Protein Deposition on Sport Mouthguards and the Effectiveness of Two Different Cleaning Protocols.

Objective: To determine which salivary proteins adhere onto sport mouthguards, and to evaluate the effectiveness of different cleaning strategies in removing deposited protein. Methods: Fifteen healthy volunteers used a mouthguard for 1 h. The deposited salivary proteins were analyzed using gel electrophoresis and Western blotting techniques and compared with the protein composition of unstimulated saliva. In addition, the effectiveness of two different cleaning strategies to remove proteins from the mouthguards were compared: rinsing the mouthguards after use with cold tap water and cleaning the mouthguard with a soluble effervescent tablet. Results: Gel electrophoresis showed deposition of proteins of 50-60 kDa and 14 kDa on the mouthguards used in the mouth for 1 h. Western blotting identified these bands as amylase and lysozyme, respectively. Rinsing the mouthguard with cold tap water after use removed 91% of the total amount of deposited proteins, while cleaning with an effervescent tablet removed 99%. Conclusions: During the use of mouthguards, salivary proteins are deposited on their surface. Because salivary proteins can potentially affect bacterial adhesion to mouthguards, proper cleaning after use is recommended. Cleaning the mouthguard with cold tap water or using an effervescent tablet both seem to be effective strategies to remove proteins deposited on sport mouthguards.

Orodental injury and mouthguard usage in Dutch and international field hockey.

Background: Mouthguards are used to prevent players from orodental injuries in field hockey. However, such injuries are still a common problem. This study describes the prevalence of orodental injury and the related mouthguard usage in field hockey. Material and Methods: A 19-item questionnaire was distributed in the Dutch field hockey competition and at the international Master World Cup. In total, 1213 questionnaires were collected. Standard descriptive statistics were used to describe the samples. Associations between data were determined using the Pearson Chi-Square test. Results: The prevalence of orodental injuries during the career of hockey players was 20% in Dutch players, and 29% in international players. Mouthguard usage among Dutch players was 95%, and among international players 88%. There was no significant association between wearing a mouthguard or not with respect to whether or not treatment was requested as a result of an orodental injury (Dutch p=0.43; international p=0.22). Conclusions: This study showed that the prevalence of orodental injuries in field hockey are high, while the majority of the players use a 'protective' mouthguard. These results imply that the current mouthguards may not provide enough protection against the forces used in field hockey. Key words:Mouthguard, prevention, sports, dental injury.

Knowledge about the emergency management of dental injuries among field hockey coaches.

BACKGROUND/AIM: Field hockey is frequently associated with oro-dental injuries. In such acute situations, appropriate management of the injury by coaches can contribute to a better clinical outcome and prognosis. Therefore, the aim of this study was to investigate the knowledge of hockey coaches in the Netherlands about the emergency management of dental injuries. MATERIAL AND METHODS: A 25-item questionnaire about the prevalence and management of oro-dental injuries was distributed amongst hockey coaches in the Netherlands. A sub-analysis was done regarding the knowledge on the management of dental injuries by using a 5-point scoring system. RESULTS: Two hundred and six hockey coaches participated in this survey. A small majority (53%) of the coaches knew the treatment of choice in the event of a permanent tooth injury. The median score of coaches' knowledge regarding management of oro-dental injuries was 3.0 (2.0-4.0) points. Coaches with a (para)medical training/occupation, and coaches with >10 years of experience had significantly higher scores compared with the other groups (p < .01 and p = .03, respectively). CONCLUSIONS: The knowledge level of hockey coaches in the Netherlands about oro-dental injuries needs to be improved, as many coaches are not aware of the appropriate first aid measures.

Maximum impact heights of currently used mouthguards in field hockey.

