The state of dental pulp is a crucial factor in the healing and recovery of damaged immature teeth. The viability of dental pulp is essential for continued root development and apical closure. Other tissue types, such as peri-radicular and surrounding soft tissues, also play a role in the healing process. Following trauma, these tissues set up an inflammatory response to fight against infection, foreign materials, and damaged necrotic tissue. This response enables repair and determines the outcome of the affected teeth. The perception of a satisfactory outcome may differ between the patient and the clinician, where retention of the tooth alone without symptoms may be satisfactory for patients, whereas absence of associated disease may be favorable for dentists. Therefore, these outcomes should be taken into consideration during subsequent management of such injuries.

Dental traumatic injuries are more common during adolescence than adulthood. Predisposing factors may include increased overjet, protrusion of upper incisors, lip incompetence, increased physical activity, and participation in contact sports and games. Boys around the ages of 8-10 years are at peak risk, and they are affected almost twice as often as girls.

Luxation injury refers to displacement of the tooth from its original position, leading to damage to the tooth and its supporting structures. The severity of the injury is vital for healing outcomes. Extrusive luxation is a partial displacement of the tooth out of its socket and is common in both primary and permanent dentitions. Avulsion injury refers to the complete displacement of a tooth out of its socket, resulting in injury to both the pulp and periodontal ligament. Avulsion injuries are relatively infrequent but account for up to 15% of all traumatic injuries in the permanent dentition. Adolescents experience more luxation and avulsion type injuries, as the periodontal ligament is loosely structured and the associated bone poorly mineralized, allowing minimal resistance to extrusive forces. Rupture of the neurovascular bundle and supply at the apical foramen may occur, leading to a variety of possible sequelae for the viability of the pulpal tissue in the medium to long term.

Factors affecting pulpal responses include the degree/type of injury severity, and the possible capacity for repair, which may be reflected by the stage of root development. Responses may range from favorable pulpal recovery and revascularization to pulp canal calcification and stenosis and unfavorable pulp necrosis and infection. Research shows that immature root development and increased apical diameter are associated with a more favorable pulpal healing response for extrusive luxation and avulsion injuries. The extra-alveolar storage period and length of the root canal are also significant predictors of pulpal healing.

Preserving the dental pulp is essential in promoting root maturation and apical closure of immature permanent teeth following trauma. These teeth are more susceptible to structural failure and premature loss due to their thin-walled roots. The health and viability of the dental pulp encourage further growth of dentine and apexogenesis, leading to improved structural integrity and better long-term outcomes.

When assessing outcomes for immature permanent teeth after traumas, it is crucial to take into account the periodontal responses. Depending on the type of healing that takes place, they can affect the continued development of immature teeth, especially in young adolescent patients.

There are two types of periodontal healing: favourable healing and unfavourable healing. Extrusive luxation and avulsion injuries result in tearing of the periodontal ligament, damaging its cellular components causing repair-related healing responses. Although extrusive luxation injuries are less likely to result in infection-related resorption, surface resorption is common. However, avulsion injuries have a higher risk of pathological resorption due to the prolonged extra-alveolar periods, leading to drying out and extensive damage. Subsequent pulp canal infection and dentinal tubule toxins contribute to inflammatory resorption, which progresses quickly in younger patients with high bone turnover.

Ankylosis-related resorption occurs when the root surface suffers extensive damage, leading to bone reaching it first. Teeth with this type of resorption cannot be treated, resulting in the progressive replacement of the tooth with bone. Unfortunately, this process occurs more frequently in adolescent patients, which can cause adverse outcomes and negatively affect their growth.

The outcome for immature permanent teeth after trauma is wide-ranging and diverse. The dental pulp's health and viability are fundamental to preserving root integrity, maturation, and development. Additionally, periodontal responses must be considered, as favourable or unfavourable healing patterns can affect overall outcomes. Healthcare providers must be aware of the potential prognostic factors to manage each case adequately.