Risk factors associated with incidence and persistence of signs and symptoms of temporomandibular disorders

Evaluation of Efficacy of 10% Dextrose Prolotherapy in Management of Temporomandibular Joint Disorders: A Prospective Study

The aim of this study was to assess the efficacy of 10% dextrose prolotherapy in the management of temporomandibular joint disorder. Thirty patients aged between 18 and 62 years, diagnosed with Temporomandibular Disorders (TMDs) persisting for more than six months and unresponsive to other conservative treatments, were enrolled in the study. Over four subsequent visits, spaced six weeks apart, each patient received injections of 3 ml of 10% dextrose solution into the temporomandibular joint space. Parameters assessed included pain levels, frequency of luxations/dislocations, episodes of locking per month, maximal mouth opening, and clicking, evaluated every six weeks for a duration of three months. All patients exhibited improvements in Temporomandibular Disorders (TMDs), manifested as reduced pain, clicking sounds, locking episodes, and increased maximal mouth opening, following prolotherapy treatment. These improvements were found to be statistically significant (p-value < 0.05). Dextrose prolotherapy is a treatment method with broad applications and should be considered prior to resorting to long-term pharmacotherapy or surgical interventions. The use of 10% dextrose prolotherapy presents a promising treatment modality for temporomandibular joint disorders, as evidenced by its therapeutic benefits.

Impact of temporomandibular disorder symptoms among 15-year-old girls

OBJECTIVE

Many adolescents, especially girls, report temporomandibular disorder (TMD) symptoms that may impact their daily life.

METHODS

At 19 different schools participating in the preventive program with dental nurses of FRAMM (Fluoride, Advise, Arena, Motivation, Food), at the Västra Götaland Region in Sweden, 15-year-old girls were invited to a cohort study about symptoms of TMD that also included headaches. Three hundred twenty-nine girls attended the study and answered a questionnaire regarding TMD symptoms and their consequences such as sick leave from school and consumption of analgesics. The girls were asked about the symptom's influence on their daily life, about their general health, use of regular medication, physical activity, and they answered the PHQ4 regarding experienced symptoms of anxiety and depression.

RESULTS

There was a significant correlation between TMD symptoms and sick leave with 31% of the girls having stayed home due to symptoms. Of the girls who answered affirmative in the screening questions (3QTMD), nearly half the group had stayed at home due to their symptoms, 24% had consulted a physician, 42% had used analgesics weekly and 59% reported that they felt the symptoms negatively affected their school performance. The girls who had regular medication had more TMD symptoms. Anxiety and depression were associated with TMD symptoms.

CONCLUSION

The study showed that TMD symptoms had a negative impact on the 15-year-old girls' daily life resulting in sick leave from school, consumption of analgesics, and experiences of negative impacts on their behavior and performance at school.

The Role of Malocclusion and Oral Parafunctions in Predicting Signs and Symptoms of Temporomandibular Disorders-A Cross-Sectional Study

BACKGROUND

The aim of this study was to examine to what extent malocclusion and parafunctional habits contribute to the development of signs and symptoms associated with temporomandibular disorders (TMD) in schoolchildren with mixed dentition in Croatia in a sample of 338 children, aged 9 to 15 years.

METHODS

TMD signs and symptoms assessed by the clinician were joint function and pain, masticatory muscles tenderness, range of mandibular motion, and joint sounds. To evaluate subjective symptoms and parafunctions, children and parents were asked about the presence of headaches, jaw locking, temporomandibular joint (TMJ) sounds, pain during mouth opening, or bruxism, as well as parafunctions like biting pencils or nails, chewing hard candies or ice, daily gum chewing, opening bottles with teeth, engaging in jaw play, thumb-sucking, and clenching/grinding teeth.

RESULTS

At least one symptom of a TMD was pronounced in 142 participants (42.0%). The most commonly reported parafunction was pencil or nail biting, present in 25.1% of participants. Class II malocclusion increased the likelihood by 2.6 times, pencil or nail biting by 2.34 times, and clenching/grinding teeth by 8.9 times that the subject would exhibit at least one TMD symptom.

CONCLUSIONS

Every child with mixed dentition should undergo a brief examination of the TMJ, especially in cases of Class II malocclusion, pencil or nail biting, and teeth clenching or grinding, as these have all been identified as significant risk factors that increase the likelihood of experiencing TMD symptoms. This highlights the need for proactive screening and assessment by healthcare providers to reduce the risk and prevalence of TMDs in affected children and ensure timely diagnosis and treatment.

Can temporomandibular disorder symptoms and headaches be prevented in 13- to 15-year-old girls by information provided in a school setting?

OBJECTIVE

Temporomandibular disorders (TMD) may develop, especially among girls, during the adolescence period. The aim of this study was to study if information and advice in a school setting could prevent development of TMD symptoms and headaches during the early teenage period.

METHODS

Thirteen-year-old girls, at 19 upper elementary schools were invited to participate in a study with structured information about the jaw system, TMD symptoms and risk factors, as well as advice how to manage risk factor and TMD. Six hundred and fifty-one girls enrolled, of which 507 girls were followed for 2-2.5 years. Half received information on three occasions (cases), and the other half served as controls. Included in the analysis of incidence of TMD symptoms were those without frequently occurring TMD symptoms (not including headaches) at baseline (n = 396) and included in the analysis of incidence of headaches were those without frequent headaches at baseline (n = 297).

RESULT

The 2-year incidence of TMD symptoms was significantly lower in the information cohort (19%) compared to the controls (28%) (p = .03). The 2-year incidence of headaches was lower among those who were allocated to information (30%) compared to controls (40%), but the difference was not statistically significant (p = .099). Cases who had headaches at baseline reported a significantly lower prevalence at follow-up compared to controls (p = .03).

CONCLUSION

Standardized information in school settings can prevent development of TMD symptoms and headaches among young girls.

