MOUTH GUARDS AND MOUTH PROTECTION

By: Jonathan OlesuUGDS, Class of 2012

Outline

IntroductionHistoryGeneral ConsiderationsFunction of Mouth GuardsIndications and ContraindicationsMaterials for Making Mouth GuardsTypes of Mouth GuardsDesign Specifications and DimensionsHow Mouth Guards WorkUse and Care InstructionsSetbacksOther Mouth Protection DevicesConclusionReferences

What are we talking about?

Introduction

Definitions

Mouth protection basically involves all the devices, substances and measures put in place to prevent injury of any form to the oral cavity and its related structures.The injury may be:

Pathological Traumatic

A mouth guard (MG) is a resilient intraoral device worn during participation in contact sports to reduce the potential for injury to the teeth and associated tissue (Mosby’s Dental Dictionary, 2004).

How Can the Mouth be protected?Protection implies prevention, rather than cure.Personal oral hygiene and professional care like scaling and polishing can sufficiently protect the mouth against pathological injury.Protection against trauma is done only when mouth injury is anticipatedWhen traumatic oral injury is anticipated, a mouth guard is the most effective means of protection.

Increasing number of participation in sports, and attendance to health clubs and gymnasiums, implies a corresponding increase in the risk of trauma.This calls for a concomitant increase in the adoption of protective means. The use of the mouth guard in particular is on the rise, as a result of this.

Never throughout history has a man who lived a life of ease left a name worth remembering.Theodore Roosevelt

History of Mouth Guards

The MG has had a long and dramatic timelineExact origin of the idea of mouth guard is not knownAs “necessity is the mother of invention” would have it, boxers were the first to employ the idea of mouth protection against trauma.They were then called gum shields.Innovative but crude; being manufactured from cotton, tape, sponge, or small pieces of woodThese were prepared by the boxers themselves or their trainers.

Problems with the First Gum ShieldsThey were not very effectiveThey were uncomfortable to wearThey had no means of retentionThey were not reusableThey were not hygienic to useWere not standardizedImpaired breathing and speech Because of the above reasons, gum shields were not popular.

1982– Woolf Krause

Seeing the problem, Woolf Krause, a British dentist based in London, began to fashion mouthpieces for boxers in 1892Krause’s mouth guards were manufactured from gutta-percha, a natural plant resinHe made the rubber into single strips which he placed personally on the maxillary incisors of boxers just before they entered the ringKrause’s appliance was popular among amateur boxers.Professional boxing mangers refused it because they thought it was an added unfair advantage

Other Claims to Developing Mouth Guards Early 1900s: Jacob Marks created a custom fitted mouth guard in London.1916: Thomas Carlos (USA) claimed he made his first customized mouth guard which was used by a professional athlete.1919: Allen Franke (USA) claimed he also made his first custom mouth guard for a professional boxer.

The Breakthrough

All this while, mouth guards had not been made legalizedIn 1927, there was a professional boxing match between Jack Sharkey and Mike McTigueNeither of them wore a mouth guardMcTigue broke his tooth and cut his lip. He was forced to forfeit the match due to the bleedingAfter that match, mouth guards were legalized for professional sports

The American Dental Association (ADA )continued to promote the use of mouth guards from the 1940s onwards.In the later 1960s and early 70s, the ADA and National Collegiate Athletic Association (NCAA) in the United States made mouth guards mandatory in college football.Currently, the ADA recommends mouth guards be used in 29 sports: acrobatics, basketball, bicycling, boxing, equestrian, football, gymnastics, handball, ice hockey, inline skating, lacrosse, martial arts, racquetball, rugby, shot putting, skateboarding, skiing, skydiving, soccer, softball, squash, surfing, volleyball, water polo, weightlifting and wrestling.

Mouth Protection-General Considerations:

Injury to the mouth may come in the form of trauma, inflammation, or other pathological processes.Trauma to the mouth can result in several forms of injury.The exact form of injury that results from a traumatic episode depends on several factors including; direction of force, intensity of impact and the tissues involved.

Types of oral injury

Fractures:ConcussionSubluxationExtrusive luxation:Lateral luxation:Intrusive luxationAvulsionContusionAbrasionLacerationConcussionTempromandibular joint (TMJ) dislocation:All the injuries mentioned above can be prevented or reduced in severity by a mouth guard.

Functions of the Mouth Guard

Prevent hard and soft tissue injuryPrevent concussions and TMJ dislocationProvide psychological motivation

Who should were a mouth guard?When should it be worn?

