INTRODUCTION:

Trismus is original from the greek term "trismós" and means "gnashing“. It can be defined as a tonic contraction of the muscles of mastication and results in a limited ability to open the mouth. 1,3 Trismus can occur due to several factors such as tumor invasion of the masticatory muscles and/or temporomandibular joint, fibrosis induced by radiotherapy, oral infections, oedema after surgery or pain This limitation in the ability to open the mouth can have serious health implications, including reduced nutrition due to impaired mastication, difficulty in speaking, and compromised oral hygiene. 3,4 In persons who have received radiation to the head and neck, the condition is often observed in conjunction with difficulty in swallowing.Trismus, also called as lock jaw, It is the tonic contraction of the muscles of the mastication and spasm. It results in the limited ability to open the mouth. 2,3 It occurs due to several factors such as tumour invasion in the masticatory muscles or in the Temporo mandibular joint, fibrosis induced by radiotherapy, oral infections, and oedema after surgery or due to pain. This limitation in the opening of mouth causes serious health implication including reduced nutritional supply due to impaired masticatory muscles, difficulty in speaking and compromised oral hygiene. In persons who have received radiation to the head and neck; the condition is often observed as difficulty in swallowing and in some cases it results in aspiration. Trismus presents with altered facial expression. 5,7 The condition may be distressing or painful to the patient. Normal mouth opening ranges from 35-45mm. Males usually have slightly greater mouth opening than females. Limitations can be caused internally and externally to the joint. The internal factors are bony ankylosis, fibrous ankylosis, arthritis, trauma and micro trauma. 6,8 The internal factors are neoplasm, acute infection, myositis, systemic disease, pseudo ankylosis, burn injuries. Central nervous system disorders causing lesion to the trigeminal nerve is one of the factor. Joints which are immobilized quickly begin to show degenerative changes in the joint, including thickening of synovial fluid and thinning of cartilage. 8,9 In the case of patients receiving radiation treatment of the head and neck, trismus may progress slowly, even unnoticed for months, causing secondary changes to both muscles and joints.1 In cancer patients this frequently results from scar tissue from radiation or surgery, nerve damage, or a combination of factors in cases of trismus caused by radiation treatment, patients also frequently present with Xerostomia, mucusitis, and pain as a result of radiation burns. There may also be associated symptoms such as headache, jaw pain, ear ache, deafness, or pain on moving the jaw. 3,9 In cases of Temporomandibular tightness, the joint itself may become fibrotic, or even ankylotic. Radiation in excess of 60Gr. is more likely to cause trismus, than in radiation at levels below that amount. Patients who have been previously irradiated, and who are being treated for a recurrence, appear to be at higher risk of trismus than those who are receiving their first treatment. 3,4 Radiation induced trismus may begin toward the end of radiation treatment, or at any time during the subsequent 12 months. 8 Most often, we observe tightening that increases slowly over several weeks or months. On occasion, we see cases where the condition suddenly worsens with no apparent instigating factor. The condition may worsen over time, remain the same, or the symptoms may reduce over time, even in the absence of treatment. However, the condition is most likely to worsen if not treated. Some patients who have not received radiation treatment may develop trismus secondary to scarring and oedema after surgery.13 The use of Therabite exercises can increase the joint ROM and helps in relieving pain without causing any adverse effects to the cancer patients. It also provides strengthening of the muscles of mastication also increases oral and nutritional hygiene.15

OBJECTIVE OF THE STUDY:

To find out the effects of TheraBite exercises to relieve pain and increase range of motion in Trismus among oral cancer patients.

SUBJECTS AND METHODOLOGY:

A randomized clinical trial was designed which included two groups namely Control Group and Experimental Group. A convenient sample of oral cancer subjects was solicited from Saveetha dental college and hospital. Participants were n=20 and age range =18-40 years. Subjects were then allocated in two groups; each group had a physiotherapist who carried out all interventions. Group A is Control group which received only Jaw mobilization exercises and Group B is Experimental group which received Therabite exercises and also Jaw mobilization exercises. Subjects were assessed after two weeks to measure the pain and jaw ROM for the difference between pre and post-test values. Both the groups received the exercises continuously for two weeks, thrice a day of three sets per while and 10 repetitions in each sets.

INCLUSION CRITERIA:

Oral cancer with radiation therapy, Both males and females, 18 to 40 years of age, Spasticity in muscles of mastication, Stage 3 and 4 of oral cancer patients, Restricted mouth opening.

EXCLUSION CRITERIA:

Fracture of maxilla, Fracture of mandible, Weakness of bones of the jaw, Infections of the jaw, Osteomyelitis, Osteo radio necrosis, weakened dentition, periodontal disease, chronic cancer patients, any mouth deviation, metal tooth implantation.

PROCEDURE:

The oral cancer patients were selected for this study. The pre interventional pain and jaw ROM is assessed using NPRS scale and jaw ROM scale. The Group A, control group received jaw mobility exercise by opening the mouth as wide as possible without causing pain and holding it for 10 seconds on either sides with applying gentle pressure and returning to the neutral position. The Group B, experimental group received Therabite exercises as well as jaw mobility exercises. The Therabite instrument consists of a

· Fine adjustment knob thumb screw.

