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Middle East Current Psychiatry
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Alexithymia, oral behaviors, and temporomandibular disorders: a dark triad?

Middle East Current Psychiatry volume 30, Article number: 111 (2023) Cite this article

Abstract

Background

Alexithymia is a condition in which cognitive processing of emotions is impaired. Associations between alexithymia and temporomandibular disorders (TMD) have been described in multiple studies, yet the coexistence or influence of oral behaviors has never been addressed. This study aimed to clarify the relationship between alexithymia, oral behaviors, and temporomandibular pain disorders.

Results

A total of 264 participants were included in this study. The mean age was 25.70 ± 5.99 years, with a range from 18 to 65 years. Eighty-two (31.1%) were possibly alexithymic, and 93 (35.2%) were alexithymic. A total of 12.5% of the participants were at high risk for TMD. With respect to oral behavior risk, 62.5% were at low risk, and 35.2% were at high risk. Alexithymia appeared to be a positive predictor of TMD risk (p < 0.001). Participants with high-risk oral behaviors were found to have an increased likelihood of TMD risk (p < 0.001). Moreover, both high-risk oral behavior and alexithymia correlated with increased somatic symptom burden levels (p < 0.001). Pain disorders exert significant distress on individuals and lead to poorer quality of life.

Conclusion

Understanding the association of alexithymia, somatic symptom burden, and coping strategies with oral behaviors and temporomandibular pain disorders can help improve the management of this condition. By tailoring the chosen therapy to the dominant co-existing psychosocial comorbidities in TMD patients, the risk of treatment failure or relapse may be diminished.

Background

Alexithymia, a complex condition wherein individuals struggle to articulate their emotions, is primarily characterized by a disruption in the cognitive processing of emotions [1]. This distinctive personality construct denotes a profound deficit or incapacity to identify, differentiate, or express emotions, often confounding emotional states with physical ones [2]. Current estimates suggest that alexithymia affects approximately 10% of the general population [3]. A substantial body of research links alexithymia to a range of physical symptoms, psychosomatic illnesses, and mental disorders. Intriguingly, a growing number of studies have identified a noteworthy association between specific pain disorders, such as migraines and temporomandibular disorders (TMD) and the hallmark features of alexithymia [4].

TMD holds the distinction of being the second most common cause of orofacial musculoskeletal pain, trailing only chronic low back pain [5]. It encompasses a varied collection of neuromuscular and musculoskeletal disorders, impacting the hard and soft tissues of the temporomandibular joint, as well as its surrounding muscular and skeletal structures [6]. Traditionally, dental occlusion was presumed to be a primary factor linked to TMD. However, most experts now lean toward a multifactorial approach, acknowledging that a combination of biological, behavioral, and cognitive factors contributes to the manifestation of TMD symptoms. This paradigm shift underscores the importance of the biopsychosocial model in understanding TMD, mirroring the approach taken for other chronic pain disorders [7,8,9]. Contributing factors to TMD symptoms include diverse aspects like joint trauma—which may be precipitated by injuries to the jaw or joint overload due to oral behaviors—and altered pain perception possibly associated with central sensitization in TMD patients, leading to heightened neural signaling in the central nervous system in response to normal or subthreshold stimuli [10, 11]. Particularly noteworthy are the reports that identify a correlation between oral behaviors and TMD. These behaviors, which are habits performed outside the normal functions of the mouth like mastication, phonation, breathing, and swallowing, have the potential to instigate or exacerbate TMD. Encompassing a range of both conscious actions (like gum chewing) and unconscious ones (such as teeth clenching), these behaviors may transpire during wakefulness or sleep [12]. Research has shown that oral behaviors are markedly more prevalent among TMD patients compared to those without the condition [13, 14]. Certain theorists propose a causative correlation between TMD and these habits, positing that pain or even TMD may be a downstream consequence of such behaviors on masticatory structures. This could ultimately precipitate dysfunction in the stomatognathic system and disorders of peripheral nociception [15, 16]. The roots of these oral behaviors are multifaceted as per the literature and can be shaped by a myriad of factors, such as emotional and psychological disturbances or disorders within an individual [17, 18].

Various studies have described a positive association between alexithymia and TMD in community-based and clinical settings. The largest Northern Finland Birth Cohort study found higher alexithymia rates among patients with painful TMD than asymptomatic ones [4]. Also, Meldolesi et al. showed that little awareness of inner states and emotions is present among people with TMD [19]. In fact, it was shown that stressful experiences exert a strong effect on patients with TMD, specifically with respect to the severity and intensity of oral behavior [20]. It is unclear how these two conditions interact until now, and the underlying mechanism has not been investigated, yet it is hypothesized that alexithymia may contribute to both functional symptoms and an increase in oral behaviors [21].

Nevertheless, the bulk of the literature on alexithymia and TMD has only examined the relationship between alexithymia and pain in TMD patients, without considering the presence of oral behaviors, somatic symptom burden levels, or coping strategies in the target population. Moreover, there is still a paucity of alexithymia as well as TMD research in Lebanon. Thus, in this study, we aimed to investigate the association between alexithymia, oral behaviors, and the risk of TMD among a sample from the general population in Lebanon.

