Abstract

The aim of this study was to evaluate the prevalence of temporomandibular disorders (TMD) signs and symptoms, its correlation with gender, parafunctional habits, emotional stress, anxiety, and depression and its impact on oral health-related quality of life (OHRQL) in college preparatory students at public and private institutions in João Pessoa, Paraíba (PB). The sample consisted of 303 students. Presence of TMD symptoms was determined by an anamnesis questionnaire containing questions related to the presence of parafunctional habits and emotional stress. A simplified clinical evaluation protocol was used. Anxiety and depression were determined with the Hospital Anxiety and Depression (HAD) scale and the OHRQL using the short version contained in the Oral Health Impact Profile (OHIP-14). The Chi-square, Fisher Exact, Mann Whitney, and Kruskal-Wallis tests were performed. Presence of signs and symptoms of TMD was statistically associated (p ≤ 0,05) with female gender, parafunctional habits, emotional stress, and anxiety, and represented greater impairment of the OHRQL. The physical pain domain was the most affected. The increased prevalence of signs and symptoms of TMD among college preparatory students indicates that there is a need for education and clarification among teachers and students to improve early diagnosis and to prevent the problem.

Key words
Temporomandibular joint disorders; Adolescence; Habits; Anxiety; Quality of life

Introduction

The American Academy of Orofacial Pain (AAOP) defines temporomandibular disorder (TMD) as a group of painful and/or dysfunctional conditions related to the muscles of mastication, temporomandibular joints (TMJs), and related structures¹1. De Leeuw R. Dor orofacial: guia de avaliação, diagnóstico e tratamento. 4ª ed. São Paulo: Quintessence; 2010..

The major signs and symptoms related to these disorders are pain in the TMJ region and palpation of the muscles of mastication, ear pain and other otologic signs, joint noise, mandibular misalignment, limited mouth opening, tiredness and muscular fatigue, headaches, and dental wear²2. Gavish A, Halachmi M, Winocur E, Gazit E. Oral habits and their association with signs and symptoms of temporomandibular disorders in adolescent girls. J Oral Rehabil 2000; 27(1):22-32.^–66. Hilgenberg PB, Saldanha AD, Cunha CO, Rubo JH, Conti PC. Temporomandibular disorders, otologic symptoms and depression levels in tinnitus patients. J Oral Rehabil 2012; 39(4):239-244..

TMD has a multifactorial etiology, including genetic and behavioral factors, direct and indirect trauma, psychological factors, and postural and parafunctional habits²2. Gavish A, Halachmi M, Winocur E, Gazit E. Oral habits and their association with signs and symptoms of temporomandibular disorders in adolescent girls. J Oral Rehabil 2000; 27(1):22-32.^,77. Thilander B, Rubio G, Pena L, Mayorga C. Prevalence of Temporomandibular Dysfunction and Its Association With Malocclusion in Children and Adolescents: An Epidemiologic Study Related to Specified Stages of Dental Development. Angle Orthod 2002; 72(2):146-154.^–99. Monteiro DR, Zuim PRJ, Pesqueira AA, Ribeiro PP, Garcia AR. Relationship between anxiety and chronic orofacial pain of Temporomandibular Disorder in a group of university students. J Prosthodont Res 2011; 55(3):154-158.. However, the effects of these etiological agents are controversial and remain not completely understood.

The biopsychosocial model has recently gained attention, promoting a wide discussion on the influence of emotional factors on the etiology of TMD⁸8. Gameiro GH1, Silva Andrade A, Nouer DF, Ferraz de Arruda Veiga MC. How may stressful experiences contribute to the development of temporomandibular disorders? Clin Oral Investig 2006; 10(4):261-268.^–1212. Fernandes G, Gonçalves DA, De Siqueira JT, Camparis CM. Painful temporomandibular disorders, self reported tinnitus, and depression are highly associated. Arq Neuropsiquiatr 2013; 71(12):943-947.. Thus, emotional distress, stress, anxiety, and depression have been linked to the presence of the signs and symptoms of this disorder in several populations⁹9. Monteiro DR, Zuim PRJ, Pesqueira AA, Ribeiro PP, Garcia AR. Relationship between anxiety and chronic orofacial pain of Temporomandibular Disorder in a group of university students. J Prosthodont Res 2011; 55(3):154-158.^,1111. Giannakopoulos NN, Keller L, Rammelsberg P, Kronmüller KT, Schmitter M. Anxiety and depression in patients with chronic temporomandibular pain and in controls. J Dent 2010; 38(5):369-376.^,1313. Mottaghi A, Razavi SM, Elham Zamani Pozveh E, Jahangirmoghaddam M. Assessment of the relationship between stress and temporomandibular joint disorder in female students before university entrance exam (Konkour exam). Dent Res J (Isfahan) 2011; 8(Supl. 1):76-79.^–1515. Calixtre LB, Grüninger BLS, Chaves TC, Oliveira AB. Is there an association between anxiety/depression and Temporomandibular Disorders in college students? J Appl Oral Sci 2014; 22(1):15-21.. These factors, especially stress and anxiety, may cause muscular hyperactivity and the development of parafunctional habits, leading to microtraumas of the TMJ and muscular lesions¹⁶16. Winocur E, Gavish A, Finkelshtein T, Halachmi M, Gazit E. Oral habits among adolescent girls and their association with symptoms of temporomandibulardisorders. J Oral Rehabil 2001; 28(7):624-629.^–1818. Medeiros SP, Batista AUD, Forte FDS. Prevalência de sintomas de disfunção temporomandibular e hábitos parafuncionais em estudantes universitários. RGO 2011; 59(2):201-208..

Recent studies have also shown that the symptoms of TMD, especially pain, can increase the level of physical and mental harm, with negative effects on quality of life (QL)¹⁹19. John MT, Reissmann DR, Schierz O, Wassell RW. Oral health-related quality of life in patients with temporomandibular disorders. J Orofac Pain 2007; 21(1):46-54.^–2323. Lemos GA, Paulino MR, Forte FDS, Beltrão RTS, Batista AUD. Influence of temporomandibular disorder presence and severity on oral health-related quality of life. Rev Dor 2015; 16(1):10-14.. In addition, the literature has shown that the severity of TMD is reflected in the decrease in oral health-related quality of life (OHRQL)²³23. Lemos GA, Paulino MR, Forte FDS, Beltrão RTS, Batista AUD. Influence of temporomandibular disorder presence and severity on oral health-related quality of life. Rev Dor 2015; 16(1):10-14..

In this study, we address the presence of signs and symptoms of TMD in a population of college preparatory students, mainly adolescents in the last year of high school. According to Godoy et al.²⁴24. Godoy F, Rosenblatt A, Godoy-Bezerra J. Temporomandibular Disorders and Associated Factors in Brazilian Teenagers: A Cross-Sectional Study. Int J Prosthodont 2007; 20(6):599-604., this phase is often characterized as a period of confusion and ambiguity due to the youths’ needs to begin to become part of the adult world and changes to their bodies, which affect their role in society. In addition, the college entrance exam, which is considered to be a competitive and stressful system for acceptance to Brazilian universities, may be reflected by increased social and familial pressure, anxiety, stress, and other emotional disorders closely related to a diagnosis of TMD²⁵25. Melo GM, Barbosa JFS. Parafunção × DTM: a influência dos hábitos parafuncionais na etiologia das desordens temporomandibulares. POS 2009; 1(1):43-48.^,2626. Guhur MLP, Alberto RN, Carniatto N. Influências biológicas, psicológicas e sociais do vestibular na adolescência. Roteiro 2010; 35(1):115-138..