· Top squeeze handle with 5 limit holes.

· Millimetre set pin.

· Millimetre set arm, which attaches to the top squeeze handle by sliding the set pin into one of the 5 holes

· Upper and Lower Bite Plates. These are where you would rest your upper and lower teeth.

· TheraBite body and lower handle.

Crescent shaped pads for the upper and lower mouth pieces are provided with the Thera Bite system. The pad cushions the teeth and creates a guide to place the teeth when using the TheraBite device. 26 To apply a pad, remove the backing from the pad and stick the pad to the crescent shaped mouthpieces on the sides that the teeth will contact. The stretching effect occurs by squeezing the handle and holding it for 10 seconds.24 This device consists of a Millilitre Set arm, this arm has 5 holes and can adjust the opening of the TheraBite from 25 mm to 45 mm by removing the set pin and sliding the arm to another hole higher or lower on the arm. This is used to restrict opening so that it don't over stretch the joints or muscles. The TheraBite device provides curved and anatomical correct stretch for the patients. By using this, the joint ROM can be increased and the patient feels reduction of pain.21 The post interventional pain and jaw ROM are measured and the readings are tabulated.

RESULTS:

Data analyzed using unpaired t- test to measure the difference between the Pre and the Post test values within the group. The two-tailed P value is less than 0.0001. By conventional criteria, this difference is considered to be extremely statistically significant of Experimental group.

Table: 1 Pre Intervention Values Of Pain Group A and B

Statistical Measurements	Control Group	Experimental Group
Mean	8.5	8.3
Standard Deviation	0.52	0.48

Table.2: Pre Intervention Values Of Rom In Group AandB

Statistical Measurements	Control Group	Experimental Group
Mean	3.9	3.7
Standard Deviation	1.8	1.2

Fig 1 Pre intervention- Pain and ROM values

Table.3 Post Intervention Values Of Pain In Group A and B

Statistical Measurements	Control Group	Experimental Group
Mean	7.3	0.9
Standard Deviation	0.94	0.31

Table.4 Post Intervention Values Of Rom In Group A and B

Statistical Measurements	Control Group	Experimental Group
Mean	27.7	5.4
Standard Deviation	3.46	1.42

Fig 2 Post intervention Pain and ROM values.

DISCUSSION:

A recent systematic review has shown that exercises with devices to mobilise the jaw after treatment yield better results than no exercise in patients with radiotherapy-induced trismus after treatment for cancer of the head and neck.¹² Our study has shown that exercises with the Therabite or wooden spatulas, before, during, and after radiotherapy, can relieve radiation-induced trismus in this group. Melchers et al described an increase in mouth opening when patients did the exercises more often. The authors also found that self-discipline and clearly-set objectives were important for maintaining the necessary effort. The main factor that negatively affected adherence was painful mucositis, as in our study. Other factors, such as anxiety, ill-fitting Therabitepads, and failure to set goals during treatment, also had a negative effect. Tang et al showed that rehabilitation training can slow down the progress of trismus in patients with nasopharyngeal carcinoma after radiotherapy.²¹ Several studies have shown that use of a Therabite was no more effective than use of wooden spatulas or active range-of-motionexercises. However, Pauli et al reported that mouth opening increased more after use of a Therabitethan after use of the Engström device (a wooden clothespeg with an attached rubber band), although compliance was comparable. An earlier study by Buchbinder et al also showed that the Therabitewas more efficient than unassisted stretching or stretching using wooden spatulas, although it included only a small number of patients. The results shows that the post intervention phase NPRS scale 95% confidential interval and t value is 20.44, standard error of difference 0.313.the two tailed p value is less than 0.0001 by conventional criteria this difference is considered to be extremely statistically significant. Then inter insial measurement 95% confidential interval and t value is 19.17, standard error of difference 1.163, The two tailed p value is less than 0.0001 by conventional criteria this is considered to be extremely statistically significant. The results show that in Experimental group Therabite exercises was very effective for improving mouth opening and relive pain among trismus affecting oral cancer patients.

SUGGESTIONS AND LIMITATIONS:

This study was done in a short period of with a small number of subjects. Therefore to make the results more valid, long-term study with a larger sample size is recommended. Mandibular functioning or quality of life was not assessed; however, the TheraBite is primarily developed for increasing mouth opening. Further research is needed to compare the TheraBite with the DTS in a randomized controlled trial. The costs of a DTS are about five times higher than those of a TheraBite. Cost effectiveness of both jaw-stretching devices should be analyzed. Effects of the exercises should ideally be measured in millimeters, in mandibular functioning, and in quality of life.

CONCLUSION:

Patients with oral cancer can experience a variety of complications following surgery and radiation, including limited mouth opening or trismus.The dental team is at increased risk of jaw problems due to limited work area and impaired vision associated with oral cavity. This study was to investigate the therapeutic effects of therabite exercises in the alleviation of pain and mouth opening increased averagely with 5.4 mm. Finally, in a generalized way, its impact should be minimized in the patient's daily life, in order to increase their quality of life.