Prevalence of Clinical Signs and Symptoms of Temporomandibular Joint Disorders Registered in the EUROTMJ Database: A Prospective Study in a Portuguese Center

Temporomandibular joint disorders (TMDs) are characterized by their multifactorial etiology and pathogenesis. A 3-year prospective study was conducted in a Portuguese TMDs department to study the prevalence of different TMDs signs and symptoms and their association with risk factors and comorbidities. Five hundred ninety-five patients were included using an online database: EUROTMJ. Most patients were female (80.50%), with a mean age of 38.20 ± 15.73 years. The main complaints were: (1) temporomandibular joint (TMJ) clicking (13.26%); (2) TMJ pain (12.49%); (3) masticatory muscle tension (12.15%). The main clinical findings were myalgia (74%), TMJ clicking (60-62%), and TMJ arthralgia (31-36%). Risk factors such as clenching (60%) and bruxism (30%) were positively associated with TMJ pain and myalgia. Orthodontic treatment (20%) and wisdom tooth removal (19%) were positively associated with TMJ clicking, while jaw trauma (6%), tracheal intubation (4%) and orthognathic surgery (1%) were positively associated with TMJ crepitus, limited mandibular range of motion, and TMJ pain, respectively. In total, 42.88% of TMDs patients had other associated chronic diseases, most of them were mental behavioral or neurodevelopmental disorders (33.76%), namely, anxiety (20%) and depression (13%). The authors also observed a positive association of mental disorders with the degree of TMJ pain and myalgia. The online database seems to be a relevant scientific instrument for healthcare providers who treat TMDs. The authors expect that the EUROTMJ database can serve as a milestone for other TMDs departments.

Prevalence of temporomandibular disorders and its association with malocclusion in children: A transversal study

This study investigated the prevalence of temporomandibular disorders (TMDs) in a sample of children and adolescents and evaluated the correlation with occlusal variables. TMD signs and symptoms were recorded in 411 subjects (age range 7-15 years), divided into two groups: 214 subjects treated in Chieti (Italy) CG group and 197 in Murcia (Spain) MG group. Once the Angle dental class was identified, it was recorded if there were signs and symptoms of temporomandibular disorders (TMDs) and occlusal interferences. The percentages of signs and symptoms were compared to determine the differences among the groups for TMDs, bruxism, joint sounds, deviation during the opening, reduced opening/lateral/protrusive movements, malocclusions, and myofascial pain. There is no statistically significant difference between the two groups (χ² = 1.057, p > 0.05). Subjects with Angle Class I (37.37%), deep bite (43.43%), and increased overjet (41.41%) showed a higher prevalence of TMD symptoms.

The prevalence and symptoms of temporomandibular disorders in head and neck cancer patients

OBJECTIVES

This retrospective patient survey aimed to assess the prevalence of temporomandibular disorders (TMD) before and after curative oncological treatment and to identify possible risk factors.

MATERIALS AND METHODS

Patients with squamous cell carcinoma in the tonsil or base of the tongue were included (n = 217). Medical records were collected to assess TMD prevalence before oncological treatment and at 6- and 12-month follow-up. Fisher's test and Pitman's test were used.

RESULTS

Significantly reduced mouth opening was observed after oncological treatment at 6- and 12-month follow-up (p < .001). Symptoms from the temporomandibular joint and jaw muscles plus pain upon palpation (p = .0083, p < .001, respectively) and self-reported pain upon chewing (<0.001) and opening the mouth (<0.001) increased 12 months following radiotherapy. Pain and degree of mouth opening prior to treatment, self-reported depression, overall health status, brachytherapy and jaw exercise during radiotherapy were factors affecting the increase of TMD symptoms.

CONCLUSION

All TMD symptoms escalated significantly one year after radiotherapy except self-reported sounds from the temporomandibular joint. Reduction in the degree of mouth opening and pain in the jaw muscles and the temporomandibular joint when opening the mouth and upon chewing were commonly reported symptoms following radiotherapy. Several potential risk factors were identified.

Are oral overuse behaviours associated with painful temporomandibular disorders? A cross-sectional study in Portuguese university students

BACKGROUND

Many different types of oral overuse behaviours occur frequently in adult populations with painful temporomandibular disorders (TMDs). Less is known regarding these behaviours and their associations with TMDs in university students.

OBJECTIVES

Test the association between frequency of different oral overuse behaviours evaluated by the Oral Behaviour Checklist (OBC) and the severity of painful TMDs.

METHODS

In this cross-sectional study, 1381 students from 19 universities in the Oporto District, Portugal, completed the Research Diagnostic Criteria for TMD (RDC/TMD) Personal History Questionnaire and the OBC, and they received an RDC/TMD clinical examination. The OBC sum score (ranging from 0 to 84 points) was classified as normal (0 ≤ 16 points), low overuse (17 ≤ 24) or high overuse (≥25). Painful TMD subtypes (myalgia, arthralgia or combined) were identified. Associations were tested using multivariable binary logistic regression models (α = .05), adjusted for age and sex, and referencing the normal parafunction group.

RESULTS

University students with high overuse were more likely to have a painful TMD: myalgia (OR = 1.9, 95% CL: 1.3-3.0); arthralgia (OR = 2.2; 95% CL: 1.4-3.4), combined (OR = 5.0; 95% CL: 3.1-8.1). Students with low overuse were more likely to have only the combined painful TMD (OR = 2.4; 95% CL: 1.4-4.0) but not the individual painful disorders. Of the 21 different behaviours, 13 were reported at least 50% of the time.

CONCLUSIONS

In this university student sample, oral overuse behaviours are widespread, and their overall extent exhibited a dose-response relationship with respect to severity of painful TMDs based on pain and chronicity. Only some behaviours were independently associated with painful TMDs, suggesting the value of further OBC instrument development.

An International Survey on Temporomandibular Joint Surgeon's Implementation and Management of Discectomy in Treating Temporomandibular Joint Internal Derangement

PURPOSE

To survey temporomandibular joint (TMJ) surgeons to determine current practice trends and perceptions regarding the role of discectomy for the treatment of TMJ internal derangements.

METHODS

An anonymous 5-part web-based survey was sent to TMJ surgeons. The survey was created and distributed, and the data were collected with the University of Michigan Qualtrics platform. Responses were compared based on operative volume, tendency to replace the disc, and likelihood of requiring temporomandibular joint replacement (TJR) after discectomy. Spearman correlations were used to test statistically significant differences. Domain-level analyses were also performed by summarizing items into 3 domain scores. Analyses were performed in SAS V9.4 (SAS Institute Inc., Cary, NC, USA).

