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Abstract

Objective

To determine the relationship between temporomandibular dysfunction syndrome (TMDS), sex and pain severity.

Methods

Data were collected prospectively from consecutive patients with TMDS. Patients were divided into four subgroups according to signs and symptoms: myofascial pain; intra-articular disorders; extra-articular disorders; degenerative disorders. Intergroup sex distribution differences were evaluated, the pain severity between the four subgroups was compared, and the rates of bruxism and inco-ordination were measured. A visual analogue scale was used to rate the pain.

Results

A total of 255 patients with TMDS were included in the study. A significantly higher rate of extra-articular disorders was found in male patients. Bruxism was found to be significantly more common in females than in males. There was no significant difference in the prevalence of inco-ordination based on sex. The overall pain score was higher in females than in males, but there was no significant difference. The pain score was significantly higher in patients in the degenerative disorders subgroup, compared with other subgroups.

Conclusions

There was no relationship between TMDS and pain and sex. Pain scores were significantly higher in the degenerative disorders subgroup, compared with other subgroups.

Keywords

Temporomandibular dysfunction syndrome pain bruxism inco-ordination

Introduction

Temporomandibular dysfunction syndrome (TMDS) includes various clinical conditions that involve the masticatory muscles or temporomandibular joints and their associated structures.¹ Typical signs and symptoms of TMDS are pain, joint sounds, limited mouth opening, chewing disability and mandibular deviation; signs and symptoms may exist alone or in combination.² The aetiology of TMDS is multifactorial and is related to dental and medical conditions.^2,3 Factors that contribute to TMDS are thought to be anatomical, genetic, trauma, pathophysiological and psychosocial.⁴ The purpose of this study was to determine the relationship between TMDS, sex and pain severity.

Patients and methods

Patient population

This prospective study enrolled consecutive patients seeking treatment for TMDS at the Department of Physical Medicine and Rehabilitation, Medical Faculty, Istanbul University, Istanbul, Turkey between February 2012 and February 2013. Patients were initially questioned using a questionnaire based on the Research Diagnostic Criteria for TMDS.⁵ The following items were included in the questionnaire: age; sex; social status; general health; antidepressant use; dental status (missing/filled teeth, fixed/removable prosthetic restorations); occlusion type; limited mouth opening; temporomandibular joint sounds; and parafunctions (bruxism, clenching). Patients with fibromyalgia, trigeminal neuralgia, burning mouth syndrome, atypical facial pain, migraine, atypical odontalgia and cervical or neuropathic pain, as well as those with a history of TMDS treatment, were excluded from the study.

The study was approved by the Ethics Committee of the Medical School, Dicle University, Diyarbakir, Turkey. All patients included in the study gave verbal informed consent.

Pain assessment

After demographic information was obtained from each patient, the extent of temporomandibular joint pain was evaluated with a visual analogue scale (VAS), where a score of 0 represented no pain and 10 represented the worst possible pain. Patients were divided into four subgroups, based on the VAS score and their signs and symptoms of TMDS: patients with a taut band in the muscles and painful trigger points (myofascial pain group, G1); patients with joint tenderness, clicking sounds, or crepitation, along with decreasing joint movement (intra-articular disorders group, G2); patients with malocclusion and joint hypermobility (extra-articular disorders group, G3); patients with painful joint degeneration (degenerative disorders group, G4).

Statistical analyses

All statistical analyses were performed using the SPSS® statistical software package, version 16.0 (SPSS Inc., Chicago, IL, USA) for Windows®. Independent-samples t-test was used to compare the pain severity between the four subgroups; χ²-test was used to compare the sex distribution between the groups and to compare rates of bruxism and inco-ordination between both sexes. A P-value < 0.05 was considered statistically significant.

Results

A total of 255 patients (191 [74.9%] females; 64 [25.1%] males) with TMDS were included in the study; thus, females were found to have three times the risk of TMDS than males. The mean ± SD age of the patients was 34.9 ± 13.2 years (males 34.4 ± 14.5 years; females 35.0 ± 12.8 years; range 18–80 years). There were 112 patients in G1, 110 patients in G2, 16 patients in G3 and 17 patients in G4. No significant differences were found in G1, G2, or G4 according to sex distribution (Table 1); in G3, a significantly higher rate of extra-articular disorders was found in male patients (P = 0.024).