Materials and methods

Study design and population

This study was a community-based cross-sectional survey targeting the general population in Lebanon between January and May 2022. The study included Lebanese adults aged 18 and above from all governorates of Lebanon. The exclusion criteria included no knowledge of English language and digital illiteracy. For recruitment, the questionnaire was set up online on LimeSurvey (LimeSurvey GmbH, Hamburg, Germany), and an invitation was disseminated via social media with a convenience snowball sampling. Electronic consent was obtained from all participants. The Ethical Committee of the Neuroscience Research Center approved the conduct of this study.

Minimal sample size calculation

According to Cochran’s formula, with a prevalence of 20.8% of alexithymia in Lebanon [22] and a 95% confidence level, the minimal sample size needed was 253.

Questionnaire

The questionnaire consisted of 65 closed-ended questions, in English language, divided into six sections:

  1. a.

    Sociodemographic characteristics that included age, gender, residence location, marital status, educational level, and monthly income

  2. b.

    Toronto Alexithymia Scale-20 (TAS-20)

    • The most widely used, self-reported measure of alexithymia is the Toronto Alexithymia Scale-20 (TAS-20), published by Bagby and colleagues in 1994 [23]. TAS-20 is a 20-item scale that captures three-factor elements of “difficulties describing feelings (DDF),” “difficulties identifying feelings (DIF),” and “externally oriented thinking (OET).” The TAS-20 is scored in a 5-point Likert manner with a score ranging from 0 to 100. A score of ≤ 51 = no alexithymia, 52–60 = possible alexithymia, and ≥ 61 = alexithymia. For those with a positive result, greater scores reveal greater levels of alexithymia [23].

  3. c.

    Somatic Symptom Scale-8 (SSS-8)

    • The Somatic Symptom Scale-8 (SSS-8) was derived from the Patient Health Questionnaire-15 (PHQ-15) and developed as a brief 8-item version and self-reported measure of somatic symptom burden [24]. It was first established as a reference measure for the Diagnostic and Statistical Manual of Mental Disorders-Fifth Edition (DSM-5) to investigate the newly added somatic symptom disorder [25]. Answers were graded on a 5-point response option (0–4), with higher scores indicating higher somatic symptom burden [26].

  4. d.

    Brief Resilient Coping Scale

    • The Brief Resilient Coping Scale (BRCS) is a reliable and validated 4-item measure that describes the individual’s abilities to cope with stress in an adaptive manner. It is a self-reported scale that has positive correlations with psychological well-being and pain-coping behaviors. It is based on a 5-point scale (1–5), with a higher score revealing higher resilient coping [27].

  5. e.

    Oral Behavior Checklist-21 (OBC-21)

    • The Oral Behavior Checklist-21 (OBC-21) instrument was initially developed by Ohrbach and the RDC/TMD Validation Project group [28] and later expanded. It is a self-report scale that consists of a 21-question checklist on oral behaviors divided into two parts: (1) oral behaviors during sleep (2 questions) and (2) oral behaviors during waking hours (19 questions). It identifies and quantifies the frequency of oral behaviors activity in an individual over a period of 1 month. Each question is scored on a 5-Likert-type scale as 0 (none of the time) to 4 (all of the time) with a total score ranging between 0 and 84. The scores are interpreted as follows: no risk grade (0), moderate risk grade (1–24), and high-risk grade (> 25).

  6. f.

    TMD-Pain Screener (full version)

    • It is a practical, brief self-report instrument that screens for temporomandibular disorder pain [29]. The full version has six items, with the first scored as 0–2 (a = 0, b = 1, or c = 2), while the rest as 0–1 (a = 0 or b = 1). A threshold value of above 3 indicates that TMD may be present. Although it depicts pain-related TMD, it was shown to be accurate in detecting non-painful TMD as well [29,30,31].

Statistical analyses

Data entry and statistical analyses were conducted using IBM SPSS Statistics for Windows, version 25 (IBM Corp., Armonk, NY, USA). Descriptive statistics were expressed as mean ± standard deviation for continuous variables and as frequencies and percentages for categorical variables. The normality of the distribution was assessed using graphical plots. The chi-square test was used to evaluate differences within each variable and to test for associations between categorical variables. Depending on the nature of the data, suitable parametric or nonparametric tests were employed to evaluate associations and test hypotheses. Regression models were used to assess predictors of TMD risk and examine the relationships between alexithymia, somatic symptom burden, coping strategies, and oral behaviors. The level of significance was set at α = 0.05.

Results

Overall participant characteristics

During the study period, a total of 264 participants who met the eligibility criteria completed the survey. The mean age was 25.70 ± 5.99 years, with ages ranging from 18 to 65 years. Among the participants, 61.7% were female, and the majority resided in the Beirut and Mount Lebanon governorates, at 38.3% and 36.7%, respectively. The participants’ sociodemographic characteristics are summarized in Table 1.