RESULTS

Fifty-nine surgeons (33.9%) completed the survey. Discectomy was not considered to be a useful procedure by 85% of respondents, and 74% would not consider discectomy as a first surgical option. Most would consider discectomy (64%) before alloplastic total joint replacement. Discectomy was preferred over discopexy for the management of anterior disc displacement with reduction by high volume surgeons (89%), but most (72%) did not feel that discectomy was beneficial over arthroscopy in the treatment of anterior disc displacement without reduction and concomitant degenerative bony changes. In managing symptomatic disc perforation, 66% agreed that discectomy is the procedure of choice and 49% felt that interpositional tissue is indicated in most cases after discectomy. Respondents who reported fewer re-operations requiring alloplastic TJR after discectomy had, on average, more positive perceptions of discectomy on the benefits domain (P = .03), better than alternatives domain (P = .03), and fewer concerns on the perceived adverse effects domain (P = .03).

CONCLUSIONS

TMJ surgeons do not employ TMJ discectomy in most cases of TMJ internal derangement. However, discectomy is considered useful in cases of disc perforation or for persistent symptomatic disc displacement without reduction, in an attempt to avoid alloplastic TJR. Common adverse effects included joint noises and osteoarthrosis, and the use of interpositional disc replacement tissue did not alter the incidence of adverse effects or complications reported.

Sleep bruxism and temporomandibular disorders: A scoping review of the literature

OBJECTIVE

To provide a scoping review of the literature by assessing all the English-language papers that investigated the relationship between sleep bruxism (SB) and temporomandibular disorders (TMDs).

STUDY DATA AND SOURCES

A search was performed in the National Library of Medicine (PubMed) and Scopus databases, in order to identify all the articles published assessing the relationship between SB and TMDs, by several different approaches. The selected articles were then structurally read and summarized in PICO tables. The articles were selected independently by the two authors.

STUDY SELECTION

Out of 185 references that were initially retrieved, 47 articles met the inclusion criteria and were thus included in the review. The studies were divided into four categories based on the type of SB assessment: 1. questionnaire/self-report (n = 26), 2. clinical examination (n = 7), 3. electromyography (EMG) (n = 5), and 4. polysomnography (PSG) (n = 9).

CONCLUSIONS

Studies based on questionnaire/self-report SB featured a low specificity for SB assessment, and in general they found a positive association with TMD pain. On the contrary, instrumental studies (i.e., electromyography, polysomnography) found a lower level of association or even a negative relationship between SB and TMD pain. Findings from this updated review confirmed the conclusions of a previous review by Manfredini & Lobbezoo, suggesting that literature findings on the relationship between SB and TMDs are dependent on the assessment strategies that are adopted for SB. Future studies should consider SB as a multifaceted motor behavior that must be evaluated in its continuum spectrum, rather than using a simplified dichotomous approach of presence/absence.

Chairside risk assessment for first-onset temporomandibular disorders: Result from the Orofacial Pain: Prospective Evaluation and Risk Assessment data set

BACKGROUND

Temporomandibular disorders (TMD) risk assessment is difficult in general dentistry owing to the complexity of multifactorial risk contributions and the lack of standardized education. The authors explored a health history-based chairside risk assessment.

METHODS

Secondary data analysis was performed on the Orofacial Pain: Prospective Evaluation and Risk Assessment data set. Potential demographic, systemic, and local risk contributors were conceptualized into 10 risk categories. Multivariate Cox proportional hazards modeling with backward selection was applied. Variables with P values < .05 were kept in each successive model.

RESULTS

The analysis included data from 2,737 participants. The final model indicated that people with any psychological conditions, pain disorders, sleep disorders, or orofacial symptoms were at elevated risks of developing first-onset TMD. Results of post hoc analysis showed the coexistence of conditions from multiple body systems conferred greater risk of developing TMD.

CONCLUSIONS

Coexisting conditions and symptoms from multiple body systems substantially increase the risk of developing TMD pain. Therefore, multisystem risk assessment and interprofessional collaborations are important for the prevention of TMD.

PRACTICAL IMPLICATIONS

Dentists should include psychological conditions, pain disorders, sleep disorders, and orofacial symptoms when assessing patients' risk of developing TMD pain.

Dentists working conditions - factors associated with perceived workload

BACKGROUND

Dentists are often exposed to occupational health hazards such as stress, high workload, and ergonomic and mental strain. However, there are limited studies focussing on occupational health and factors associated with working conditions. The aim of this study was to identify possible gender differences and factors associated with a high workload.

METHOD

The study population comprised of 187 dentists (123 women and 64 men) who had been working between 5 and 12 years. All participants completed a questionnaire regarding perceived workload and different working conditions. In the logistic regression analyses, gender and employment (employee or employer/manger), influence over work, social support, ergonomics, and working hours were used as independent covariates.

RESULTS

Poor satisfaction with ergonomic conditions and low influence on the work situation were reported by 40 and 47% of the participants, respectively. Female dentists were more often employees, reported lower influence over work situation, and more often worked part-time compared to male dentists. Those who reported a high workload significantly more often experienced that they had low influence over work, low levels of social support, and were not satisfied with ergonomic working conditions.

CONCLUSION

Dentists with low influence over work, low levels of social support, and who were unsatisfied with the ergonomic conditions reported higher levels of workload. The dentists experienced a similar workload, regardless of employment and gender. Preventive actions at the workplace in order to maintain a moderate workload promote both individual and organizational measures, to minimize the risk of poor occupational health.

Temporomandibular joint osteoarthritis at Chelechol ra Orrak, Palau

OBJECTIVE

To explore the frequency and severity of temporomandibular joint osteoarthritis (TMJ-OA) and its causative factors in a skeletal assemblage from the prehistoric site of Chelechol ra Orrak, Palau, western Micronesia.

MATERIALS

50 temporomandibular joint surfaces (mandibular condyles and articular eminences), representing a minimum of 22 adult individuals, 17 of which retain teeth.

METHODS

Joint surfaces were macroscopically evaluated for characteristics associated with TMJ-OA and joint morphology. Dental remains were scored for tooth wear and staining.

RESULTS

Nine individuals (40.1 %) displayed lesions typical of TMJ-OA. The strongest associations were between tooth wear and TMJ-OA.

CONCLUSIONS

Indirect effects of parafunctional dental activity appear to be a factor in TMJ-OA frequency at Chelechol ra Orrak. While betel nut chewing may be one of those activities, it does not appear to be solely driving the presence of TMJ-OA.

SIGNIFICANCE

This study highlights the association between a specific parafunctional use of the temporomandibular joint and the potential pathological consequences. It also reinforces the need to carefully evaluate the archaeological context of skeletal remains in order to evaluate specific etiological factors in the presence of TMJ-OA in present and past populations.

