Effect of external airflow resistive load on postural and exercise-associated cardiovascular and pulmonary responses in pregnancy: a case control study.

BACKGROUND: Facial coverings (e.g., balaclavas, niqabs, medical/surgical masks, respirators, etc.), that impose low levels of airflow resistive loads, are worn by millions of pregnant women worldwide, but little data exist addressing their impact on pregnancy-associated cardiovascular and pulmonary responses. METHODS: 16 pregnant and 16 non-pregnant women were monitored physiologically (heart rate, blood pressure, mean arterial pressure, total peripheral resistance, stroke volume, cardiac output, oxygen saturation, transcutaneous carbon dioxide, fetal heart rate) and subjectively (exertion) for 1 h of mixed sedentary postural activity (sitting, standing) and moderate exercise (bicycle ergometer) with and without wearing N95 filtering facepiece respirators with filter resistive loads of 94.1 Pa (9.6 mm H2O) - 119.6 Pa (12.2 mm H2O) pressure. RESULTS: The external airflow resistive loads were associated with increases in diastolic pressure (p = 0.004), mean arterial pressure (p = 0.01), and subjective exertion score (p < 0.001) of all study subjects. No significant differences were noted with the external resistive loads between the pregnant and non-pregnant groups for any cardiovascular, pulmonary and subjective variable over 1 h. CONCLUSIONS: Low external airflow resistive loads, during combined sedentary postural activity and moderate exercise over 1 h, were associated with increases in the diastolic and mean arterial pressures of all study subjects, but pregnancy itself was not associated with any significant differences in physiologic or subjective responses to the external airway resistive loads utilized in the study.

Easy fabrication of a new type of mouthguard incorporating a hard insert and space and offering improved shock absorption ability.

The positive effects of wearing a mouthguard have been indicated in various epidemiological surveys and experiments, and their usage appears to be increasing in many sports. However, many preventable sports-related dental injuries still occur even with the use of a conventional mouthguard. We have developed a mouthguard (the Hard & Space mouthguard) with sufficient injury prevention ability (more than 95% shock absorption ability against impact with a steel ball carrying 15.2 kg m(2) S(-2) potential energy) and ease of clinical application. This mouthguard consists of an outer and an inner EVA layer and a middle layer of acrylic resin (hard insert), with a space to prevent contact between the inner surface of the mouthguard and the buccal surfaces of the maxillary front teeth or teeth already weakened through prior damage or treatment. The purpose of this article is to describe the method by which the Hard & Space mouthguard may easily be fabricated. We believe that this new type of mouthguard has the potential to reduce sports-related dental injuries.

Formulation and evaluation of mucoadhesive buccal patch of acyclovir utilizing inclusion phenomenon

Mucoadhesive buccal patch releasing drug in the oral cavity at a predetermined rate may present distinct advantages over traditional dosage forms, such as tablets, gels and solutions. A buccal patch for systemic administration of acyclovir in the oral cavity was developed using polymers hydroxy propyl methyl cellulose (K4M), hydroxy propyl methyl cellulose (K15M), sodium carboxy methyl cellulose and poly vinyl pyrolidone (K30), plasticizer poly ethylene glycol (400) and a backing membrane of Eudragit (RL100). The films were evaluated in terms of swelling, residence time, mucoadhesion, release, and organoleptic properties. The optimized films showed lower release as compared to controlled drug delivery systems. Hence, an inclusion complex of acyclovir was prepared with hydrophilic polymer hydroxylpropyl beta-cyclodextrin in the molar ratio of 1:1. The inclusion complex was characterized by optical microscopy, FAB mass spectroscopy, and FTIR spectroscopy. Patches formulated with the acyclovir inclusion complex were evaluated along the same lines as those containing acyclovir alone. The in vitro release data revealed a substantial increase from 64.35 percent to 88.15 percent in the case of PS I and PS II batches, respectively, confirming the successful use of inclusion complexes for the formulation of buccal patch of acyclovir.

