Introduction
Trauma has increased with advances in transportation, expansion of living environments, and an increase in sports and leisure activities. Head and neck injuries account for nearly 50% of all trauma, and although the oral area comprises only 1% of the body surface, it represents 5% of injuries, reflecting the disproportionately high frequency of traumatic dental injuries (TDIs)[1].
TDIs are among the most common dental emergencies in children and adolescents, accounting for 18% of all injuries in the 0 - 6 age group, ranking the mouth as the second most affected area[1]. The global prevalence is 22.7% in the primary dentition[2], with approximately 25% of schoolchildren and 33% of adults experiencing dental trauma, mainly before the age of 19[3]. Dental caries and periodontal disease are major oral health problems. However, TDIs have become a major oral health concern with declining caries rates, particularly in younger populations[4]. They occur most frequently before the age of 10, decline with age, and are rare after the third decade, ranging from enamel fractures to severe pulp and periodontal injuries, including luxation and avulsion, which may lead to tooth loss[5].
In addition to acute pain and esthetic concerns, TDIs may impair mastication, speech, and maxillofacial development[6]. Trauma to primary teeth may affect permanent successors due to the close anatomical relationship, causing crown discoloration, enamel hypoplasia, crown malformation, and eruption disturbances[7]. Pulpal necrosis occurs in 3 - 85% of traumatized teeth with periodontal injury[8].
Accurate history-taking, prompt diagnosis, and early treatment are essential because prognosis depends on immediate management. Delays related to uncertain pulpal outcomes or parental unawareness may lead to malocclusion, while the complexity and risk of poor prognosis increase over time[9]. Because teeth have limited healing capacity, timely functional and esthetic rehabilitation is crucial.
Few studies have comprehensively examined children and adolescents with long-term outcomes. This study investigates the distribution and clinical characteristics of pediatric TDIs over a 10-year period at Seoul National University Dental Hospital, analyzing sex, age, cause, site of injury, number of affected teeth, type of trauma, elapsed time before treatment, initial management, reattendance, follow-up duration, and complications. The findings aim to guide timely treatment, appropriate management, and long-term follow-up of TDIs in children and adolescents.
Materials and Methods
1. Study design and population
This retrospective study was approved by the Institutional Review Board of the Seoul National University Dental Hospital (IRB No. ERI25029) and conducted at its Department of Pediatric Dentistry, South Korea. Patients aged 0 - 16 years who presented with TDIs between January 2015 and December 2024 were identified through electronic records, diagnostic codes, and radiographs. The exclusion criteria included incomplete records, inadequate radiographs, prior emergency care at another facility, repeated trauma at the same site, or soft tissue injuries only.
A total of 1,332 patients with 2,442 teeth met the inclusion criteria.
2. Data collection and classification
Data included age, gender, cause and place of injury, date of trauma, number and location of injured teeth, type of TDI, time to presentation, initial management, follow-up visits, and clinical outcomes. Age was grouped into 1-year intervals for 0 - 9 years and broader categories for ages ≥ 10. For temporal comparisons, cases were categorized as pre-COVID (2015 - 2019) and COVID (2020 - 2024). Dentition stage was classified as primary (0 - 5 years), mixed (6 - 12 years), and permanent (≥ 13 years), based on developmental stage and activity patterns. Dentition type was further classified as primary or permanent to reflect the biological and healing differences between the primary and permanent teeth. Etiology was categorized as fall, collision, drop, sports, traffic accident, or other. The place of occurrence was classified as home, street/stairs, kindergarten/school, playground, indoor public facilities, other outdoor location, or unknown. Time to presentation was grouped as within 1 hour, 24 hours, 1 week, 3 months, or longer.
Injuries were classified according to the 2020 International Association of Dental Traumatology (IADT) guidelines[10,11] as hard dental tissue and pulp injuries (uncomplicated/complicated crown or crown-root fractures, root fracture, and alveolar fracture) and periodontal injuries (concussion, subluxation, lateral luxation, extrusion, intrusion, and avulsion). Cases with multiple diagnoses at the same site were categorized as combined injuries. Because a single tooth could sustain more than one type of trauma (e.g., uncomplicated crown fracture and subluxation), both the number of traumatized teeth (n = 2,442) and the total number of dental injuries (n = 2,671) were recorded, with each injury type counted separately. Initial management included follow-up, restoration, pulp therapy (vital or non-vital), splinting, reduction with splinting, replantation, and extraction.