Table 1.

Comparison of sex distribution differences in four groups of patients with temporomandibular dysfunction syndrome, categorized according to the signs and symptoms experienced (n = 255).

Group	Total	Female n = 191	Male n = 64	Statistical significance^a
G1	112	87 (45.5)	25 (39.1)	NS
G2	110	82 (42.9)	28 (43.8)	NS
G3	16	8 (4.2)	8 (12.5)	P = 0.024
G4	17	14 (7.3)	3 (4.7)	NS

Data presented as number of patients (% of the same sex).

χ²-test.

G1, myofascial pain; G2, intra-articular disorders; G3, extra-articular disorders; G4, degenerative disorders; NS, not statistically significant (P ≥ 0.05).

Bruxism was significantly more common in female patients than in males (P = 0.021), but there was no significant difference in the rate of inco-ordination according to sex (Table 2).

Table 2.

Comparison of the number of patients with temporomandibular dysfunction syndrome who experienced bruxism and inco-ordination, stratified according to sex (n = 255).

Symptom	Total	Female n = 191	Male n = 64	Statistical significance^a
Bruxism	172	136 (71.2)	36 (56.3)	P = 0.021
Inco-ordination	88	65 (34.0)	23 (35.9)	NS

Data presented as number of patients (% of the same sex).

χ²-test.

NS, not statistically significant (P ≥ 0.05).

The mean ± SD VAS score for the entire patient population was 5.4 ± 1.4. Pain scores were higher in females (5.4 ± 1.3) compared with males (5.2 ± 1.5), but there was no significant difference. The mean ± SD VAS scores for the four subgroups are presented in Table 3. The mean VAS score for patients in G4 (6.8 ± 1.6) was significantly higher than scores for the other three subgroups (P < 0.05 for all comparisons; Table 3).

Table 3.

Mean visual analogue scale (VAS) scores for the four groups of patients with temporomandibular dysfunction syndrome, categorized according to the signs and symptoms experienced (n = 255).

Group	n	VAS score
G1	112	5.2 ± 1.5^a
G2	110	5.4 ± 1.3^a
G3	16	5.6 ± 1.5^b
G4	17	6.8 ± 1.6

Data presented as mean ± SD.

P < 0.001 compared with G4; independent-samples t-test.

P = 0.02 compared with G4; independent-samples t-test.

G1, myofascial pain; G2, intra-articular disorders; G3, extra-articular disorders; G4, degenerative disorders.

A VAS score of 0 represented no pain; a VAS score of and 10 represented worst possible pain.

Discussion

Temporomandibular dysfunction syndrome is a chronic disorder. In general, epidemiological studies have documented a greater frequency and severity of TMDS in females than in males.^5,6 Fillingim et al.⁷ reported a higher ratio of female patients (89%), as did another prevalence study in Turkey.⁸ Although sex differences have been explained by behavioural, psychosocial, hormonal and constitutional factors, no conclusions have been drawn.^5,9 In the present study, females were found to have a higher risk of TMDS (3 : 1) than males. Manfredini et al.⁶ made similar observations in a study of 433 patients, in whom the female:male risk ratio was 2.6 : 1.

Psychosocial factors can be a cause of TMDS.¹⁰ In the literature, the most common diagnosis of TMDS is myofascial pain syndrome, which is associated with psychosocial factors.¹¹ A high incidence of myofascial pain was also found in the current study.

The incidence of TMDS pain in females has been studied widely.¹² Females were reported to have approximately three times the risk of myofascial pain than males in a series of 83 patients.¹³ An investigation of 71 patients found that chewing significantly increased pain in patients with a history of chronic masticator muscle pain, and also in females with no such history.¹⁴ According to our current results, females had a higher mean VAS pain score than males but there was no significant difference in pain score, between the two sexes.

Reissmann et al.¹⁵ reported no relationship between VAS scores and TMDS subgroups. In contrast, the mean VAS pain score in G4 was significantly higher than in the other three subgroups in our current study.

