Are all mouthguards equal?*

The main reasons for non-compliance are:

• Comfort
• Poor fit
• Difficulty in breathing and speaking
• Cost

The main function of mouthguards is to protect teeth. However recent laboratory research has demonstrated that custom-made mouthguards can reduce dislocation to the mandible and acceleration of the head from the same blow. The proven benefit is the dissipation of the forces delivered to the skull and TMJ complex when the mandible receives a blow.

There will also be stabilisation for the skull through increases neck muscle activity by clenching on the mouthguard as well as a benefit from the altered open position of the condyle in the fossa. This open position, provided the mouthguard has a balanced occlusion will dramatically reduce damage to the condyle and TMJ complex.

The quality of the mouthguard, particularly the thickness of the labial and occlusal surfaces is closely related to the mouthguard’s ability to absorb and spread the impact energy.

Impact testing has shown improvement in energy absorption up to a 4 mm thickness. Generally, 4 mm is too thick for players’ comfort so the challenge is to design mouthguards thinner than 4 mm, consider new designs and investigate better materials.

Studies have examined ways to improve the energy absorption of mouthguards by including air cells, sorbothane, metal wires, sponges and harder material such as polycarbonate. Combining different materials always risks mouthguard failure through delamination.

Mouthguard research at the University of Tokyo Dental School has established a balanced occlusion is indispensable in reducing impact force ad tooth distortion.

Possibly their most exciting development is placing a hard EVA insert with a buffer space over the anterior teeth with a dramatic increase in the energy being absorbed.

Types of Mouthguards

A mouthguard is defined as a protective device worn on the upper jaw to reduce injuries to the teeth, jaws and associated soft tissues.

Boil and bite

The ’boil and bite’ mouthguard is defined as a mouthguard fitted and formed in the mouth by finger, tongue and biting pressure.

Even though they are the most common type of mouthguard used, it affords negligible protection, is poor fitting, too thin, poor durability, unstable and interferes with speech and breathing.

The Australian Dental Association and Standards Australia do not recommend ‘Boil and Bite’ mouthguards.

Mouth-formed

Mouth formed mouthguards have the disadvantages of lack of retention at impact single tooth contact, inadequate thickness and often rapid deterioration of the material increases the risk of injury.

Critical for injury prevention, a mouthguard should have an ideal thickness of 3 mm after fabrication and provide an occlusal surface balanced to the mandible teeth.

Custom-made

Custom-made mouthguards are formed on a cast of the wearer’s upper jaw, sometimes in conjunction with a cast of the lower jaw in order to obtain even occlusal contact.

A custom-made pressure laminated mouthguard offers flexibility in design and construction. Ethly vinyl acetate (EVA) of different hardness and thickness can be laminated together to provide increase protection.

Efficient and complete lamination cannot be achieved by vacuum machine but it is possible using the high heat, high pressure machines available today. The results of pressure lamination are:

• Precise adaptation
• Negligible distortion
• Capacity to thickness as required
• Ability to place inserts, air spaces or modify the shore hardness of the mouthguard blanks to achieve better fit and stiffness

Custom-made mouthguards are the most acceptable.

Consideration should be given to wearing custom-made mouthguards in all sporting activities where there is a risk of trauma to the teeth and associated structures. Such activities include bat and ball sports, all football codes, martial arts and other sports such as basketball, high level netball and water polo where close physical contact is expected.

Start wearing mouthguards early. Dental injuries are common in children and the affects can be devastating to the developing dentition. Good habits are maximised with the early introduction of using protective equipment. Children should commence wearing a custom-made mouthguard as soon as they start participating in contact sports.

Custom-made professionally fitted mouthguards can be fabricated for the deciduous dentition and also for children undergoing orthodontic treatment.

Conclusion

It is dangerous to assume all types of mouthguards provide the same level of protection. Mouthguards should be custom-made, fit accurately, have sufficient thickness, even occlusal contact and not interfere with breathing and speech. Mass produced ‘Boil and Bite’ mouthguards cannot fulfill these requirements.

The correct approach for preventing dental injuries is to prepare and fit custom-made pressure laminated mouthguards made on models from impressions of the player’s mouth. There is a cost in providing professional care but this must be evaluated against the risk of dental injuries and the associated expenses.

*This article was published by The Australian Dental Association, March 2016