[version 1; peer review: 2 not approved]
No competing interests were disclosed.
Music, a profound human expression, can have physical implications for its practitioners. Musicians face various physical challenges that can impact their well-being, with craniofacial and temporomandibular pain being prevalent yet understudied. Temporomandibular joint disorder (TMJD) affects up to one-third of the population, though prevalence varies by study. While musculoskeletal issues like carpal tunnel syndrome are well-documented in musicians, craniofacial and temporomandibular pain is less explored. This study aims to determine the differences in TMJD frequency among music students of different instrumental specialties.
The sample was composed of students between 12 and 25 years of age from the National University of Music of Peru. A stratified random probability sample was chosen. Data were collected using a structured instrument covering general data, academic information, dental malocclusion, the Fonseca Simplified Anamnestic Index, and the Global Stress Perception Scale. Statistical analysis included Pearson's Chi-square test and a generalized linear model regression.
The sample included 71.4% males with a median age of 23 years. Class II dental occlusion was most common (51.4%). TMJD prevalence was: 14.3% no TMJD, 60.0% mild TMJD, 22.9% moderate TMJD, and 2.9% severe TMJD. Metal wind (PR=0.04, 95%CI [0.00; 50.04], p=0.002) and woodwind players (PR=0.03, 95%CI [0.00; 0.56], p=0.018) had lower TMJD prevalence compared to plucked string and percussion players. Post-regression analysis indicated significant differences between metal wind and percussion students (p=0.030) and between percussion and woodwind students (p=0.025). These results are supported by the adjusted ratio of proportions analysis, which maintains statistical significance.
We found significant differences in TMJD prevalence among music students based on their instrumental specialty, with lower rates in metal wind and woodwind players compared to plucked string and percussion players.
Music, often considered one of the most sublime human expressions, is not without physical implications for those who produce it. Professional and amateur musicians, regardless of the instrument they play or the musical style they practice, are exposed to several physical challenges that can have a significant impact on their well-being.
Although the scientific literature has extensively explored musculoskeletal ailments in musicians, such as carpal tunnel syndrome or tendonitis, there is a gap regarding the assessment of pain-associated disabilities in the craniofacial and temporomandibular region. It is plausible to assume that they may be at increased risk due to the muscle strain associated with practicing and performing their art.
Disability associated with craniofacial and temporomandibular pain in musicians is a phenomenon that can be influenced by a combination of biomechanical, psychological and occupational factors. Postures and techniques, fundamental to the art of music making, can also be the epicenter of biomechanical stress that could lead to craniofacial and temporomandibular pain and disability. The biomechanical complexities of playing a musical instrument cannot be underestimated. And then there is posture. The way a musician positions himself or herself in relation to his or her instrument can have enormous repercussions. A stooped posture or an incorrect head angle can strain the musculature and joints of the craniofacial area, creating fertile ground for the appearance of temporomandibular problems. Let us not forget the phenomenon of overuse either. The muscles of the face and jaw, like any other muscle in the body, have their limits. In the heat of practice or during marathon performance sessions, these limits can easily be exceeded. The resulting muscle fatigue can become a critical factor contributing to the development of painful conditions in the craniofacial region. Even technique, that holy grail of musical mastery, can be a double-edged sword. Poor technique can multiply the biomechanical load on the craniofacial structures. On the other hand, even “correct” technique is no guarantee against the risk of disability, as the physical demands of musical performance often transcend anatomical capabilities.
The aim of this study was to determine the differences in the frequency of temporomandibular joint disorder among music students of different instrumental specialties.
The research was applied, with an observational, cross-sectional, and descriptive correlational design.
Our study followed the STROBE (Strengthening the Reporting of Observational Studies in Epidemiology) guidelines for cross-sectional studies. The study was approved by the Research Ethics Committee of the School of Stomatology of the Universidad César Vallejo with Official Letter No. 0103-2023-/UCV/P, dated December 20, 2023. We adhered to the principles of the Declaration of Helsinki. Written informed consent was obtained from all participants.