Table 1 Baseline sociodemographic characteristics of the sample
Full size table

Physical and psychological symptoms

Table 2 presents the prevalence of alexithymia, somatic symptom burden, brief resilience coping abilities, TMD risk, and oral behavior among the sample population. According to the clinical cutoffs of the TAS-20, 89 (33.7%) suggested alexithymia, 82 (31.1%) were possible alexithymic, and 93 (35.2) were alexithymic. Concerning the somatic symptom burden among the sample population, 25.0% were at very high risk. Along similar lines, the majority of the participants (48.9%) had low brief resilience coping abilities. A total of 12.5% of the participants had high TMD risk. With respect to oral behavior risk, 1.9% had no-risk grade, 62.7% had low-risk grade, and 35.4% had high-risk grade.

Table 2 The prevalence of alexithymia, somatic symptom burden, brief resilience coping abilities, TMD risk, and oral behavior among the sample population as per the TAS-20, SSS-7, BRCS, TMD-pain screener, and OBC-21
Full size table

Significant correlation was observed between alexithymia and TMD-risk scores yet with a weak positive correlation. OBC score was significantly associated with TMD-risk score, with a good positive correlation (Table 3).

Table 3 The Pearson correlation coefficients between alexithymia, OBC, and TMD-risk scores
Full size table

Results of the multivariable logistic and linear regressions are presented in Tables 4, 5 and 6 for alexithymia, OBC, and TMD, respectively. Interestingly, any somatic symptom burden level above a low category significantly affected alexithymia score; in fact, increasing estimate (B) was observed with the increased level of somatic symptom burden, which means the higher the somatic symptom burden level (per the SSS scale), the higher the alexithymia score. Moreover, coping scale significantly correlated with alexithymia score. Medium and high coping categories were significant predictors of decreased alexithymia score, as compared with low coping scale category. Neither age, sex, nor the interaction between them seemed to influence alexithymia score. As seen in model 2 (Table 4), participants with an income lower than 10,000,000 L.L were associated with increased alexithymia scores as compared with the unemployed. Therefore, an increase in the income was negative predictor of alexithymia score.

Table 4 Predictors of alexithymia
Full size table
Table 5 Binary logistic regression model for OBC category
Full size table
Table 6 Results of multivariable linear regression for TMD-risk score and logistic regression for TMD-risk category
Full size table

Table 5 suggests that increased categories of somatic symptom burden have increasing likelihood of high-risk oral behaviors grade. For instance, those with moderate somatic symptom burden (moderate SSS category) were 5.5 times more likely to suffer from high-risk OBC grade than those with minimal somatic symptom burden; the odds ratio increased with high and very high levels of somatic symptom burden. Only high risk of oral behaviors was predictive of TMD risk. Others did not appear to directly associate with TMD-risk category. Nevertheless, when analyzed on the continuous score, alexithymia was a significant positive predictor of TMD risk (model 2 of Table 6). Also, female sex was significantly associated with increased TMD-risk score than the male sex.

Discussion

To the best of our knowledge, this is the first study in Lebanon that aimed to assess the possible relationship between alexithymia, oral behaviors, and TMD.

Prevalence of symptoms

Our study showed that the prevalence of alexithymia among our general population is 35.2%. Our result was high compared to other countries such as Germany and Japan and a Lebanese study on alexithymia done in 2019 [32,33,34]. The higher alexithymia levels compared to those studies could be explained by differences in the age groups of the participants and general stressors during the recruitment timeframe. Although the age of our sample population ranged between 18 and 63 years, the majority were in their 20s which could lead to higher alexithymia scores. Also, since 2019, Lebanon has been crippled by a triad of the COVID-19 pandemic, the Beirut explosion, and a dreadful economic crisis [35]. Such ongoing conflicts and instabilities could have contributed to the higher prevalence observed [36,37,38]. The prevalence of TMD risk in our population was 33%. This finding is consistent with a recent systematic review and meta-analysis reporting the prevalence of TMD among the generation population for adults/elderly to be approximately 31% [39]. It is noteworthy to mention that the lack of underestimation or overestimation of the presence of TMD in our sample may be attributed to the use of the TMD-Pain Screener Questionnaire, which has been shown to investigate the presence of both painful and non-painful TMD. Further, the prevalence of oral behaviors was not low (35.2%). Although studies on the prevalence of oral behaviors or parafunctions in the general population are lacking, the prevalence in the current report corroborated that of prior studies on oral behaviors that ranged between 21 and 27% in specific populations [40,41,42].

