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

impaired jaw mobility are frequently reported symptoms.Headache is often associated with the condition. 5,6TMD symptoms seem to be increasing in the population. 7,82][3] Children below 10 years of age seldom have any TMD symptoms, whereas the prevalence rapidly increases during puberty for both genders, especially for females to about one-fifth being affected in their 20s.
The aetiology of TMD is complex and involves several risk factors and detrimental behaviours. 11,12Psychological factors, comorbidity and socioeconomical factors have been identified to affect the risk for developing TMD symptoms. 8,13,14The symptoms decrease the quality of life as well as increase the absence at work. 15,16owledge of risk factors and that treatment directed at behaviour change, indicate a possibility for preventive interventions with the aim to decrease the incidence of TMD symptoms.In general, treatment directed at TMD symptoms has been shown to be effective and with a favourable prognosis. 17unselling, including information and advice related to jaw function/dysfunction and parafunctions, is often the first step in the treatment and is combined with attention to the patient's unaware parafunctions.This is sometimes enough to initiate a change of behaviour and to decrease the symptoms.Counselling has been reported to significantly reduce the patient's symptoms. 18Also cognitive behaviour therapy is useful in the treatment of harmful oral habits, even when treated in a group setting, 19 and advice in muscle exercise and ergonomics is an effective treatment approach in the management of TMD symptoms. 20,21areness of general tension and general relaxation training is important for reducing tension and related pain.General relaxation training can thus have a positive effect on pain conditions both locally and generally in the body and it was found to reduce the frequency of headaches. 22ere are few studies concerning the prevention of TMD symptoms.Kirveskari and Jämsä 23 found that recurrent examinations and adjustments of any inaccuracies in the occlusion decreased the incidence of TMD symptoms among children and adolescents.There are also reports on decreased incidence of TMD symptoms after orthodontic adjustments. 24Population based intervention with counselling regarding lifestyle and diet was shown to give long-term changes. 25eventive intervention has been suggested, but to our knowledge, there is only one study of preventive interactions for TMD symptom due to information about the jaw system and about risk factors. 26That study, which comprised 60 females 16 years of age and with a 3-month follow-up after the information, showed a significant reduction of headache and analgesic consumption.With increasing incidence for TMD symptoms from puberty, prevention of first onset TMD symptoms should start in early adolescence.

Recurrent information provided by dental nurses to children in
Västra Götaland, Sweden about oral hygiene and risk factors for carious and periodontal diseases combined by fluoride administration resulted in a decrease of these diseases among children 27 ; thus, it is obvious that repeated information can influence habits in childhood and among teenagers.
The aim of the study was to test the hypothesis that development of TMD symptoms and headaches can be affected by information and advice given in a school setting to girls in their early teenage period.

| ME THODS
Thirteen-year-old girls at the seventh grade of the upper compulsory elementary school in a western district of Sweden were invited to participate in a study on the effect that information and advice about the jaw system and risk factors related to development of TMD symptoms and headaches has on headaches and TMD symptoms.The study was performed in cooperation with a regular prevention program (FRAMM) within the Public Dental Service in Sweden, 27 with the aim to give preventive information to children up to the age of 15 years about carious, periodontal disease, consequences from drugs and smoking habits, along with administration of fluoride varnish twice a year.Only girls were invited to the study since the incidence of TMD symptoms and headaches has been shown to increase, especially among girls from the age of 13 years and onwards. 1 The school managers of 21 schools were contacted.The schools were geographically spread and situated in areas of the countryside, suburbs, municipalities and cities.The headmasters and the school nurses had to approve participation in the study; 19 schools in Västra Götaland, Sweden, accepted.The girls received information about the study both orally and in writing, and written information was provided to their parents with a paper to sign if they did not want their child to participate.Participation in the study was voluntary, and the girls were only identified with their name and class.
The information was given at school during schooldays.No parent declined their child from participation in the preventive information.
The inclusion of the girls started in September 2019 and ended in October 2020.Not all girls on the class lists appeared when the semester started.Girls with a poor understanding of the Swedish language were excluded resulting in 651 13-year-old girls being included in the study.The plan was to follow the girls for 2-2.5 years; however, there was a large amount of relocation and changes of school during the study period, especially in areas with many new immigrants.Some girls permanently or temporarily discontinued school during the follow-up period.There were 507 girls that participated both at 13 and 15 years of age.The flow chart of participants is presented in Figure 1.Due to some incomplete filled-out questionnaires, there were 484 included in the analysis of development of TMD symptoms (not including headaches) (Figure 1), and 500 participants included and in the analysis of development of headaches (Figure 2).The girls answered a standardized questionnaire (Table 1) regarding the presence and frequency of symptoms of the jaw and head.
They also answered yes or no to the three screening questions of 3Q/TMD 28    The prevalence of TMD symptoms was based on the following symptoms that were reported to occur once a week or more often: feelings of tiredness/stiffness of the jaw, temporomandibular joint clicking, pain in oro-facial region, difficulties to open wide, or the jaw being locked.The incidence cases were those who at baseline (13 years old) had none of the TMD symptoms but reported TMD symptoms at the follow-up (15 years old).The incidence cases with headaches were similarly based on those who did not report headaches once a week or more at baseline but reported headache at follow-up.Those who had TMD symptoms or headaches at baseline were also analysed for whether symptoms remained or changed during the follow-up period.