LIMITATIONS

Sample sizes are limited in this study. This will increase as excavations continue.

SUGGESTIONS FOR FURTHER RESEARCH

Because dental occlusion appears to be associated with TMJ-OA, focus on dental conditions affecting occlusal patterns, such as third molar agenesis, antemortem tooth loss, and malocclusion, and their relationship to TMJ-OA frequency, are recommended.

Prevalence of temporomandibular disorders in patients seeking orthodontic treatment: A systematic review

The objective of this systematic review was (a) to establish the prevalence of temporomandibular disorders (TMDs) in patients seeking orthodontic treatment and (b) to determine the association between the presence of TMD and sex, age and malocclusion. A systematic literature search was performed according to PRISMA guidelines from 1969 to 2019 using the PubMed and LIVIVO databases. Eight study articles met the inclusion and exclusion criteria. An additional three contributions were identified through manual searching of the reference lists of retrieved articles. The methodological quality of the 11 articles was assessed with the Joanna Briggs Institute Critical Appraisal Checklist for prevalence studies. TMD prevalence ranged from 21.1% to 73.3%. The frequency of painful TMD signs/symptoms varied from 3.4% to 65.7%, while non-painful signs/symptoms ranged from 3.1% to 40.8%. The percentage of males and females presenting with TMD varied from 10.6% to 68.1% and 21.2 to 72.4%, respectively. In all studies, TMD prevalence was higher among females. The majority of articles reported more TMD signs/symptoms in individuals older than 18 years as compared to younger ones (≤18 years). While in four studies no association between TMD and malocclusion was found, another three investigations indicated that TMD may be related to certain occlusal traits. The TMD prevalence in patients seeking orthodontic treatment was high, with many individuals presenting painful TMD signs/symptoms. Female and older patients appear to have a greater occurrence of TMD. Although no strong association between TMD and malocclusion was established, several occlusal traits were implicated.

Work ability and productivity among dentists: associations with musculoskeletal pain, stress, and sleep

Purpose

Work ability can be measured by the work ability index (WAI), and work-related questions measuring productivity loss in terms of quality and quantity of work. Dentists have high occupational risk of musculoskeletal pain and the exposure of ergonomic strain is already high during dental education. The aim was to evaluate work ability and productivity among dentists, and to identify gender differences and associations with sleep, stress, and reported frequent pain.

Methods

The study population comprised 187 dentists (123 women and 64 men) who had been working as dentists between 5 and 12 years. Participants completed a questionnaire regarding sleep, stress, presence of pain at different sites, work ability assessed by WAI, and productivity in terms of quality and quantity of work.

Results

Poor sleep quality and high level of stress were reported by 31% and 48.1% of participants, respectively, with no gender differences and no association with age. The prevalence of frequent pain ranged 6.4–46.5% with shoulders being the most prevalent site. Thirty-three percent reported reduced work ability. Poor sleep, high amount of stress, and multi-site pain were associated with decreased work ability.

Conclusions

A high prevalence of pain was shown among dentists. Decreased work ability in terms of productivity loss was associated with poor sleep quality, high amount of stress, and multi-site pain. Preventive actions at the workplace should promote good musculoskeletal health, and measures taken, both individual and organizational, to minimize the risk of high, persistent stress and work-related pain.

Early responses to 3 mm resilient stabilization appliance therapy for sub-acute and chronic temporomandibular disorder pain predict 12-months follow-up outcomes

Objective: To estimate whether outcomes at 12-month follow-up may be predicted by an intermediate and early response to a 3 mm resilient splint therapy for unilateral arthralgia and myofascial pain assessed at 3- and 6-month follow-ups. Methods: Data obtained from one retrospective cohort study consisting of 78 patients suffering from chronic and sub-acute unilateral arthralgia and myofascial pain who were managed with 3 mm resilient splint therapy were subjected to analysis. Results: Baseline visual analog scale (VAS) intensity, gender as well as changes in the intensity of VAS pain at 3- and 6-month follow-ups predicted unilateral arthralgia and myofascial pain group membership (p < .001). The function classified 83.3% of the cross-validated and 87.2% of original grouped cases correctly. Discussion: The proposed model may be used to timely identify patients who are at risk of developing prolonged non-responsive unilateral arthralgia and myofascial pain chronicity.

Prevalence and occupational risk factors of musculoskeletal diseases and pain among dental professionals in Western countries: A systematic literature review and meta-analysis

Background

This review aimed at examining the prevalence of musculoskeletal diseases and pain among dental professionals in Western countries. Furthermore, possible occupational risk factors were analyzed.

Methods

The literature search was conducted from June to July 2016, with an update in December 2017 using the databases MEDLINE, CINAHL, LIVIVO, Science Direct, PubMed, and Web of Science. The quality assessment was performed with a standardized instrument consisting of 10 items. A meta-analysis was carried out to compute pooled prevalence rates for musculoskeletal diseases and pain.

Results

A total of 41 studies were included in this review; 30 studies met the criteria for the meta-analysis. Prevalence rates of musculoskeletal diseases and pain among dental professionals ranged from 10.8% to 97.9%. The neck was the body region affected most often (58.5%, 95% CI = 46.0–71.0) followed by the lower back (56.4%, 95% CI = 46.1–66.8), the shoulder (43.1%, 95% CI = 30.7–55.5) and the upper back (41.1%, 95% CI = 32.3–49.9). Potential occupational risk factors included an awkward working posture, high number of treated patients, administrative work, vibration, and repetition.

Conclusions

Musculoskeletal diseases and pain are a significant health burden for dental professionals. This study showed high prevalence rates for several body regions. Therefore, suitable interventions for preventing musculoskeletal diseases and pain among dental professionals are needed.

Is quality of life affected by temporomandibular disorders?

OBJECTIVE

To determine the impact of temporomandibular disorders in quality of life.

METHODS

A total of 102 volunteer patients (68 female) aged 19 to 86 years, who sought medical care in health clinics of the university and were evaluated in the period from September to December 2013. The subjects were examined according to the Research Diagnostic Criteria for Temporomandibular Disorders, using a mechanical algometer (Palpeter®) with standardized pressure of 0.5 and 1.0kg, and Medical Outcomes Study 36-Item Short Form Health Survey (SF-36) questionnaire, to assess quality of life. The data were tabulated for statistical analysis and the variables were correlated with the clinical findings of the temporomandibular disorders and quality of life.