Association of physical and psychological symptoms

With the growing substantial body of research throughout the years, the definition of TMD has undergone a paradigm shift from an isolated localized orofacial pain to a complex condition best viewed within a biopsychosocial model of illness. In this investigation, alexithymia seemed to be a positive predictor of TMD risk. The role of alexithymia in the etiology of TMD remains unclear. The effect of alexithymia in TMD patients may result in an intricate and multifactorial biological response that can cause modifications in the neuroendocrine function along with psychosocial and physical adjustments [9]. Literature data demonstrate that individuals with alexithymia have increased neural response in the limbic and paralimbic systems to stimuli within a physical context [43]. In line with these results, Younger et al. and his colleagues found that patients with TMD exhibit an increase in gray matter volume in limbic regions that may reflect deficits in central emotional processing [44]. One can postulate that alexithymia reduces the individual’s ability to describe and label emotions which causes misperceptions and response bias of undifferentiated physiological facets of emotions and, therefore, may account for higher levels of dysfunction and pain [45, 46]. As such, alexithymia may be a risk factor for the subsequent pain or dysfunction in patients with TMD. In fact, multiple clinical trials have demonstrated that selecting behavioral therapies based on the psychosocial profile of patients with TMD is effective [47, 48]. Thus, the management of TMD could be optimized by adding tailored behavioral therapies based on the predominant psychosocial traits of the patients in conjunction with the usual treatment.

There has been controversy about whether oral behaviors are considered a possible cause of TMD. It could be attributed to the lack of consensus regarding the definition of oral behaviors. In our study, participants with high-risk oral behaviors were found to have an increased likelihood of TMD risk. This comes in concordance with recent studies that supported the latter association [49, 50]. The major proposed mechanisms by which oral behaviors serve as an etiological role in the development of TMD involve exerting increased muscular tension in the masticatory system or excessive load affecting the temporomandibular joints [10].

In agreement with previous reports, our study showed that higher TMD-risk score was found to be gender related and more frequent in females [51,52,53,54]. The explanation behind the differences between genders has not been clearly established; however, hormonal, cultural, and psychosocial factors certainly play a vital role [55, 56]. In addition, disparities in stress levels, sensitivity to pain, and treatment-seeking behaviors seem to corroborate the gender variance [53]. Indeed, women appear to be more vulnerable to stress and display a greater pain sensitivity in comparison to men [57, 58].

In this study, high-risk oral behavior grade correlated with increased somatic symptom burden levels. This highlights the complex interrelationship between oral behaviors and the psychological state of the patient. The majority of the previous studies on oral behaviors focused primarily on its association with depression [4, 59,60,61] rather than somatic symptom burden. For instance, S. J. Park et al. showed that oral health behaviors and depression are associated to some extent in women mainly [60]. Similarly, a birth cohort in Northern Finland indicated that less favorable oral health behaviors were more present in participants with a higher number of depression symptoms [4]. Thus, further investigation on the interaction of somatic symptom burden in oral behaviors is warranted. Identifying factors that contribute to the initiation, maintenance, or even exacerbation of oral behaviors can help enhance the therapeutic alliance with patients.

In this present study, alexithymia was associated with higher levels of somatic symptoms. Patients with alexithymia are characterized by having difficulties identifying and communicating one’s emotions. As such, in the circumstances with underlying psychological stress, they are more likely to focus on physical rather than affective sensations of emotions. Therefore, such patients tend to express and manifest psychosocial stress through an alternate psychological dimension [62]. In a similar context, multiple studies revealed a close association between alexithymia and somatic burden [63, 64]. The latter demonstrated that patients with alexithymia exhibit somatosensory amplification. Consequently, they tend to perceive normal and visceral sensations as unusually intense, noxious, and disturbing, along with hypervigilance to bodily sensations [63, 64]. Moreover, alexithymia has also been linked to maladaptive coping mechanisms and behaviors that include overreporting of physical symptoms and overusing medical resources [64, 65]. This is in line with our hypothesis that people with higher coping skills are less likely to be affected by alexithymia.

Regarding sociodemographic characteristics and their relation to alexithymia, participants with a lower income showed a higher alexithymia score. This highlights that the financial state has a major effect on the emotional state of participants. Several studies have pointed out similar results associating low socioeconomic status with alexithymia [66, 67]. It is hypothesized that poor socio-relational skills and interaction in people with alexithymia may lead to lesser success in an individual’s social and professional life.

This study has a number of limitations. The use of a cross-sectional design did not allow us to establish causal relationships between psychological disturbances and physical symptoms. However, the findings of our study highlighted the need for additional longitudinal studies to evaluate a causal association. The study may also be subjected to recall and outcome biases as it used self-reported questionnaires that might have led to underreporting or amplifying symptom severity.

Conclusion

Notably, alexithymia, oral behaviors, and TMD are prevalent among the Lebanese adult population. Our study found that while alexithymia was linked to a higher risk of TMD, the association with somatic symptom burden was only evident in relation to oral behaviors. The established relationship between TMD and oral behaviors, as well as emotional traits, highlights the importance of healthcare providers assessing the psychological status of patients with TMD before choosing a treatment plan. By considering the dominant psychosocial comorbidities of patients with TMD when selecting therapy, the risk of treatment failure or relapse may be reduced.

Availability of data and materials

The data that support the findings of this study are available from the corresponding author upon reasonable request.