In addition, several studies have investigated the prevalence of TMD and associated factors in children³3. Santos ECA, Bertoz FA, Pignatta LMB, Arantes FM. Avaliação clínica de sinais e sintomas da disfunção temporomandibular em crianças. Rev Dent Press Ortodon Ortop Facial 2006; 11(2):29-34.^,77. Thilander B, Rubio G, Pena L, Mayorga C. Prevalence of Temporomandibular Dysfunction and Its Association With Malocclusion in Children and Adolescents: An Epidemiologic Study Related to Specified Stages of Dental Development. Angle Orthod 2002; 72(2):146-154.^,1414. Pizolato RA, Freitas-Fernandes FS, Gavião MB. Anxiety/depression and orofacial myofacial disorders as factors associated with TMD in children. Braz Oral Res 2013; 27(2):156-162.^,2727. Sena MF, Mesquita KS, Santos FR, Silva FW, Serrano KV. Prevalence of temporomandibular dysfunction in children and adolescents. Rev Paul Pediatr 2013; 31(4):538-545., adolescents²2. Gavish A, Halachmi M, Winocur E, Gazit E. Oral habits and their association with signs and symptoms of temporomandibular disorders in adolescent girls. J Oral Rehabil 2000; 27(1):22-32.^,44. Winocur E, Littnerusb D, Adamsusb I, Gavish A. 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 Endod 2006; 102(4):482-487.^,1616. Winocur E, Gavish A, Finkelshtein T, Halachmi M, Gazit E. Oral habits among adolescent girls and their association with symptoms of temporomandibulardisorders. J Oral Rehabil 2001; 28(7):624-629., college students⁹9. Monteiro DR, Zuim PRJ, Pesqueira AA, Ribeiro PP, Garcia AR. Relationship between anxiety and chronic orofacial pain of Temporomandibular Disorder in a group of university students. J Prosthodont Res 2011; 55(3):154-158.^,1515. Calixtre LB, Grüninger BLS, Chaves TC, Oliveira AB. Is there an association between anxiety/depression and Temporomandibular Disorders in college students? J Appl Oral Sci 2014; 22(1):15-21.^,1818. Medeiros SP, Batista AUD, Forte FDS. Prevalência de sintomas de disfunção temporomandibular e hábitos parafuncionais em estudantes universitários. RGO 2011; 59(2):201-208.^,2323. Lemos GA, Paulino MR, Forte FDS, Beltrão RTS, Batista AUD. Influence of temporomandibular disorder presence and severity on oral health-related quality of life. Rev Dor 2015; 16(1):10-14.^,2828. Minghelli B, Morgado M, Caro T. Association of temporomandibular disorder symptoms with anxiety and depression in Portuguese college students. J Oral Sci 2014; 56(2):127-133., adults¹⁰10. McMillan AS, Wong MCM, Lee LTK, Yeun RWK. Depression and diffuse physical symptoms in Southern Chinese with Temporomandibular Disorders. J Oral Rehabil 2009; 36(6):403-407.^,1212. Fernandes G, Gonçalves DA, De Siqueira JT, Camparis CM. Painful temporomandibular disorders, self reported tinnitus, and depression are highly associated. Arq Neuropsiquiatr 2013; 71(12):943-947.^,2121. Schierz O, John MT, Reissmann DR, Mehrstedt M, Szentpétery A. Comparison of perceived oral health in patients with temporomandibular disorders and dental anxiety using oral health-related quality of life profiles. Qual Life Res 2008; 17(6):857-866.^,2929. Selaimen C, Brilhante DP, Grossi ML, Grossi PK. Avaliação da depressão e de testes neuropsicológicos em pacientes com desordens temporomandibulares. Cien Saude Colet 2007; 12(6):1629-1639. and elderly³⁰30. Schmitter M, Rammelsberg P, Hassel A. The prevalence of signs and symptoms of temporomandibular disorders in very old subjects. J Oral Rehabil 2005; 32(7):467-473., however few information is available about college preparatory students, subjected to high psychosocial burden, including psychological and physical manifestations of stress and anxiety²⁴24. Godoy F, Rosenblatt A, Godoy-Bezerra J. Temporomandibular Disorders and Associated Factors in Brazilian Teenagers: A Cross-Sectional Study. Int J Prosthodont 2007; 20(6):599-604.^,2626. Guhur MLP, Alberto RN, Carniatto N. Influências biológicas, psicológicas e sociais do vestibular na adolescência. Roteiro 2010; 35(1):115-138.^,3131. Peruzzo AS, Cattani BC, Guimarães ER, Boechat LC, Argimon IIL, Scarparo HBK. Estresse e vestibular como Desencadeadores de somatizações Em adolescentes e adultos jovens. Psicol Argum 2008; 26(55):319-327.^,3232. Soares AB. Ansiedade dos estudantes diante da expectativa do exame vestibular. Paideia 2010; 20(45):57-62..

Thus, the aim of this study is to evaluate the presence of signs and symptoms of TMD, its correlation with gender, reports of parafunctional habits, emotional stress, anxiety, and depression and its effects on OHRQL in college preparatory students enrolled in their last year of high school or college entrance exam courses in João Pessoa, Paraíba (PB).

Materials and methods

This research was a non-probability cross-sectional study performed using college preparatory students in the third year of high school or taking college entrance exam preparation courses in public and private institutions in the city of João Pessoa (PB) in 2011. The sample consisted of 303 volunteers from both sexes, between 15 to 25 years of age, who agreed to participate in the study. Students who did not sign (or whose guardians did not sign) the consent form, students who had orthodontic treatment (attached or removable appliance), and students who had received treatments for TMD or other orofacial pain were excluded.

In concordance with the requirements and criteria established by Resolution num. 196/96 of the National Health Council (NHC), the project was presented to the Research Ethics Committee (REC) of the Lauro Wanderley University Hospital at the Federal University of Paraíba (UFPB).

Data collection

Permission slips were provided in duplicate to 10 high schools (five private and five public), together with a copy of the research study. Institutions were selected by convenience from all of the high schools and pre-entrance exam courses in the city of João Pessoa (PB). Permission to perform the study was given in only three private and three public institutions.

Questionnaires were given during the break between classes, which varied between 20 and 30 minutes, during both sessions (morning and afternoon), depending on the availability of each school.

A majority of the institutions were visited more than once due to both the limited time to conduct the surveys and the inclusion in the study of minors whose participation was dependent on the consent form being signed by their legal guardians.

Evaluation of the presence of TMD symptoms and parafunctional habits

A self-reporting questionnaire containing objective questions on the presence of parafunctional habits and the “DMF anamnestic index” from Fonseca et al.³³33. Fonseca DM, Bonfante G, Valle A, Freitas SFT. Diagnóstico pela Anamnese da Disfunção Craniomandibular. RGO 1994; 42(1):23-28. was used to evaluate the severity of the TMD and the need for treatment.

The DMF index consisted of 10 questions related to symptoms of TMD, with three possible answers for each question: “yes,” “no,” or “occasionally,” which were assigned values of 10, 0, and 5, respectively. The sum of the values for the responses allowed the population to be classified according to the severity of the TMD, based on the reported symptoms: absent (0-15), mild (20-40), moderate (45-65), or severe (70-100). The data from the DMF anamnesis index also allowed the sample to be classified by need for treatment, based on the TMD symptoms reported, as: “no need for treatment” (absent or mild TMD) and “treatment needed” (moderate to severe TMD).

For parafunctional habits, the volunteers were asked to indicate the habits that they performed most often on a multiple-choice question containing options previously selected from the literature⁴4. Winocur E, Littnerusb D, Adamsusb I, Gavish A. 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 Endod 2006; 102(4):482-487.^,1616. Winocur E, Gavish A, Finkelshtein T, Halachmi M, Gazit E. Oral habits among adolescent girls and their association with symptoms of temporomandibulardisorders. J Oral Rehabil 2001; 28(7):624-629.^,3434. Emodi-Perlman A, Eli I, Friedman-Rubin P, Goldsmith C, Reiter S, Winocur E. Bruxism, oral parafunctions, anamnestic and clinical findings of temporomandibular disorders in children. J Oral Rehabil 2012; 39(2):126-135.. Participants were informed that they could mark more than one option.

Evaluation for the presence of clinical signs of TMD

Two previously calibrated examiners, with inter and intra-examiner Kappa coefficients of 0.82 and 0.95, respectively, performed the simplified clinical exam on the youths in rooms selected by the institutions. The evaluation was performed with the students sitting in a chair with a backrest with an erect back, legs and feet parallel and firmly placed on the ground under ambient light. Examiners also used proper personal protection equipment (gloves, masks, protective eyewear, and protective clothing).

The following parameters were evaluated:

Muscular sensitivity: the masseter (lower, middle, and upper thirds) and temporal (anterior, middle and posterior thirds) muscles were palpated with a pressure of approximately 1.0 kg/cm²²³23. Lemos GA, Paulino MR, Forte FDS, Beltrão RTS, Batista AUD. Influence of temporomandibular disorder presence and severity on oral health-related quality of life. Rev Dor 2015; 16(1):10-14.^,3535. Lemos GA, Moreira VG, Forte FDS, Beltrão RTS, Batista AUD. Correlação entre sinais e sintomas da Disfunção Temporomandibular (DTM) e severidade da má oclusão. Rev Odontol UNESP 2015; 44(3):175-180., and the resistive protrusion method was used to analyze the lateral pterygoid. A total of seven sites were analyzed by palpation on each side (three temporal, three masseter, and one lateral pterygoid), resulting in 14 muscular palpation sites per volunteer. Pain was quantified using objective values in which “0” indicated no pain, “1” tenderness was reported by the volunteer, “2” tenderness with physical manifestations, and “3” tenderness with evasion by the volunteer²³23. Lemos GA, Paulino MR, Forte FDS, Beltrão RTS, Batista AUD. Influence of temporomandibular disorder presence and severity on oral health-related quality of life. Rev Dor 2015; 16(1):10-14.^,3535. Lemos GA, Moreira VG, Forte FDS, Beltrão RTS, Batista AUD. Correlação entre sinais e sintomas da Disfunção Temporomandibular (DTM) e severidade da má oclusão. Rev Odontol UNESP 2015; 44(3):175-180..