RESULTS

Fifty percent of patients were positive for temporomandibular disorders and 39.2% classified as myofascial pain group. The temporomandibular disorder group was significantly associated with uncomfortable bite (p=0.0000), temporomandibular joint clicking (p=0.0001) and tooth clenching (p=0.0001). The Mann Whitney test used to analyze the SF-36 revealed that the domains of pain (mean score of 47.80%; p<0.0001) and mental health (62.67%; p<0.05) were strongly associated with temporomandibular disorders.

CONCLUSION

The quality of life of individuals with temporomandibular disorders was negatively affected by the presence of pain and mental health disorders.

Correlation of Condylar Translation During Maximal Mouth Opening with Presence of Signs of Temporomandibular Joint Disorders in an Asymptomatic Population of 18-25 Years Age Group of Northern India

Objective(s):

The objective of this study was to determine the frequency of “subluxation” and presence of clinical signs of Temporomandibular Joint Disorder (TMD) in asymptomatic individuals and its distribution according to age and sex.

Materials and Methods:

The material investigated comprised of 200 asymptomatic subjects with 400 joints. The subjects were divided into two groups of 18-25 years and 50-60 years of age consisting of equal number of males and females. Clinical examination involved measurement of maximal inter-incisal distance, joint sounds and deviation. For radiological examination, Temporomandibular Joint (TMJ) open mouth close mouth view option (TMJ1/2) was used on a Digital Panoramic Machine. All the radiographs were traced to assess subluxation and anterior translation of the condyle. The statistical analysis was carried out using Statistical Package for Social Sciences (SPSS Inc., Chicago, IL, version 15.0 for Windows).

Results:

The prevalence of the signs of TMDs in the asymptomatic population was found to be very high and more predominant in females as compared to males. Furthermore, the older age group had comparatively less signs of TMDs. It was of interest that the subjects presenting with clinical signs of TMD were significantly less as compared to the subjects presenting with subluxation. The value of anterior translation was found to be more in females in the younger age group as compared to the males. Similarly, it was more in males as compared to females in older age group. But the mean anterior translation difference in females in 18-25 years and 50-60 years showed a statistically significant difference with P-value 0.017.

Conclusion:

Subluxation is a very common feature found in almost all the subjects in this study with a high prevalence. Hence, we may assume that the increased incidence of TMDs could be a direct result of the phenomena of subluxation. The decrease in mandibular length could be the cause of decreased mouth opening and increased subluxation.

A method for preventive intervention regarding temporomandibular pain and dysfunction

OBJECTIVE

Adolescent girls frequently suffer from temporomandibular disorder (TMD) symptoms and associated headache. A program aimed at informing about risk behavior for TMD symptoms, how to influence harmful habits and about general relaxation was tested.

MATERIAL AND METHODS

Eighty girls at two high schools, 16 years of age, with or without symptoms, were invited to the health information on two occasions and 60 girls participated. Firstly, a questionnaire regarding symptoms and oral parafunctional habits was administrated. Structured information was given about the normal anatomy and function of muscles and joints, about the occlusion, oral habits and symptoms of orofacial pain/dysfunction and headache. General relaxation was instructed and trained. At a three-month follow-up, the same questionnaire regarding symptoms as at baseline was completed.

RESULT

The information provided was perceived as useful and instructive. At the follow-up, 77% reported that they used what they had learned. Headache once a week or more decreased from 49% at baseline to 35% and headache 'never/rarely' changed from 11% to 25% (p = .002). Reported joint sounds had decreased by the follow-up (p = .053), as had the use of chewing gum (p = .002). A majority of the girls suggested that the information should be scheduled during school hours.

CONCLUSION

Health information about the jaw system can influence risk factors for TMD symptoms and the frequency of symptoms among adolescent girls.

Frequency of Symptoms of Temporomandibular Disorders among Prishtina Dental Students

BACKGROUND

Early diagnosis of temporomandibular disorders (TMD) is important for prevention of greater damages of the parts of the oro-facial system. There are early symptoms that can be used as predictors of TMD.

AIM

The study aimed to assess the frequency of the symptoms of TMD among dental students.

METHODS

Total number of 166 respondents, all undergraduate dental students, (84 female, 82 male), mean age 22, participated in this study. For the study, the questionnaire of Fonseca was used. There were ten questions to answer with: no, sometimes and yes. Fonseca-Clinical index classification is: 0-15 points, no TMD; 20-40 points, mild TMD; 45-65 points, moderate TMD and 70-100 points, severe TMD.

RESULTS

Forty-six point four percentages of the students, had no symptoms of TMD, 44.6 % had mild TMD, 7.8% moderate TMD and only 1.2 % had severe TMD. By conventional criteria, there is not any statistical difference of the TMD between male and female (χ² = 1.133, p = 0.769).

CONCLUSION

Fonseca questionnaire has its importance in the early diagnosis of TMD that can occur in the young population.

Interaction Between Awake and Sleep Bruxism Is Associated with Increased Presence of Painful Temporomandibular Disorder

AIMS

To explore whether awake and sleep bruxism interact in their associations with painful temporomandibular disorders (TMD) and whether the interaction is multiplicative or additive.

METHODS

In this case-control study, all participants (n = 705) were part of the multicenter Validation Project and were recruited as a convenience sample of community cases and controls and clinic cases. Logistic regression analyses were applied to test for the association between self-reported bruxism (sleep and/or awake) and the presence of painful TMD, and odds ratios (ORs) with 95% confidence intervals (95% CIs) were computed. Regression models included an interaction term to test for multiplicative interaction, and additive interaction was calculated as the relative excess risk due to interaction (RERI).

RESULTS

Based on logistic regression analyses adjusted for age and gender, the main effects for both awake (OR = 6.7; 95% CI: 3.4 to 12.9) and sleep (OR = 5.1; 95% CI: 3.1 to 8.3) bruxism were significant. While the multiplicative interaction (OR = 0.57; 95% CI: 0.24 to 1.4) was not significant, the results indicated a significant positive additive interaction (RERI = 8.6; 95% CI: 1.0 to 19.7) on the OR scale.

CONCLUSION

This study has demonstrated that awake and sleep bruxism are associated with an increased presence of painful TMD, and that both types of bruxism are not independently associated, but interact additively. As such, the presence of each factor amplifies the effect of the other.