Abbreviations

BRCS:

Brief Resilient Coping Scale

DDF:

Difficulty describing feelings

DIF:

Difficulty identifying feelings

EOT:

Externally oriented thinking

OBC-21:

Oral Behavior Checklist-21

SSS-8:

Somatic Symptom Scale-8

TAS-20:

Toronto Alexithymia Scale-20

TMDs:

Temporomandibular disorders

TMJ:

Temporomandibular joint

References

  1. Grabe HJ, Frommer J, Ankerhold A et al (2008) Alexithymia and outcome in psychotherapy. Psychother Psychosom 77:189–194. https://doi.org/10.1159/000119739

    Article  PubMed  Google Scholar 

  2. Larsen JK, Brand N, Bermond B, Hijman R (2003) Cognitive and emotional characteristics of alexithymia. J Psychosom Res 54:533–541. https://doi.org/10.1016/S0022-3999(02)00466-X

    Article  PubMed  Google Scholar 

  3. Honkalampi K, Koivumaa-Honkanen H, Tanskanen A et al (2001) Why do alexithymic features appear to be stable? Psychother Psychosom 70:247–253. https://doi.org/10.1159/000056262

    Article  CAS  PubMed  Google Scholar 

  4. Sipilä K, Veijola J, Jokelainen J et al (2001) Association of symptoms of TMD and orofacial pain with alexithymia: an epidemiological study of the Northern Finland 1966 Birth Cohort. Cranio J Craniomandib Pract 19:246–251. https://doi.org/10.1080/08869634.2001.11746175

    Article  Google Scholar 

  5. National Institute of Dental and Craniofacial Research (2018) Prevalence of TMJD and its signs and symptoms. https://www.nidcr.nih.gov/research/data-statistics/facial-pain/prevalence. Accessed 11 Nov 2021

  6. Schiffman E, Ohrbach R, Truelove E, et al (2014) Diagnostic criteria for temporomandibular disorders (DC/TMD) for clinical and research applications: recommendations of the International RDC/TMD Consortium Network* and Orofacial Pain Special Interest Group†. J Oral Facial Pain Headache 28:6–27. https://doi.org/10.11607/jop.1151

  7. De Rossi SS, Greenberg MS, Liu F, Steinkeler A (2014) Temporomandibular disorders: evaluation and management. Med Clin North Am 98:1353–1384. https://doi.org/10.1016/j.mcna.2014.08.009

    Article  PubMed  Google Scholar 

  8. Kothari SF, Baad-Hansen L, Svensson P Psychosocial profiles of temporomandibular disorder pain patients: proposal of a new approach to present complex data. J Oral Facial Pain Headache 31:199–209. https://doi.org/10.11607/ofph.1666

  9. Slade GD, Ohrbach R, Greenspan JD et al (2016) Painful temporomandibular disorder: decade of discovery from OPPERA studies. J Dent Res 95:1084–1092. https://doi.org/10.1177/0022034516653743

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  10. Chisnoiu AM, Picos AM, Popa S, et al (2015) Factors involved in the etiology of temporomandibular disorders - a literature review. Clujul Med 1957 88:473–8. https://doi.org/10.15386/cjmed-485

  11. Li DTS, Leung YY (2021) Temporomandibular disorders: current concepts and controversies in diagnosis and management. Diagn Basel Switz 11:. https://doi.org/10.3390/diagnostics11030459

  12. van der Meulen MJ, Lobbezoo F, Aartman IHA, Naeije M (2006) Self-reported oral parafunctions and pain intensity in temporomandibular disorder patients. J Orofac Pain 20:31–35

    PubMed  Google Scholar 

  13. Michelotti A, Cioffi I, Festa P et al (2010) Oral parafunctions as risk factors for diagnostic TMD subgroups. J Oral Rehabil 37:157–162. https://doi.org/10.1111/j.1365-2842.2009.02033.x

    Article  CAS  PubMed  Google Scholar 

  14. Ohrbach R, Bair E, Fillingim RB et al (2013) Clinical orofacial characteristics associated with risk of first-onset TMD: the OPPERA prospective cohort study. J Pain 14:T33-50. https://doi.org/10.1016/j.jpain.2013.07.018

    Article  PubMed  Google Scholar 

  15. Celić R, Jerolimov V, Pandurić J (2002) A study of the influence of occlusal factors and parafunctional habits on the prevalence of signs and symptoms of TMD. Int J Prosthodont 15:43–48

    PubMed  Google Scholar 

  16. Winocur E, Littner D, Adams I, Gavish A (2006) Oral habits and their association with signs and symptoms of temporomandibular disorders in adolescents: a gender comparison. Oral Surg Oral Med Oral Pathol Oral Radiol Endodontology 102:482–487. https://doi.org/10.1016/j.tripleo.2005.11.007

    Article  Google Scholar 

  17. Almutairi AF, Albesher N, Aljohani M et al (2021) Association of oral parafunctional habits with anxiety and the Big-Five personality traits in the Saudi adult population. Saudi Dent J 33:90–98. https://doi.org/10.1016/j.sdentj.2020.01.003