Joint sensitivity: Lateral palpation of the TMJ was performed with the volunteer at rest, and posterior palpation of the TMJ was palpated with maximum opening. Both were conducted with a pressure of approximately 0.5 kg/cm²²³23. Lemos GA, Paulino MR, Forte FDS, Beltrão RTS, Batista AUD. Influence of temporomandibular disorder presence and severity on oral health-related quality of life. Rev Dor 2015; 16(1):10-14.^,3535. Lemos GA, Moreira VG, Forte FDS, Beltrão RTS, Batista AUD. Correlação entre sinais e sintomas da Disfunção Temporomandibular (DTM) e severidade da má oclusão. Rev Odontol UNESP 2015; 44(3):175-180.. Pain was quantified using objective values, as described above²³23. Lemos GA, Paulino MR, Forte FDS, Beltrão RTS, Batista AUD. Influence of temporomandibular disorder presence and severity on oral health-related quality of life. Rev Dor 2015; 16(1):10-14.^,3535. Lemos GA, Moreira VG, Forte FDS, Beltrão RTS, Batista AUD. Correlação entre sinais e sintomas da Disfunção Temporomandibular (DTM) e severidade da má oclusão. Rev Odontol UNESP 2015; 44(3):175-180..

Joint Noise: The volunteers were asked to open and close their mouths three times. The examiner's index fingers were positioned over the TMJs, allowing the evaluation of presence/absence of clicking or crepitus (grinding sound during mandibular movement) to be detected. The presence of TMJ noise was considered when they were reproducible in at least two of three movements²³23. Lemos GA, Paulino MR, Forte FDS, Beltrão RTS, Batista AUD. Influence of temporomandibular disorder presence and severity on oral health-related quality of life. Rev Dor 2015; 16(1):10-14.^,3535. Lemos GA, Moreira VG, Forte FDS, Beltrão RTS, Batista AUD. Correlação entre sinais e sintomas da Disfunção Temporomandibular (DTM) e severidade da má oclusão. Rev Odontol UNESP 2015; 44(3):175-180..

Active mouth opening: With the patient in maximum opening, the distance between the edges of the upper and lower middle incisors was measured, in millimeters (mm), using a caliper (NSK, Nippon Sokutei, Japan). In addition, the vertical overlap was also measured by vertical superposition of the upper incisors on the lower, with the volunteer in maximal intercuspation, using a caliper. The sum of the two measurements (opening and vertical overlay) provided the active mouth opening of each volunteer. The size of the active mouth opening was classified as restricted opening (< 40 mm), normal opening (40-59 mm), or hypermobility (more than 60 mm)²³23. Lemos GA, Paulino MR, Forte FDS, Beltrão RTS, Batista AUD. Influence of temporomandibular disorder presence and severity on oral health-related quality of life. Rev Dor 2015; 16(1):10-14.^,3535. Lemos GA, Moreira VG, Forte FDS, Beltrão RTS, Batista AUD. Correlação entre sinais e sintomas da Disfunção Temporomandibular (DTM) e severidade da má oclusão. Rev Odontol UNESP 2015; 44(3):175-180..

Jaw movement alterations: The volunteers were asked to open and close their mouths three times, allowing the presence or absence of mandibular deviations (the mandible deviates during opening but returns to the midline when opened completely) or deflections (when the mandible is off the midline through maximal opening). The presence of jaw movement alterations was defined when they were reproducible in at least two of three movements²³23. Lemos GA, Paulino MR, Forte FDS, Beltrão RTS, Batista AUD. Influence of temporomandibular disorder presence and severity on oral health-related quality of life. Rev Dor 2015; 16(1):10-14.^,3535. Lemos GA, Moreira VG, Forte FDS, Beltrão RTS, Batista AUD. Correlação entre sinais e sintomas da Disfunção Temporomandibular (DTM) e severidade da má oclusão. Rev Odontol UNESP 2015; 44(3):175-180..

The presence of clinical signs allowed the volunteers classification as follows:

Signs of muscular TMD: two or more sites of muscular sensitivity;

Signs of articular TMD: two or more sites of TMJ alterations (joint pain, joint noise, restricted mouth opening or mandibular hypermobility, or altered movement);

Signs of mixed muscular and articular TMD: the presence of two or more sites with muscular pain and simultaneous joint signs.

Analysis of the presence of anxiety, depression, and emotional stress

The Hospital Anxiety and Depression (HAD) scale, translated into and validated in Portuguese, was used to evaluate the frequency of anxiety and depression³⁶36. Botega NJ, Bio MR, Zomignani MA, Garcia-Júnior C, Pereira WAB. Transtornos do humor em enfermaria de clínica médica e validação de Escala de Medida (HAD) de Ansiedade e Depressão. Rev Saude Publica 1995; 29(5):355-363.. The scale includes 14 items, seven that address anxiety (HADS-A) and seven that address depression (HADS-D). Each of these items can receive 0 to 3 points, resulting in a maximum score of 21 points for each subscale. The total scores in each subscale are classified using the following cutoffs: no anxiety from 0 to 8 and anxiety ≥ 9; no depression 0 to 8 and depression ≥ 9.

The volunteers also responded, in the same questionnaire, to a question related to the presence/absence of emotional stress and indicated their stress level on an Analog Visual Scale (AVS) from 0 to 10.

Oral Health-Related Quality of Life Analysis

OHRQL was measured using the Oral Health Impact Profile (OHIP), in a shortened and validated Portuguese version (OHIP-14)³⁷37. Soe KK, Gelbier S, Robinson PG. Reliability and validity of two oral health related quality of life measures in Myanmar adolescents. Community Dent Health 2004; 21(4):306-311.^,3838. Oliveira BH, Nadanovsky P. Psychometric properties of the Brazilian version of the Oral Health Impact Pro-file-short form. Community Dent Oral Epidemiol 2005; 33(4):307-314.. The questionnaire consists of 14 questions, two for each of the seven survey dimension. Each question has five possible answers: never, rarely, sometimes, often, and always for 0, 1, 2, 3, and 4 points, respectively. The sum of the ordinal responses gives the total OHIP-14 score, which can range from 0 to 56, with higher scores indicating a larger negative impact for oral health³⁷37. Soe KK, Gelbier S, Robinson PG. Reliability and validity of two oral health related quality of life measures in Myanmar adolescents. Community Dent Health 2004; 21(4):306-311.^,3838. Oliveira BH, Nadanovsky P. Psychometric properties of the Brazilian version of the Oral Health Impact Pro-file-short form. Community Dent Oral Epidemiol 2005; 33(4):307-314..

The OHIP-14 comprises seven areas of oral health with two questions for each area (functional limitation, physical pain, psychological discomfort, physical impairment, psychological impairment, social impairment, and disability). The points from each of the seven OHIP-14 areas can range from 0 to 8 points, with higher scores representing more harm.

Data analysis

The data were recorded and tabulated in the Statistical Package for Social Sciences (SPSS), version 22.0, and analyzed by descriptive and by inferential statistics. Frequencies and percentages were used for descriptive analysis, and the following non-parametric tests were used for inferential statistical analysis: Chi-square, Fisher exact, and significance calculations for identifying correlations between the variables. For the OHIP-14 scores, the Kolmogorov-Smirnov normality test showed that the data were not normally distributed; thus, the non-parametric Mann-Whitney and Kruskal-Wallis tests were used to compare the means of the OHIP-14 scores in the different groups analyzed. For all statistical tests, a 95% confidence interval and a 5% (p < 0.05) significance level were adopted.

Results

Sample characterization

A total of 303 students were evaluated in this study. From this sample, most were female (69%), between 15 to 19 years of age (93.1%), and from public schools (74.6%). Based on the DMF index, some level of TMD was identified in 89.8% of the participants, of which 50.2% had mild TMD, 33.0% moderate and only 6.6% severe. 39.6% of volunteers exhibited an active need for treatment (moderate and severe TMD). The TMD severity and need for treatment were determined by the DMF index according to the TMD symptoms reported. However, the physical exam showed the presence of clinical TMD signs in 56.4% of the sample. 31.0% showed clinical signs of articular TMD, 11.2% signs of muscular TMD and 14.2% combined signals of articular and muscular TMD.