The sample consisted of 35 students from the National University of Music of Peru evaluated from December 21 to December 28, 2023. The sample was calculated with the Epidat software: program for epidemiological data analysis version 4.2 (Xunta de Galicia, Spain; Pan American Health Organization; Universidad CES, Colombia).
The instrument for data collection consists of four sections. The first section considers the collection of general data. The second section includes the collection of academic information related to the music specialty studied. The second section is based on the questionnaire used in the study conducted by Manrique-Olivares.
Permission was requested from the pertinent authorities to conduct the study and collect the data necessary for this research. Each student was explained the purpose and importance of our research, asking them to voluntarily participate in the study. They or their parents signed a written informed consent and assent form authorizing us to use their information in the study. We proceeded with the general data and academic information sections. In a naturally lit environment, a dental ev'aluation was performed. Subsequently, Fonseca's simplified anamnesis was performed. Finally, the Global Perception of Stress Scale for University Students was applied.
The data collected were first saved in Google Sheets. Analysis of these data was then carried out using JASP 0.18.3. Regarding the descriptive analysis, tabulations were generated to synthesize the qualities of the participating individuals, focusing on the central variables of the research. To analyze the proposition that there are differences in the frequency of temporomandibular joint disorder among music students according to their instrumental specialty, Pearson's Chi-square test and a regression study were carried out using a generalized linear model after verifying the statistical assumptions. Calculations were performed considering a confidence level of 95% (p<0.05).
The sample studied is significantly skewed towards the male sex, representing 71.4% (25 out of 35) versus 28.6% of women (10 out of 35). The median age of the participants is 23 years, with an interquartile range of 21 to 25 years, suggesting a young population. In terms of marital status, the majority are single (97.1%), probably reflecting their stage of student life.
Regarding dental occlusion, there was a predominance of Class II (51.4%), followed by Class I (31.4%) and Class III (17.1%).
The instrumental specialty is evenly distributed among five categories, each with 20% of the total number of participants.
Regarding temporomandibular joint disorder, 14.3% of the students had no signs or symptoms, while 60.0% showed mild TMJD, 22.9% moderate TMJD and 2.9% severe TMJD.
Finally, the mean stress score for students is 44.7, with a standard deviation of 5.6, which could indicate moderate levels of stress in this population.
The distribution of musical instruments practiced by students is diverse, ranging from guitar in the plucked string category (20%), to wind, percussion and bowed string instruments, with varied representations. For example, in bowed string, the double bass is practiced by 8.6% of the students, while the cello, violin and viola have smaller representations. In metal wind, trombone and trumpet are practiced by 8.6% and 5.7% respectively. In percussion, timpani stand out with 11.4%. Finally, in woodwind, the saxophone is practiced by 8.6% of the students.
The time since they started playing their specialty instrument shows a median of 9 years, with an interquartile range of 8 to 12 years. This indicates considerable experience in their musical specialty. In addition, weekly practice with their specialty instrument has a median of 20 hours, reflecting a high degree of commitment and practice.
Interestingly, 82.9% of the students also practice other instruments in addition to their major, suggesting musical versatility, but also possibly overcharge. The time spent weekly practicing their major and other instruments has a median of 23 hours.