Mucoadesivos bucais liberadores de fármacos para a cavidade oral com taxa de liberação pré-determinada podem apresentar distintas vantagens em relação às formas farmacêuticas convencionais como comprimidos, géis e soluções. Neste trabalho, um adesivo bucal para administração sistêmica de aciclovir através da cavidade oral foi desenvolvido empregando-se os polímeros hidroxipropilmetil celulose (K4M), hidroxipropilmetil celulose (K15M), carboximetil celulose sódica e polivinil pirrolidona (K30), polietilenoglicol plastificado (400) e uma membrana suporte de Eudragit (RL100). Os filmes obtidos foram avaliados em termos de intumescimento, tempo de residência, mucoadesão, liberação e propriedades organolépticas. Os filmes otimizados apresentaram liberação mais lenta em comparação a outros sistemas de liberação controlada. Desta maneira, um complexo de inclusão de aciclovir foi preparado com o polímero hidrofílico hidroxipropil beta-ciclodextrina em proporções molares 1:1. O complexo de inclusão foi caracterizado por microscopia ótica, espectrometria de massas FAB e espectroscopia FTIR. Os adesivos formulados com o complexo de inclusão de aciclovir foram avaliados em paralelo com adesivos contendo aciclovir isolado. Os dados de liberação in vitro revelaram um aumento substancial, de 64,34 por cento para 88,15 por cento, nos lotes PS I e PS II, respectivamente, confirmando o sucesso do uso de complexos de inclusão para a formulação de adesivos bucais de aciclovir.

Prevalence of dental trauma in Pan American games athletes.

The aim of this cross-sectional epidemiological survey was to assess the prevalence of dental trauma in athletes representing 42 countries competing at the most recent Pan American Games (XV Pan Am) held in Rio de Janeiro, Brazil in July of 2007, and to determine prior use and type of mouthguard among this group of athletes. The examiners participated in standardization and calibration training sessions before the field phase began. Invitations were sent to >5500 participating athletes competing in 41 sports and to the Medical Committee of the Pan American Sports Organization before and during the XV PAN. A convenience sample of 409 athletes was recruited. After signing an informed consent, all athletes answered a questionnaire. Data were collected at the clinical examination and recorded on a specific trauma form. The mean age of the athletes was 24.4 +/- 5.3 years. Males comprised 55% of the sample; females 45%. The prevalence of dental trauma among the athletes was 49.6% (n = 203) with no gender-based differences. Most of these injuries (63.6%) were related to activities during training or competition. Sports with the highest injury prevalence were wrestling (83.3%), boxing (73.7%), basketball (70.6%) and karate (60%). The most common injury was enamel fracture (39.8%); root fracture was the least common (0.4%). The teeth most affected were the maxillary permanent central incisors (n = 113), followed by the mandibular central incisors (n = 19). Based on the results of this study, nearly one-half of the subjects had experienced previous dental trauma; the majority related to sports activities. Furthermore, only 17% of the athletes reported prior mouthguard use; the most frequent mouthguards reported were boil-and-bite. These results suggest the importance of enhanced educational efforts and the use of properly fitted mouthguards to reduce dental trauma among athletes in international sports competition, especially in sports where mouthguards are not mandatory.

Preventive strategies for traumatic dental injuries.

Traumatic dental and maxillofacial injuries are common occurrences, and affect worldwide approximately 20% to 30% of permanent dentition, often with serious aesthetic, functional, psychological, and economic consequences. With such a high frequency of injuries, prevention becomes a primary goal. A prevention approach relies on the identification of etiologic factors, and on giving rise to measures aimed at avoiding those factors or at reducing their impact. This article reviews the etiology and preventive strategy regarding dental injuries, and examines the role and manufacture of appliances, especially mouthguards, in preventive dentistry.

Characterization of mouthguard materials: physical and mechanical properties of commercialized products.

OBJECTIVES: Contemporary mouthguard materials need to perform consistently over a wide range of possible temperatures (-20 to 40 degrees C). Therefore the specific aim of this study was to characterize commercialized mouthguard materials' properties and investigate the effect of temperature on these properties. METHODS: Five commercially representative thermoplastic mouthguard materials (Essix Resin, Erkoflex, Proform-regular, Proform-laminate, and Polyshok) were tested. The durometer hardness, water absorption, tear strength, and impact attenuation of the mouthguard materials were measured according to ASTM D2240-05, D570-98 (2005), D624-00, and ASTM D6110-06f (modified) guidelines. Tests were conducted on five separate specimens at both room 23+/-2 degrees C and intra-oral 37+/-2 degrees C temperatures. Independent t-tests (alpha=0.05) were used to test for differences between room and intra-oral temperatures. RESULTS: Material hardness decreased (p<0.05) from room to intra-oral temperatures for all mouthguard materials. Water absorption increased (p<0.05) from room to intra-oral temperatures for all mouthguard materials. Tear strength decreased (p<0.05) from room to intra-oral temperatures for all mouthguard materials. Impact attenuation between room and intra-oral temperatures was different (p<0.05) for the Erkoflex, Proform-laminate, and Polyshok material respectfully. However, there was no difference between temperatures for the Essix Resin (p=.058) or Proform-regular (p=.275) materials. SIGNIFICANCE: Temperature measureably affects the physical and mechanical properties of mouthguard materials. It is particularly noteworthy that none of the commercialized products met current ANSI and SAI standards for impact attenuation.