Parafunctional habits were highly prevalent (95.4%), but the variables of emotional stress, anxiety, and depression were found in 82.5%, 40.3%, and 10.6% of the analyzed population, respectively.

Factors associated with the presence of signs and symptoms of TMD

Table 1 shows that the presence of TMD symptoms (DMF index) was statistically correlated with female gender (p < 0.001), reported parafunctional habits (p < 0.001), reported emotional stress (p < 0.001), and anxiety (p < 0.001). There was no statistically significant association between TMD symptoms and the type of educational institution or the presence of depression. The “treatment need” (DMF index, based on the symptoms of TMD reported) was statistically associated with the female gender (p < 0.001), reported parafunctional habits (p = 0.039), reported emotional stress (p < 0.001), anxiety (p < 0.001), and depression (p < 0.001) (Table 2). However, the presence of clinical signs of TMD following the physical exam was only associated with female gender (p < 0.001) and anxiety (p < 0.001) (Table 3).

When the symptoms of TMD (DMF index) was compared to each type of parafunctional habit, we found a statistically significant association with the following habits: chewing gum (p = 0.027); clenching teeth (p = 0.020); resting your chin on your hand (p = 0.002); biting the tongue (p = 0.014); biting lips (p = 0.008); unilateral chewing (p = 0.008); lateral sleeping (p = 0.003); and chewing ice and/or lollipops (p = 0.039) (Table 4).

Impact of TMD on oral health-related quality of life

Table 5 shows that volunteers with TMD symptoms (DMF index) had a statistically higher OHIP-14 score than volunteers without symptoms (p < 0.001), suggesting a negative impact on OHRQL. The average OHIP-14 score was statistically higher in the group of volunteers needing treatment than in the group not needing treatment (p < 0.001), and the more severe the TMD (DMF index) was, the larger the impact on OHRQL.

Regarding the physical exam, volunteers with clinical signs of articular, muscular, or mixed TMD had higher OHIP-14 scores than volunteers with no signs of TMD, but this difference was only significant for those with mixed signs of articular and muscular TMD (p = 0.01) (Table 4). Of the OHIP-14 seven domains, physical pain was the domain that presented the highest impact on the groups with clinical signs of articular (p = 0.033), muscular (p = 0.019), and mixed (p < 0.001) TMD.

Discussion

In this study it was proposed to evaluate the prevalence of signs and symptoms of TMD and its associated factors in a sample of students in the last year of high school and that would be submitted to the college entrance examination. The choice of this specific group is justified by the absence of further studies related to TMD in this specific sample, demonstrably subjected to high emotional burden, including anxiety, anguish, restlessness and stress²⁶26. Guhur MLP, Alberto RN, Carniatto N. Influências biológicas, psicológicas e sociais do vestibular na adolescência. Roteiro 2010; 35(1):115-138.^,3131. Peruzzo AS, Cattani BC, Guimarães ER, Boechat LC, Argimon IIL, Scarparo HBK. Estresse e vestibular como Desencadeadores de somatizações Em adolescentes e adultos jovens. Psicol Argum 2008; 26(55):319-327.^,3232. Soares AB. Ansiedade dos estudantes diante da expectativa do exame vestibular. Paideia 2010; 20(45):57-62.. Furthermore, recent studies have shown that these emotional factors may be closely related to the diagnosis and progression of TMD⁹9. Monteiro DR, Zuim PRJ, Pesqueira AA, Ribeiro PP, Garcia AR. Relationship between anxiety and chronic orofacial pain of Temporomandibular Disorder in a group of university students. J Prosthodont Res 2011; 55(3):154-158.^,1111. Giannakopoulos NN, Keller L, Rammelsberg P, Kronmüller KT, Schmitter M. Anxiety and depression in patients with chronic temporomandibular pain and in controls. J Dent 2010; 38(5):369-376.^,1313. Mottaghi A, Razavi SM, Elham Zamani Pozveh E, Jahangirmoghaddam M. Assessment of the relationship between stress and temporomandibular joint disorder in female students before university entrance exam (Konkour exam). Dent Res J (Isfahan) 2011; 8(Supl. 1):76-79.^–1515. Calixtre LB, Grüninger BLS, Chaves TC, Oliveira AB. Is there an association between anxiety/depression and Temporomandibular Disorders in college students? J Appl Oral Sci 2014; 22(1):15-21..

In the present study, sample consisted mainly of female students from public schools. These results are due to the lack of responses for permission to collect data and negativity in some private institutions. Add to this the better reception among female volunteers, and it was difficult to obtain a balanced sample for gender and type of teaching institution.

The prevalence of symptoms and clinical signs of TMD were determined in this study by the “DMF index”³⁴34. Emodi-Perlman A, Eli I, Friedman-Rubin P, Goldsmith C, Reiter S, Winocur E. Bruxism, oral parafunctions, anamnestic and clinical findings of temporomandibular disorders in children. J Oral Rehabil 2012; 39(2):126-135. and simplified clinical examination²2. Gavish A, Halachmi M, Winocur E, Gazit E. Oral habits and their association with signs and symptoms of temporomandibular disorders in adolescent girls. J Oral Rehabil 2000; 27(1):22-32.^,44. Winocur E, Littnerusb D, Adamsusb I, Gavish A. 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 Endod 2006; 102(4):482-487.^,1616. Winocur E, Gavish A, Finkelshtein T, Halachmi M, Gazit E. Oral habits among adolescent girls and their association with symptoms of temporomandibulardisorders. J Oral Rehabil 2001; 28(7):624-629.^,2323. Lemos GA, Paulino MR, Forte FDS, Beltrão RTS, Batista AUD. Influence of temporomandibular disorder presence and severity on oral health-related quality of life. Rev Dor 2015; 16(1):10-14.. The DMF index sorts the volunteers in categories based on the severity of TMD symptoms and the absence/presence of treatment need, but does not provide diagnostic classification³⁹39. Chaves TC, Oliveira AS, Grossi DB. Principais instrumentos para avaliação da disfunção temporomandibular, parte I: índices e questionários; uma contribuição para a prática clínica e de pesquisa. Fisioter pesqui 2008; 15(1):92-100.. Another limitation arises from its scoring system, since if three affirmative responses are attributed to questions about headache, cervical pain and perception of emotional tension, the volunteer will be classified as mild DTM carrier, and these symptoms may occur an isolated manner, without any relation to this dysfunction³⁹39. Chaves TC, Oliveira AS, Grossi DB. Principais instrumentos para avaliação da disfunção temporomandibular, parte I: índices e questionários; uma contribuição para a prática clínica e de pesquisa. Fisioter pesqui 2008; 15(1):92-100..

However, the DMF index brings some advantages such as simplicity, speed of aplication and low cost, enabling it use in epidemiological studies, for plotting population profiles, for patients screening or, in the assessment of quality of life²³23. Lemos GA, Paulino MR, Forte FDS, Beltrão RTS, Batista AUD. Influence of temporomandibular disorder presence and severity on oral health-related quality of life. Rev Dor 2015; 16(1):10-14.^,3939. Chaves TC, Oliveira AS, Grossi DB. Principais instrumentos para avaliação da disfunção temporomandibular, parte I: índices e questionários; uma contribuição para a prática clínica e de pesquisa. Fisioter pesqui 2008; 15(1):92-100.^,4040. Campos JADB, Gonçalves DAG, Camparis CM, Speciali JG. Confiabilidade de um formulário para diagnóstico da severidade da disfunção temporomandibular. Rev Bras Fisioter 2009; 13(1):38-43., being used in several studies to evaluate the prevalence of TMD symptoms¹⁸18. Medeiros SP, Batista AUD, Forte FDS. Prevalência de sintomas de disfunção temporomandibular e hábitos parafuncionais em estudantes universitários. RGO 2011; 59(2):201-208.^,4141. Pedroni CR, De Oliveira AS, Guaratini MI. Prevalence study of signs and symptoms of Temporomandibular Disorders in university students. J Oral Rehabil 2003; 30(3):283-289.^–4343. Bonjardim LR, Lopes-Filho RJ, Amado G, Albuquerque-Júnior ALC, Gonçalves SRJ. Association between symptoms of Temporomandibular Disorders and gender, morphological occlusion and psychological factors in a group of university students. Indian J Dent Res 2009; 20(2):190-194.. Campos et al.⁴⁰40. Campos JADB, Gonçalves DAG, Camparis CM, Speciali JG. Confiabilidade de um formulário para diagnóstico da severidade da disfunção temporomandibular. Rev Bras Fisioter 2009; 13(1):38-43. suggested the suppression of some of the DMF index questions, which would increase its reliability. However, the removal of this questions would make the instrument very similar to the AAOP questionnaire, would not allow the classification of the severity of symptoms of TMD. Besides, the validity trial of the modified index was not yet performed. Thus, we decided to use the DMF index in its original version.