Indications of a mouth guard

For individuals who are at risk of trauma to the face or mouthSporting activities as mentioned earlier. Both professional and amateurish.Children during casual playPatients with increased overjet

Who does not qualify to wear a mouth guard?When should it not be worn?

Contraindications

When there is an active unresolved pathological oral condition.If a patient is wearing a fixed orthodontic appliance some mouth guards are contraindicated.Patients with TMJ disorders.Patients with severe malocclusion. This arrangement of teeth may not allow the MG to function properly.

What are mouth guards made of?

Materials for Making Mouth Guards

Earliest gum shield users made them fromcotton, tape, sponge, or small pieces of woodSeveral materials have been used to manufacture mouth guards:Ethylene vinyl acetate (EVA): CommonestLatex rubberAcrylic resinPolyurethane

Ethylene Vinyl Acetate

IUPAC namebut-3-enoic acid; ethane

In simple terms EVA

Is highly flexibleDelivers high cohesive strength and compatibilityEnsures excellent adhesion to a wide range of substratesIs highly resistant to ruptureHas good tear resistanceIs tough and can last long under constant stressIs odourlessResistant to ultra-violet radiationIs biocompatibleAll the above make EVA a good shock absorber

Types of Mouth Guards

There are three main types of mouth guards. These types emerged based on the processes involved in their fabrication and how customized they are for an individual:

1. Stock Mouth Guards2. Boil and Bite Mouth Guards3. Custom Made Mouth Guards

Stock Mouth Guards

These are mouth guards that are pre-formed in the factory and are made available as over-the-counter devices.Once bought, they can be fitted immediatelyFabrication:Factory-madeDifferent shapes, sizes and colours.Advantages:Easy to access and use.Least cost of all mouth guardsThey are versatile and allow for easy addition of technological advancements.

Disadvantages:Inadequate fitBulky, making them uncomfortable.Short life span.Significant amount of effort required to retain in position especially for long durations. Focusing on the game is difficult. Speech and Breathing impairmentRecommendation:Affordable, but ineffective optionNot recommended by dentists

Boil-And-Bite Mouth Guards

Currently the most widely used on the marketFabrication:They come in a form similar to plain stock mouth guardsPrepared by user: Boil Bite MouldAdvantages:Do not require much expert technique to prepare.Provide better retention than stock mouth guards.Versatile and allow for easy technological advancements.More affordable than custom mouth guards.

Disadvantages:The fit is not ideal.Research has shown that most mouth-formed mouth guards are under-extended.They have the risk of becoming non uniform, because they are moulded hurriedly with the hands and bite.

Recommendation:85-90% of all mouth guards being used currently is of the boil-and-bite typeMouth guards have a “not so good” name– because of boil-and-bite mouth guards.Most controversial

Claims that they can be better than custom mouth guardsNot prepared by dentistsManufacturers claim good dentists are behind their good products.

Custom Mouth Guards

Dentists’ choiceFabricated and delivered by the dentistCurrently provide the best fit. The highest level of protection and comfort are provided by this type of mouth guard.A detailed fabrication process will be given

Fabrication of Custom Mouth GuardThere are Five (5) main steps:DiagnosisImpressionLaboratory FabricationTrimming and polishingPlacement and Occlusal Equilibration

1. Diagnosis:History, Examination, InvestigationsSome questions that need to be answered:

Does the client present with cavities and or missing teeth? Does the client have any history of previous dental injury or

concussion? Is there a prospect of an eruption? Will the design of the mouth guard be appropriate for the level of

competition being played? Is the client undergoing orthodontic treatment? Has the client ever used any mouth guards? How successful were

they? Can the patient afford and maintain the device?

1. Impression:Very important step. Will determine fit.Impression is taken after all treatments have been done.After the impression, major changes like restorations, prosthesis, medical treatment, surgeries or extractions are not madeMust be made for both archesThe most common impression material used for mouth guards is silicone impression materialAll precautions required for taking a good impression apply.

1. Laboratory Fabrication:Impression is poured immediately with hard die stone.Outline the “Mouth guard bearing area”.The model is trimmed to remove excess stone.

The base is preferably left thin up to about five millimetersModel is then left to dryModel is coated with a lubricant or separating medium

The lubricant of choice is the orthodontic model soap (Padilla, 2005).

The model is soaked in the soap for one hour and dried with a towel.