    Article  PubMed  Google Scholar 

  18. B Murad, NG Sepah, B Rehman, T Ahmad (2016) Parafunctional habits among undergraduate clinical students and house officers at Khyber College of Dentistry. J Khyber Coll Dent

  19. Meldolesi GN, Picardi A, Accivile E et al (2000) Personality and psychopathology in patients with temporomandibular joint pain-dysfunction syndrome. Psychother Psychosom 69:322–328. https://doi.org/10.1159/000012415

    Article  CAS  PubMed  Google Scholar 

  20. Schwartz SM, Gramling SE, Grayson R (2001) Stress induced oral behaviors and facial pain. Int J Stress Manag 8:35–47. https://doi.org/10.1023/A:1009501429467

    Article  Google Scholar 

  21. Talay Çevlik E, Alkan Demetoğlu G, Çevik Akyıl R, Akyıl MŞ (2020) Investigation of alexithymia, anxiety and loneliness state in bruxism patients. Meandros Med Dent J 21:182–188. https://doi.org/10.4274/meandros.galenos.2020.85547

    Article  Google Scholar 

  22. Obeid S, Akel M, Haddad C et al (2019) Factors associated with alexithymia among the Lebanese population: results of a cross-sectional study. BMC Psychol 7:80. https://doi.org/10.1186/s40359-019-0353-5

    Article  PubMed  PubMed Central  Google Scholar 

  23. Bagby RM, Parker JDA, Taylor GJ (1994) The twenty-item Toronto Alexithymia Scale—I. Item selection and cross-validation of the factor structure. J Psychosom Res 38:23–32. https://doi.org/10.1016/0022-3999(94)90005-1

    Article  CAS  PubMed  Google Scholar 

  24. Kroenke K, Spitzer RL, Williams JBW (2002) The PHQ-15: validity of a new measure for evaluating the severity of somatic symptoms. Psychosom Med 64:258–266. https://doi.org/10.1097/00006842-200203000-00008

    Article  PubMed  Google Scholar 

  25. Narrow WE, Clarke DE, Kuramoto SJ et al (2013) DSM-5 field trials in the United States and Canada, part III: development and reliability testing of a cross-cutting symptom assessment for DSM-5. Am J Psychiatry 170:71–82. https://doi.org/10.1176/appi.ajp.2012.12071000

    Article  PubMed  Google Scholar 

  26. Gierk B, Kohlmann S, Kroenke K et al (2014) The Somatic Symptom Scale–8 (SSS-8). JAMA Intern Med 174:399. https://doi.org/10.1001/jamainternmed.2013.12179

    Article  PubMed  Google Scholar 

  27. Sinclair VG, Wallston KA (2004) The development and psychometric evaluation of the Brief Resilient Coping Scale. Assessment 11:94–101. https://doi.org/10.1177/1073191103258144

    Article  PubMed  Google Scholar 

  28. Markiewicz MR, Ohrbach R, McCall WD (2006) Oral behaviors checklist: reliability of performance in targeted waking-state behaviors. J Orofac Pain 20:306–316

    PubMed  Google Scholar 

  29. Gonzalez YM, Schiffman E, Gordon SM, et al (2011) Development of a brief and effective temporomandibular disorder pain screening questionnaire: reliability and validity. J Am Dent Assoc 1939 142:1183–91. https://doi.org/10.14219/jada.archive.2011.0088

  30. Meer HA van der, Bakke M, Schytz HW, Madsen BK (2021) Validation of the temporomandibular disorder pain screener in a specialized headache center. J Oral Facial Pain Headache 35:150–156. https://doi.org/10.11607/ofph.2787

  31. Schiffman E, Ohrbach R, Truelove E et al (2014) Diagnostic criteria for temporomandibular disorders (DC/TMD) for clinical and research applications: recommendations of the International RDC/TMD Consortium Network and Orofacial Pain Special Interest Group. J Oral Facial Pain Headache 28:6–27

    Article  PubMed  Google Scholar 

  32. Franz M, Popp K, Schaefer R et al (2008) Alexithymia in the German general population. Soc Psychiatry Psychiatr Epidemiol 43:54–62. https://doi.org/10.1007/s00127-007-0265-1

    Article  PubMed  Google Scholar 

  33. Shibata M, Ninomiya T, Jensen MP et al (2014) Alexithymia is associated with greater risk of chronic pain and negative affect and with lower life satisfaction in a general population: the Hisayama Study. PLoS ONE 9:e90984. https://doi.org/10.1371/journal.pone.0090984

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  34. Obeid S, Akel M, Haddad C, et al (2019) Factors associated with alexithymia among the Lebanese population: results of a cross-sectional study. BMC Psychol 7:. https://doi.org/10.1186/s40359-019-0353-5

  35. Farran N (2021) Mental health in Lebanon: tomorrow’s silent epidemic. Ment Health Prev 24:200218. https://doi.org/10.1016/j.mhp.2021.200218