The simplified clinical examination protocol²2. Gavish A, Halachmi M, Winocur E, Gazit E. Oral habits and their association with signs and symptoms of temporomandibular disorders in adolescent girls. J Oral Rehabil 2000; 27(1):22-32.^,44. Winocur E, Littnerusb D, Adamsusb I, Gavish A. 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 Endod 2006; 102(4):482-487.^,1616. Winocur E, Gavish A, Finkelshtein T, Halachmi M, Gazit E. Oral habits among adolescent girls and their association with symptoms of temporomandibulardisorders. J Oral Rehabil 2001; 28(7):624-629.^,2323. Lemos GA, Paulino MR, Forte FDS, Beltrão RTS, Batista AUD. Influence of temporomandibular disorder presence and severity on oral health-related quality of life. Rev Dor 2015; 16(1):10-14.^,3535. Lemos GA, Moreira VG, Forte FDS, Beltrão RTS, Batista AUD. Correlação entre sinais e sintomas da Disfunção Temporomandibular (DTM) e severidade da má oclusão. Rev Odontol UNESP 2015; 44(3):175-180. allows the evaluation of the presence of joint, muscle or mixed TMD clinical signs. This clinical evaluation protocol is quick and simple, allowing its use in studies with larger samples, complementing the information of anamnesis questionnaire³³33. Fonseca DM, Bonfante G, Valle A, Freitas SFT. Diagnóstico pela Anamnese da Disfunção Craniomandibular. RGO 1994; 42(1):23-28.. However, it does not provide a standardized diagnostic classification for TMD. Currently, the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD), and its most recent version, the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) are the “gold–standard” instruments available in the literature for TMD evaluation, providing an accurate diagnosis this dysfunction⁴⁴44. Chaves TC, Oliveira AS, Grossi DB. Principais instrumentos para avaliação da disfunção temporomandibular, parte II: critérios diagnósticos; uma contribuição para a prática clínica e de pesquisa. Fisioter pesqui 2008; 15(1):101-106.. However, RDC/TMD is a complex instrument, making its use difficult in large samples, and the calibration of examiners is time-consuming. In this study, all evaluations were conducted with students during the interval between classes. This is a short period, around 20-30 minutes, which would difficult the application of the RDC/TMD. Furthermore, the DC/TMD was not yet translated or validated for Portuguese, which difficult it use in research in Brazil. The difficulty in establishing an “ideal” protocol of epidemiological evaluation of TMD can be confirmed by the absence of representative data of TMD prevalence in the Brazilian population, since, until this moment, no TMD protocol exam has yet been included in the National Oral Health Survey - the “SB Brasil”, performed in 2003 and 2010.

Considering the facts previously described and the limitations of the instruments used in this study, a high prevalence of clinical signs and symptoms of TMD by the anamnestic DMF index (89.8%) and the physical exam (56.4%) was observed. In addition, a large portion of this population showed an active “treatment need” (39.6%). It is noteworthy that the need for treatment was based on reported symptoms³³33. Fonseca DM, Bonfante G, Valle A, Freitas SFT. Diagnóstico pela Anamnese da Disfunção Craniomandibular. RGO 1994; 42(1):23-28. rather than the diagnosis of TMD. The prevalence of the signs and symptoms of TMD in adolescents varies widely due to individual differences, sample variability (heterogeneous age groups, sample size, and selection criteria), and different evaluation methods²⁷27. Sena MF, Mesquita KS, Santos FR, Silva FW, Serrano KV. Prevalence of temporomandibular dysfunction in children and adolescents. Rev Paul Pediatr 2013; 31(4):538-545.^,4545. Karibe H, Shimazu K, Okamoto A, Kawakami T, Kato Y, Warita-Naoi S. Prevalence and association of self-re-ported anxiety, pain, and oral parafunctional habits with temporomandibular disorders in Japanese children and adolescents: a cross-sectional survey. BMC Oral Health 2015; 15:8.. Thus, epidemiological studies in children have found a TMD prevalence between 21-74%⁴4. Winocur E, Littnerusb D, Adamsusb I, Gavish A. 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 Endod 2006; 102(4):482-487.^,1616. Winocur E, Gavish A, Finkelshtein T, Halachmi M, Gazit E. Oral habits among adolescent girls and their association with symptoms of temporomandibulardisorders. J Oral Rehabil 2001; 28(7):624-629.^,2828. Minghelli B, Morgado M, Caro T. Association of temporomandibular disorder symptoms with anxiety and depression in Portuguese college students. J Oral Sci 2014; 56(2):127-133.. In this study, the age range varied between 15-25 years of age, including adolescents and young adults. Indeed, the latter group had a higher prevalence of TMD signs and symptoms⁵5. Gonçalves DA, Dal Fabbro AL, Campos JA, Bigal ME, Speciali JG. Symptoms of Temporomandibular Disorders in the Population: An Epidemiological Study. J Orofac Pain 2010; 24(3):270-278.^,4141. Pedroni CR, De Oliveira AS, Guaratini MI. Prevalence study of signs and symptoms of Temporomandibular Disorders in university students. J Oral Rehabil 2003; 30(3):283-289.^,4343. Bonjardim LR, Lopes-Filho RJ, Amado G, Albuquerque-Júnior ALC, Gonçalves SRJ. Association between symptoms of Temporomandibular Disorders and gender, morphological occlusion and psychological factors in a group of university students. Indian J Dent Res 2009; 20(2):190-194., supporting the results found.

The majority of volunteers had mild TMD (50.2%), and only 6.6% had severe TMD. It is noteworthy that the severity of TMD was based on symptoms reported³³33. Fonseca DM, Bonfante G, Valle A, Freitas SFT. Diagnóstico pela Anamnese da Disfunção Craniomandibular. RGO 1994; 42(1):23-28. by volunteers. A higher percentage of individuals with mild TMD was also observed by Medeiros et al.¹⁸18. Medeiros SP, Batista AUD, Forte FDS. Prevalência de sintomas de disfunção temporomandibular e hábitos parafuncionais em estudantes universitários. RGO 2011; 59(2):201-208., Pedroni et al.⁴¹41. Pedroni CR, De Oliveira AS, Guaratini MI. Prevalence study of signs and symptoms of Temporomandibular Disorders in university students. J Oral Rehabil 2003; 30(3):283-289., Oliveira et al.⁴²42. Oliveira AS, Dias EM, Contato RG, Berzin F. Prevalence study of signs and symptoms of temporomandibular disorder in Brazilian college students. Braz Oral Res 2006; 20(1):3-7. e Bonjardim et al.⁴³43. Bonjardim LR, Lopes-Filho RJ, Amado G, Albuquerque-Júnior ALC, Gonçalves SRJ. Association between symptoms of Temporomandibular Disorders and gender, morphological occlusion and psychological factors in a group of university students. Indian J Dent Res 2009; 20(2):190-194.. Considering the clinical exam protocol, the clinical signs of articular TMD were most prevalent (31%), followed by signs of mixed articular and muscular TMD (14.2%) and muscular TMD (11.2%). Consistent with our results, epidemiological studies have shown a prevalence of joint sounds in approximately 23-47% and joint pain in 16-45% of children and adolescents²2. Gavish A, Halachmi M, Winocur E, Gazit E. Oral habits and their association with signs and symptoms of temporomandibular disorders in adolescent girls. J Oral Rehabil 2000; 27(1):22-32.^,44. Winocur E, Littnerusb D, Adamsusb I, Gavish A. 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 Endod 2006; 102(4):482-487.^,55. Gonçalves DA, Dal Fabbro AL, Campos JA, Bigal ME, Speciali JG. Symptoms of Temporomandibular Disorders in the Population: An Epidemiological Study. J Orofac Pain 2010; 24(3):270-278.^,2424. Godoy F, Rosenblatt A, Godoy-Bezerra J. Temporomandibular Disorders and Associated Factors in Brazilian Teenagers: A Cross-Sectional Study. Int J Prosthodont 2007; 20(6):599-604.. Furthermore, muscular sensitivity to palpation was recorded in 23-43% of this population²2. Gavish A, Halachmi M, Winocur E, Gazit E. Oral habits and their association with signs and symptoms of temporomandibular disorders in adolescent girls. J Oral Rehabil 2000; 27(1):22-32.^,44. Winocur E, Littnerusb D, Adamsusb I, Gavish A. 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 Endod 2006; 102(4):482-487.^,1616. Winocur E, Gavish A, Finkelshtein T, Halachmi M, Gazit E. Oral habits among adolescent girls and their association with symptoms of temporomandibulardisorders. J Oral Rehabil 2001; 28(7):624-629..