It is now ready for construction of the mouth guard.

Two types of machines and thus two methods can be used to adapt the thermoplastic material unto the stone modelMethod 1: Vacuum-formed mouth guardsA through-and-through hole is made in the center of the model not covered by the pencil mark.A sheet of EVA is heated in a vacuum-forming machine and then adapted to the stone model with negative pressure.When the material has softened enough and is mouldable, it is lowered quickly onto the model on the platform.The machine sucks air from between the EVA material and the model. This adapts the material to the model

The setup is then removed and the model and thermoplastic material allowed to cool to room temperature.After cooling, the mouth guard is removed for trimming and polishing.The main limitation of this of method is that it does not adequately support adding several sheets in layers.

Method 2: Pressure-laminated mouth guardsThis is the better and more commonly used method.Uses specialized machines that apply high heat and pressureAllows for lamination of multiple layersTo achieve 3-4mm of mouth guard thickness, two sheets of EVA each of 3mm are usedFirst, a 3-mm sheet of EVA is placed in the disk positioning ring of the machine and clamped in positionThe model is placed on the platform below this ring, slightly offset lingually.

The heater is brought over the model to heat the sheet of EVA until soft enough to slump downwards and touch the model. The pressure is then activated with a button which brings down a pressure chamber on the model, adapting the EVA to it. The button is held in position until a signal on the machine shows that it can be released. Once released, the EVA material is allowed to cool to room temperature. The EVA is removed and trimmed grossly with a trimming knife. The process is repeated with a second layer of EVA. Care should be taken to adequately heat this layer so that it can bind with the first layer. The EVA is allowed to cool and then trimmed and polished.

1. Trimming and Polishing:Gross trimming: Trimming knife to remove excess material.The buccal extension is trimmed up to the height ofAn acrylic polishing bur is then used to smoothen the edges of the applianceWax removal fluid can be used to give it luster.

1. Placement and Occlusal EquilibrationWith the mouth guard in place, the patient should feel comfortable when biting. The occlusion must be balanced. To achieve this, the posterior portion of the appliance is slightly warmed. It is placed in the mouth and the patient is made to bite down gently into habitual occlusion. All impinging areas can be trimmed at the chair side. At this point, major adjustments should be avoided.The patient is given instructions on how to care for the appliance, and then discharged.

Advantages of Custom Mouth Guards:They provide the best fit, since they are customized.The client gets the benefit of having total oral care.They do not interfere significantly with speech or breathing.Personalization like incorporating a name can be made.Disadvantages of Custom Mouth Guards:Most expensive type.Least versatile and do not allow many advanced technological advancements.

Cast Model Model trimming Sheet of EVA locked into place

EVA slumping to touch model First layer completed Finished appliance

DESIGN SPECIFICATIONS AND DIMENSIONS

Scott et al., 1994

It should enclose the maxillary teeth to the distal surface of the second molar, or cover all the teeth.Thickness should be 3 mm on the labial aspects, 2 mm on the occlusal aspect, and 1 mm on the palatal aspect.The labial flange should extend to within 2 mm of the vestibular reflection.The palatal flange should extend about 10 mm apical to the gingival margin.The edge of the labial flange should be rounded in cross section whereas the palatal edge is tapered.Even when a single maxillary protector is constructed it should be articulated against the matching mandibular model to give optimum comfort.

Greasly et al., 1998

Found that the following guidelines should be added:Multiple layers of EVA should be utilized to build a 5 mm thick layer in the thicker parts of a custom made protector.The protector should be extended to at least behind the first molar or as far along the second molar to provide wearer comfort.

The Perfect Mouth Guard:

It should be made from the best elastic and strong material available (currently EVA)It should be constructed to the appropriate dimensions and shape as stated above.It should provide an accurate fit.Adjustments must easily be made without reducing effectiveness of the appliance.It should not interfere with speech and breathing.It should be easy to fabricate.It should be effective. That is, it should actually work.It should not be bulky.It should not interfere with the occlusion of the individual wearing it.It should be durable and last long.It should not cause damage to the oral tissuesIt should be easy to clean.It should be biocompatible.

Certainly, these little appliances cannot protect against a blow from a heavy-weight champion… or can they?

HOW MOUTH GUARDS WORK

How do mouth guards work? They definitely do not feel like a cushion, and they do not feel like a metal shied. Dr Anthony Lovat, a dentist, mouth protection specialist, and founder of the world’s biggest supplier of mouth guards, OPRA Mouthguards did a lot of extensive work to publish exactly how mouth guards work. Most of the information in this text is credited to him.