Clinical outcomes were classified as favorable or unfavorable based on the IADT criteria[10,11], including only cases with follow-up exceeding 3 months, excluding avulsed teeth. Favorable outcomes were defined as the absence of symptoms and lack of adverse effects on successor development in primary teeth, and as maintained pulp vitality, continued root development in immature teeth, and bone healing in permanent teeth. Unfavorable outcomes were defined as pulpal/periapical complications, inflammatory or replacement root resorption, structural tooth loss, functional deterioration, and sequelae in permanent successors.
3. Statistical analysis
Analyses were conducted at three levels: patients (n = 1,332), traumatized teeth (n = 2,442), and dental injuries (n = 2,671). Unless otherwise specified, the unit of analysis is indicated in the title and caption of each table and figure. Data were analyzed using SPSS version 29.0 (IBM Corp., Armonk, NY, USA). Descriptive statistics were calculated, and categorical variables were compared using the chi-square test. Linear regression was used to analyze temporal trends. Multivariable logistic regression was performed at the tooth level to identify independent predictors of unfavorable outcomes. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated. A significance level of α = 0.05 was set for all statistical analyses.
Results
1. Distribution of age and gender
Of the 1,332 patients, 844 (63.4%) were boys and 488 (36.6%) were girls (male-to-female ratio of 1.73 : 1), with a mean age of 4.2 ± 3.3 years (range 0 - 16). The most frequent age groups were 1 - 2 years (20.0%) and 2 - 3 years (16.9%), with significant differences observed across dentition stages (Table 1, p= 0.012).
2. Etiology and place of occurrence
The main causes of TDI were fall (48.4%), collision (33.0%), and drop (6.7%), and significant differences were observed according to the dentition stage (Table 2, p < 0.0001). TDI occurred most frequently on streets or stairs (14.8%), at home (14.7%), and in kindergarten or school (12.5%), with variation by dentition stage (p < 0.0001). Home injuries increased significantly during the COVID-19 pandemic (11.5 - 20.0%), in which cases with an unknown year of occurrence were excluded (Table 3, p < 0.0001).
3. Yearly and monthly incidence
Linear regression analysis demonstrated a significant temporal decrease (β = - 9.24, p= 0.010), whereas comparison between the pre-COVID and COVID periods indicated a significant reduction in patient numbers (Fig. 1, p < 0.0001). Monthly variation in TDI frequency was not statistically significant (p > 0.05). Cases with an unknown year of occurrence were excluded.
4. Number and location of traumatized teeth
Most patients had one (43.7%) or two (40.2%) injured teeth, while multiple injuries were more frequent in the mixed and permanent dentitions (Fig. 2, p= 0.031). Of 2442 teeth, primary teeth accounted for 72.8% of the cases, with the maxillary central incisors most frequently affected in both dentitions. The maxillary arch was significantly more involved than the mandibular (p < 0.0001), with no side difference (Table 4, p= 0.416).
5. Types of TDI
A total of 2,671 dental injuries were recorded, as some teeth sustained multiple types of trauma that were counted separately. Periodontal injuries (65.6%) occurred at approximately twice the rate of hard tissue injuries, and subluxation (32.7%) was the most common type. They predominated in the primary dentition (2.4 : 1 vs. 1.2 : 1 in permanent), and most cases were isolated (90.9%), although trauma type was significantly associated with dentitions and combined injuries (Table 5, Fig. 3, p < 0.0001).
6. Time to presentation after trauma
Most patients presented within 1 week (84.3%), with 57.7% attending within 24 hours. Of 2,671 dental injuries, early visits were associated with alveolar bone fracture and avulsion (Table 6, p < 0.0001), and no age-related differences were observed (p= 0.05).
7. Initial management of dental injuries
Management varied greatly according to the type of injury and dentition (Tables 7-1 to 8-2, p < 0.0001). In the primary dentition, follow-up was most common, followed by extraction. In the permanent dentition, follow-up was also most common, but a wider range of treatments was performed: for hard dental tissue and pulp injuries, restoration, pulp therapy, and splinting followed in frequency, while for periodontal tissue injuries, splinting—often combined with reduction or replantation—was the next most common treatment. Treatment varied according to the time of presentation (Fig. 4).
