Pathophysiology
Linear and angular head kinematics from impacts are associated with brain injury risk and can elevate blood biomarkers of brain injury, alter oculomotor function, and cause structural and functional brain changes [PMID:34549342].
The paper emphasizes that inertial forces, particularly linear and rotational accelerations, are the primary causes of concussive injuries common in mild traumatic brain injuries (TBI), distinguishing these from focal injuries more prevalent in moderate and severe TBI [PMID:21074079].
Despite differences in impact mechanisms, head accelerations were not significantly altered, indicating that multiple types of impacts could potentially lead to similar traumatic injuries [PMID:29809079].
The study using finite element modeling in women's lacrosse impacts highlights that maximum principal strain values, particularly from falls and ball impacts, can indicate concussion risk [PMID:29414471].
Finite element analyses revealed that von Mises stress, alongside strain rate and cumulative strain damage measures, effectively predicts concussion outcomes in unhelmeted head impacts [PMID:25781376].
Epidemiology
Wearing a mouthguard was associated with a 28% lower concussion rate and 57% lower concussion odds across various age groups and divisions in youth ice hockey [PMID:36918257].
The study highlights the importance of consistent use of protective equipment, specifically mouthguards, in reducing concussion risk across different levels of play [PMID:36918257].
Over one million male high school athletes participate in American football, where concussion and repeated head impact exposure are frequent, potentially increasing the risk of neurodegeneration and long-lasting neurological consequences [PMID:34549342].
The review highlights that SRC emergency department visits have increased by over 85% in 8–13 year-olds and more than 200% in 14–19 year-olds, emphasizing the growing concern in youth sports [PMID:34083330].
The review points out that data is particularly lacking for youth and female athletes, indicating a critical area for future research [PMID:34083330].
A case-control study using propensity score matching found that mouthguard use among college sports players was associated with reduced odds of SRC, although previous evidence has been mixed [PMID:32580527].
Studies indicate that repetitive head impact exposure (RHIE) in sports like football can lead to cognitive and brain structural changes, highlighting the need for continuous monitoring beyond just concussion incidence [PMID:31946308].
The NCAA Injury Surveillance Program reported 496 concussions in men's ice hockey versus 131 in women's ice hockey over the 2009-2010 through 2013-2014 academic years, with a significantly higher rate in men (1.75 versus 1.16 per 1000 athlete-exposures) [PMID:28662349].
The review found that the use of mouthguards significantly decreased the incidence of dentofacial injuries, highlighting their protective role in sports settings [PMID:40586455].
Clinical Presentation
Both off-the-shelf and dentist-fit mouthguards showed protective effects against concussion, indicating that type of mouthguard does not diminish protective benefits [PMID:36918257].
Most concussions in men's competitions occurred due to player contact while checking (25.9%), while in practices, player contact during general play was the leading cause (25.9%) for men, and similar proportions were noted in women's competitions (25.0%) and practices (24.0%) [PMID:28662349].
Given that concussions are mainly due to the brain's acceleration within the skull, clinicians should consider the dynamics of head movement and inertial forces when assessing patients for concussion [PMID:21074079].
Of the surveyed NRLW players, 37% did not disclose possible concussions to medical staff, with the primary reasons being 'not wanting to be ruled out of the game or training session' and uncertainty about symptom relation to concussion [PMID:40316489].
The study found that reporting 4 out of 22 symptoms and a high severity score on the total severity scale was uncommon, indicating that most players may not exhibit multiple or severe symptoms [PMID:40118744].
The study highlights that higher magnitude HAEs (PLA > 25 g; PAA > 2000 rad/s2) were notably more frequent during matches, suggesting a heightened risk period for traumatic brain injuries, including those impacting the periodontal ligament [PMID:39428738].
The most frequent locations for suspected injuries were head/neck (28.4%) and lower extremity (27.6%), highlighting areas where concussion symptoms might manifest [PMID:35909055].
Female athletes tend to have worse outcomes after concussions, possibly because of anatomical factors like shorter necks that increase vulnerability to head-neck injuries [PMID:33654036].
In pediatric ice hockey participants following sports-related concussion (SRC), specific cytokine profiles in saliva were associated with increased symptom burden, suggesting a potential biomarker for clinical assessment [PMID:32881769].
Players subjectively reported an average sleep duration of 7:16 hours, whereas actigraphy measured a shorter duration of 6:04 hours during the season, underscoring discrepancies between self-reporting and objective data [PMID:31895289].
Among football players presenting to the ED, sprains/strains (25.6%) and limb fractures (20.7%) were the most frequent injuries, followed closely by head injuries (17.5%) [PMID:27185745].
Diagnosis
Instrumented mouthguards, particularly the MiG2.0 with MiGNet algorithm, have been shown to accurately record head kinematics and distinguish true positive impacts from false positives [PMID:34549342].
The Impact Monitoring Mouthguard (IMM) system, capable of sampling at 3.2kHz and storing impact data, offers a reliable method to detect head impacts that could lead to concussions, even in the absence of immediate loss of consciousness [PMID:31946308].