Do patients with malocclusion have a higher prevalence of temporomandibular disorders than controls both before and after orthognathic surgery? A systematic review and meta-analysis

PURPOSE

The aim of this study was to identify, through meta-analysis, whether patients who require orthognathic surgery have a higher prevalence of temporomandibular disorders (TMDs) than controls, both before treatment and after.

MATERIAL AND METHODS

A systematic review and meta-analysis were conducted based on PRISMA guidelines, to address the study purposes. A search of major databases through PubMed, EMBASE, and Cochrane CENTRAL was performed to locate all pertinent articles published from inception to June 2016. Inclusion criteria were controlled clinical studies, either prospective or retrospective, and case-control studies comparing preoperative and postoperative signs and symptoms of TMDs in patients who undergo orthognathic surgery to those of a healthy volunteer population with no dentofacial deformities. The predictor variables were patients with dentofacial deformities who underwent orthognathic surgery and patients with no dentofacial deformities and with good maxillomandibular relations and normal occlusion. The outcomes variables were the weighted, prevalence rate (proportion) in signs and symptoms of TMDs in patients with dentofacial deformities and risk ratio (RR) of signs and symptoms of TMDs before and after orthognathic surgery, compared to the control group.

RESULTS

A total of 542 patients enrolled in 6 studies were included in this analysis. The overall pooled weighted rate or prevalence of TMDs for orthognathic surgery patients preoperatively was 32.5% (95% CI = 26.7%-38.9%). There was a significant difference between the 2 groups with respect to TMDs before surgery, but no significant difference in TMDs after surgery. The RR for patients who had dentofacial deformities before orthognathic surgery compared with a control group was 1.634 (95% CI = 1.216-2.194; P = 0.001). The RR for patients after orthognathic surgery compared with a control group was 1.262 (0.718; 95% CI = 0.805-1.979; P = 0.311).

CONCLUSION

The results of this study show that patients who are going to have a correction of their malocclusion by orthodontics and orthognathic surgery have a significant incidence of TMDs when compared to a control population, but that after treatment, the incidence of TMDs does not differ from a control population. The reasons for these findings are not clear.

Sleep and awake bruxism in adults and its relationship with temporomandibular disorders: A systematic review from 2003 to 2014

OBJECTIVE

In order to establish a relationship between bruxism and temporomandibular disorders (TMDs), a systematic review was performed.

MATERIALS AND METHODS

A systematic research was performed based on PubMed, Cochrane Library, Medline, Embase, BIREME, Lilacs and Scielo data bases, between 2003 and 2014 including all languages. Descriptive clinical cases were identified. Two independent authors selected the articles. PICO format was used to analyse the studies and the Newcastle-Ottawa Scale (NOS) was used to verify the quality of the evidence.

RESULTS

Thirty-nine studies (n = 39) were analysed in this review. According to bruxism diagnosis, articles were grouped as follows: polysomnographic diagnosis (PSG) (n = 7), clinical diagnosis (n = 11) and survey/self-report (n = 21). Thirty-three articles (n = 33) established a positive relation between bruxism and TMD and six (n = 6) did not. Quality of evidence was low to moderate. In general, the most part of the studies showed shortcomings on their design with bias risk, and also had a low sensitivity on bruxism diagnosis.

CONCLUSIONS

The evidence based on PSG was not as conclusive as the studies that used surveys and clinical exam to diagnosis bruxism, when bruxism was related to TMD. Sleep bruxism could be associated with myofascial pain, arthralgia and joint pathology as disc displacement and joint noises. Although the evidence at present is inconclusive and does not provide information according to the type of bruxism (bruxism sleep and wakefulness), it is possible to suggest that bruxism would be associated with TMD.

Assessment of risk factors for oro-facial pain and recent developments in classification: implications for management

Oro-facial pain research has during the last decades provided important novel insights into the basic underlying mechanisms, the need for standardised diagnostic procedures and classification systems, and multiple treatment options for successful rehabilitation of the patient in pain. Notwithstanding the significant progress in our knowledge spanning from molecules to chair, there may also be limitations in our ability to integrate and interpret the tremendous amount of new data and information, in particular in terms of the clinical implications and overriding conceptual models for oro-facial pain. The aim of the present narrative review is to briefly summarise some of the current thoughts on oro-facial pain mechanisms and recent attempts to identify biomarkers and risk factors leading to the proposal of a new risk assessment diagram for oro-facial pain (RADOP) and a provocative new concept based on stochastic variation between multiple risk factors. Finally, the implications for novel management strategies will briefly be discussed.

Self-reported temporomandibular disorder symptoms and severity of malocclusion in prospective orthognathic-surgical patients

OBJECTIVE

The objective of this study is to analyze the association between self-reported symptoms of temporomandibular joint disorder (TMD) and the severity of malocclusion in prospective orthognathic-surgical patients.

MATERIAL AND METHODS

The subjects consisted of 50 consecutive patients (13 males and 37 females) referred to two university clinics for assessment of orthodontic-surgical treatment need. Data considering self-reported TMD symptoms were gathered using a semi-structured diary. At the first appointment, all patients rated the importance of treatment (on a scale of 1-10) and assessed self-perceived dental appearance using a VAS scale. The scale was anchored with photographs 1 and 10 from the Aesthetic Component (AC) of the Index of Orthodontic Treatment Need (IOTN). Study models were assessed by an experienced orthodontic specialist using the Peer Assessment Rating (PAR) index and the Index of Complexity, Outcome and Need (ICON). Association between the PAR and ICON scores and the number of reported symptoms was analyzed statistically.

RESULTS

Seventy-one percent of patients reported experiencing TMD symptoms. The most prevalent symptoms were pain in the head and/or neck region and fatigue in the TMJ region. The number of symptoms was highest in the morning. Ninety percent of males and 86% of females rated the importance of treatment as high; males experiencing TMD symptoms tended to rate surgery as more important compared with males with no symptoms (p = 0.056).

CONCLUSIONS

In this sample, the results cannot unambiguously confirm an association between self-reported symptoms of TMD and objectively defined severity of malocclusion.

Computerized analysis of the distribution of occlusal contacts in individuals with Parkinson's disease and temporomandibular disorder

OBJECTIVES

The aims of the present study were to determine the prevalence of temporomandibular disorder (TMD) in a sample of patients with Parkinson's disease (PD) and to analyze the distribution of occlusal contacts.

