INQUIRY

Dental TraumaOrofacial protective sports equipment

Background.—Patients with facial injuries report thehighest percentage of injury-related disability. Included isvisual impairment, altered sense of smell, masticatorydysfunction, respiratory difficulty, and psychological prob-lems, especially if reconstructive surgery is needed. Mostsports injuries result from impact with the ground, equip-ment, or a fellow athlete. Protective equipment is designedto reduce the risk of injury. Orofacial protection includesheadgear, mouthguards, helmets, protective goggles, andspecial facemasks. Type of sport, player factors, technologicaspects, anatomic issues, and incidence of fractures were as-sessed for various types of equipment.

Mouthguards.—Mouthguards prevent violent contactbetween the upper and lower dentition. They can becustom-made of materials such as polyvinyl acetate�poly-ethylene or ethylene vinyl acetate (EVA) copolymer, whichacts like a shock absorber and dissipates the force of impactthrough surrounding orofacial structures. The thickness ofthe mouthguard directly correlates with the rate at whichenergy is absorbed.

Mouthguards are mandated for some sports, such as icehockey, fencing, boxing, and lacrosse. With mandatory useof mouthguards, several UK sports report a reduction indental injuries of 60%. Injuries can still occur with mouth-guards in place because players may not be aware of thebest type of device or wear one that is the wrong size.Poor fit results, and the athlete can suffer injury as a result.Often dental insurance companies exclude coverage ofsports injuries if a mouthguard or other protection is notworn, even during training activities. Thus there is a finan-cial impact on players who do not wear mouthguards.

Helmets and Headgear.—Helmets reduce head andorofacial injuries by redistributing load and attenuatingenergy from impact forces. The outer shell of modern hel-mets is usually made of polycarbonate or other high-quality plastic composite. Liners are usually made fromexpanded polystyrene (EPS) foam, which cushions thehead, dissipates energy from impacts, and increases pro-tection. Both the shell’s thickness, density, and stiffnessand the lining’s qualities determine how well the helmet

performs. A study of American football helmets foundthe shell has little influence on performance, but a thicker,denser lining increases the potential for energy to be ab-sorbed and improves performance. Extra features suchas grates and polycarbonate visors or half shields protectagainst trauma to the nose and sometimes the mouth.Helmets for cricket, baseball, and ice hockey were shownto protect well at lower impact speeds, but the potentialfor head injury increased substantially when impacts ex-ceeded 27 m/sec. A ‘‘multiuse’’ helmet could be difficultto develop, since most sports have unique requirementsfor protection and use. For example, helmets for cyclingand downhill skiing must protect the head against violentimpact and remain aerodynamic to maximize drag resis-tance, but helmets for baseball must protect againsthigh-velocity impacts to the side of the head.

Headgear may also place athletes in contact sports atgreater risk for injury. They persuade the athlete that heor she can use greater force because the head is ‘‘pro-tected.’’ Many helmets only protect the cranium and notthe mid and lower face. Full-face helmets should be consid-ered for sports with a high risk for injuries to the mid tolower face, such as road cycling. These would minimally in-crease helmet weight but guard against direct impact andoffer advantages that far outweigh the disadvantages.Among cyclists who wear helmets, the incidence of head in-juries is 85% lower than among cyclists who do not wearthem.

Eyewear and Face Masks.—It is estimated that up to90% of sports-related eye injuries are preventable. Polycar-bonate plastic eyewear is durable and impact resistant, of-fering optimal protection from debris. Sports goggles canand should be worn during most sports activities, but par-ticipants in racquet sports, fishing, boxing, swimming,hockey, and baseball are especially prone to eye injuries.Such injuries can be as simple as minor swellings or cornealabrasion or as serious as hyphema, zygomatic fracture,orbital blow-out fracture, and globe rupture.