    Article  PubMed  PubMed Central  Google Scholar 

  36. Engelmann P, Löwe B, Brehm TT et al (2022) Risk factors for worsening of somatic symptom burden in a prospective cohort during the COVID-19 pandemic. Front Psychol 13:1022203. https://doi.org/10.3389/fpsyg.2022.1022203

    Article  PubMed  PubMed Central  Google Scholar 

  37. Osimo SA, Aiello M, Gentili C, et al (2021) The influence of personality, resilience, and alexithymia on mental health during COVID-19 pandemic. Front Psychol 12:

  38. Craparo G, La Rosa VL, Commodari E et al (2022) What is the role of psychological factors in long COVID syndrome? Latent class analysis in a sample of patients recovered from COVID-19. Int J Environ Res Public Health 20:494. https://doi.org/10.3390/ijerph20010494

    Article  PubMed  PubMed Central  Google Scholar 

  39. Valesan LF, Da-Cas CD, Réus JC et al (2021) Prevalence of temporomandibular joint disorders: a systematic review and meta-analysis. Clin Oral Investig 25:441–453. https://doi.org/10.1007/s00784-020-03710-w

    Article  PubMed  Google Scholar 

  40. Perrotta S, Bucci R, Simeon V et al (2019) Prevalence of malocclusion, oral parafunctions and temporomandibular disorder-pain in Italian schoolchildren: an epidemiological study. J Oral Rehabil 46:611–616. https://doi.org/10.1111/joor.12794

    Article  PubMed  Google Scholar 

  41. Chatzopoulos GS, Sanchez M, Cisneros A, Wolff LF (2019) Prevalence of temporomandibular symptoms and parafunctional habits in a university dental clinic and association with gender, age, and missing teeth. Cranio J Craniomandib Pract 37:159–167. https://doi.org/10.1080/08869634.2017.1399649

    Article  Google Scholar 

  42. Reda B, Lobbezoo F, Contardo L et al (2023) Prevalence of oral behaviours in general dental patients attending a university clinic in Italy. J Oral Rehabil 50:370–375. https://doi.org/10.1111/joor.13427

    Article  PubMed  Google Scholar 

  43. Moriguchi Y, Komaki G (2013) Neuroimaging studies of alexithymia: physical, affective, and social perspectives. Biopsychosoc Med 7:8. https://doi.org/10.1186/1751-0759-7-8

    Article  PubMed  PubMed Central  Google Scholar 

  44. Younger JW, Shen YF, Goddard G, Mackey SC (2010) Chronic myofascial temporomandibular pain is associated with neural abnormalities in the trigeminal and limbic systems. Pain 149:222–228. https://doi.org/10.1016/j.pain.2010.01.006

    Article  PubMed  PubMed Central  Google Scholar 

  45. Kano M, Hamaguchi T, Itoh M et al (2007) Correlation between alexithymia and hypersensitivity to visceral stimulation in human. Pain 132:252–263. https://doi.org/10.1016/j.pain.2007.01.032

    Article  PubMed  Google Scholar 

  46. Nyklíček I, Vingerhoets AJJM (2000) Alexithymia is associated with low tolerance to experimental painful stimulation. Pain 85:471–475. https://doi.org/10.1016/S0304-3959(99)00295-X

    Article  PubMed  Google Scholar 

  47. Dworkin SF, Huggins KH, Wilson L et al (2002) A randomized clinical trial using research diagnostic criteria for temporomandibular disorders-axis II to target clinic cases for a tailored self-care TMD treatment program. J Orofac Pain 16:48–63

    PubMed  Google Scholar 

  48. Dworkin SF, Turner JA, Mancl L et al (2002) A randomized clinical trial of a tailored comprehensive care treatment program for temporomandibular disorders. J Orofac Pain 16:259–276

    PubMed  Google Scholar 

  49. Ohrbach R, Fillingim RB, Mulkey F et al (2011) Clinical findings and pain symptoms as potential risk factors for chronic TMD: descriptive data and empirically identified domains from the OPPERA case-control study. J Pain 12:T27-45. https://doi.org/10.1016/j.jpain.2011.09.001

    Article  PubMed  PubMed Central  Google Scholar 

  50. Chow JC, Cioffi I (2019) Effects of trait anxiety, somatosensory amplification, and facial pain on self-reported oral behaviors. Clin Oral Investig 23:1653–1661. https://doi.org/10.1007/s00784-018-2600-1

    Article  PubMed  Google Scholar 

  51. Yap AU, Sultana R, Natu VP (2022) Stress and emotional distress: their associations with somatic and temporomandibular disorder-related symptoms. Psychol Health Med 27:876–887. https://doi.org/10.1080/13548506.2021.1908571

    Article  PubMed  Google Scholar 

  52. Cheng Q, Xu Y, Xie L, et al (2019) Prevalence and environmental impact factors of somatization tendencies in eastern Chinese adolescents: a multicenter observational study. Cad Saúde Pública 35:. https://doi.org/10.1590/0102-311X00008418

  53. Bueno CH, Pereira DD, Pattussi MP et al (2018) Gender differences in temporomandibular disorders in adult populational studies: a systematic review and meta-analysis. J Oral Rehabil 45:720–729. https://doi.org/10.1111/joor.12661

