1 INTRODUCTION

It is estimated that over one billion people across the world have suffered a traumatic dental injury (TDI) to their permanent teeth.1 Injuries frequently occur in the course of participation in contact sports via interpersonal collisions, falls and impacts with sporting equipment (bats, balls, etc.).2 Sports-related TDI’s account for 10%–39% of all dental injuries in children.3 The management of these injuries and their sequelae can extend across a person's lifetime, involving significant financial and time-related costs.4 The experience of a TDI, the resulting functional and aesthetic impairments, and the often lengthy dental treatment required are all associated with poorer oral health-related quality of life outcomes in children, especially following a severe TDI.5 Every effort must be made to prevent or mitigate such injuries.

Mouthguards (MG) increase the surface area over which the impact force of a TDI is applied, distributing the forces more widely and reducing the stress on any single tooth.6 It has been reported that those who wear a MG are less likely to suffer a sports-related TDI than those who do not wear one.7

Various sports organizations have attempted to reduce the risk of TDI among their players by mandating the use of mouthguards during practice and competition.8 Mouthguard rules vary worldwide and between different sports. Globally, MG are required for boxing and mixed martial arts.9, 10 They are recommended, but not mandated, by the international sporting bodies governing field hockey11 and rugby,12 but local MG rules may apply in individual clubs.

Gaelic football is a high-speed amateur contact sport and is very popular in communities across Ireland from childhood to adulthood. In 2020, 401,850 players were registered from 8–16 years of age across 1650 clubs in the Republic of Ireland. The Gaelic Athletic Association (GAA) and the Ladies’ Gaelic Football Association (LGFA) implemented rules requiring the use of MG for male and female players of all ages during training and competition in 2014.13-15 The penalty for non-wear is to be sent off from play. This is enforced by referees during competition. During training, responsibility for MG wear lies with players or, in the case of minors, parents of players.15 The GAA has reported a reduction in claims to their Injury Benefit Scheme of 37% and 39% respectively for minor (under-18) and senior grades since the MG rules were introduced.15

Rates of MG use are often lower than levels of player awareness of the need for MG to prevent TDI.16, 17 Mouthguard use is reportedly improved by a previous history of TDI,16, 17 MG rules,18 older player age,19, 20 and a dental professional advising use of a MG.21 Mouthguards tend to be used more frequently during competition than during training,17 indicating that interpretation and enforcement of MG rules can be inconsistent. Players often wear their MG only for sports with MG rules.18 Player-reported reasons for not wearing MG include perceived lack of need for MG,16 discomfort,16 and difficulty with breathing, speech and swallowing.16, 18, 19, 22, 23

In Ireland, two questionnaire-based studies have been carried out, surveying parents of 9–13-year-old schoolchildren in relation to their awareness of MG, their children's use of MG, and their children's history of TDI over the previous year. The children were not surveyed or examined.24, 25 No other studies directly correlating parent and child reports in relation to child MG use were found. The authors’ clinical experience suggests that parents and children have limited knowledge on how to care for their MG.

The aim of this study was to investigate children's compliance with the MG rules for Gaelic football training and matches. A secondary aim was to investigate and compare the knowledge and behaviours of children and their parents in relation to the use and care of MG.

2 MATERIALS AND METHODS

Ethical approval was obtained from the Trinity College Dublin Faculty of Health Sciences Research Ethics Committee (2nd November 2018, reference 180901). Permission was granted by the Gaelic Athletic Association (GAA) and Ladies’ Gaelic Football Association (LGFA) to conduct this research at their clubs.

A cross-sectional observational cohort study design was employed, using separate questionnaires to survey parents and children. The parent questionnaire for this study (Table 1) was based on questions previously used and published by O’Malley et al. to allow comparison between studies.25 Additional questions pertaining to MG cost, compliance with GAA MG rules for training and competition, and MG hygiene behaviours were added by the authors of this study. The parent questionnaire was piloted among parents of children attending the paediatric dental clinics at the Dublin Dental University Hospital, for the purposes of language and understanding. Minor language adjustments were made to the questionnaires in response to parent feedback. The child questionnaire (Table 2) was developed based on the parent questionnaire, with the addition of questions relating to their experience of using a MG.