Ethical Consideration:

This study was approved by the Research Committee Institutional Scientific Review Board in the college university and study start-up at the site. Great care will be taken to fully explain the study to the patients before fully informed consent is taken.

REFERENCES:

1. Goldstein M, Maxymix G, Cummings B, et al. The effects of antitumour irradiation on mandibular opening and mobility. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 1993;88:365–73.

2. Fingeret MC, Vidrine DJ, Reece GP, et al. Multidimensional analysis of body image concerns among newly diagnosed patients with oral cavity cancer. Head Neck 2010;32:301–9.

3. McNeely ML, Armijo Olivo S, Magee DJ. A systematic review of the effectiveness of physical therapy interventions for temporomandibular disorders. Phys Ther 2006;86:710–25.

4. Melchers LJ, Van Weert E, Beurskens CH, et al. Exercise adherence in patients with trismus due to head and neck oncology: a qualitative study into the use of the Therabite. Int J Oral Maxillofac Surg 2009;38:947–54.

5. J. Johnson, C.J. van As-Brooks, B. Fagerberg-Mohlin, et al.Trismus in head and neck cancer patients in Sweden: incidence and risk factors Med SciMonit, 16 (2010), Article CR278-82

6. N. Pauli, P. Andréll, M. Johansson, et al.Treating trismus: a prospective study on effect and compliance to jaw exercise therapy in head and neck cancer Head Neck, 37 (2015), pp. 1738-1744

7. N. Høgdal, C. Juhl, M. Aadahl, et al.Early preventive exercises versus usual care does not seem to reduce trismus in patients treated with radiotherapy for cancer in the oral cavity or oropharynx: a randomised clinical trial Acta Oncol, 54 (2015), pp. 80-–87

8. L.J. Melchers, E. Van Weert, C.H. Beurskens, et al.Exercise adherence in patients with trismus due to head and neck oncology: a qualitative study into the use of the Therabite Int J Oral Maxillofac Surg, 38 (2009), pp. 947-–954

9. Therabite jaw motion rehabilitation system Atos Medical (2009) Available from URL: https://www.atosmedical.co.uk/product/therabite-jaw-motion-rehabilitation-system/ (last accessed 10 February 2018)

10. I. Kamstra, J.L. Roodenburg, C.H. Beurskens, et al.TheraBite exercises to treat trismus secondary to head and neck cancer Support Care Cancer, 21 (2013), pp. 951-957

11. A.P. Carvalho, M.L. McNeely, F.M. VitalInterventions for preventing and treating trismus in patients with head and neck cancer Cochrane Database of Systematic Reviews, 8 (2016), Article CD012316

12. Montalvo C, Finizia C, Pauli N, Fagerberg-Mohlin B, Andréll P. Impact of exercise with Thera Bite device on trismus and health-related quality of life: A prospective study.

13. Scope of physiotherapy in oral medicine. Dr.Jignashah(MDS),October 2014,vol-01.

14. P.U. Dijkstra, M.W. Sterken, Exercise therapy for trismus in head and neck cancer,MAY 2007.

15. Ana pauladall ,Early and long-term effects of physiotherapy for trismus in patients treated for oral and oropharyngeal cancer,vol 30,no4(2010).

16. Amruth,Trismus in head and neck cancer patiens treated by telecobalt and effect of early rehabilitation measures :sindhu naga raja:voloume :12,year 2016.

17. Amruth, Trismus in head and neck cancer patiens treated by telecobalt and effect of early rehabilitation measures :sindhu naga raja:voloume:12, year 2016.

18. Nelson SJ, Nowlin TP, BoeseltBJ. Consideration of linear and angular values of maximum Mandibular opening. Compend Contin Educ Dent 1992; 13: 362–363

19. The Mechanisms of Massage and Effects on Performance, Muscle Recovery and Injury Prevention Article ,February 2005, Pornratshanee Weerapong Patria Hume

20. Lee R, Molassiotis A, Rogers SN, Edwards RT, Ryder D, Slevin N.Protocol for the trismus trial-therabite versus wooden spatula in the amelioration of trismus in patients with head and neck cancer: randomised pilot study.

21. Role of physiotherapy in treatment of certain Oro facial disorders. Anshul Aggarwal and Vaishali Keluskar Department of Oral Medicine and Radiology,Received: 11/10/09.

22. Jolanda I Kamstra ,therabite exercises to treat trismus secondary to head and neck cancer:

23. MilindNaphade,Maintenance of increased mouth opening in oral submucous fibrosis patient treated with nasolabial flap technique.March 2014

24. P.U. Dijkstra, M.W. Sterken, Exercise therapy for trismus in head and neck cancer, MAY 2007.

25. Therapeutic exercises for the control of temporomandibular disorders. Alberto da rocha moraes.oct.2013,vol.18.

26. Ana pauladall ,Early and long-term effects of physiotherapy for trismus in patients treated for oral and oropharyngeal cancer,vol 30, no4(2010).

Received on 08.03.2019 Modified on 28.05.2019

Research J. Pharm. and Tech 2020; 13(2):519-522.

DOI: 10.5958/0974-360X.2020.00098.0