    Article  CAS  PubMed  Google Scholar 

  54. Grover S, Kumar V, Chakrabarti S et al (2012) Prevalence and type of functional somatic complaints in patients with first-episode depression. East Asian Arch Psychiatry 22:146–153

    CAS  PubMed  Google Scholar 

  55. Al-Harthy M, Ohrbach R, Michelotti A, List T (2016) The effect of culture on pain sensitivity. J Oral Rehabil 43:81–88. https://doi.org/10.1111/joor.12346

    Article  CAS  PubMed  Google Scholar 

  56. Vilanova LS, Gonçalves TM, Meirelles L, Garcia RC (2015) Hormonal fluctuations intensify temporomandibular disorder pain without impairing masticatory function. Int J Prosthodont 28:72–74. https://doi.org/10.11607/ijp.4040

  57. Pieretti S, Di Giannuario A, Di Giovannandrea R et al (2016) Gender differences in pain and its relief. Ann Ist Super Sanita 52:184–189. https://doi.org/10.4415/ANN_16_02_09

    Article  PubMed  Google Scholar 

  58. Verma R, Balhara YPS, Gupta CS (2011) Gender differences in stress response: role of developmental and biological determinants. Ind Psychiatry J 20:4–10. https://doi.org/10.4103/0972-6748.98407

    Article  PubMed  PubMed Central  Google Scholar 

  59. Okoro CA, Strine TW, Eke PI et al (2012) The association between depression and anxiety and use of oral health services and tooth loss. Community Dent Oral Epidemiol 40:134–144. https://doi.org/10.1111/j.1600-0528.2011.00637.x

    Article  PubMed  Google Scholar 

  60. Park SJ, Ko KD, Shin S-I et al (2014) Association of oral health behaviors and status with depression: results from the Korean National Health and Nutrition Examination Survey, 2010. J Public Health Dent 74:127–138. https://doi.org/10.1111/jphd.12036

    Article  PubMed  Google Scholar 

  61. Anttila SS, Knuuttila ML, Sakki TK (2001) Relationship of depressive symptoms to edentulousness, dental health, and dental health behavior. Acta Odontol Scand 59:406–412. https://doi.org/10.1080/000163501317153275

    Article  CAS  PubMed  Google Scholar 

  62. Komaki G (2013) Alexithymia and somatic symptoms. In: Koh KB (ed) Somatization and Psychosomatic Symptoms. Springer, New York, NY, pp 41–49

    Chapter  Google Scholar 

  63. Nakao M, Takeuchi T (2018) Alexithymia and somatosensory amplification link perceived psychosocial stress and somatic symptoms in outpatients with psychosomatic illness. J Clin Med 7:112. https://doi.org/10.3390/jcm7050112

    Article  PubMed  PubMed Central  Google Scholar 

  64. Tominaga T, Choi H, Nagoshi Y et al (2013) Relationship between alexithymia and coping strategies in patients with somatoform disorder. Neuropsychiatr Dis Treat 10:55–62. https://doi.org/10.2147/NDT.S55956

    Article  PubMed  PubMed Central  Google Scholar 

  65. Kooiman CG, Bolk JH, Brand R et al (2000) Is alexithymia a risk factor for unexplained physical symptoms in general medical outpatients? Psychosom Med 62:768–778. https://doi.org/10.1097/00006842-200011000-00005

    Article  CAS  PubMed  Google Scholar 

  66. Salminen JK, Saarijärvi S, Aärelä E et al (1999) Prevalence of alexithymia and its association with sociodemographic variables in the general population of Finland. J Psychosom Res 46:75–82. https://doi.org/10.1016/s0022-3999(98)00053-1

    Article  CAS  PubMed  Google Scholar 

  67. Kokkonen P, Karvonen JT, Veijola J et al (2001) Prevalence and sociodemographic correlates of alexithymia in a population sample of young adults. Compr Psychiatry 42:471–476. https://doi.org/10.1053/comp.2001.27892

    Article  CAS  PubMed  Google Scholar 

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Authors and Affiliations

  1. Faculty of Medical Sciences, Neuroscience Research Center, Lebanese University, Beirut, Lebanon

    Nour Ibrahim & Wafaa Takash Chamoun

  2. Private Practice of Dentistry, Observe Clinical Research Group, Beirut, Lebanon

    Abbass El-Outa

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  2. Wafaa Takash Chamoun
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  3. Abbass El-Outa
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NI made substantial contributions to the study conception and design. NI and AE completed data collection and analysis and wrote the first draft of the manuscript. All authors contributed to intellectual and critical review of the manuscript drafts. All authors read and approved the final manuscript.

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Ibrahim, N., Chamoun, W.T. & El-Outa, A. Alexithymia, oral behaviors, and temporomandibular disorders: a dark triad?. Middle East Curr Psychiatry 30, 111 (2023). https://doi.org/10.1186/s43045-023-00383-5

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