| Variables | Temporomandibular joint disorder | p-value | |||
|---|---|---|---|---|---|
| No signs and symptoms (n=5) | Mild TMJD (n=21) | Moderate TMJD (n=8) | Severe TMJD (n=1) | ||
| n (%) | n (%) | n (%) | n (%) | ||
| Sex | 0.827
|
||||
| Female | 1 (10.0) | 6 (60.0) | 3 (30.0) | 0 (0.0) | |
| Male | 4 (16.0) | 15 (60.0) | 5 (20.0) | 1 (4.0) | |
| Age | 23.2 (± 1.9) | 23.8 (± 4.2) | 21.7 (± 3.3) | 25 (n.d.) | 0.579
|
| Molar relation | 0.577
|
||||
| Class I | 3 (27.3) | 7 (63.6) | 1 (9.1) | 0 (0.0) | |
| Class II | 2 (11.1) | 10 (55.6) | 5 (27.8) | 1 (5.6) | |
| Class III | 0 (0.0) | 4 (66.7) | 2 (33.3) | 0 (0.0) | |
| Instrumental specialty | 0.222
|
||||
| Plucked string | 0 (0.0) | 4 (54.1) | 2 (28.6) | 1 (14.3) | |
| Bowed string | 0 (27.5) | 5 (71.4) | 2 (28.6) | 0 (0.0) | |
| Metal wind | 2 (28.6) | 5 (71.4) | 0 (0.0) | 0 (0.0) | |
| Percussion | 0 (0.0) | 4 (57.1) | 3 (42.9) | 0 (0.0) | |
| Woodwind | 3 (42.9) | 3 (42.9) | 1 (14.3) | 0 (0.0) | |
| Stress score | 44.4 (± 4.4) | 45.7 (± 5.1) | 42.1 (± 7.6) | 47 (n.d.) | 0.490
|
Statistical test:
Fisher's exact test.
One-way ANOVA.
In terms of sex, no significant differences were observed in the frequency of TMJD (p=0.827), with a similar proportion between women and men in each TMJD category.
Regarding age, similar means were observed among the different degrees of MDD, varying slightly between 21.7 and 23.8 years, but without statistically significant differences (p=0.579). This homogeneous trend suggests that age is not a clear differentiating factor in the prevalence of TMJD in this population.
The molar ratio presents a varied distribution in the different degrees of TMJD, with a slight tendency to a higher prevalence of mild TMJD in Class II and Class III, but without statistically significant differences (p=0.577).
Regarding instrumental specialty, variations in the distribution of TMJD according to specialty were observed, but no statistically significant differences were found (p=0.222) in the bivariate analysis.
Finally, the stress score, although varying slightly between groups (44.4 in no TMJD, 45.7 in mild TMJD, 42.1 in moderate TMJD and 47 in severe TMJD), does not show significant statistical differences (p=0.490), indicating that the level of perceived stress does not correlate obviously with TMJD severity.
| Variable | Simple model | Adjusted model | ||||||
|---|---|---|---|---|---|---|---|---|
| PR | 95% CI | p-value | PR | 95% CI | p-value | |||
| Instrumental specialty | ||||||||
| Plucked string | Ref. | Ref. | ||||||
| Bowed string | 0.47 | 0.06 | 3.91 | 0.485 | 0.75 | 0.00 | 1.94 | 0.119 |
| Metal wind | 0.04 | 0.00 | 50.04 | 0.022
|
0.01 | 0.00 | 0.48 | 0.021
|
| Percussion | 0.78 | 0.10 | 6.07 | 0.815 | 0.42 | 0.03 | 5.76 | 0.520 |
| Woodwind | 0.03 | 0.00 | 0.56 | 0.018
|
0.01 | 0.00 | 0.45 | 0.018
|
| Molar ratio | ||||||||
| Class I | Ref. | |||||||
| Class II | 2.17 | 0.28 | 17.10 | 0.460 | ||||
| Class III | 1.20 | 0.08 | 18.02 | 0.895 | ||||
| Time since starting to play the specialty instrument (in years) (median; RIC) | 0.84 | 0.66 | 1.07 | 0.166 | ||||
| Hours of practice per week (with the instrument of your specialty and another instrument if practiced) | 1.04 | 0.95 | 1.14 | 0.364 | ||||
| Weight of the instrument of your specialty | 0.99 | 0.99 | 1.00 | 0.970 | ||||
Statistical test: Ordinal logistic regression
Wald test for difference between categories of instrumental specialty variable in simple model:
prevalence of TMJD in bowed string’s students= prevalence of TMJD in metal wind’s students [p=0.070];
prevalence of TMJD in bowed string’s students= prevalence of TMJD in percussion’s students [p=0.628];
prevalence of TMJD in bowed string’s students= prevalence of TMJD in woodwind’s students [p=0. 058];
prevalence of TMJD in metal wind’s students= prevalence of TMJD in percussion’s students [p=0. 030*];
prevalence of TMJD in metal wind’s students= prevalence of TMJD in woodwind’s students [p=0. 866];
prevalence of TMJD in percussion’s students= prevalence of TMJD in woodwind’s students [p=0. 025*].