METHOD

The sample was composed of patients with PD aged 50-75 years. Temporomandibular disorder was evaluated using the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD). The distribution of occlusal contacts was determined using the portable T-Scan III^® occlusal analysis system during maximum voluntary clenching. Fisher's exact test was used to test the association between TMD and occlusal contact symmetry.

RESULTS

Forty-two individuals with PD were analyzed. The prevalence of TMD was 23.8%. No statistically significant association was found between TMD and occlusal contact symmetry. Moreover, no significant difference in the distribution of occlusal contacts was found between the groups with and without TMD.

DISCUSSION

The present data suggest no association between TMD and occlusal contact asymmetry in individuals with PD.

CONCLUSION

The results of this study identified a prevalence of 23.8% of TMD signs in subjects with PD and a high frequency of occlusal asymmetry in this sample.

[Facial pain]

Diagnosis and treatment of facial pain is a problem for physicians of different specialties (neurologists, dentists, surgeons, oculists, otolaryngologists and psychiatrists). A classification of this pathology is far from ideal and an interdisciplinary comprehensive approach is needed. Current approaches to etiotropic, symptomatic and pathogenetic treatment of patients with most frequent variants of orofacial pain are presented.

Risk factors associated with incidence and persistence of frequent headaches

OBJECTIVE

Headaches represent a significant public health problem, but the knowledge of factors specifically related to incidence and persistence of headaches is still limited. The aim of this study was to evaluate whether gender, self-reported bruxism and variations in the dental occlusion contribute to onset and persistence of frequent headaches.

MATERIALS AND METHODS

The study population comprised 280 dental students, examined annually in a 2-year prospective study with a questionnaire and a clinical examination of the jaw function. In the analysis subjects were dichotomized into cases with frequent (once a week or more) or without frequent headaches (controls). The 2-year cumulative incidence was based on subjects without frequent headaches at baseline. Cases with 2-year persistent headaches reported such symptoms at all three examinations. Self-reported bruxism and factors in the dental occlusion at baseline were used as independent variables in logistic regression analyses.

RESULTS

The 2-year cumulative incidence of frequent headaches was 21%. Female gender (OR = 2.6; CI = 1.3-5.4), self-reported bruxism (OR = 2.3; CI = 1.2-4.4) and mandibular instability in intercuspal position (OR = 3.2; CI = 1.4-7.5) were associated with incidence of frequent headaches. Persistent headaches during the observation period were present in 12 individuals (4%) and significantly related to mandibular instability in intercuspal position (OR = 6.1; CI = 1.6-22.6).

CONCLUSIONS

The results indicate that female gender, self-reported bruxism and mandibular instability in intercuspal position are of importance in the development of frequent headaches. In management of these patients a multidisciplinary approach including dentists may be important and, thus, advocated.

Temporomandibular Disorders in a Sample Population of the Brazilian Northeast

Temporomandibular disorder (TMD) is a common condition. This study is part of a research group and it investigated the prevalence of TMD and myofascial pain and its association with gender, age and socioeconomic class. The sample comprised 100 subjects, aged 15 to 70, users of the Family Health Units' services, in the city of Recife, PE, Brazil. The TMD degree was evaluated using the Research Diagnostic Criteria for TMD and socioeconomic class by the Economic Classification Criteria Brazil. Categorical variables were analyzed by chi-square test for proportions and Fisher's exact test for 2x2 tables, and binary logistic analysis to track the relationship between the independent and dependent variables. According to the results, 42% of the subjects had TMD and 14% myofascial pain. No statistically significant association could be found between TMD and gender or socioeconomic class, but it was found to have statistically significant association with age, and myofascial pain was associated with socioeconomic class. Considering that the results of the present study should be confirmed by further studies and the fact that this was a pilot study, the prevalence must be analyzed with caution.

The role of occlusal factors on the occurrence of temporomandibular disorders

AIMS

The aim of this study was to investigate the relationship between occlusal factors and temporomandibular disorders (TMD).

METHODOLOGY

One hundred patients were selected among those who sought medical or dental care in public practice in Recife, Brazil. The presence of malocclusions and absence of five or more posterior teeth were evaluated by the clinical exam. TMD diagnosis was given using Research Diagnostic Criteria (RDC/TMD). Statistics were carried out using Fisher and Mann-Whitney methods with 5% significance level, as well as multiple logistic regression analysis.

RESULTS

The sample was mainly comprised of women (83%), individuals over 30 years old (57%) and singles (53%). The percentage of TMD and malocclusion in total sample was 42% and 50%, respectively, while in TMD subjects, malocclusion was present in 38.1%. There was no association between TMD and the occlusal factors studied.

CONCLUSION

It can be concluded that malocclusion and loss of five or more posterior teeth does not contribute to TMD.

Replacement of Missing Anterior Teeth in a Patient with Temporomandibular Disorder

The loss of anterior teeth leads to extreme psychological trauma, along with functional and esthetic debilitations. Healthy anterior teeth play an important role of protecting the posterior teeth during excursive mandibular movement. Loss of anterior teeth induces posterior interference with extended disocclusion time. Posterior disocclusion is critical to remove the harmful force on the teeth temporomandibular joint and eliminate muscle hypertonicity. Occlusal interference is considered as contributing factor to temporomandibular disorder (TMD) symptoms. Prosthesis design should eliminate deleterious tooth contacts. Establishing optimum anterior guidance is a key to establishing harmonious functional occlusion in addition to the correction of the esthetic and phonetic disabilities. This case report explains the steps involved in the rehabilitation of the TMD patient with loss of maxillary anterior teeth.

Digital Evaluation of Functional Occlusion Parameters and their Association with Temporomandibular Disorders

CONTEXT

Dental researchers are contradictory in their opinion on the role of occlusion in TMD. Occlusal evaluation of both conventional and digital methods in TMD patients will provide the accurate information about the factors accountable for occlusal instability. Identifying the factors responsible will facilitate precise diagnosis and treatment for TMD.

AIM

The AIM of the study was to determine the dynamic occlusal parameters strongly associated with the etiology of Temporomandibular disorders.

MATERIAL AND METHODS

Study group consisted of 100 patients; it included 50 patients with normal TMJ(Group I) and remaining 50 patients had a minimum of one positive sign or symptom of Temporomandibular disorder (GroupII). The patient's dynamic occlusal contacts were evaluated by both conventional and digital methods. The Articulating paper was utilized for conventional occlusion analysis. During conventional analysis centric, lateral and protrusive interferences were evaluated along with loss of vertical dimension. Digital occlusal analysis was performed with T-Scan III. Clusion time, disclusion times were recorded for both groups. Chi-square and Student't' statistical analyses were performed to ascertain the association and statistically significant difference between the groups using SPSS19.

