Prevention and Risk Factors - Wearing a mouthguard or helmet can reduce the risk of dental injury in contact sports. - Mouthguards are more effective when properly fitted. - Despite their availability, mouthguard use is relatively uncommon. - Many people do not use mouthguards even in high-risk situations or when mandated. - Certain occlusal traits, such as class II malocclusions and increased overjet, are associated with a higher incidence of dental trauma and can be corrected by an orthodontist. - Post-normal occlusion - Over-jet exceeding 4mm - Short upper lip - Incompetent lips - Mouth breathing

Management and Initial Assessment - Prompt management within 20-40 minutes of dental avulsion affects the prognosis of the tooth. - Avulsed permanent teeth should be gently rinsed with saline to avoid damaging the root. - Replantation in the original socket and splinting by a dentist is recommended. - Failure to re-plant the tooth within the first 40 minutes may result in a less favorable prognosis. - Avulsed primary teeth should not be re-planted to avoid damage to the permanent dental crypt. - Patients should be seen quickly and with urgency upon arrival at the dentist. - Suitable storage medium should be used for the avulsed tooth. - Thorough extra-oral and intra-oral examinations should be performed. - Age, injury history, and clinical findings should be considered. - Safeguarding procedures should be followed if non-accidental injury is suspected. - Local anesthetic should be administered to minimize discomfort. - Gentle irrigation with saline removes clots and allows proper re-positioning of the tooth. - The tooth should be handled via the enamel on the crown, not the root. - Debris can be removed by dabbing with saline-soaked gauze. - Soaking the avulsed tooth in an immune-modulating drug prior to re-implantation can increase periodontal healing and tooth survival.

Biologic Basis for Success of Replantation - The tooth is connected to the surrounding bone by the periodontal ligament. - Replantation is possible if the halves of the ligament can be kept alive. - Treatment should focus on preventing cell crushing and loss of normal cell metabolism. - Tooth root cells must be protected from trauma during handling and transportation. - Debris should be gently washed off with physiologic saline to avoid further cell crushing. - Normally metabolizing tooth root cells have an internal cell pressure (osmolality) of 280–300 mOs and a pH of 7.2. - Uninterrupted blood supply provides all the necessary metabolites (calcium, phosphate, potassium) and glucose for the cells. - When a tooth is knocked out, the blood supply is cut off, leading to depletion of stored metabolites and cell death. - Rejection of the replanted tooth by the body can occur due to replacement root resorption, where the tooth root cells become necrotic and are eaten away by the body. - Root resorption is a slow and non-painful process that can cause bone development problems in growing children.

Storage Media - Recommended storage media for knocked-out tooth storage include saliva, physiologic saline, milk, and pH balanced cell preserving fluids. - Water and ice should not be used as storage media as they can damage the tooth root cells. - Saliva causes more damage than water and can infect the tooth root cells. - Physiologic saline has a compatible osmolality but lacks the necessary metabolites and glucose for normal cell metabolism. - Milk is less damaging than water or saliva but does not have regenerative properties for the cells on knocked-out teeth.

Prognosis, Epidemiology, and Research - Dental avulsion has a poor prognosis, with 73-96% of replanted teeth eventually being lost. - Prognosis is significantly influenced by the extent of damage to the periodontal ligament (PDL), storage conditions of the avulsed tooth, and duration prior to replantation. - Replantation within 15 minutes of the accident or storage in an optimal storage medium within one hour can improve prognosis. - Unfavorable healing of the PDL can lead to the loss of tooth root and fractures of the crown. - Long-term survival of the tooth depends on favorable healing of the periodontal ligament. - Research has shown that dental avulsion is a common occurrence. - The exact prevalence of dental avulsion varies, but it is estimated to affect a significant number of individuals. - Dental trauma, including avulsion, can occur in both children and adults. - The incidence of dental avulsion may be higher in certain populations or geographic regions. - Further research is needed to fully understand the epidemiology of dental avulsion. - Research has focused on finding the most optimum storage media for knocked-out teeth. - Hanks Balanced Salt Solution (HBSS) is a well-known and extensively tested storage solution that maintains normal cell metabolism for long periods of time. - Cells stored in HBSS for 24 hours maintain 90% viability, and after four days, they still have 70% viability. - Soaking knocked-out teeth in HBSS for 30 minutes prior to replantation can reduce replacement resorption. - Other storage liquids, such as powdered milk, Enfamil, Gatorade, and contact lens solution, have been found to be ineffective or damaging to avulsed teeth. - Approximately 5 million teeth are knocked out each year in the United States. - Dental avulsion is the fourth most prevalent type of dental trauma. - The prevalence of dental trauma is estimated at 17.5% and can vary geographically. - Males are three times more likely to suffer from dental avulsion than females. - Up to 25% of school-aged children and military trainees and fighters experience dental trauma each year. - The first reported cases of replanting knocked-out teeth date back to 1593. - In 1966, a