A technique for fabricating modern athletic mouthguards.

The prevention and treatment of orofacial trauma is now a very important part of the general practice. Children as well as adults are participating more in events where the probability of trauma is apparent. Attendance at health clubs and gymnasiums is on the rise. With the increase in sports participation comes an increase in orofacial injuries. The general population is taking its health more seriously. Athletic participation is on the rise, and Title IX4 has introduced increased female participation at all levels. This only increases the possibility that our patients will present themselves in our offices with the need for trauma treatment and also our opinions on the methods of preventing such traumatic experiences.

Mouthguards and orthodontic patients.

All orthodontic patients who wear fixed appliances and participate in contact sports are recommended to wear a mouthguard for protection against dental trauma and injury. An overview of the different types of mouthguards currently available is described together with their relative suitability for orthodontic patients.

Effect of mouthguards on the transmission of force across the human jaw.

OBJECTIVE: To determine if impact responses (stiffness and damping values) of the jaw and neck are significantly different between mouthguards of varying material and manufacturing properties, in controlled conditions involving specified upper limb orientation and applied loading. DESIGN: Quasi-experimental design. SETTING: Simon Fraser University biomechanical laboratory. PARTICIPANTS: Twelve male subjects between the ages of 19 to 28 participated in this study. All subjects were healthy, had no missing teeth, and had no mechanical (orthodontic) appliances. MAIN OUTCOME MEASUREMENTS: For each condition, the system stiffness and damping values were estimated using the free vibration technique. Stiffness and damping values are relevant because they are the major determinants of impact force and, potentially, injury risk. It is the first study to show experimentally the quantitative effects of mouthguard in situ. RESULTS: All the mouthguards lowered the system stiffness as compared with the no mouthguard condition (P < 0.001). There was no observed effect on stiffness between the 2 limb orientation positions. Excitation weight had an unexpected effect on system stiffness (P = 0.041), with increasing weight leading to increased stiffness. CONCLUSIONS: The findings suggest that wearing any mouthguard is better than wearing none at all due to their ability to reduce system stiffness and damping values after a blow to the chin.

Scale of protection and the various types of sports mouthguard.

OBJECTIVES: To present a grading system of the protection offered by various types of mouthguard, together with an indication of associated risks, in order to make athletes aware of the consequences of improper or no mouth protection. METHODS: A review of the literature on mouthguards, mouthguard materials, and novel laminates for mouthguards was carried out as it was apparent that information on mouthguards was lacking. Studies on stock (or unfitted) mouthguards, mouth formed (boil and bite) mouthguards, and custom mouthguards are reviewed. RESULTS: A scale of protection offered by various mouthguards and novel laminates has been produced, where 0 indicates no mouthguard and 10 indicates a custom made mouthguard offering excellent protection. CONCLUSIONS: From work carried out on laminates and the manufacturing processes of mouthguards, it became apparent that information was lacking to enable athletes make informed decisions about the best oral protection for their chosen sport.

Adaptations of mouthguards for patients with special needs.

The adaptations and applications of mouthguard appliances are many and varied, with uses ranging from protective to therapeutic. These modifications serve the individual needs of patients. This requires problem-solving based on combining form and function with the skills of the dentist.

Incidence of cerebral concussions associated with type of mouthguard used in college football.