8. Follow-up visits
Overall, 76.3% of patients attended follow-up (Table 9). The rate was higher in permanent than in primary teeth (p < 0.0001). Follow-up was most frequent for alveolar bone and crown fractures and least for subluxation and root fracture (p= 0.003).
9. Clinical outcomes
Of 1,509 teeth, 71.6% showed favorable healing. Permanent teeth showed a significantly lower risk of unfavorable outcomes (adjusted odds ratio [AOR], 0.45; 95% CI, 0.34 - 0.60) compared with primary teeth, whereas combined injuries (AOR, 2.46; 95% CI, 1.70 - 3.55) and delays beyond 3 months (AOR, 7.30; 95% CI, 2.92 - 18.20; n = 29) increased the risk of unfavorable results (Table 10, p < 0.0001). When analyzed per injury, outcomes also varied significantly by trauma type (Table 11). The most common unfavorable results were pulpal or periapical complications (Fig. 5), and sequelae in permanent successors were observed in 10 cases, affecting 11 permanent teeth following trauma to primary teeth (Table 12).
Discussion
This 10-year retrospective study analyzed 1,332 children and adolescents with 2,442 traumatized teeth and 2,671 dental injuries at the Seoul National University Dental Hospital, providing comprehensive long-term data on the epidemiology, etiology, clinical features, treatment patterns, and outcomes of pediatric TDIs.
TDIs occurred more frequently in boys than in girls. This male predominance aligns with previous findings reporting male-to-female ratios of 1.3 - 2.5 : 1, attributed to greater involvement in vigorous activities, contact sports, and risk-taking behavior[12]. Although some studies have detected minor or insignificant differences in the primary dentition[13], other studies have reported higher rates in boys (1.5 - 1.6 : 1)[7,14]. Recent evidence indicates that this disparity is narrowing as girls increasingly participate in sports and share similar risk factors[12].
Age is a well-recognized risk factor for TDIs, with incidence skewed toward younger populations. In this study, peaks occurred at 1 - 2 years in the primary dentition, 8 - 9 years in the mixed dentition, and 13 - 15 years in the permanent dentition. Similarly, previous studies have reported early peaks at 1 - 2 years[6,15], attributed to immature motor coordination, and later peaks at 8 - 10 years[16], associated with active play, school activities, and contact sports.
Falls were the leading cause of TDIs, followed by collisions. They predominated in the primary and mixed dentitions, whereas sports injuries increased in the mixed and permanent dentition stages. These findings are consistent with those of previous studies reporting falls as the leading cause of TDIs, with sports- and violence-related injuries increasing in older children and adolescents[15-17]. This shift reflects the developmental transition from involuntary falls in toddlers to injuries associated with sports and broader social activities in adolescence.
According to this study, TDIs occurred most frequently on streets or stairs, followed by the home and educational settings, with the home predominating in the primary dentition and streets or schools being more common in mixed and permanent dentitions. Likewise, previous studies have reported home as the main location for younger children and school as the outdoor setting for older children[18-20]. Consistent with Waseem et al.[21], home injuries increased and outdoor injuries decreased during the COVID-19 pandemic. These findings indicate that both dentition stage and pandemic-related lifestyle changes influenced TDI distribution.
This study reported that TDIs peaked in 2017 - 2018, declined from 2019, and fell sharply during the COVID-19 pandemic, with only a partial recovery afterward. Regression analysis confirmed an overall downward trend that began before the pandemic but was further accentuated by restrictions and lifestyle changes related to COVID-19, consistent with reports of a 20 - 85% global decrease[21]. Monthly distribution exhibited peaks in November, May, and October, and the lowest incidence in August, without statistical significance, contrasting with studies reporting higher rates during warmer months with greater outdoor activity[22].
Most patients sustained one or two injured teeth, although multiple injuries were more frequent in the mixed dentition and occurred in more than half of permanent dentition cases. This finding is consistent with reports that single-tooth trauma predominates, whereas multiple injuries increase with age and with sports, violence, or traffic accidents[17]. The maxillary central incisors were most frequently affected in primary and permanent dentition, followed by the maxillary lateral incisors, reflecting the particular vulnerability of anterior maxillary teeth due to their protrusive position, proclination, and insufficient lip coverage[9,23]. The predominance of maxillary over mandibular involvement highlights this susceptibility.
