BACKGROUND: Traumatic dental injuries (TDI) comprise six types of luxation and seven types of tooth fractures. The risk of pulp necrosis is increased in teeth with combination injuries where fractures and luxations occur concomitantly.

AIM: To report and compare the distributions of luxations and fracture types among children, adolescents, and adults, and to analyze the distribution and prevalence of combination injuries.

MATERIAL AND METHOD: The study group included 4754 patients (3186 men and 1568 women) with 10 166 traumatized permanent incisors treated at Copenhagen University Hospital, Rigshospitalet. Differences in the distributions of trauma types among age groups (children <12 years, adolescents 12-20 years, and adults >20 years) and distributions of concomitant crown fractures for each luxation type were analyzed with the Chi-square test.

RESULTS: A total of 7464 teeth (73.4%) had suffered a luxation injury and 5914 teeth (58.2%) a fracture. The overall most frequent injuries were crown fractures without pulp exposure (34.9%), concussions (24.2%), and subluxations (22.2%). The relative frequency of crown fractures without pulp exposure decreased across age groups (children 45.2%, adolescents 36.5%, adults 26.3%, P < 0.001), whereas the relative frequencies of other injury types increased across age groups : crown-root fractures (children 1.8%, adolescents 6.3%, adults 9.2%, P < 0.001), root fractures (children 2.5%, adolescents 4.6%, adults 8.7%, P < 0.001), and lateral luxations (children 5.7%, adolescents 10.9%, adults 13.0%, P < 0.001). One-third of the traumatized teeth (n = 3212) had sustained a combination of a fracture and a luxation injury. The luxation types most frequently presenting with a concomitant crown fracture were concussion (57.9%), intrusion (47.2%), and subluxation (33.4%) (P < 0.001).

CONCLUSION: The majority of TDI were minor injuries. The relative frequencies of injury types varied among age groups. Combination injuries were observed in one-third of the traumatized teeth and occurred most frequently in teeth with concussion, intrusion, and subluxation.