In the present study, female gender was strongly associated with the presence of symptoms and clinical signs of TMD (DMF index and simplified clinical examination), as with “treatment need” (DMF index). A higher prevalence of TMD in females has been widely reported in the literature²2. Gavish A, Halachmi M, Winocur E, Gazit E. Oral habits and their association with signs and symptoms of temporomandibular disorders in adolescent girls. J Oral Rehabil 2000; 27(1):22-32.^,44. Winocur E, Littnerusb D, Adamsusb I, Gavish A. 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 Endod 2006; 102(4):482-487.^,55. Gonçalves DA, Dal Fabbro AL, Campos JA, Bigal ME, Speciali JG. Symptoms of Temporomandibular Disorders in the Population: An Epidemiological Study. J Orofac Pain 2010; 24(3):270-278.^,2828. Minghelli B, Morgado M, Caro T. Association of temporomandibular disorder symptoms with anxiety and depression in Portuguese college students. J Oral Sci 2014; 56(2):127-133.^,4545. Karibe H, Shimazu K, Okamoto A, Kawakami T, Kato Y, Warita-Naoi S. Prevalence and association of self-re-ported anxiety, pain, and oral parafunctional habits with temporomandibular disorders in Japanese children and adolescents: a cross-sectional survey. BMC Oral Health 2015; 15:8., but the reasons for this prevalence remain controversial. Factors such as increased sensitivity to pain, the increased prevalence of emotional stress, anxiety, or depression, physiological differences (hormonal differences), differences in muscular structure, and increased preoccupation and treatment seeking¹1. De Leeuw R. Dor orofacial: guia de avaliação, diagnóstico e tratamento. 4ª ed. São Paulo: Quintessence; 2010.^,99. Monteiro DR, Zuim PRJ, Pesqueira AA, Ribeiro PP, Garcia AR. Relationship between anxiety and chronic orofacial pain of Temporomandibular Disorder in a group of university students. J Prosthodont Res 2011; 55(3):154-158.^,4141. Pedroni CR, De Oliveira AS, Guaratini MI. Prevalence study of signs and symptoms of Temporomandibular Disorders in university students. J Oral Rehabil 2003; 30(3):283-289. in females have all been proposed. Conversely, studies on children have not shown significant differences between genders for the signs and symptoms of TMD¹⁴14. Pizolato RA, Freitas-Fernandes FS, Gavião MB. Anxiety/depression and orofacial myofacial disorders as factors associated with TMD in children. Braz Oral Res 2013; 27(2):156-162.^,3434. Emodi-Perlman A, Eli I, Friedman-Rubin P, Goldsmith C, Reiter S, Winocur E. Bruxism, oral parafunctions, anamnestic and clinical findings of temporomandibular disorders in children. J Oral Rehabil 2012; 39(2):126-135., reinforcing the possible role of hormones in the development of this disorders, considering that these studies were conducted on prepubescent children who were therefore not influenced by reproductive hormones¹⁴14. Pizolato RA, Freitas-Fernandes FS, Gavião MB. Anxiety/depression and orofacial myofacial disorders as factors associated with TMD in children. Braz Oral Res 2013; 27(2):156-162..

The report of parafunctional habits was statistically associated with the presence of TMD symptoms and the “treatment need” (DMF index). In addition, the habits of clenching teeth, chewing gum, resting chin on hand, biting the tongue, biting lips, lateral sleep position, and chewing ice/lollipops were associated with the presence of this disorder symptoms (DMF index). Similar to this results, several studies have shown a positive association between parafunctional habits and the presence of signs and symptoms of TMD⁴4. Winocur E, Littnerusb D, Adamsusb I, Gavish A. 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 Endod 2006; 102(4):482-487.^,1818. Medeiros SP, Batista AUD, Forte FDS. Prevalência de sintomas de disfunção temporomandibular e hábitos parafuncionais em estudantes universitários. RGO 2011; 59(2):201-208.^,4545. Karibe H, Shimazu K, Okamoto A, Kawakami T, Kato Y, Warita-Naoi S. Prevalence and association of self-re-ported anxiety, pain, and oral parafunctional habits with temporomandibular disorders in Japanese children and adolescents: a cross-sectional survey. BMC Oral Health 2015; 15:8.^,4646. Michelotti A, Cioffi I, Festa P, Scala G, Farella M. Oral parafunctions as risk factors for diagnostic TMD subgroups. J Oral Rehabil 2010; 37(3):157-162.. Other studies, however, have contested this association³⁴34. Emodi-Perlman A, Eli I, Friedman-Rubin P, Goldsmith C, Reiter S, Winocur E. Bruxism, oral parafunctions, anamnestic and clinical findings of temporomandibular disorders in children. J Oral Rehabil 2012; 39(2):126-135.^,4747. Cheifetz AT, Osganian SK, Allred EN, Needleman HL. Prevalence of bruxism and associated correlates in children as reported by parents. J Dent Child (Chic) 2005; 72(2):67-73.^,4848. Merighi LBM, Silva MMA, Ferreira AT, Genaro KF, Berretin-Felix G. Ocorrência de disfunção temporomandibular (DTM) e sua relação com hábitos orais deletérios em crianças do município de Monte Negro – RO. Rev CEFAC 2007; 9(4):497-503.. The results of this study suggest that parafunctional habits may be important associated factors to TMD occurrence and progression, but further examination, relating each habit to specific diagnosis of this dysfunction is necessary for better understanding of their participation in the etiology of the different subgroups of TMD. It is noteworthy that, in the present study, bruxism and clenching habits were self-reported by the students²2. Gavish A, Halachmi M, Winocur E, Gazit E. Oral habits and their association with signs and symptoms of temporomandibular disorders in adolescent girls. J Oral Rehabil 2000; 27(1):22-32.^,44. Winocur E, Littnerusb D, Adamsusb I, Gavish A. 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 Endod 2006; 102(4):482-487.^,1616. Winocur E, Gavish A, Finkelshtein T, Halachmi M, Gazit E. Oral habits among adolescent girls and their association with symptoms of temporomandibulardisorders. J Oral Rehabil 2001; 28(7):624-629.^,3434. Emodi-Perlman A, Eli I, Friedman-Rubin P, Goldsmith C, Reiter S, Winocur E. Bruxism, oral parafunctions, anamnestic and clinical findings of temporomandibular disorders in children. J Oral Rehabil 2012; 39(2):126-135.. This type of evaluation carries a limitation that is inherent in it: its natural subjectivity, considering that most of the deleterious habits are unconscious, which means that the patient is not always aware of their presence. This factors can cause risks of over or underestimate the real prevalence of this condition⁴⁹49. Lobbezoo F, Ahlberg J, Glaros AG, Kato T, Koyano K, Lavigne GJ, de Leeuw R, Manfredini D, Svensson P, Winocur E. Bruxism defined and graded: an international consensus. J Oral Rehabil 2013; 40(1):2-4.. The literature considers the polysomnography exam as the “gold standard” for the diagnose of sleep bruxism and clenching, however is a suitable technique only for small samples due to high cost and limited availability⁴⁹49. Lobbezoo F, Ahlberg J, Glaros AG, Kato T, Koyano K, Lavigne GJ, de Leeuw R, Manfredini D, Svensson P, Winocur E. Bruxism defined and graded: an international consensus. J Oral Rehabil 2013; 40(1):2-4., which compromises its use in larger samples studies, as the present one.