It’s not Magic; it’s Science

Three aspects of science have to be considered here, and these are 1. Time2. Area 3. Elasticity

1. Time:Damage is inversely proportional to duration of impact. This can be shown by the equation:

Where f=force, m=mass, a=acceleration, v=final velocity, u=initial velocity and t=time

Damage is reduced by lengthening the time over which a force is applied. The flexible and compressive EVA allows the impacting object force to slow down and reach a halt over a longer period of time and hence the resulting transmitted force is reduced. 1.Area:Damage is inversely proportional to area over which force is applied. When a force is applied on a smaller surface, more pressure is exerted on just a few concentrated atoms. However, when the force is applied on a larger surface, it is initially received by a greater number of atoms which distribute the force to other nearby atoms, thus reducing the impact exponentially

1. Elasticity:One fundamental rule of physics is that energy cannot be created or destroyed. The mouth guard uses this principle in its function, by way of its elasticity. Energy is absorbed by elastic change.EVA will compress on impact and return to its original shape (if the distorting force is within the mouth guard's elastic limit). That compression and return takes energy. Because the material is made up of atoms that have some free movement, the energy is used as kinetic energy in compression and returning to original position. The thicker the material, the more it can compress and the more energy it can 'absorb' from the impacting object.

The Fit

The better the fit, the better the appliance because retention is better.A poor fit does not provide enough contact area and thus not enough shock absorption.A good fit also allows for easy breathing and speech.

How Mouth Guards Prevent ConcussionsControversial “ Concussion is a complex pathophysiological process affecting the brain, induced by traumatic biomechanical forces”. International Symposium on Concussion in Sport (2001)Concussion typically involves temporary impairment of neurological function that heals by itself within time, and that neuroimaging normally shows no gross structural changes to the brain as the result of the condition

The mechanism of concussion is acceleration of the brain. The brain is surrounded by cerebrospinal fluid, one of the functions of which is to protect it from light trauma, but more severe impacts or the forces associated with rapid acceleration may not be absorbed.A force applied to the jaw can be transmitted to the brain by one of two primary routes:

The diagram on the left is the path of the force when there is no mouth guard. The one on the right illustrates what happens with a mouth guard in place.

Hiking the Mouth Guard

MOUTH GUARD TECHNOLOGY

Technological advancements are applied mostly to the boil-and-bite mouth guards.There is some skepticism concerning whether these features actually work, or are just unnecessary luxuries.

Feature of a Modern Mouth GuardMultiple layers:Gel-fit liner: It improves fit.Shock transfer core: Uses an inner mould of hard and semi thermoplastic material. It transfers heavy anterior forces directly to the strong multi-rooted molar teeth.Air Spring Core™: This feature adds an additional shock absorbing system within the hard core of the molar area of the mouth guard.

Magnetic Tethered Guard:FlavoursDouble Mouth GuardLip ProtectorINSTA-FIT ™: Invented by Shock Doctor Company for patients with braces who still require a mouth guard. It is claimed that it adapts to changes in tooth position and protects from lacerations.Personalization: Some athletes prefer to customize their appliances. Images or text can be incorporated into the appliance.

POWRGARD® Mouthguard

Modern Mouth Guard

Personalization of MG

Double MG

Special Considerations

Braces and Mouth guards:

Stock or Custom Mouth guards can be made for individuals with fixed orthodontic braces.The principles are that the mouth guard should not adapt to the teeth or the brace itself, but be made with some space inside to allow movement of the teeth.This compromise in fit does mean the mouth guard may be somewhat loose. As teeth move, retention decreasesIt would not be as loose as a self-boil mouth guard as it will be in contact with the gums, and engage the natural undercuts of the mouth. The improved adaptation to the palate will still mean that an athlete can speak and breathe better than with a boil and bite mouth guard and he or she will have protection against the brace or brackets injuring the lips.