Wald test for difference between categories of instrumental specialty variable in adjusted model:
prevalence of TMJD in bowed string’s students= prevalence of TMJD in metal wind’s students [p=0.145];
prevalence of TMJD in bowed string’s students= prevalence of TMJD in percussion’s students [p=0.235];
prevalence of TMJD in bowed string’s students= prevalence of TMJD in woodwind’s students [p=0. 249];
prevalence of TMJD in metal wind’s students= prevalence of TMJD in percussion’s students [p=0. 032*];
prevalence of TMJD in metal wind’s students= prevalence of TMJD in woodwind’s students [p=0. 897];
prevalence of TMJD in percussion’s students= prevalence of TMJD in woodwind’s students [p=0. 045*].
Values with statistical significance.
In the instrumental specialty analysis, the simple model shows a statistically significant association in metal wind and woodwind students, with PR of 0.04 (95% CI [0.00; 50.04] and 0.03 (95% CI [0.00; 0.56] respectively, indicating a lower proportion of TMJD compared to the reference (Plucked string). In a post-regression test, we also found a difference in the prevalence of TMJD in metal wind students compared to percussion students (p=0.030) and in the prevalence of TMJD in percussion students compared to woodwind students (p=0.025).
However, in the adjusted model, these majors maintain a significant association (PR of 0.04; 95% CI [0.00; 50.04] and PR=0.03; 95% CI [0.00; 0.56], respectively), suggesting that, even after adjustment for other variables, students in these majors have a lower prevalence of TMJD. On the other hand, Bowed string and percussion group show no significant differences in either model. In a post-regression test, we also found a difference in the prevalence of TMJD in metal wind students compared to percussion students (p=0.032) and in the prevalence of TMJD in percussion students compared to woodwind students (p=0.045).
In our study, we have identified that instrumental specialty is a determining factor in the frequency and severity of temporomandibular joint disorder among music students. We observed that those who play metal wild and woodwind instruments have a lower prevalence of temporomandibular joint disorder compared to pulsed students. We also found a difference in the prevalence of TMJD in metal wind students compared to percussion students and in the prevalence of TMJD in percussion students compared to woodwind students.
There are several factors that might explain why students who play metal wind and woodwind instruments exhibit a lower prevalence of TMJD compared to those who play plucked string instruments. Musicians who play wind instruments tend to adopt a more ergonomic posture and experience less stress on the jaw. The technique of using diaphragmatic breathing can distribute tension more evenly throughout the body, thereby reducing the load on the jaw muscles. In contrast, playing plucked string instruments, such as the guitar, often requires postures and techniques that generate more tension in the jaw and neck, particularly when these instruments are played for extended periods without adequate breaks. The biomechanical load also varies between these types of instruments. Wind instruments necessitate a controlled and specific use of facial and mandibular muscles, which might promote balanced muscle development and less strain in these areas. On the other hand, the tension in the hands, arms, shoulders, and neck while playing plucked string instruments can translate into tension in the jaw due to the rigid posture and muscle stress associated with playing techniques. Additionally, the muscle use involved in playing these instruments differs. Correct technique for playing wind instruments involves repetitive movements that are less likely to harm the jaw, as they engage a controlled range of motion. In contrast, plucked string instruments may involve repetitive and sustained jaw movements, especially if the musician sings and plays simultaneously, which could increase the tension in the temporomandibular joint. Similarly, in percussion, the muscles involved may adopt repetitive and vigorous postures and movements that can generate greater tension in the jaw and neck due to the nature of striking and handling drumsticks or mallets.