For accurate diagnosis, clinicians might benefit from integrating knowledge of biomechanical forces, such as linear and rotational accelerations, which are key in causing concussions [PMID:21074079].
Baseline SCAT5 scores from 1005 National Rugby League players revealed median Standardized Assessment of Concussion scores of 27, symptom severity of 0, and a Modified Balance Error Scoring System error score of 3, providing clinicians with specific normative data for interpretation [PMID:40118744].
The use of smart mouthguards in contact sports like rugby aims to enhance player safety by providing real-time data on head impacts, potentially identifying concussions that might otherwise go unnoticed during gameplay [PMID:39266049].
In the study of National Rugby League head impact events, the blank/vacant look was the most sensitive video sign (0.54 sensitivity, CI: 0.44-0.63) for diagnosing concussion, though only present in 54% of concussed athletes, highlighting the limitations of current video assessment tools [PMID:33027812].
Only 43.4% of diagnosed concussions exhibited any of the six proposed video signs, indicating that these signs alone may not be sufficient for accurate concussion diagnosis in rugby league [PMID:33027812].
The study identified that certain cytokines, along with clinical features like age and history of previous concussions, significantly predicted symptom severity and number of symptoms post-SRC, indicating potential diagnostic utility [PMID:32881769].
Microtechnology devices demonstrated high sensitivity (97.6%) in identifying collision events, potentially offering a tool for clinicians to better monitor and diagnose traumatic injuries sustained during high-impact sports [PMID:28153609].
The study highlights the frequent use of video review to identify signs of concussion, suggesting its potential utility, but notes that more research is needed to confirm its effectiveness [PMID:26837928].
For diagnosing concussion risk, tentative tolerance limits include 2.24 kPa and 24.0 s-1 for von Mises stress and strain rate in the thalamus, and 3.51 kPa and 25.1 s-1 for the corpus callosum [PMID:25781376].
Differential Diagnosis
The paper discusses the ongoing debate around whether players might alter their behavior (risk compensation) due to perceived protection by headgear, potentially affecting injury outcomes [PMID:34083330].
No significant differences were observed in SCAT5 scores among players based on cultural heritage (Pasifika/Maori, Indigenous Australian, and others), implying that these factors do not affect diagnostic outcomes [PMID:40118744].
Despite examining various sleep metrics, the study found no significant associations between sleep characteristics and the incidence of time-loss injuries among the athletes [PMID:31895289].
Restricted vision and perceived poor quality of the helmet/faceguard were common reasons for modifications, which could indirectly relate to the differential diagnosis and management of concussions [PMID:30465597].
By comparing proficiency scores in concussive versus non-injury contact events, clinicians and coaches can better understand the technical factors contributing to concussions, aiding in differential diagnosis [PMID:26223002].
Management
The study supports introducing policies that mandate mouthguard use to potentially reduce concussion incidence among youth ice hockey players [PMID:36918257].
Factors like skill level, helmet model, impact location, and player position influence head impact kinematics, highlighting the need for targeted interventions in protective equipment and training to enhance athlete brain safety [PMID:34549342].
Included studies generally lacked robust evidence and did not assess headgear as the primary outcome for concussion prevention, suggesting a need for further research [PMID:34083330].
The study highlighted that wearing a custom-made, properly fitted mouthguard statistically reduced the incidence of SRC compared to over-the-counter mouthguards [PMID:32580527].
By accurately assessing head impact severity and frequency through devices like the IMM, clinicians can better manage athletes' exposure to repetitive impacts, potentially mitigating long-term neurological risks [PMID:31946308].
Given that a larger proportion of head, face, and neck injuries in men were associated with checking, targeted prevention strategies aimed at reducing checking-related injuries could be beneficial [PMID:28662349].
The study by Nakatsuka AS and Yamamoto LG [PMID:25157327] demonstrated that incorporating 1.3 cm thick polyolefin foam to the exterior of football helmets significantly reduced impact severity measures when subjected to simulated helmet-to-helmet collisions. This suggests a practical modification to enhance protective gear in sports medicine.
An umbrella review of systematic reviews indicated that mouthguards (MGs), particularly custom-made designs, effectively prevent dentofacial injuries such as avulsions and fractures [PMID:40586455].
Despite 86% of surveyed players reporting attendance at mandatory concussion education sessions, high rates of non-disclosure persisted, indicating a need for further supportive measures to encourage symptom reporting [PMID:40316489].
Providing clinicians with normative SCAT5 values can facilitate better monitoring of recovery processes and inform evidence-based return-to-play decisions for concussed rugby players [PMID:40118744].
Introducing smart mouthguards raises ethical concerns regarding device efficacy, player autonomy, data management, and potential misuse, which are crucial for effective management strategies [PMID:39266049].
Given the significantly higher incidence of HAEs during matches, particularly at higher thresholds, targeted mitigation strategies in match-play could be crucial for reducing concussion risks, including those affecting the periodontal ligament [PMID:39428738].
During the study period, 31% of players returned without missing a game, 39% missed 1 game, and 30% missed 2 or more games, indicating diverse recovery trajectories [PMID:38735562].