Dental injuries were observed more frequently in the primary than in the permanent dentition. Periodontal injuries were more frequent than hard tissue injuries and predominated in both dentitions, whereas the difference was minor in the permanent dentition. Overall, subluxation was the most common injury, followed by uncomplicated crown fracture. This result is consistent with previous findings that higher rates of supporting structure injuries and subluxation are the most frequent type[14,15]. Luxation-type injuries, particularly subluxation, root fracture, intrusion, and lateral luxation, predominated in primary teeth. However, the uncomplicated crown fracture was second to subluxation in permanent teeth. These patterns reflect anatomical and developmental differences: the flexible alveolar bone and large crown-to-root ratio in primary teeth predispose to displacement injuries[6], whereas with age, reduced bone flexibility and stronger supporting structures increase the likelihood of direct impact on permanent teeth[24].
Combined injuries were most frequently associated with alveolar bone and crown fractures, whereas avulsion, intrusion, and subluxation usually occurred as single injuries. Accordingly, high-impact forces tend to produce multiple injuries, while luxation injuries occur alone, reflecting different trauma mechanisms. Clinically, these findings stress the importance of assessing concomitant injuries when diagnosing fractures.
The majority of patients presented within 24 hours of trauma, and some within 1 hour, although the timing varied according to the type of injury. Previous studies have reported wide variability in 24-hour attendance (17.1 - 76.5%)[25-27]. Acute injuries, including alveolar bone fracture, avulsion, extrusion, and subluxation, prompted earlier visits, whereas root fractures, intrusion, and uncomplicated crown fractures were often delayed beyond 1 week. These findings align with reports that early attendance is driven by acute symptoms (bleeding, pain, mobility, and esthetic concerns) and parental anxiety or awareness of services[9,28]. Although age was not a significant factor in this study, previous studies have stated that younger children (0 - 2 years) present earlier, whereas older preschoolers (5 - 6 years) delay care[22].
Initial management varied by dentition and timing of presentation. In the primary dentition, the treatment goal is to minimize harm to developing permanent successors rather than to preserve the traumatized tooth itself. Conservative observation was most common, while extraction was frequently performed in cases with severe displacement or non-restorability to protect developing successors[29]. Minor injuries, such as concussion or subluxation, often require only observation[6,16,24]. In contrast, permanent teeth were rarely extracted, with treatment aimed at preservation through pulp therapy, splinting, or replantation[16]. Timing was critical, as early presentation enabled vital pulp therapy or replantation with splinting. Delayed visits more often required non-vital therapy or extraction. Follow-up was the most common approach, increasing in proportion with delay in treatment.
The follow-up visit status of pediatric TDI patients was also investigated. Follow-up was analyzed per tooth for dentition and per dental injury for trauma type, as presented in Table 9. More than 75% of patients completed follow-up, with higher attendance for permanent than for primary teeth, consistent with previous reports[27] and reflecting the greater emphasis on preserving permanent dentition. In addition, the follow-up rates differed according to the type of trauma. Injuries with significant structural damage or displacement (e.g., alveolar bone fractures, crown fractures, and intrusion) exhibited higher compliance. In contrast, subluxation, root fracture, and avulsion showed lower rates, likely due to milder symptoms in subluxation or poor prognosis in avulsion and root fracture. Garcia-Godoy et al.[28] noted that patients rarely seek care for minor injuries such as concussion or enamel fracture. These results indicate that both dentition stage and injury type influence follow-up behavior, highlighting the need to emphasize recall and long-term management in clinical practice.
The prognosis of dental trauma is inherently uncertain and often requires repeated treatment and long-term follow-up. Andreasen[30] highlighted the value of periodic monitoring, as some luxated permanent teeth may exhibit spontaneous healing despite initial negative pulp tests, described as “transient apical breakdown”. Pulp canal calcification occurs in 2 - 4% of traumatized permanent teeth, with a minority later becoming infected, whereas 10 - 15% of affected primary teeth have been suggested to progress to infection[31]. Andreasen and Pedersen[8] reported that pulpal necrosis usually develops within 3 months of trauma. Barkin[32] stated that pulp vitality can be reliably assessed afterward. Therefore, prognosis was evaluated only in patients with at least 3 months of follow-up, and avulsion cases were excluded because they generally required extraction in primary teeth and root canal treatment in permanent teeth.