The relationship between our research and the studies conducted by Reijani N and Benetti FA
In addition, the results of Clemente MP et al.
The studies by Bourne D et al. and Vastamäki M et al.
These intersections between the studies and our research underscore the complexity of temporomandibular joint disorder in musicians. They highlight the importance of considering a variety of factors, from posture to instrumental technique and practice, for a comprehensive approach to the prevention and management of TMJD in this specific population.
In acknowledging the limitations of our study, it is critical to consider that, although we have included and measured stress as a key variable, there are other factors that we have not assessed that could have influenced the results. These factors include specific pain management techniques and the individual medical history of the participants. However, these limitations do not undermine the robustness of our findings, as our study provides an important basis for understanding the relationship between instrumental specialty and temporomandibular joint disorder in musicians. Considering many variables not addressed in other studies and focusing specifically on the music student population ensures the relevance of our results.
Looking forward, the limitations of our study open avenues for future research. These studies could further explore how other individual factors interact with the physical demands of instrumental specialties in the development and management of temporomandibular joint disorder. This could lead to the development of more specific and effective strategies to prevent and treat temporomandibular joint disorder in musicians, considering both the physical demands of their musical practice and psychosocial aspects such as stress. This future research could provide a more detailed and comprehensive understanding of the multiple factors that influence temporomandibular joint disorder in the musician population.
Our central finding highlights instrumental major as a significant factor in the prevalence of temporomandibular joint disorder among music students. Furthermore, we suggest the need for additional research that explores how the combination of stress management strategies and music practice techniques may influence the prevention and treatment of temporomandibular joint disorder. This conclusion leads us to recommend the implementation of educational and training programs that focus on ergonomics and instrument-specific techniques to minimize the risks of developing this condition.
Ultimately, our findings not only contribute to the field of musicians' health, but also establish a foundation for future research that seeks a more complete understanding of how the various aspects of a musician's life and practice interact and affect his or her physical and psychological well-being. By addressing these areas, we will be able to significantly improve the quality of life and the sustainability of musicians' careers.
There are significant differences in the prevalence of temporomandibular joint disorder (TMJD) among music students, which vary according to their instrumental specialty. Students who play metal wind and woodwind instruments show a lower prevalence of TMJD compared to those who specialize in pulsed instruments. Also, there are a difference in the prevalence of TMJD in metal wind students compared to percussion students and in the prevalence of TMJD in percussion students compared to woodwind students.
The study was approved by the Research Ethics Committee of the School of Stomatology of the Universidad César Vallejo with Official Letter No. 0103-2023-/UCV/P, dated December 20, 2023. We adhered to the principles of the Declaration of Helsinki. Written informed consent was obtained from all participants.
Figshare: Dataset TMJD in music students.
Data are available under the terms of the
Thank you for the opportunity to review the paper.
Unfortunately, upon a thorough review of the article 'Temporomandibular Joint Disorder among Peruvian Music Students of Different Instrumental Specialties', I have identified methodological flaws that compromise the validity of the results and the robustness of the conclusions.
The study aims to investigate whether musical specialty influences the prevalence of TMD. While the topic is a very interesting, the research lacks a well-defined central objective. The authors identify a gap in the literature regarding the assessment of disabilities associated with craniofacial and temporomandibular pain, but they fail to establish a clear link between this gap and the objective of comparing the frequency of TMD among different groups of musicians.
Could the authors please elucidate where in the text the hypothesis of this study can be found?
Do the authors deem the study's rationale to be commensurate with its primary objective?
The Introduction presents structural flaws, as it lacks numerous references, particularly in the sentence beginning on line 4 and the paragraph starting on line 13, as well as in some parts of the discussion. Citing these studies is essential. Without references, the text is merely opinion. Additionally, the third paragraph is excessively long.