Contact lenses offer no protection, and everyday glassesare too thin to adequately protect against projectiles. In

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addition, glass lenses can break with impacts as low as 15mph/24 km. The American Society for Testing and Materials(ASTM) standard requires that polycarbonate lenses be atleast 3 mm thick at their thinnest section for use in sportssuch as hockey and squash. The eyewear must also mini-mally hinder the player’s field of vision. Specially designedprotective eyewear reduces eye injuries dramatically insome sports, but it is not mandatory in most sports. TheAmerican Academy of Ophthalmology recommends protec-tive eyewear for all sports where eye injury is possible. Foot-ball is rapidly becoming the sport resulting in the mostocular injuries worldwide.

Protective masks are used after an individual suffersfacial fractures and are usually custom-made to preventrecurrent injuries during and after healing. Pressure orvacuum forming of polycarbonate blanks over an impres-sion cast of the defect creates these masks, which physi-cally guard against injury by redistributing impact loadsover a large surface area. The theory behind their usehas not yet been supported by published scientificevidence.

202 Dental Abstracts

Clinical Significance.—Sports participantsoften decide not to wear protective gear, butthey may simply not know what style is bestor choose one that fits poorly. Orofacial injuriesmay not be completely prevented, but the risk isreduced, depending on the magnitude of force,the source of energy, and the anatomic siteinvolved in the specific sport. Helmets, goggles,and mouthguards are readily available andshould be used to protect against severe facialinjuries.

Farrington T, Onambele-Pearson G, Taylor RL, et al: A review of facialprotective equipment use in sport and the impact on injury inci-dence. Br J Oral Maxillofac Surg 50:233-238, 2012

Reprints available from K Winwood, Dept. of Exercise and Sport Sci-ence/Inst. for Performance Research, Manchester MetropolitanUniv., Crewe Green Rd., Crewe, Cheshire CW1 5DU, UnitedKingdom; e-mail: k.winwood@mmu.ac.uk

Energy DrinksIntraoperative bleeding

Background.—The consumption of energy drinks isincreasing, with particular use by adolescents and US sol-diers deployed to Iraq and Afghanistan. Most of the energyfrom these drinks comes from their caffeine content, whichcan range from 50 to 145mg per 8-oz serving. Becausemanycome in 16-oz cans, most contain more than 200 mg ofcaffeine. In addition, these drinks contain other ingredientssuch as taurine, panax ginseng root extract, carnitine, andguarana seed extract. Some case studies indicate thatincreased bleeding complications are associated with herb-al supplements, some of which are included as energy drinkingredients. Two cases of orthognathic surgery complicatedby bleeding in persons who were chronic energy drink con-sumers were reported.

Case Reports.—Case 1.—Man, 18, a military depen-dent with Saethre-Chotzen syndrome, came for treatmentof a Class II dentofacial deformity secondary to mandib-ular hypoplasia. The treatment plan was to extract the re-tained maxillary left third molar, perform a multi-piece LeFort I advancement with transverse expansion, and add amandibular bilateral sagittal split osteotomy with advance-ment. The patient was given 2% lidocaine with 1:100,000epinephrine and 0.5% bupivacaine with 1:200,000

epinephrine for local anesthesia and vasoconstriction. Hy-potensive general anesthesia was used to limit bleedingduring the procedure. As the Le Fort I advancement pro-ceeded, the patient was noted to have moderate amountsof bleeding, although no specific vascular source could beidentified. Generalized direct pressure was used. An im-mediate complete blood count after the maxilla wasfixated revealed the patient’s hematocrit had fallen from39 g/dL preoperatively to 24 g/dL, so a packed red bloodcell transfusion was started with 1 U of fresh frozenplasma. The maxillary incisions were closed. Since thebilateral sagittal split osteotomy was unlikely to add signif-icant blood loss, surgery was continued. The patient wasgiven additional transfusions at the discretion of the anes-thesia team. Mild generalized oozing from the incisioncontinued after the procedure was completed, but the pa-tient was safely extubated and spent the night in the inten-sive care unit for close observation. He had received 3600mL of lactated Ringer’s solution, 1500 mL of normal salinesolution, 1500 L of 5% albumin, 1400 mL of hetastarch, 4 Uof packed red blood cells, 2 U of fresh frozen plasma, anda 4-pack of platelets. His estimated blood loss was 5100mL, but he had remained hemodynamically stable. A coag-ulation panel performed postoperatively revealed an