RESULTS

Group II patients predominantly (66%)had Group-function occlusion compared to Group I subject. Centric slide more than 2 mm found to have strong influence (p value 0.008) on the etiology of TMD. Among the occlusal interferences evaluated balanced side interferences had a strong correlation with TMD with p-value of 0.003. Working side interferences, protrusive interferences had a p-value of 0.157, 0.826 respectively, indicating weak association. T-Scan analysis showed Group I had 0.689, 0.9136, 0.7952, 0.9794 seconds of clusion, left, right, protrusive disclusion time respectively compared to corresponding 1.862, 1.7995, 1.6978, 1.9296 seconds for Group II. Statistically significant difference (p≤0.05) was found between the mean values of both groups.

CONCLUSION

Among the dynamic occlusal parameters evaluated centric slide and balancing side interferences were found to be highly influential in TMD etiology. TMD patients had prolonged clusion and disclusion times compared to healthy TMJ patients.

Orofacial pain and temporomandibular disorders: the impact on oral health and quality of life

Many conditions may cause painful symptoms in orofacial structures. Among the chronic conditions that affect this area, temporomandibular disorders are the most common. Temporomandibular Disorder is a collective term that includes a number of clinical complaints involving the masticatory muscles, the Temporomandibular Joint and associated structures. In some cases, these complaints can be associated with depression, catastrophizing behavior and impact on quality of life. The present study aims to explain the relationship between Temporomandibular Disorders and pain chronification and their relation to a variety of psychosocial and behavioral comorbid conditions. The mechanisms of pain conduction and suggestions for management are also addressed.

Temporomandibular disorders after orthognathic surgery in patients with mandibular prognathism with depression as a risk factor

OBJECTIVE

To examine the prevalence of temporomandibular disorders (TMD) after orthodontic-surgical treatment in patients with mandibular prognathism and analyze psychosocial variables related to TMD.

MATERIALS AND METHODS

The case-control study comprised 40 patients with mandibular prognathism who underwent combined orthodontic-surgical treatment (orthognathic surgery group). Forty-two patients with untreated mandibular prognathism served as a control group. Research diagnostic criteria for temporomandibular disorders was used in order to assess the clinical diagnosis of TMD (Axis I) and to estimate depression, somatization and patient's disability related to chronic pain (Axis II).

RESULTS

The overall prevalence of TMD was not significantly different between the groups. Myofascial pain was significantly higher, while arthralgia, arthritis and arthrosis was significantly lower in the orthognathic group compared with the controls (90.5% vs 50.0%, 0.0% vs 27.8%, respectively) (p < 0.05). Females in orthognathic surgery group showed higher prevalence of TMD (p < 0.05) and myofascial pain (p < 0.01) and increased level of chronic pain (p < 0.05) in comparison with post-operative males. No significant difference in chronic pain, somatization and depression scores was found between investigated groups. With respect to presence of TMD within the groups depression was higher in untreated subjects with dysfunction (p < 0.05).

CONCLUSION

Prevalence of TMD immediately after completion of orthodontic-surgical treatment for mandibular prognathism is similar to frequency of dysfunction in untreated subjects, is significantly higher in females and is most commonly myogenic. Furthermore, females show an increased level of chronic pain post-operatively. Somatization and depression levels do not differ between patients with corrected prognathism and untreated prognathic patients.

A review of the oral health-related evidence that supports the orthodontic treatment need indices

BACKGROUND AND OBJECTIVES

To date, there is no evidence-based method of quantification for malocclusion. Consequently, how deviant occlusal traits should be scored and weighted relative to one another is a matter of serious debate. Orthodontic Treatment Need Indices (OTNI) use the subjective opinion of the experts, as their foundation, to define the pathological boundaries (cut-offs) of occlusal traits. This paper reviews the evidence relating malocclusions or deviated occlusal traits to oral health problems, and investigates if this evidence supports the cut-off points and the rationale used for OTNI.

MATERIALS AND METHODS

The relevant cited studies and reviews from the MEDLINE, Web of Science, Scopus, Cochrane databases, and scientific textbooks were used. The citation rate was confirmed by using the Google Scholar.

RESULTS

So far, the evidence for harmful effects of deviated occlusal traits on oral health is either lacking or exists as cross-sectional (mostly) and longitudinal (a few and primarily short-term) studies. When an association was reported between a deviated occlusal trait and an oral health problem, either the strength of that association was weak, or due to methodological issues, findings were not conclusive. Consequently, establishing a cause and effect relationship is difficult. Further, commonly used OTNI do not record a full spectrum of occlusal traits, and relating their ranking or scoring systems to the available evidence is difficult. Therefore, there is little evidence to suggest that individuals with a high need (high score), as measured by OTNI, will necessarily put at risk their oral health if they turn down orthodontic therapy.

CONCLUSION

OTNI have a role in the epidemiology and can be used for resource planning, but their predictive value to detect the future objective functional deficits or oral health problems is questionable. OTNI will need revalidation over time with emerging research findings.

The dental occlusion as a suspected cause for TMDs: epidemiological and etiological considerations

The relationship between the dental occlusion and temporomandibular disorders (TMDs) has been one of the most controversial topics in the dental community. In a large epidemiological cross-sectional survey - the Study of Health in Pomerania (Germany) - associations between 15 occlusion-related variables and TMD signs or symptoms were found. In other investigations, additional occlusal variables were identified. However, statistical associations do not prove causality. By using Hill's nine criteria of causation, it becomes apparent that the evidence of a causal relationship is weak. Only bruxism, loss of posterior support and unilateral posterior crossbite show some consistency across studies. On the other hand, several reported occlusal features appear to be the consequence of TMDs, not their cause. Above all, however, biological plausibility for an occlusal aetiology is often difficult to establish, because TMDs are much more common among women than men. Symptom improvement after insertion of an oral splint or after occlusal adjustment does not prove an occlusal aetiology either, because the amelioration may be due to the change of the appliance-induced intermaxillary relationship. In addition, symptoms often abate even in the absence of therapy. Although patients with a TMD history might have a specific risk for developing TMD signs, it appears more rewarding to focus on non-occlusal features that are known to have a potential for the predisposition, initiation or perpetuation of TMDs.