This review article summarizes a systematic review of literature on criteria for defining trismus, risk factors for trismus, and interventions to treat trismus. The review found that there is no consistent definition of trismus, with studies using 9 different criteria without justification. Only 4 studies met basic requirements of prospectively measuring mouth opening at baseline and follow-up. Radiotherapy involving the TMJ and pterygoid muscles was found to increase the risk of trismus in 18% of patients. Short-term exercises and medications showed benefits, but more research is needed due to lack of studies meeting quality standards.

1. Journal club
Presented by,
Devi
MDS ‘15
1
Int. J. Oral Oncology (2004) 40 879–889

2. CONTENTS
• Introduction
• Review of literature
• Discussion
• Conclusion
• References
2

3. Introduction
• Trismus :
The word “trismus”, from the Greek word
“trismos” is defined as a prolonged, tetanic
spasm of the jaw muscles by which the
normal opening of the mouth is restricted .
(Management of temporomandibular disorders and occlusion ,
Okeson , 7th
edition )
3

4. Aetiologies of trismus
4
Trismus : Aetiology, Differential Diagnosis and Treatment ; Dental
Update: March 2002

5. How does it affect the
individual ????
5

6. How to measure ??
6The TMJ Book, Kaplan

7. Incidence rate !!
• Prevalence of trismus in patients who had
undergone treatments for tumour
• Trismus is defined variously
• Mouth opening of 35 mm or less regarded
as trismus in H&N oncology patients.
7
(Radiation induced trismus in head and neck cancer
atients. Support.Care Cancer 16, 305-309
(Analysis of late complications after rapid hyperfractioned radiotherapy in advanced head
and neck cancer. Inter.J. Radiat.Oncol.Biol.Phys 14 23-25 Nguyen, PanisFriossart et al )
(Criteria for trismus in head and neck oncology . Int.J.Oral MaxFac Surgry
35 337-342 2006 Dijkestra PU)

8. No uniform criteria !
8
Authors that do provide criteria for trismus do
not explain why they define trismus in that
specific way

9. Aim of this review was to identify
systematically
• criteria for trismus,
• evidence for risk factors for trismus
• interventions to treat trismus.
9

10. Methodology
• Literature databases
• “trismus” and “restricted mouth opening”
• 1966 to June 2003
• two observers
• 203 papers
10

11. Criterias assessed
1. prospective study (yes, no),
2. inclusion criteria described (yes, no),
3. percentages or numbers of men and women included in
the study reported (yes, no),
4. descriptive statistics, mean and sd, or median and inter
quartile range, for age reported (yes, no),
11

12. 5. location of tumour reported with sufficient detail, for
instance floor of the mouth, tongue, salivary glands etc.
oropharyngeal or oral cavity tumour is not detailed
enough (yes, no),
6. baseline assessment of mouth opening (yes, no),
7. criteria for trismus described (yes, no),
8. trismus described in subjective terms, for instance
patients experience stiffness during mouth opening or
patients experience a restricted mouth opening during
eating (yes, no),
12

13. 9. trismus measured (yes, no),
10. measurement instrument described (yes, no),
11. repeated measurements performed to increase reliability
(yes, no),
12. percentage or number of patients with trismus described
(yes, no),
13. number of patients included in the study
14. number of patients assessed for trismus
13

14. • Final selection criterias :
• Prospective study design
• Base line assessment of trismus
• Measurement of trismus
• If the trismus was absent before the
exposure to the risk factors & in what % of
the patient at risk
14
Criteria for
trismus

15. • Excluded studies
• Selection bias
• Case series/ case reports
• ≤ 10 patients
• Language bias
15

16. Results
• Total of 203 papers were identified
• 24 were excluded -written in a foreign language
• 179 papers - majority of papers were clinical
studies
• The criteria list used was based on basic
requirements of research methodology and
statistical description of the population under
study (RCT & Observational studies are
excluded)
16

17. 1.Risk factors
• For evaluation of risk factors for trismus or
treatment effectiveness, base line assessment
of trismus is required.
• sufficient detail should be provided with respect
to location of the tumour.
• Radiotherapy involving the structures of the TMJ
and or pterygoid muscles reduces mouth
opening with 18%
.
17

18. 2. Criteria for trismus
• A wide range of criteria was used without
documenting why these specific criteria
were used.
• no gold standard exists as to which
amount of mouth opening should be
regarded as trismus
18

19. • For adequate evaluation of trismus, mouth
opening should be measured, because visual
assessment of mouth opening is highly
inaccurate and leads to discrepancies between
the assessed mouth opening and the actual
mouth opening.
• For a reliable assessment of mouth opening,
repeated measurements should be performed.
19

20. • In 12 studies nine different criteria for
trismus were found without justifying
these criteria
20

21. • To overcome this dilemma trismus might be
assessed in subjective terms such as
 “Does your mouth opening feel restricted”
or
“Are you limited in eating because of your mouth
opening”.
Only 10 studies described trismus subjectively.
21

22. 3. Interventions to treat trismus
• Case studies and case series may be interesting
from a clinical point of view but from a statistical
point of view case series and case studies lack
power
22

23. • Exercises using a therabite device or
tongue blades significantly increase mouth
opening on short term, the effect sizes
were large.
• Pentoxifylline increased mouth opening on
short term and electrotherapy increases
mouth opening (follow-up: 3 months) but
the effect sizes are small.
23

24. Conclusion
• secondary outcome variable
• Only four papers fulfilled three basic
requirements.
• Research into criteria for trismus,
functional consequences of trismus, risk
factors for trismus and interventions
studies are needed.
24

25. References
• Trismus in head and neck oncology: a systematic review P.U.
Dijkstraa,b,*, W.W.I. Kalka, J.L.N. Oral Oncology (2004) 40 879–
889
• Management of temporomandibular disorders and occlusion ,
Okeson , 7th
edition
• Trismus : Aetiology, Differential Diagnosis and Treatment ; Dental
Update: March 2002
• (Radiation induced trismus in head and neck cancer atients.
Support.Care Cancer 16, 305-309
• (Analysis of late complications after rapid hyperfractioned
radiotherapy in advanced head and neck cancer. Inter.J.
Radiat.Oncol.Biol.Phys 14 23-25 Nguyen, PanisFriossart et al )
25

26. • (Criteria for trismus in head and neck oncology . Int.J.Oral MaxFac
Surgry 35 337-342 2006 Dijkestra PU)
• The TMJ Book, Kaplan
26

27. 27