Bruxism has been reported to cause hypermobility of the mandibular muscles, leading to TMDS.¹⁶ The association between bruxism and muscle pain can be ascribed to either muscle fibre damage¹⁷ or a reduction in the blood supply.¹⁸ Indeed, it has been shown that perfusion of the masseter muscle is substantially impaired in individuals performing voluntary isometric contractions.¹⁹ In our current study, 172 (67.5%) patients had bruxism. While a significantly higher rate of bruxism was observed in females, a significantly higher rate of extra-articular disorders was observed in males.

In conclusion, in the present study, a higher rate of TMDS was found in females than in males. There was no relationship between pain and sex; however, the pain score was significantly higher in patients in the degenerative disorders subgroup compared with the other three subgroups. In addition, there was a significantly higher rate of bruxism in females than in males, and a significantly higher rate of extra-articular disorders in males than in females.

Footnotes

Declaration of conflicting interest

The authors declare that there are no conflicts of interest.

Funding

This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.

References

McNeill

. Management of temporomandibular disorders: concepts and controversies. J Prosthet Dent 1997; 77: 510–522.

Cooper

Kleinberg

. Examination of a large patient population for the presence of symptoms and signs of temporomandibular disorders. Cranio 2007; 25: 114–126.

Jensen

. Pathophysiological mechanisms of tension-type headache: a review of epidemiological and experimental studies. Cephalalgia 1999; 19: 602–621.

Okeson

. Management of temporomandibular disorders and occlusion, 6th ed. St. Louis: Mosby-Year Book, 2008, pp. 130–163.

Poveda Roda

Bagan

Díaz Fernández

. Review of temporomandibular joint pathology. Part I: classification, epidemiology and risk factors. Med Oral Patol Oral Cir Bucal 2007; 12: E292–E298.

Manfredini

Chiappe

Bosco

. Research diagnostic criteria for temporomandibular disorders (RDC/TMD) axis I diagnoses in an Italian patient population. J Oral Rehabil 2006; 33: 551–558.

Fillingim

Maixner

Kincaid

. Pain sensitivity with temporomandibular disorders: relationship to clinical and psychosocial factors. Clin J Pain 1996; 12: 260–269.

Ozan

Polat

Kara

. Prevalence study of signs and symptoms of temporomandibular disorders in a Turkish population. J Contemp Dent Pract 2007; 8: 35–42.

Mohlin

Axelsson

Paulin

. TMD in relation to malocclusion and orthodontic treatment. Angle Orthod 2007; 77: 542–548.

10.

Phillips

Gatchel

Wesley

. Clinical implications of sex in acute temporomandibular disorders. J Am Dent Assoc 2001; 132: 49–57.

11.

Manfredini

Marini

Pavan

. Psychosocial profiles of painful TMD patients. J Oral Rehabil 2009; 36: 193–198.

12.

Dao

LeResche

. Gender differences in pain. J Orofac Pain 2000; 14: 169–184.

13.

Velly

Gornitsky

Philippe

. Contributing factors to chronic myofascial pain: a case–control study. Pain 2003; 104: 491–499.

14.

Karibe

Goddard

Gear

. Sex differences in masticatory muscle pain after chewing. J Dent Res 2003; 82: 112–116.

15.

Reissmann

John

Wassell

. Psychosocial profiles of diagnostic subgroups of temporomandibular disorder patients. Eur J Oral Sci 2008; 116: 237–244.

16.

Peterson

Dixon

Talcott

. Habit reversal treatment of temporomandibular disorders: a pilot investigation. J Behav Ther Exp Pyschiatry 1993; 24: 49–55.

17.

Larsson

Bengtsson

Bodegård

. Muscle changes in work-related chronic myalgia. Acta Orthop Scand 1988; 59: 552–556.

18.

Larsson

Björk

Kadi

. Blood supply and oxidative metabolism in muscle biopsies of female cleaners with and without myalgia. Clin J Pain 2004; 20: 440–446.

19.

Nakamura

Torisu

Noguchi

. Changes in masseter muscle blood flow during voluntary isometric contraction in humans. J Oral Rehabil 2005; 32: 545–551.

Temporomandibular dysfunction syndrome: A prospective study of 255 consecutive patients

Abstract

Objective

Methods

Results

Conclusions

Keywords

Introduction

Patients and methods

Patient population

Pain assessment

Statistical analyses

Results

Discussion

Footnotes

Declaration of conflicting interest

Funding

References