TABLE 1. Parent questionnaire used in this study What age is your child? Which sports do they play? (Tick as appropriate)

Gaelic football

Hurling/Camogie

Soccer

Rugby

Hockey

Tennis

Basketball

Badminton

Volleyball

Boxing/Martial arts

Other (please specify)

Do they wear a mouthguard? Yes/No Do they wear it for some sports, or all sports? All Some (please specify which sports) Does every sport require them to wear a mouthguard? Yes/No If no, please specify which sports do require a mouthguard. Which type of mouthguard do they wear?

Shop bought, ready to wear

Shop bought, boil and bite

Made by dentist

In your opinion, which types of mouthguard will protect teeth properly?

Shop bought, ready to wear

Shop bought, boil and bite

Made by dentist

How old is their mouthguard?

0–3 months

4–6 months

7–9 months

10–12 months

>12 months

Where is their mouthguard kept when not in their mouth?

In gear bag

In mouthguard box

Other (please specify)

How is their mouthguard cleaned? How often is it cleaned? Do they wear it for:

Training only

Match only

Training and matches

Don't wear it

Has your child ever had a dental injury to their permanent (adult) teeth? Yes/No If yes, was it while playing sport? What type of injury was it?

Tooth broke

Tooth loosened

Tooth pulled out of the gum, but not all the way out

Tooth pushed up into gum

Tooth fell out completely

Tooth pulled forwards

Tooth pushed backwards

Don't know/Not sure

Were they wearing a mouthguard at the time? Yes/No

How much would you be willing to pay for a mouthguard specially made to fit your child's teeth? Please indicate with a mark along the line below

TABLE 2. Child questionnaire used in this study What age are you? Which sports do you play? Do you wear a mouthguard for all of them? Yes/No If no, which ones do you wear your mouthguard for? Why don't you wear your mouthguard for the others? Which sports make you wear a mouthguard? Do you wear your mouthguard for Gaelic football training? Yes/No Do you wear your mouthguard for Gaelic football matches? Yes/No Do you like your mouthguard? Yes/No If not, why not? Can you talk while you're wearing it? Yes/No Can you breathe while you're wearing it? Yes/No Does your mouthguard taste okay? Yes/No When did you get this mouthguard?

0–3 months ago

4–6 months ago

7–9 months ago

10–12 months ago

>12 months ago

Where do you keep your mouthguard when you're not wearing it? Do you clean your mouthguard? Yes/No How is the mouthguard cleaned? How often is it cleaned? Did you ever have an accident that hurt your permanent (adult) teeth? Yes/No What age were you? If yes, was it while playing sport? Were you wearing a mouthguard at the time? Yes/No

A convenience sample of 14 GAA clubs was invited to participate in the study. Only four clubs were willing to participate, under GAA-specified child safety protocols. Parents of 9–16-year-old male and female Gaelic football players, along with their parents who provided informed consent for their participation, were recruited via their GAA clubs for this study. Each parent signed two consent forms, one for their own participation and one for their child's participation. Access was restricted to designated training evenings at the sports facility, and only children who were available on the day of the data collection were included.

A sample size calculation based on the primary outcome (compliance of children playing sports with specific MG rules) could not be performed due to the lack of previous studies evaluating this outcome. A target sample size of 30–50 participants per club was selected based on the number of children anticipated to attend for training on the evenings in question.

Players and their parents presented themselves to the research team at the sports facility. The research team consisted of dentists who verbally asked each child the questions from the child questionnaire and recorded their answers, to ensure consistency in the data collection. Dentists verified the type of MG used by each child. At the same time, parents self-completed hard copies of the parent questionnaire. A visual analogue scale was provided to parents to indicate the price they would be willing to pay for a custom MG (CMG).