The authors provide a brief overview of 'craniofacial and temporomandibular pain', leading the reader to expect an evaluation of 'pain'. However, such an assessment is absent from the text, creating a disconnect. Additionally, the paper fails to sufficiently emphasize the role of Temporomandibular Disorders (TMDs), their definition, and recent epidemiological findings, as exemplified by this meta-analysis [ ref 1 ]
In addition, although the authors evaluated “Stress” levels, they neglected to provide a contextualization of this variable in the Introduction, thereby omitting a justification for its significance in the research.
Throughout the article, the authors use the term 'Temporomandibular Joint Disorder (TMD),' however, this term is incorrect. Instead, the term 'TMDs' should be used, which highlights the importance of acknowledging the spectrum of conditions that fall under the Temporomandibular Disorders (TMDs) umbrella. According to the latest literature [ ref 2 ], it is recommended to emphasize 'disorders' rather than 'disorder'.
The study design exhibits methodological shortcomings that undermine the reliability of its findings. The absence of clearly defined inclusion and exclusion criteria hampers the replicability of the research and restricts the generalizability of its conclusions to other populations.
The selection of the Fonseca Anamnestic Index as the primary diagnostic tool is questionable, given its low specificity for diagnosing Temporomandibular Disorders (TMDs) and its limited use in recent research [ ref 3 ]. The reliance on a 2009 study to justify the choice of a less accurate and less validated instrument indicates an inadequate literature review. Due to these limitations, the study's diagnosis of TMDs is incomplete and susceptible to bias, potentially leading to ineffective treatment options.
The current scientific literature identifies the DC/TMD protocol as the gold standard for diagnosing TMDs, making its use more appropriate to ensure diagnostic accuracy [ ref 4 ]
Additionally, what solid scientific evidence would justify the inclusion of occlusal evaluation, given that most current studies question its causal relationship with TMD? [ ref 5 ]
The table legends in the "Results" section are insufficiently detailed. While all abbreviations have been mentioned in the main text, it is essential that the legends are self-explanatory, enabling the reader to comprehend the data without having to refer back to the main text.
I also believe it's premature to assert that 'repetition of movements' in blowing techniques with 'controlled range of motion' results in less mandibular load compared to other methods.
How do the authors classify these movements in the blowing technique (isotonic, isometric)?
What are the physiological explanations for these claims?
Is there a difference in muscle overload depending on the classification of movements?
Furthermore, I am not convinced by the argument that: “musicians, who are likely to adopt specific postures and perform repetitive movements, have lower prevalence of temporomandibular joint disorder.” Authors should be cautious when generalizing their findings. In its current form, the study lacks the physiological and scientific foundation to support the claim that repetitive movements differentially impact the musculature in the mentioned musical techniques.
On page 7, the authors make a controversial claim, attributing to Clemente et al. the conclusion that craniofacial morphology influences the predisposition to TMD: “Clemente et al. highlight the relevance of craniofacial morphology not only in musical performance, but also in predisposition to conditions such as temporomandibular joint disorder”. The conclusions mentioned do not seem to be directly related to the data presented in the study.
Could the author explain how they arrived at these claims?
Additionally, the authors generalize by stating that "certain physical characteristics can influence the development of TMD".
What is the concrete evidence from this study that supports this claim?
What other recent studies corroborate this conclusion?
What limitations should the authors have considered in this study? Could the absence of a control group have influenced the results? Did the authors consider the relevance of analyzing the masticatory muscles?
Finally, I consider that the discussion is brief and lacks a solid scientific foundation.
Is the work clearly and accurately presented and does it cite the current literature?
No
If applicable, is the statistical analysis and its interpretation appropriate?
Partly
Are all the source data underlying the results available to ensure full reproducibility?
No
Is the study design appropriate and is the work technically sound?
No
Are the conclusions drawn adequately supported by the results?
No
Are sufficient details of methods and analysis provided to allow replication by others?
No
Reviewer Expertise:
TMDs, Biomechanics, Postural Control, Osteopathy
I confirm that I have read this submission and believe that I have an appropriate level of expertise to state that I do not consider it to be of an acceptable scientific standard, for reasons outlined above.