BACKGROUND/AIM: The effectiveness of mouthguards used in field hockey is unknown. The aim of this study was to compare the maximum impact heights between currently used mouthguards in field hockey to prevent dental injury. METHODS: Four boil-and-bite mouthguards (Dita, Shock Doctor, SISU, and Stag) and one custom-made mouthguard (Elysee) were tested for maximum impact height. A hockey ball was released in a tube from increasing heights onto plaster and polymethylmethacrylate (PMMA) dental models. Models were tested without mouthguard as a control. The experiment was repeated 10 times per mouthguard and for the control on each dental model. The maximum impact height for when the dental model broke was used to calculate the speed. The mouthguards and controls were compared. RESULTS: The maximum impact heights (median [25%-75%] in meters) onto plaster dental models were as follows: control 0.23 (0.15-0.25), Dita 0.35 (0.30-0.35), Elysee 0.45 (0.34-0.50), Shock Doctor 0.68 (0.60-0.74), SISU 0.23 (0.20-0.26), and Stag 0.35 (0.35-0.46). The maximum impact height for Shock Doctor was significantly higher than all other mouthguards and the control (all P < .05). The maximum impact heights onto PMMA dental models were as follows: control 2.00 (1.30-2.50), Dita 3.80 (2.65-6.95), Elysee 3.30 (2.30-4.20), Shock Doctor 6.20 (2.80-8.10), SISU 2.60 (1.90-3.15), and Stag 3.90 (1.25-5.15). The maximum impact height for Shock Doctor was significantly higher than for SISU, Stag, and the control (all P < .05), but did not differ significantly from Dita (P = .43) and Elysee (P = .12). CONCLUSION: Shock Doctor had the highest maximum impact height compared to the other mouthguards and appears to be the most effective mouthguard tested in this study.

FDG-PET/CT for differentiating between aseptic and septic delayed union in the lower extremity.

BACKGROUND: 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET)/computed tomography (CT) has proven to have a high diagnostic accuracy for the detection of bone infections. In patients with delayed union it may be clinically important to differentiate between aseptic and septic delayed union. The aim of this study was to evaluate the efficacy and to assess the optimal diagnostic accuracy of FDG-PET/CT in differentiating between aseptic and septic delayed union in the lower extremity. METHODS: This is a retrospective study of consecutive patients who underwent FDG-PET/CT scanning for suspicion of septic delayed union of the lower extremity. Diagnosis of aseptic delayed union or septic delayed union was made based on surgical deep cultures following PET/CT scanning and information on clinical follow-up. FDG-uptake values were measured at the fractured site by use of the maximum standardized uptake value (SUVmax). Sensitivity, specificity and diagnostic accuracy of FDG-PET/CT were calculated at various SUVmax cut-off points. RESULTS: A total of 30 patients were included; 13 patients with aseptic delayed unions and 17 patients with septic delayed unions. Mean SUVmax in aseptic delayed union patients was 3.23 (SD ± 1.21). Mean SUVmax in septic delayed union patients was 4.77 (SD ± 1.87). A cut-off SUVmax set at 4.0 showed sensitivity, specificity and diagnostic accuracy of FDG-PET/CT were 65, 77 and 70% to differentiate between aseptic and septic delayed union, respectively. CONCLUSION: Using a semi-quantitative measure (SUVmax) for interpretation of FDG-PET/CT imaging seems to be a promising tool for the discrimination between aseptic and septic delayed union.

Physiological uptake values of 18F-FDG in long bones of the lower extremity on PET/CT imaging.

INTRODUCTION: Fluorine-18 fluorodeoxyglucose (F-FDG) PET/computed tomography (CT) has proven to be a valuable imaging modality with high diagnostic accuracy for the detection of bone infections. However, the physiological uptake values for F-FDG in the long bones of the lower extremity have not been established yet. This hampers correct interpretation of a F-FDG-PET/CT scan. PURPOSE: The purpose of this study was to determine the physiological uptake values of F-FDG in the long bones of the lower extremities, including the femur and the tibia. PATIENTS AND METHODS: We retrospectively analyzed the F-FDG-PET/CT scan of 84 consecutive patients from our database. F-FDG uptake parameters included mean standardized uptake value (SUVmean) and maximum standardized uptake value (SUVmax). Both SUVs were determined in the diaphyseal region of the femur and the tibia. RESULTS: SUVmean for the femoral diaphysis was 0.46 [95% confidence interval (CI) 0.42-0.49] and SUVmax was 0.81 (95% CI 0.74-0.88). For the tibial diaphysis, SUVmean was 0.34 (95% CI 0.32-0.37) and SUVmax was 0.61 (95% CI 0.56-0.65). SUVmean and SUVmax of the femur were significantly higher than that of the tibia (both P<0.01). SUVs for men were not significantly different from that for women and did not discriminate between age classes. CONCLUSION: For a correct interpretation of the F-FDG-PET/CT scan, we have determined the F-FDG uptake values in the long bones of the femur and the tibia. A SUVmean less than 0.5 and a SUVmax less than 0.8 can be considered as normal bone, irrespective of sex or age.