| The intervention
Information about anatomy and function of the temporomandibular system, risk factors for TMD symptoms and headaches and about how to handle oral habits and stress factors, was presented school class or with two to three classes together at two meetings with 1-2 weeks in between (Table 2).The instructed jaw exercise was free wide opening of the mouth and lateral movements, and then to stay with the jaw at rest.General relaxation instructions for 7-8 min were presented on both occasions.The girls were advised to practice at home what they had been instructed in.At the second meeting they were asked to reflect on their training.The school nurses at the intervention schools received information about the content of the preventive information.
The information was provided by the same author (CM) for all schools and a strict protocol was followed.About 1 year later, the girls at the intervention schools received a short reminder of the information (about 20 min) and could again ask questions.
After 2-2.5 years, at the end of the ninth grade, when the girls were 15 years old, a follow-up was performed.All the girls, both cases and controls, again answered the same questionnaire as at baseline.This time they all answered in their classes with a teacher present.All the girls in the study had regular check-ups and treatment at the Community Dentistry for children and youth.The study was approved by the regional Committee of Ethics in Göteborg (no.457-18).

| Statistical methods
Statistical analyses were processed using the software SPSS 26 (SPSS Inc., Chicago, IL), and was performed in cooperation with the Academicals Statistics at the University of Gothenburg.The chisquared test was used.A statistically significant difference was set at p < .05.

| TMD symptoms
At baseline, when the girls were 13 years old, 20% of the girls reported one or more TMD symptoms occurring once a week or more often.The prevalence increased to 31% when they were TA B L E 1 Questions included in questionnaire regarding symptoms during the preceding 3 months.
1. Frequency of symptoms (never/rarely, 1-2 times/month, 1-2 times/week, 3-4 times/week, daily) for the following; tiredness of the jaw, joint sounds, headaches, pain in the face or jaws, difficulties to open the mouth wide or locking of the jaw.
3. If the reported symptoms had led to the need for analgesic (yes/ no), sick leave from school (number of days).
4. Evaluation of the symptoms severity according to the Visual Analogue Scale (VAS): 0-100 (0 no pain, 100 worst imaginable pain). 5. General health on a five-point scale (excellent to poor) and any regular medication.
6. Frequency of physical activity (nearly no physical activity, sometimes a walk or cycling, lighter exertion in total 2 h/week, exercise in total at least 3 h/week, hard exercise or competition several times/week at least 2 h/occasion).

TA B L E 2
Schematic specification of the content and length of the information and advice provided on two separate visits of 35-40 min each at school classes. 26

Introduction
Background and purpose 5 Discussion last meeting, questions 5

Normal function and activity
The jaws, muscles, joint, bite and their interaction (p = .03).
Among those with TMD symptoms at baseline, 55% reported such symptoms at follow-up with no significant difference depending on whether or not they had received information (p = .7).

| Headaches
At baseline, when the girls were 13 years old, 41% reported headaches occurring once a week or more often.The prevalence increased to 51% when they were 15 years old.Among the 13-year-old girls, 297 reported no headaches, of which 168 were controls and 129 were cases.At follow-up, the prevalence of headaches was lower among cases (30%) compared to controls (40%) but the difference was not statistically significant (p = .099).
Among those with headaches at the start, 70% also reported headaches at follow-up.Those who had been allocated to information reported a significantly lower prevalence of headaches at the age of 15 compared to the controls (p = .03).