Children

Dental trauma may be due to sports, falling at home, collisionsPeak period for trauma to the primary teeth is 18 to 40 months of ageAveragely 30% of such children experience dental traumaTwo times more common in boys

Upper centrals are most commonly injuredProtruding incisors 2-3 times more commonly traumatized.All children involved in contact sports should wear a mouth guardCustom mouth guards are bestMouth guards have to be changed to adapt to changing dentition

The Dos and Don'tsInstructions are given by dentists or manufactures

MOUTH GUARDS: USE AND CARE INSTRUCTIONS

Mouth guards should be worn in practices first, as well as games. The appliance should not be chewed on.Rinse the mouth guard with cold water or with a mouth rinse before and after each use.It should be cleaned with toothpaste and a toothbrush or cleaned in cool, soapy water followed by thorough rinsing. The mouth guard should be stored and transported in a firm, perforated container Mouth guards should not be shared.

The condition of the mouth guard should be checked occasionally and replaced if it has holes or tears, becomes loose, or irritates the teeth or gums.If the mouth guard absorbs a strong blow, it may need to be replaced.The material deteriorates and loses resilience over time. Therefore, they should be replaced every two to three years. Earlier replacement is recommended if any damage is detected.They should be taken to every dental visit.

Setbacks

Speech:Athletes may need to communicate. A Custom Mouth guard provides a good fit an makes speech easier.Breathing:Optimum athletic performance requires unrestricted flow of air into the lungs. A well fitted custom mouth guard allows easy breathing. Boil-and-bite mouth guards may inhibit breathing.Double mouth guards impair breathing.Comfort:In truth, the ideal mouth guard is one that the athlete forgets he or she is wearing. Most publications show that the custom mouth guards are the most comfortable to wear; but the recent technological additions make the boil-and-bite mouth guards also equally comfortable.

OTHER MOUTH PROTECTION DEVICES

Face Mask:

The face mask is basically a helmet with a spacy metallic extension over the face. This puts the entire head in a protective cage. It is used mainly by football players. The main aim of the face mask is to prevent maxillofacial injuries. Though it provides a good barrier against injury to the mouth, a mouth guard is still required to ensure total mouth protection.Lip Guard:

This device is also made from thermoplastic material. It is more flexible than the mouth guard. It is used as an accessory with the mouth guard.Night Guards:

Night guards protect the teeth against bruxism.Bruxism occurs significantly during the night.

Every tooth in a man's head is more valuable than a diamond.Miguel de Cervantes, Don Quixote, 1605

In Conclusion…

Mouth protection is an important aspect of the health of every individual. The importance of wearing mouth guards is now clear among professional sportsmen. The only debate now is probably whether the better choice is the traditional dentist’s custom mouth guards, or the flashy, technologically improved but more affordable boil-and-bite mouth guards. Either way, the mouth guard has prevented oral injuries greatly over many centuries and is definitely a field of dentistry worth exploring and perfecting

Thank You

References:

Andreasen J, Andreasen F, Andreasen L. Textbook and Color Atlas of Traumatic Injuries to the Teeth. Blackwell Mungkar, Copenhagen. 2007. Pages 404-444.Canadian Dental Hygienists’ Association. Information for Dental Hygiene Clients: Mouthguard use and care. 2010.Craig, G.R., Powers J.M. Restorative Dental Materials, 11th edition. Mosby Inc, USA 2002. Pages 217-222Craig RG, Godwin WC: Physical properties of materials for custom-made mouth protectors, Mich Dent Assoc J 49:34, 1967DeYoung AK, Robinson E, Godwin WC. Comparing comfort and wearability: Custom-made vs. self-adapted mouth guards, American Dent Association 125:1112, 1994.Langfitt TW. Measuring the outcome from head injuries. J Neurosurgery 1978;48:673–8Lovat Anthony, BDS. How Mouth Guards Work. 2005. Pages 3-12.Miloro Michael, Peterson’s Principles of Oral and Maxillofacial Surgery. Second edition. B.C. Decker Inc, London. 2004. P327Mosby’s Dental Dictionary, Mosby Inc. 2004.

Padilla R. A Technique for Fabricating Modern Athletic Mouthguards. Canadian Dental Association Journal. Vol 44. No 5. May 2005.Using Mouth guards to reduce the Incidence and Severity of Sports-related Oral Injuries." Journal of the American Dental Association 137.12 (2006): 1712-1720http://en.wikipedia.org/wiki/Mouth_guardhttp://www.catalogs.com/info/bestof/top-10-mouth-guard-instructionshttp://sportsmedicine.about.com/od/shop/tp/mouthguardpicks.htmhttp://www.mogosport.com/mogo-technologyhttp://www.powrgardsports.com/index.php?technologyhttp://www.sportsdentistry.info/mouthguards.html http://www.sportsdentistry.info/prevention.html

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