The outcome and prognostic factors affecting the success of traumatic injuries of permanent teeth: a retrospective study.

Background: Severe dento-alveolar trauma to anterior teeth in children can have a devastating long-term consequence for function and aesthetics. Successful treatment of traumatic injuries in a growing child is dependent on many factors; some related to the injury itself and some to the treatment provided. Aims: To identify the prognostic factors which affect the outcome for two groups of traumatic injuries to permanent teeth in children and adolescents; luxation injuries (intrusion, extrusion, lateral luxation) and complicated crown fractures and to determine their final success. Method: This study was a retrospective study evaluating the factors, which affect the clinical and radiographic outcomes of luxation injuries and complicated crown fractures. Clinical dental records and radiographs of 620 patients who attended the Paediatric Dentistry Department at Leeds Dental Institute during the period 2003-2013 were screened. The initial treatment outcome for the complicated crown fractures and the final outcome for both groups of injuries were classified as success or failure according to the criteria developed for this study. Various prognostic factors that could influence the clinical and radiographic outcomes of traumatised teeth were recorded using a special data extraction proforma. Statistical analysis involved simple descriptive analysis followed by a univariate regression analysis to determine the association between the prognostic factors and the outcomes. Additionally, a multivariable logistic regression analysis was conducted to identify which predictors remained significant when in combination with each other.   Results: The study recruited 108 cases with 146 traumatised permanent teeth. In the group of complicated crown fractures, the initial treatment success following pulp capping or partial pulpotomy was 40%. Partial pulpotomy had a higher success rate (54.4%) than pulp capping (15.4%). The final clinical success rate was 93% and the radiographic success rate was 85.3%. The univariate regression analysis revealed that the type of initial treatment significantly affected the initial treatment outcome whereas the stage of root development affected the final outcome. For luxation injuries, 81.5% were clinically successful and 72.6% were radiographically successful. Univariate regression analysis revealed the predictors that significantly affected the clinical and radiographic success were; severity of injury, combination injury, method of repositioning and duration of splinting. The multivariable regression model revealed that the method of repositioning and time since trauma to repositioning significantly affected the clinical success whereas only the method of repositioning significantly affected the radiographic success. Conclusion: Complicated crown fractures were considered to have a higher clinical and radiographic success than luxation injuries. The stage of root development appeared to significantly affect the final outcomes in complicated crown fractures. The severity of luxation injury, presence of crown fracture, method of repositioning and duration of splinting had significant associations with the final outcomes in the group of luxation injuries.