Co-ordinated coding allowed collation of data and comparison of the results for data from each parent-player pair. Data were tabulated using Excel (Microsoft Corporation, 2018) and were then exported into SPSS (Statistical Package for Social Sciences, version 26, IBM Corp.) for analysis. Statistical tests used included Kolmogorov-Smirnov test for normality, descriptive statistics (mean and standard deviation for values which were normally distributed, median and interquartile range (IQR) for values that were not normally distributed), comparative statistics (Cohen's kappa (κ), chi-squared (χ2)) and multiple logistic regression analysis. The Hosmer-Lemeshow and Nagelkerke's pseudo R2 tests were used to determine the goodness of fit of the multiple regression model. Results were reported with a 95% confidence interval and a significance level set at 5%.

3 RESULTS

One-hundred and twenty-one children and 118 parents from four GAA clubs participated in the study. It was estimated that 30–50 children would be available for assessment at each club based on the numbers attending for training. The response rate for two of the clubs was high (N = 40 and N = 46) but was low for the remaining two clubs (N = 16 and N = 19).

Children ranged in age from 9–16 years, with a median age of 12 years (interquartile range =10–13 years; Kolmogorov-Smirnov test, p < .001). There were more males (N = 68, 56.7%) than females (N = 52, 43.3%). Participants in this study played a median of 3 sports (IQR = 2), and a median of 2 contact sports (IQR = 1). Thirty-two parents (27.1%) and 17 children (14%) reported that a MG was worn for all sports, with poor agreement between child and parent answers (κ = 0.271, p = .001).

Most parents (N = 105, 89.7%) reported that their child was wearing the MG for both training and competition. One hundred and nineteen children (99.2%) reported wearing their MG for competition. Fewer children (N = 97, 80.8%) reported wearing their MG for training, a reduction in compliance of 18.3%. Females demonstrated proportionately greater compliance than males for all age categories (Table 3).

TABLE 3. Proportion of players wearing and not wearing MG during Gaelic football training, according to age and gender

Age 9–10 years

(N = 36)

Age 11–12 years

(N = 33)

Age 13–14 years

(N = 26)

Age 15–16 years

(N = 24)

Male Female Male Female Male Female Male Female Wearing MG, N (%) 16 (100) 20 (100) 9 (90) 23 (100) 17 (85) 6 (100) 4 (18) 1 (50) Not wearing MG, N (%) 0 0 1 (10) 0 3 (15) 0 18 (81) 1 (50) Total (N) 16 20 10 23 20 6 22 2

A binary logistic regression analysis investigated factors influencing MG compliance during training (Table 4). The univariate analysis identified a number of significant factors that increased compliance with MG wear during training. Younger children, females, those playing multiple sports, those who could speak and breathe with the MG in place, and those who liked their MG were all more likely to wear their MG during training. Age was the only variable to retain significance in the adjusted model (OR = 0.18, p < .001) and was a moderate predictor of compliance (Hosmer and Lemeshow goodness-of-fit test, p = .668; Nagelkerke's pseudo R2 = 0.683). Compliance reduced by 82% with each incremental age increase of one year.

TABLE 4. Binary logistic regression analysis investigating factors influencing player compliance with MG rules during Gaelic football training sessions Variable

Not wearing

N (%)

Wearing

N (%)

Total

N (%)