Controversy exists among sports dentists as to whether or not a 'custom made' mouthguard is more effective in reducing the incidence of cerebral concussion than the boil-and-bite 'non-custom made' mouthguard. While members on each side remain steadfast in their opinion, not a single epidemiological study has been conducted to investigate the effect of type of mouthguard worn on the incidence of cerebral concussion. The aim of this study was to determine if there was a difference between the type of mouthguard worn and the incidence of cerebral concussions among National Collegiate Athletic Association (NCAA) Division I-A football players. During the 15-week 2001 college football season, trainers entered, via an interactive web site, weekly data for each game and practice sessions for the preceding week. Eighty-seven (76%) out of a possible 114 Division I teams participated. A total of 506 297 athletic exposures were recorded; 369 brain concussions were reported. The incidence of cerebral concussions per 1000 exposures was 0.73. Utilizing a risk ratio with a 95% confidence interval, no statistical difference occurred in the incidence of cerebral concussions between football players wearing custom made versus non-custom made mouthguards (0.990,1.750). In this study, there was no advantage of wearing a custom made mouthguard over a boil-and-bite mouthguard to reduce the risk of cerebral concussion in football players.

Are all mouthguards the same and safe to use? The influence of occlusal supporting mouthguards in decreasing bone distortion and fractures.

The safety benefits of mouthguards have been demonstrated in many studies, with many authors and sports dentists strongly recommending the wearing of mouthguards. However, wearing a mouthguard with incorrect occlusion might cause a variety of problems. It comes as no surprise that a traumatic blow to the chin, while wearing an insufficient mouthguard lacking anterior contact, can result in severe distortions to the mandibular bone, and bone fractures. The aim of this study was to clarify how ineffective insufficient occlusal supporting mouthguards are and how dangerous they can be to use. Consequently, in this study, occlusal supportive areas were varied and accelerations of head and distortions of the mandible were measured using an artificial skull model and a pendulum impact device. As a result, the distortions of the mandible tended to increase as the supported area decreased. On the contrary, accelerations of the head decreased as the occlusion part decreased. Thus, a lot of impact energy was consumed in the distortion of the mandible; accordingly, it seemed that only a little destructive energy was transferred to the head. From this study, it would seem that wearing a mouthguard, which is insufficient in the occlusion, has the potential of causing a bone fracture of the mandible. Consequently, mouthguards should have proper occlusion.

A thirty-year review of oral appliances used to manage microstomia, 1972 to 2002.

Patients who have sustained a facial burn often contend with cosmetic and functional challenges, including microstomia. Many devices have been created by a variety of professionals to provide oral stretching. These devices can be classified as intraoral or extraoral and deliver a stretch either horizontally, vertically, or circumorally. The purpose of this article is to present a comprehensive review of oral-stretching devices.

Knowledge and attitudes of coaches of secondary school athletes in Ibadan, Nigeria regarding oro-facial injuries and mouthguard use by the athletes.

- The objective of this study was to assess the perceptions of secondary school sports' coaches about oro-facial injuries and mouth protector usage in sports by the adolescent athletes. A 10-item, self-completion questionnaire was distributed to 42 coaches from 23 secondary schools randomly selected from different parts of Ibadan city in Nigeria between May and June, 2002. The questionnaire sought information on why a mouth protector (mouthguard) is used, when it is required; the types of mouth protector used, the major reasons for choosing a specific mouth protector, and personal feeling as to whether mouthguards prevent oral injury. Descriptive statistics were used for the data while the chi-square statistic was employed to test the significance of association between variables. All the coaches, 25 (59.5%) males and 17 (40.5%) females with age range of 19-51 years and mean age of 38.07 +/- 8.97 years (mean +/- SD), completed and returned the forms (100% completion rate). 95.2% of the coaches believed that mouthguards prevent oral injuries and 95.2% of them also would like more information on different types of mouthguard, while 4.8% each felt otherwise. The main factor determining the choice of the type of mouthguard for athletes by the coaches was the quality of oral protection (57.1%), and the next was the cost (23.8%). Acceptance of mouthguard was scored as positive by 88.1% of the athletes. 81.0% of the coaches felt that mouthguard should be worn at all times (during practices and competitions) while 19.0% would prefer the use during competitions only. The majority of the coaches (71.4%) believed that boxing needs mouthguards, 2.4% each indicated football (soccer) and Judo while 11.9% of the coaches did not indicate any sport. The majority of these Nigerian coaches agreed on the protective effectiveness of mouthguard against sport-related oro-facial injuries, but they are yet to be adequately informed about mouthguards generally so as to correctly advise and influence these adolescent athletes in this regard.