The majority of dental injuries are caused by falls and is true for all age groups. The next most common cause of dental injury is violence, followed by motor traffic accidents and then sporting injuries. Recently, there has been a substantial increase of injuries from bicycle riding. In the primary dentition the incidence of injury peaks at age 2 to 2 when motor coordination is developing and children are starting to move around on their own. Sport plays little part in traumatic dental injuries for the primary dentition. The increasing occurrence of dental injuries for boys seems to begin around 8 to 9 years of age and continues through the teenage years. Playing contact sports during the mid-teen years seems to be a peak for traumatic dental sporting injuries. The dental profession continues to promote the use of custom-built pressure laminated mouthguards in this at-risk age group.

Factors influencing dental injuries

In contact or collision sports it is easy to understand why there is a regular occurrence of dental injuries. However there are other sports and factors that can influence how dental injuries occur. These factors include:

• Athletes in the mixed dentition stage
• Recreational sports men or women
• Athletes where a helmet and possibly a face guard forms part of the protective equipment
• Sports where hard objects such as bats and/or balls are used
• Athletes involved in boxing or martial arts
• Elite athletes with specific needs
• Athletes with dental implants, crown and bridgework or other previous indications of dental injuries.

Provision of custom-built mouthguards to prevent traumatic dental injuries is strongly supported by the Australian and American Dental Associations. Today, it appears many sports previously regarded as non-contact sports are now seeing a significant number of dental injuries. Foremost amongst these sports is basketball where aggression and full body contact results in many injuries including dental. Other sports where dental injuries have been identified are softball and even T-ball. Dental injuries also occur in cricket where the batsman is most likely to be injured followed by the wicket keeper. In contact sports each athlete has a one in ten chance of a dental injury per season and one in three chance in their career. As well an athlete is 60 times more liable to sustain dental damage when not wearing a protective mouthguard.

The pattern of dental injury depends on three factors:

• The energy of the impact
• The direction and the location of the impact
• The resilience of the periodontal structures

Until recently a custom-built mouthguard made on a plaster cast of the athlete’s teeth was regarded as acceptable even though there were no specifications of thickness, material or design for the athlete’s sports. The introduction of thermoforming, which is the use of high heat and high pressure and the classification of custom-built mouthguards specific to sports have laid down a standard for care.

For many years, it was thought all dental injuries should be treated on an emergency basis. Certainly this has logic for the parents and injured patients. Immediate treatment will make them more comfortable and may reduce healing complications. However, for practical and even economic reasons a new approach is required. The clinician should assess whether the injury is classified as acute, requiring immediate treatment, subacute, treatment in the first 24 hours or delayed with treatment initiated after 24 hours. Dental injuries involving a tooth being avulsed, an extrusive luxation or an alveolar fracture are definitely acute treatment priority. When a tooth is avulsed the injury is classified as a separation injury, with cells remaining vital in the periodontal ligament and also in the alveolar socket. If the tooth can be repositioned within five minutes there will be a very acceptable outcome. The outcome of tooth avulsion depends on how long the tooth has been out of the mouth, the age of the individual and whether some storage medium has been used to preserve the cells on the outside of the tooth.

Acute requiring immediate treatment

An injury requiring acute priority is alveolar fracture. Clinical studies have found a significant relationship between the incidence of pulp necrosis and treatment delays of more than three hours. Unfortunately, there have been few studies into the effect of dental trauma on pulp health. One of the studies to look at luxation (displacement) injuries to teeth indicated there was a significant difference to healing following treatment delays of five hours. Unless new research indicates otherwise, lateral luxation and root fracture should also be included in the acute category for treatment.

Subacute treatment

A subacute approach, which is treatment within a few hours of the trauma, can be utilised for the following types of injuries. Intrusive luxation, the forceful apical positioning of the tooth, has been studied and it appears immediate surgical repositioning or delayed orthodontic repositioning had similar results. It seems reasonable to use a subacute approach for this traumatic injury. Other injuries which can be included in this subacute approach are minor luxation injuries, teeth with simple enamel/dentine fractures and teeth which have crown fractures with pulp exposure. Recent studies have shown that crown fractures with pulp exposure had the same long-term prognosis whether treated acute, subacute or delayed. However, due to discomfort of an exposed pulp it is reasonable to try for a subacute treatment approach if possible.

Primary teeth can be treated with a subacute or delayed strategy unless there is occlusal interference to the displacement indicating an acute approach should be taken. Clinical experience has shown the most common injury is an enamel/dentine fracture and the modern approach is to find the fragment, store it in water to keep hydrated then reattach it with a flowable composite using a total etch and bond system. If there is pulp exposure, it is critical the clinician understands this is a traumatic injury and there is only minor infection of the top few millimetres of the exposed pulp. If treated on a delayed basis the outcome will be the same as acute or subacute treatment options. The preferred treatment of the pulp exposure, providing it is an immature pulp is a Cvek or minimal pulpotomy using either calcium hydroxide or MTA (mineral trioxide aggregate) as the dressing material. The Cvek pulpotomy has a 98% success rate.

Severe injuries including some crown root fractures and multiple fractures of teeth with displacement cannot be treated and will have to be extracted. The modern approach in dental trauma treatment is to consider future options and whether there will be enough bone remaining to allow implant prosthetics to occur. Losing teeth at a young age is not a very good outcome with implant placement only possible after the age of 21 when the athlete will have stopped growing.

It is important for the clinician to understand all the sequale of the traumatic dental injuries and takes a long-term approach to the treatment and also the prevention of any other future injuries. Research has indicated if someone has been injured there is a one in three chance they will be injured again.

The clinician should also inform the athlete and maybe the parents that the initial injury viewed is not the total injury. Over time, other teeth adjacent to the injury site may undergo degeneration. This can include pulp necrosis, fracture or inflammatory resorption. It is critical parents are provided this information as there is often substantial cost involved in treating dental injuries and they have to be monitored over a long-term. A conservative approach is always best. This conservative approach may involve a team of the general dentist, orthodontist, periodontist and an endodontist to obtain the best result for the injured athlete.

Sporting bodies are endeavouring to make their sports more attractive by looking at reducing injuries. Government bodies and health providers are also looking at the cost of sporting injuries. It is apparent to al there are enormous benefits by recommending throughout the community the use of custom-built mouthguards for participants in a risk sports. The weight of scientific evidence and long-term clinical experience with sporting teams establishes the cost benefits of custom-built mouthguards.

Future Designs

In the future new designs and better combinations of materials will increase protection for athletes playing different sports where risk factors vary. New research from Japan indicates there will be an even greater reduction of injury in sport if the mouthguard is balanced to the lower occlusion. Today’s pressure laminating techniques will ensure the mouthguard fits accurately. New mouthguard designs using materials of different thickness and Shore hardness may also incorporate air spaces to minimise the transfer of energy.

The treatment of traumatic dental injuries requires knowledge, experience and decisive implementation of current research. An understanding of pulpal, periapical and periodontal pathology resulting from injury is critical. Inappropriate initial treatment will increase the chances of long-term complication, lessen the chance of teeth remaining vital and result in unnecessary pain, distress and cost.

*This article was published By Brett Dorney, On behalf of the Oral Health Committee ADA, The Australian Dental Association, April 2013.