When emotional factors were analyzed, it was observed an elevated prevalence of self reported emotional stress (82.5%) and anxiety (40.3%). Depression was present in 10.6% of the sample. These results are in agreement with previous studies which have also demonstrated elevated prevalence of emotional factors in this population²⁴24. Godoy F, Rosenblatt A, Godoy-Bezerra J. Temporomandibular Disorders and Associated Factors in Brazilian Teenagers: A Cross-Sectional Study. Int J Prosthodont 2007; 20(6):599-604.^,2626. Guhur MLP, Alberto RN, Carniatto N. Influências biológicas, psicológicas e sociais do vestibular na adolescência. Roteiro 2010; 35(1):115-138.^,3232. Soares AB. Ansiedade dos estudantes diante da expectativa do exame vestibular. Paideia 2010; 20(45):57-62.^,3333. Fonseca DM, Bonfante G, Valle A, Freitas SFT. Diagnóstico pela Anamnese da Disfunção Craniomandibular. RGO 1994; 42(1):23-28.. Guhur et al.²⁶26. Guhur MLP, Alberto RN, Carniatto N. Influências biológicas, psicológicas e sociais do vestibular na adolescência. Roteiro 2010; 35(1):115-138. assert that the moment of college entrance examination usually coincides with the turbulent period of life that is adolescence, and the professional decision usually generates anxiety. In addition, factors such as family interference, social pressure and the absence of a realistic view about certain areas of knowledge or professions may contribute to elevate the emotional tension and anxiety²⁶26. Guhur MLP, Alberto RN, Carniatto N. Influências biológicas, psicológicas e sociais do vestibular na adolescência. Roteiro 2010; 35(1):115-138.^,3232. Soares AB. Ansiedade dos estudantes diante da expectativa do exame vestibular. Paideia 2010; 20(45):57-62.^,3333. Fonseca DM, Bonfante G, Valle A, Freitas SFT. Diagnóstico pela Anamnese da Disfunção Craniomandibular. RGO 1994; 42(1):23-28.. The low prevalence of depression reflects the greater role of tension and stress events in the evaluated sample, as demonstrated in previous studies²⁴24. Godoy F, Rosenblatt A, Godoy-Bezerra J. Temporomandibular Disorders and Associated Factors in Brazilian Teenagers: A Cross-Sectional Study. Int J Prosthodont 2007; 20(6):599-604.^,2626. Guhur MLP, Alberto RN, Carniatto N. Influências biológicas, psicológicas e sociais do vestibular na adolescência. Roteiro 2010; 35(1):115-138.^,3232. Soares AB. Ansiedade dos estudantes diante da expectativa do exame vestibular. Paideia 2010; 20(45):57-62.^,3333. Fonseca DM, Bonfante G, Valle A, Freitas SFT. Diagnóstico pela Anamnese da Disfunção Craniomandibular. RGO 1994; 42(1):23-28.. It is noteworthy that in this study the evaluation of the presence of emotional stress was determined from an objective question related to their presence/absence directed to volunteers. This data should be analyzed with caution, since that emotional tension is subjective by nature. This type of evaluation was choosen due to the absence of more specific and precise instruments to evaluate this emotional component.

Several studies have shown a significant association between different emotional factors and the presence of signs and symptoms of TMD⁹9. Monteiro DR, Zuim PRJ, Pesqueira AA, Ribeiro PP, Garcia AR. Relationship between anxiety and chronic orofacial pain of Temporomandibular Disorder in a group of university students. J Prosthodont Res 2011; 55(3):154-158.^,1111. Giannakopoulos NN, Keller L, Rammelsberg P, Kronmüller KT, Schmitter M. Anxiety and depression in patients with chronic temporomandibular pain and in controls. J Dent 2010; 38(5):369-376.^,1313. Mottaghi A, Razavi SM, Elham Zamani Pozveh E, Jahangirmoghaddam M. Assessment of the relationship between stress and temporomandibular joint disorder in female students before university entrance exam (Konkour exam). Dent Res J (Isfahan) 2011; 8(Supl. 1):76-79.^,1414. Pizolato RA, Freitas-Fernandes FS, Gavião MB. Anxiety/depression and orofacial myofacial disorders as factors associated with TMD in children. Braz Oral Res 2013; 27(2):156-162.. In this study, the report of emotional stress was statistically associated with the presence of TMD symptoms and the need for treatment (DMF index). These findings were consistent with other studies performed in various populations¹⁷17. Carvalho LPM, Piva MR, Santos TS, Ribeiro CF, Araújo CRF, Souza LB. Estadiamento clínico da disfunção temporomandibular: estudo de 30 casos. Odontol Clín-Cient 2008; 7(1):47-52.^,2828. Minghelli B, Morgado M, Caro T. Association of temporomandibular disorder symptoms with anxiety and depression in Portuguese college students. J Oral Sci 2014; 56(2):127-133.. It is believed that stress can affect biological processes related to the transmission and perception of pain, promoting chronic muscular hyperactivity, which in turn can damage the TMJ and related structures, in addition to contributing to the creation and evolution of parafunctional habits⁸8. Gameiro GH1, Silva Andrade A, Nouer DF, Ferraz de Arruda Veiga MC. How may stressful experiences contribute to the development of temporomandibular disorders? Clin Oral Investig 2006; 10(4):261-268.^,5050. Minghelli B, Kiselova L, Pereira C. Associação entre os sintomas da disfunção temporomandibular com factores psicológicos e alterações na coluna cervical em alunos da Escola Superior de Saúde Jean Piaget do Algarve. Rev Port Sau Pub 2011; 29(2):140-147..

Several studies have also shown a significant correlation between anxiety and depression and the presence of signs and symptoms of TMD¹¹11. Giannakopoulos NN, Keller L, Rammelsberg P, Kronmüller KT, Schmitter M. Anxiety and depression in patients with chronic temporomandibular pain and in controls. J Dent 2010; 38(5):369-376.^,1212. Fernandes G, Gonçalves DA, De Siqueira JT, Camparis CM. Painful temporomandibular disorders, self reported tinnitus, and depression are highly associated. Arq Neuropsiquiatr 2013; 71(12):943-947.^,1515. Calixtre LB, Grüninger BLS, Chaves TC, Oliveira AB. Is there an association between anxiety/depression and Temporomandibular Disorders in college students? J Appl Oral Sci 2014; 22(1):15-21.^,2828. Minghelli B, Morgado M, Caro T. Association of temporomandibular disorder symptoms with anxiety and depression in Portuguese college students. J Oral Sci 2014; 56(2):127-133.^,2929. Selaimen C, Brilhante DP, Grossi ML, Grossi PK. Avaliação da depressão e de testes neuropsicológicos em pacientes com desordens temporomandibulares. Cien Saude Colet 2007; 12(6):1629-1639.. Corroborating these results, data showed that anxiety was statistically associated with the presence of TMD signs and symptoms (DMF index or simplified clinical examination) and the need for treatment (DMF index). Similarly, Karibe et al.⁴⁵45. Karibe H, Shimazu K, Okamoto A, Kawakami T, Kato Y, Warita-Naoi S. Prevalence and association of self-re-ported anxiety, pain, and oral parafunctional habits with temporomandibular disorders in Japanese children and adolescents: a cross-sectional survey. BMC Oral Health 2015; 15:8. showed a significant correlation between anxiety and the presence of TMD symptoms in a population of Japanese children and adolescents.

The depression results showed a significant correlation only with the “treatment need”. According to Fonseca et al.³³33. Fonseca DM, Bonfante G, Valle A, Freitas SFT. Diagnóstico pela Anamnese da Disfunção Craniomandibular. RGO 1994; 42(1):23-28., patients who are needing treatment represents an increased severity of TMD symptoms, making therapeutic intervention necessary. This result may suggest that depression plays a significant role in the progression and severity of this disorder, corroborating several studies in the literature¹⁰10. McMillan AS, Wong MCM, Lee LTK, Yeun RWK. Depression and diffuse physical symptoms in Southern Chinese with Temporomandibular Disorders. J Oral Rehabil 2009; 36(6):403-407.^,1212. Fernandes G, Gonçalves DA, De Siqueira JT, Camparis CM. Painful temporomandibular disorders, self reported tinnitus, and depression are highly associated. Arq Neuropsiquiatr 2013; 71(12):943-947.^,1515. Calixtre LB, Grüninger BLS, Chaves TC, Oliveira AB. Is there an association between anxiety/depression and Temporomandibular Disorders in college students? J Appl Oral Sci 2014; 22(1):15-21.^,2828. Minghelli B, Morgado M, Caro T. Association of temporomandibular disorder symptoms with anxiety and depression in Portuguese college students. J Oral Sci 2014; 56(2):127-133.^,2929. Selaimen C, Brilhante DP, Grossi ML, Grossi PK. Avaliação da depressão e de testes neuropsicológicos em pacientes com desordens temporomandibulares. Cien Saude Colet 2007; 12(6):1629-1639.^,5050. Minghelli B, Kiselova L, Pereira C. Associação entre os sintomas da disfunção temporomandibular com factores psicológicos e alterações na coluna cervical em alunos da Escola Superior de Saúde Jean Piaget do Algarve. Rev Port Sau Pub 2011; 29(2):140-147.. However, in light of the limitations of this study design, it is difficult to determine whether depression was responsible for the development of more severe TMD or whether it is caused by the symptoms of the disorder.

When we analyzed the QL data, we observed that volunteers with the signs and symptoms of TMD (DMF index or simplified clinical examination protocol) presented higher OHIP-14 scores than volunteers without signs and symptoms, suggesting that this disorder negatively impacts the OHRQL. These results are consistent with several other studies that showed significantly higher OHIP-14 scores in patients with TMD than in asymptomatic individuals¹⁹19. John MT, Reissmann DR, Schierz O, Wassell RW. Oral health-related quality of life in patients with temporomandibular disorders. J Orofac Pain 2007; 21(1):46-54.^,2121. Schierz O, John MT, Reissmann DR, Mehrstedt M, Szentpétery A. Comparison of perceived oral health in patients with temporomandibular disorders and dental anxiety using oral health-related quality of life profiles. Qual Life Res 2008; 17(6):857-866.^,2323. Lemos GA, Paulino MR, Forte FDS, Beltrão RTS, Batista AUD. Influence of temporomandibular disorder presence and severity on oral health-related quality of life. Rev Dor 2015; 16(1):10-14..