I regret to say that the manuscript "Temporomandibular joint disorder among Peruvian music students of different instrumental specialties” is not suitable for indexing in F1000Research in its present form. The authors aimed to investigate TMJD frequency among music students of different instrumental specialties.
First of all, the authors state that 'there is a gap regarding the assessment of pain-associated disabilities in the craniofacial and temporomandibular region’. This is not the case as I can recall at least a dozen studies that investigated the alleged risk of playing an instrument that somehow loads the masticatory system, or singing, on pain complaints within that region (all of them having more participants).
For instance
[ref 1] [ref 2] [ref 3] [ref 4] [ref 5] [ref 6]
In fact, this has been the topic of several systematic literature reviews, such as
The introduction starts with a description of TMD, with the focus on TMD pain. However, in the next sentence, the authors zoom out, and mention that prevalence rates may differ, and depend on the definition of temporomandibular joint disorders. Why? It should be known by now that the term that includes 'joint’ is wrong and outdated. As mentioned in the name, the term 'temporomandibular joint disorder’ should in fact only be used for disorders of the TMJ, such as ankylosis or ADD, and should not be confused with 'temporomandibular disorders’, which were in fact investigated in this study. During the decades following Costen’s first description of the TMJ being a separate source of facial pain, the field of TMDs has experienced many taxonomic and conceptual changes. Today, it is widely acknowledged that TMD is an umbrella term; see for example the paper by List et al., 2017-Temporomandibular disorders, Old ideas and new concepts. The classically described triad of clinical signs for TMDs is muscle and/or TMJ pain, TMJ sounds, and altered jaw movements. More and more researchers and clinicians don’t regard TMDs as a single diagnosis, but separate (at least) the pain-related TMDs from the functional TMD problems.
In line with this, refer to well-established scientists and journals that have international reach, especially regarding the correct definition of TMD; the Pakistan Journal of Medical & Health Sciences does currently not make part of that.
Unfortunately, the authors used the Fonseca Anamnestic Index. Even though this is an easy to use, low-cost classification system, it mixes some common TMD signs and symptoms together to come to a single diagnosis 'TMD is present or absent’, which is – to my opinion – too simplistic (see my earlier comment). Thereby, the Fonseca also includes questions of which the relationship with TMDs is questionable or obsolete (e.g. Do you feel that your teeth do not articulate well?). Such questionable aspects have to be discussed in the manuscript, or preferably, use a more sophisticated classification system like the DC/TMD. The Fonseca is rarely used nowadays…
In addition, the authors point to malocclusion as an important etiological factor, whereas sound evidence from large population-based surveys point toward no, or at most weak and inconsistent associations, supporting that the role of the occlusion in the etiology of TMD should not be overstated (Michelotti et al., 2020-Occlusion, orthodontics, and temporomandibular disorders, Cutting edge of the current evidence). Again, this questions the validity of the Fonseca index in diagnosing TMDs as this inquires for an unbalanced occlusion…
On which information was the sample size calculation performed?
I have mixed feelings about the way how the authors explain their finding that woodwind players had lower TMD prevalence compared to plucked string and percussion players. This is contradictory to most articles that report that playing a wind instrument (wood or a brass instrument) loads the masticatory system. Perhaps the small number of musicians per instrument group has distorted the outcome?
I don’t understand the choices that were made for establishing the various musician groups? Clearly describe which instruments make part of the different groups and report the numbers.
Is the work clearly and accurately presented and does it cite the current literature?
No
If applicable, is the statistical analysis and its interpretation appropriate?
Partly
Are all the source data underlying the results available to ensure full reproducibility?
Partly
Is the study design appropriate and is the work technically sound?
No
Are the conclusions drawn adequately supported by the results?
Partly
Are sufficient details of methods and analysis provided to allow replication by others?
No
Reviewer Expertise:
TMD, bruxism, musicians
I confirm that I have read this submission and believe that I have an appropriate level of expertise to state that I do not consider it to be of an acceptable scientific standard, for reasons outlined above.