| DISCUSS ION
A main finding of the study was that standardized information on the jaw system, TMD and headaches, as well as how to act to prevent development of such symptoms, when presented at school to girls in the beginning of puberty, had an effect on the incidence of TMD symptoms, among those without symptoms at start.However, there was no obvious effect on those who already had developed TMD symptoms.Girls that had received information had a lower incidence of headaches, although this was not statistically significant.Those with frequent headaches however, reported a lower prevalence compared to their respective controls at follow-up which is in accordance with the findings of a previous study. 26e study indicates, for the first time in a large study-population, that standardized information and advice about jaw function and TMD to non-patients can reduce the incidence of TMD symptoms in the early teens.The results are hopeful and encourage further development of models to be used at school and should serve as motivation for dentists to actively work with cost-effective methods for prevention of development of TMD symptom and headaches among adolescents.
Almost one-third of the 15-year-old girls reported that they had TMD symptoms occurring once/week or more often, and about half reported headaches.More details about the girl's different TMD symptoms have been reported. 29The findings correspond to what has been found previously, 2 and the increase of symptoms during a 2-year period is in accordance with other studies. 7,8The study thus confirms that the prevalence of TMD symptoms increases from early teenage among girls.Tension-type headaches were found associated with TMD, similar background factors within a biopsychosocial context have been advocated as well as the same methods and approach to manage. 30,31ong those at the start of the study who already had TMD symptoms, almost half reported no TMD symptoms at follow-up.
Such variability or fluctuation was observed previously in population samples. 32,33There was, however, no differences in this pattern depending on whether or not the adolescents had received information.The results may indicate that individually tailored counselling should be advocated for those who have TMD problems in order to get the best outcome.
The preventive idea came from other successful preventive measures in dentistry like preventing periodontal diseases and dental carious. 27Also prophylactic management for low back pain has been effective. 34To have a great impact, the information should preferably be repeated more often and in smaller groups.In the seventh grade, much is new at school, and it is important to fit in with friends and a new social context.An individual's focus may thus be less concerned on how to take care of oneself, behaviour adjustments and self-management.The preventive information probably increased knowledge of the jaw system and reduced the girls concern, worries and questions.The package of information could be more customized for this age group.During the study, it was noticed that language comprehension was lacking to some extent and even ordinary Swedish words were unknown to some 13-year-old girls, for example, 'pain' and 'the temple region' were sometimes not understood.
Another question was 'What is headache and what is facial pain?' In addition, there were several immigrants with lack of a deeper knowledge and skills of the Swedish language.
The questionnaire used was a combination of previously used portions in dental studies, and portions form continuous studies of youth health 35 ; some parts had been validated.The girls that participated both at 13 and 15 years of age are considered representative for young teenager girls in Västra Götaland, Sweden.
Possible explanations to the results from information and training are that the information about the temporomandibular joint and its function reduces worries about joint dislocation when opening and that the loading of the jaw and joints decreases by greater attention to parafunctional habits as parafunction is a risk factor for TMD. 11At the start there was no statistical difference between the control and intervention schools regarding symptoms, reported parafunctions and physical activity.
A strength of the study is that the study-population was rather large and the incidence of reported symptoms rather high, which makes the results credible.The design of involving several schools in the study, and that the randomizing of intervention or no intervention was based on schools assured that we had good control of who received the intervention or who had not.
A weakness is that the dropout rate was high and depended on relocation and change of schools among the students.In longitudinal observation studies in settings like the present study, dropouts are inevitable.As the study is based on those who did not report any frequent TMD or headache at baseline, we consider that the dropouts likely had a minor effect on the outcome of the study.
To conclude, girls of the lower teen ages are expected to present symptoms of TMD and headaches.The incidence is higher than those who recover which leads to an increase in prevalence.Preventive measures in the form of education, information and counselling in a school environment can lead to a lower incidence of pain and functional disorders in the jaw system.As oro-facial pain and headaches may be associated with high absence from school, 36,37 programs involving education and advice of self-management may be cost effective and help school students to achieve improvements in life quality and school performance.For individuals with symptoms in the jawhead region, individually tailored counselling is probably preferable to standardized information.

13652842, 2024, 9 ,
Downloaded from https://onlinelibrary.wiley.com/doi/10.1111/joor.13773 by Umea University, Wiley Online Library on [20/08/2024].See the Terms and Conditions (https://onlinelibrary.wiley.com/terms-and-conditions)on Wiley Online Library for rules of use; OA articles are governed by the applicable Creative Commons License regarding symptoms once a week or more frequent.The questionnaire was filled out at a regular visit by the nurses from the FRAMM-project, or at an ordinary class session with their teacher present.The girls filled out the questionnaire themselves and could ask if they did not understand a question.Of the participating schools, pairs of schools were created that were similar in size, geographical location, estimated proportion of F I G U R E 1 Flow chart of the 396 girls without TMD symptoms and the 99 girls with TMD symptoms included in the study.Number of girls that had missing data at follow-up * = 6 girls, † = 3 girls, ** = 1 girl.F I G U R E 2 Flow chart of the 297 girls without frequent headaches and the 206 girls with headaches included in the study.Number of girls that had missing data at follow-up * = 2 girls, † = 1 girl.
new immigrants and socio-economic standard.The pairs were randomly divided into either intervention or control schools.To avoid spreading the information provided, all classes of one school were either interventions or controls.