The DMF index data showed that volunteers needing treatment had higher OHIP-14 scores than patients who did not need treatment; furthermore, as the severity of TMD signs and symptoms increased (determined by reported symptoms), greater was the impact on OHRQL, which is consistent with previous studies²¹21. Schierz O, John MT, Reissmann DR, Mehrstedt M, Szentpétery A. Comparison of perceived oral health in patients with temporomandibular disorders and dental anxiety using oral health-related quality of life profiles. Qual Life Res 2008; 17(6):857-866.^–2323. Lemos GA, Paulino MR, Forte FDS, Beltrão RTS, Batista AUD. Influence of temporomandibular disorder presence and severity on oral health-related quality of life. Rev Dor 2015; 16(1):10-14.. A study performed on university students showed that the main complaint by volunteers with severe TMD is pain, which plays a significant role in psychosocial behavior and QL²³23. Lemos GA, Paulino MR, Forte FDS, Beltrão RTS, Batista AUD. Influence of temporomandibular disorder presence and severity on oral health-related quality of life. Rev Dor 2015; 16(1):10-14.. A recent systematic review also showed strong evidence that pain negatively impacts OHRQL in TMD patients²²22. Dahlström L, Carlsson GE. Temporomandibular disorders and oral health-related quality of life. A systematic review. Acta Odontol Scand 2010; 68(2):80-85..

When results from the simplified clinical examination protocol were evaluated, volunteers with a clinical sign of TMD had OHIP-14 scores that were statistically higher than those of patients without clinical signs, with the highest scores belonging to the group with signs of both articular and muscular TMD, followed by the group with signs of muscular TMD. These data support the claim that individuals with both articular and muscular signs presented an increased severity of TMD²³23. Lemos GA, Paulino MR, Forte FDS, Beltrão RTS, Batista AUD. Influence of temporomandibular disorder presence and severity on oral health-related quality of life. Rev Dor 2015; 16(1):10-14. and thus have a more severely impacted QL²¹21. Schierz O, John MT, Reissmann DR, Mehrstedt M, Szentpétery A. Comparison of perceived oral health in patients with temporomandibular disorders and dental anxiety using oral health-related quality of life profiles. Qual Life Res 2008; 17(6):857-866.^,2222. Dahlström L, Carlsson GE. Temporomandibular disorders and oral health-related quality of life. A systematic review. Acta Odontol Scand 2010; 68(2):80-85.^,5151. Reissmann DR, John MT, Schierz O, Wassell RW. Functional and psychosocial impact related to specific temporomandibular disorder diagnoses. J Dent 2007; 35(8):643-650.. The higher OHIP-14 scores in the group with signs of muscular TMD is supported by the clinical observation that these individuals had more painful symptoms than individuals with clinical signs of articular TMD¹⁹19. John MT, Reissmann DR, Schierz O, Wassell RW. Oral health-related quality of life in patients with temporomandibular disorders. J Orofac Pain 2007; 21(1):46-54.^,2222. Dahlström L, Carlsson GE. Temporomandibular disorders and oral health-related quality of life. A systematic review. Acta Odontol Scand 2010; 68(2):80-85.^,5151. Reissmann DR, John MT, Schierz O, Wassell RW. Functional and psychosocial impact related to specific temporomandibular disorder diagnoses. J Dent 2007; 35(8):643-650..

Regarding the seven OHIP-14 domains, physical pain was the most affected in groups with clinical signs of articular, muscular, and mixed TMD. Similarly, several studies have also shown an increased harm in the physical pain domain in several populations, reinforcing the role of pain in the QL of individuals with TMD²¹21. Schierz O, John MT, Reissmann DR, Mehrstedt M, Szentpétery A. Comparison of perceived oral health in patients with temporomandibular disorders and dental anxiety using oral health-related quality of life profiles. Qual Life Res 2008; 17(6):857-866.^–2323. Lemos GA, Paulino MR, Forte FDS, Beltrão RTS, Batista AUD. Influence of temporomandibular disorder presence and severity on oral health-related quality of life. Rev Dor 2015; 16(1):10-14.^,5151. Reissmann DR, John MT, Schierz O, Wassell RW. Functional and psychosocial impact related to specific temporomandibular disorder diagnoses. J Dent 2007; 35(8):643-650..

The data in this study presented a high prevalence of TMD signs and symptoms in college preparatory students, with a large portion in need of treatment. In addition, the negative impact of this disorder on OHRQL was evident. Among the associated factors, female gender, parafunction, and anxiety played a great role. These data indicate the need teachers and students being informed about TMDs signs and symptons and its possible link to parafunctional habits and emotional factors to improve early detection and to prevent the problem, which directly affects prognosis and the efficacy of treatment.

The elevated prevalence of self-reported emotional stress and anxiety, observed in this study reinforces the evidence of great emotional burden of which the college preparatory students are submitted, and these were statistically associated with the presence of signs and symptoms of TMD, which can suggest that this population is submitted to important risk factors for the development and progression of this disorder. Guhur et al.²⁶26. Guhur MLP, Alberto RN, Carniatto N. Influências biológicas, psicológicas e sociais do vestibular na adolescência. Roteiro 2010; 35(1):115-138. states that there is a necessity for vocational guidance service and psychological counseling to adolescents in schools, so that they can go through this period of difficult choices. Finally, it is also suggested to include other health professionals in these services such as dentists and physicians, allowing the early diagnose and management of conditions that can be aggravated or initiated during this period, as TMD.

In addition, these data, in addition to numerous other studies, which have shown high prevalence of TMD in different age ranges³3. Santos ECA, Bertoz FA, Pignatta LMB, Arantes FM. Avaliação clínica de sinais e sintomas da disfunção temporomandibular em crianças. Rev Dent Press Ortodon Ortop Facial 2006; 11(2):29-34.^,77. Thilander B, Rubio G, Pena L, Mayorga C. Prevalence of Temporomandibular Dysfunction and Its Association With Malocclusion in Children and Adolescents: An Epidemiologic Study Related to Specified Stages of Dental Development. Angle Orthod 2002; 72(2):146-154.^,99. Monteiro DR, Zuim PRJ, Pesqueira AA, Ribeiro PP, Garcia AR. Relationship between anxiety and chronic orofacial pain of Temporomandibular Disorder in a group of university students. J Prosthodont Res 2011; 55(3):154-158.^,1212. Fernandes G, Gonçalves DA, De Siqueira JT, Camparis CM. Painful temporomandibular disorders, self reported tinnitus, and depression are highly associated. Arq Neuropsiquiatr 2013; 71(12):943-947.^,1515. Calixtre LB, Grüninger BLS, Chaves TC, Oliveira AB. Is there an association between anxiety/depression and Temporomandibular Disorders in college students? J Appl Oral Sci 2014; 22(1):15-21.^,2121. Schierz O, John MT, Reissmann DR, Mehrstedt M, Szentpétery A. Comparison of perceived oral health in patients with temporomandibular disorders and dental anxiety using oral health-related quality of life profiles. Qual Life Res 2008; 17(6):857-866.^,2323. Lemos GA, Paulino MR, Forte FDS, Beltrão RTS, Batista AUD. Influence of temporomandibular disorder presence and severity on oral health-related quality of life. Rev Dor 2015; 16(1):10-14.^,2727. Sena MF, Mesquita KS, Santos FR, Silva FW, Serrano KV. Prevalence of temporomandibular dysfunction in children and adolescents. Rev Paul Pediatr 2013; 31(4):538-545.^,3030. Schmitter M, Rammelsberg P, Hassel A. The prevalence of signs and symptoms of temporomandibular disorders in very old subjects. J Oral Rehabil 2005; 32(7):467-473., suggests the need for “Temporomandibular Dysfunction and Orofacial Pain” services into the public health service, especially into the Centro de Especialidades Odontológicas – CEO (Centers of Dental Specialists). Treatment centers for TMD patients financially supported by the Sistema Único de Sáude (Brazilian National Health System) are scarse, and generally restricted to training centers and/or research institutions (universities or dental schools). The inclusion of this knowledge area may improve the access to comprehensive dental care to a larger portion of the population that suffers from the signs and symptoms of this disorder, preventing more severe complications and improving their quality of life.

Acknowledgments

We thank the CNPq for their generous financial support and research encouragement

References

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