 8. Wang CJ, Huang EY, Hsu HC, Chen HC, Fang FM, Hsiung CY. The degree and time-course assessment of radiation-induced trismus occurring after radiotherapy for nasopharyngeal cancer. Laryngoscope 2005;115:1458-60. 9. Goldstein M, Maxymiw WG, Cummings BJ, Wood RE. The effects of antitumor irradiation on mandibular opening and moArch Phys Med Rehabil Vol 91, August 2010
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21. Lund TW, Cohen JI. Trismus appliances and indications for use. Quintessence Int 1993;24:275-9. 22. Cohen EG, Deschler DG, Walsh K, Hayden RE. Early use of a mechanical stretching device to improve mandibular mobility after composite resection: a pilot study. Arch Phys Med Rehabil 2005;86:1416-9. 23. Lubit EC. The trismus exerciser: an oral dynamic bite opener. N Y State Dent J 1968;34:489-93. 24. Brown KE. Dynamic opening device for mandibular trismus. J Prosthet Dent 1968;20:438-42. 25. Kouyoumdjian JH, Chalian VA, Hutton C. An intraoral positivepressure device for treatment of trismus. Oral Surg Oral Med Oral Pathol 1986;61:456-8. 26. Dijkstra PU, Kropmans TJ, Tamminga RY. Modified use of a dynamic bite opener—treatment and prevention of trismus in a child with head and neck cancer: a case report. Cranio 1992;10: 327-9. 27. Brunello DL, Mandikos MN. The use of a dynamic opening device in the treatment of radiation induced trismus. Aust Prosthodont J 1995;9:45-8. 28. Lo LJ, Lin CL, Chen YR. A device for temporomandibular joint exercise and trismus correction: design and clinical application. J Plast Reconstr Aesthet Surg 2008;61:297-301. 29. Shulman DH, Shipman B, Willis FB. Treating trismus with dynamic splinting: a cohort, case series. Adv Ther 2008;25:9-16. 30. Usuba M, Akai M, Shirasaki Y, Miyakawa S. Experimental joint contracture correction with low torque—long duration repeated stretching. Clin Orthop Relat Res 2007;456:70-8. Suppliers a. Atos Medical Inc, 11390 W Theodore Trecker Way, West Allis, WI 53214-1135. b. Dynasplint Systems Inc, River Reach, Ste W21, 770 Ritchie Highway, Severna Park, MD 21146.