OR univariate

95% CI

p

OR adjusted

95% CI

p Age of child Continuous – Mean (SD) 14.87 (0.92) 11.27 (1.81) 0.23 (0.13–0.41) .000* 0.18 (0.08–0.44) .000* Gender Male (ref) 21 (31.3) 46 (68.7) 67 (100) – – – – Female 2 (3.8) 50 (96.2) 52 (100) 11.41 (2.54–51.39) .002* 2.49 (0.38–16.51) .344 MG type Stock (ref) 2 (6.5) 29 (93.5) 31 (100) – .546 – – Mouth-formed 9 (12.9) 61 (87.1) 70 (100) 0.47 (0.1–2.30) .350 – – Custom 1 (20.0) 4 (80.0) 5 (100) 0.28 (0.20–3.78) .335 – – Number of sports played Continuous – Mean (SD) 2.39 (1.12) 3.25 (1.34) 1.85 (1.17–2.93) .009* 1.21 (0.66–2.23) .531 Number of sports where mouthguard is worn Continuous – Mean (SD) 1.22 (0.52) 1.43 (0.59) 2.10 (0.83–5.31) .117 1.27 (0.31–5.31) .741 Ability to talk while wearing mouthguard No (ref) 15 (31.9) 32 (68.1) 47 (100) – – – – Yes 8 (11.0) 65 (89.0) 73 (100) 3.81 (1.46–9.92) .006* 2.95 (0.69–12.68) .146 Ability to breathe while wearing mouthguard No (ref) 5 (50.0) 5 (50.0) 10 (100) – – – – Yes 18 (16.5) 92 (83.6) 110 (100) 5.11 (1.34–19.5) .017* 0.63 (0.11–3.48) .597 Does the mouthguard taste okay? No (ref) 6 (37.5) 10 (62.5) 16 (100) – – – – Yes 17 (16.3) 87 (83.7) 104 (100) 3.07 (0.98–9.58) .053* 3.52 (0.51–24.29) .202 Like/dislike mouthguard Dislike (ref) 12 (36.4) 21 (63.6) 33 (100) – – – – Like 11 (12.6) 76 (87.4) 87 (100) 3.95 (1.53–10.21) .005* 2.03 (0.48–8.56) .333 Self-reported history of previous dental trauma No (ref) 21 (21.2) 78 (78.8) 99 (100) – – – – Yes 2 (9.5) 19 (90.5) 21 (100) 2.56 (0.55–11.87) .230 – – Abbreviations: CI, confidence interval; OR, odds ratio; SD, standard deviation. *p < .05, 95% CI.

Most children reported that they could breathe easily while using their MG (N = 110, 91.7%). Forty-seven children (39.2%) reported that they had difficulty speaking with their MG in place. The majority of children liked their MG (N = 87, 72.5%). This was unrelated to the type of MG worn (χ2 = 1.628, p = .443), but was related to their ability to breathe (χ2 = 15.081, p < .001) and speak (χ2 = 15.081, p = .003) with the MG in place.

Most parents (N = 87, 73.7%) believed that a CMG would best protect their child's teeth. Four children (3.8%) were wearing a CMG according to the dentist's verification. Parents indicated a willingness to pay a median price of €35.00 (interquartile range = €20.00–€50.00) for a CMG.

Seventy-seven parents (65.2%) and 69 children (57.5%) stated that the MG was 6 months old or less (κ = 0.586, p < .001). Fourteen parents (11.9%) and 30 children (25.0%) reported their MG was over a year old. Some parents did not answer the question about mouthguard cleaning method (N = 20, 16.5%) and frequency (N = 13, 10.5%). Missing data were excluded from statistical analysis. Eighty-five children (70.8%) and 77 parents (65.2%) reported that the MG was stored in a specific container when not in use. Sixty-five children (54.2%) and 68 parents (60.2%) reported that the MG was frequently cleaned, and most often with cold water according to 63 parents (61.8%) and 65 children (79.3%). Agreement between child and parent responses as to frequency and method of MG cleaning and MG storage was poor (κ = 0.258, p = .001; Table 5).

TABLE 5. Parent and child answers relating to MG storage & hygiene Parent Total κ a p Mouthguard storage Child Mouthguard box N (%) Loose in gear bag N (%) Other N (%) 0.563 <.001* Mouthguard box N (%) 68 (82.9) 12 (14.6) 2 (2.4) 82 (100) Loose in gear bag N (%) 5 (23.8) 14 (66.7) 2 (9.5) 21 (100) Other N (%) 3 (21.4) 1 (7.1) 10 (71.4) 14 (100) Total 76 (65.0) 27 (23.1) 14 (12.0) 117 Frequency of MG cleaning Child Frequently N (%) Rarely/never N (%) – 0.414 <.001* Frequently N (%) 49 (77.8) 14 (22.2) – 63 (100) Rarely/never N (%) 18 (36.7) 31 (63.3) – 49 (100) Total 67 (59.8) 45 (40.2) 112 Method of MG cleaning Child Cold water N (%) Warm water N (%) Other N (%) 0.258 .001* Cold water N (%) 43 (69.4) 9 (14.5) 10 (16.1) 62 (100) Warm water N (%) 1 (14.3) 5 (71.4) 1 (14.3) 7 (100) Other N (%) 3 (50.0) 1 (16.7) 2 (33.3) 6 (100) Total