A systematic review [PMID:37524627] found that wearing mouthguards, particularly custom-made ones, improved athletic performance compared to not wearing them, suggesting additional benefits for athletes beyond the prevention of orofacial and dental trauma.
The study noted that 29% of suspected injuries led to permanent removal from play, underscoring the severity and potential long-term implications of these injuries, including concussions [PMID:35909055].
The study highlights the importance of improving 'pre-season intensity' and 'current medical standards' to mitigate injury risks, suggesting that similar enhancements in sports medicine protocols could benefit the management and prevention of periodontal ligament injuries [PMID:35694782].
Only 27.6% of athletes reported using mouthguards during gameplay, with usage significantly higher among contact sport athletes (43.3%) compared to noncontact sport athletes (1.2%) [PMID:33710051].
The increased risk of concussions in female players suggests a potential need for improved coaching training to manage trauma effectively [PMID:33654036].
While predictive accuracy for return to sports (RTS) was less robust, cytokine profiles still showed some predictive value alongside clinical factors, suggesting a role in tailoring management and follow-up plans [PMID:32881769].
While the impact of MGs on concussion incidence was modest (summary RR [nonusers/users] = 1.25, 95% CI 0.90-1.74) across five cohort studies, their use is still advised in sports with significant orofacial injury risk [PMID:31148073].
Complications
Among admitted patients, 15.7% required surgical interventions, predominantly orthopedic (89.9%), highlighting the potential for serious complications necessitating further treatment [PMID:27185745].
Prognosis & Follow-up
Given the correlation between years of exposure and severity of chronic traumatic encephalopathy (CTE), ongoing monitoring of head impacts using advanced systems like the IMM is crucial for long-term prognosis and follow-up care [PMID:31946308].
By mitigating the force of impacts through enhanced helmet design as shown in [PMID:25157327], there is potential for decreased incidence and severity of concussions, which could positively influence long-term prognosis and recovery for athletes [PMID:25157327].
The established normative reference values can serve as a benchmark for follow-up evaluations, helping to accurately assess changes in player status following a concussion [PMID:40118744].
Players on playoff teams missed fewer weeks (0.86 weeks) compared to those on non-playoff teams (1.37 weeks) after sustaining a concussion (P = 0.002) [PMID:38735562].
For those admitted to inpatient care, the mean hospital length of stay was 2.4 days, with 95.6% undergoing routine discharge home, suggesting a generally favorable short-term prognosis [PMID:27185745].
Despite apparent signs of concussion, more than half of the players were cleared to return to play later in the same match, highlighting the importance of thorough follow-up [PMID:26837928].
Special Populations
Given the high participation and frequent head impacts in high school football, this demographic is particularly important for monitoring and mitigating brain injury risks through accurate impact measurement and protective strategies [PMID:34549342].
Key Recommendations
Helmet age, whether newer or older, was not found to be associated with the rate or odds of concussion in this study [PMID:36918257]. (Evidence: Moderate)
The review indicates that while there is a belief in the protective benefits of padded headgear, the evidence is insufficient to definitively support or refute its efficacy in preventing SRC in youth athletes [PMID:34083330]. (Evidence: Expert opinion)
Given the inconsistent results from previous studies, the authors emphasize the necessity for more robust research designs, such as the case-control study conducted, to definitively establish the role of mouthguards in SRC prevention [PMID:32580527]. (Evidence: Expert opinion)
The development and use of inexpensive, sport-agnostic, and reliable head impact monitoring systems, such as the IMM, are essential for enhancing concussion detection and management practices in sports medicine [PMID:31946308]. (Evidence: Expert opinion)
The study recommends implementing mandatory mouthguard use policies and enhancing athlete education to improve compliance and safety, noting that custom-made designs offer superior protection [PMID:40586455]. (Evidence: Expert opinion)
The study suggests that enhancing concussion education initiatives to foster a more supportive environment could improve disclosure rates among players [PMID:40316489]. (Evidence: Expert opinion)
The review [PMID:37524627] recommends advocating for the use of mouthguards among athletes, highlighting their dual benefit of enhancing performance and preventing orofacial injuries, though methodological variability should be noted. (Evidence: Moderate)
The study concludes that there is a need to particularly reinforce mouthguard use and knowledge of dental first aid among contact sport athletes due to their higher incidence of dento-facial injuries and concussions [PMID:33710051]. (Evidence: Expert opinion)
The findings support the creation of a user-friendly algorithm for evaluating craniofacial injuries in lacrosse players, addressing the unique injury profiles by age and gender [PMID:33654036]. (Evidence: Expert opinion)
The study emphasizes the need for rigorous assessment of video signs across various sports to improve their predictive value and diagnostic accuracy for concussion [PMID:33027812]. (Evidence: Expert opinion)
The systematic review and meta-analysis conclude that MGs should be used in sports activities where there is significant orofacial injury risk, supporting their role in injury prevention strategies [PMID:31148073]. (Evidence: Strong)
The study suggests making mouthguard use mandatory in all high-risk sports and those with medium-risk for dental injuries to improve prevention [PMID:29526055]. (Evidence: Expert opinion)
References
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32 papers cited of 44 indexed.