Clinical outcomes were investigated in Table 10, with analyses performed per tooth and per injury. Dentition, combined injury, and time elapsed the until visit were analyzed per tooth, whereas trauma type was analyzed per dental injury. Prognosis was better in permanent teeth than in primary teeth, reflecting the emphasis on conservative management to preserve permanent teeth. In contrast, extraction was more frequently performed in the primary dentition, which may partly account for the less favorable outcomes. As noted above, the primary aim in managing injured primary teeth is to protect developing permanent successors, and extraction is therefore considered an appropriate option when teeth are severely displaced or non-restorable[29]. In cases with visits delayed more than 3 months, 72.4% of teeth showed unfavorable outcomes; however, given the small sample size (n = 29), this result should be regarded as a trend rather than a definitive conclusion, although it underscores the importance of timely management. Combined injuries further worsened the prognosis. Notably, combined luxation and fracture increased the risk of pulp necrosis due to neurovascular disruption and bacterial invasion[33]. Severe injuries, particularly crown-root fractures, root fractures, and major luxations, were associated with poorer outcomes, whereas uncomplicated fractures and minor luxations generally healed well. Crown fractures generally had favorable outcomes, with uncomplicated cases rarely progressing to necrosis and complicated fractures responding well to conservative pulp therapy[34]. Root fractures also exhibited good healing when the vascular supply was preserved, particularly in immature teeth[35]. Conversely, luxation injuries carried higher risks of pulp necrosis, from concussion and subluxation to extrusion and lateral luxation, with the highest risk in intrusion, particularly in teeth with developed roots[36].
Pulpal/periapical complications, including pulp necrosis and periapical lesions, were the most frequent unfavorable outcomes, with reported necrosis rates of 15 - 59% depending on the type of injury, root development, and age[37]. Other sequelae included root resorption (inflammatory or replacement), structural tooth loss due to unrestorable fractures, and functional deterioration from pathologic mobility or luxation. Complications were more varied in the primary dentition, whereas pulpal/periapical complications predominated in permanent teeth. Trauma to primary teeth occasionally caused sequelae in the permanent successors, including enamel hypoplasia, crown malformation, and eruption disturbances, with younger children being particularly vulnerable[38]. Because the permanent tooth germ is in close proximity to the roots of the primary teeth during early childhood, trauma to primary teeth poses a high risk of damaging the developing permanent successors[39]. Thus, the treatment goal should focus on protecting the permanent dentition rather than preserving the primary teeth. Pediatric dental trauma must therefore be regarded not only as an acute emergency but also as a condition with long-term consequences for growth and development.
Interpretation of some subgroup results should be made with caution due to limited sample sizes. Certain rare trauma types, such as crown-root fractures and alveolar fractures, were represented by only a small number of cases, and the corresponding percentages may therefore be unstable. In particular, the subgroup with visits delayed for more than 3 months and those with an unknown presentation time were very small, and although poorer outcomes were observed, interpretation is limited. Logistic regression based on these data similarly produced high odds ratios for these categories but with wide confidence intervals, again reflecting limited statistical power.
This study confirms that pediatric dental trauma requires prompt management and long-term follow-up, as early trauma to primary teeth can result in permanent sequelae. The prognosis was primarily influenced by the trauma type and timing of presentation, with poorer outcomes associated with delayed visits and combined injuries. However, the retrospective single-center design, incomplete follow-up, and unassessed factors—such as socioeconomic background and parental awareness—limit generalizability. Furthermore, presenting the timing of unfavorable outcomes would have added valuable clinical guidance for determining the appropriate follow-up duration and intensity, highlighting an important area for further investigation. Future studies should adopt prospective multicenter designs with standardized follow-up and explore preventive education and advanced treatment strategies to improve outcomes.
Conclusion
Pediatric dental trauma poses a clinical challenge, because injuries can affect the function, esthetics, and development of permanent successors. This study highlights the importance of timely intervention and structured follow-up in reducing complications and improving outcomes. Careful treatment planning is required to preserve traumatized teeth while protecting developing successors, and greater awareness among caregivers and clinicians may contribute to better outcomes in pediatric dental trauma care. Continued efforts to develop preventive strategies and evidence-based guidelines will enhance clinical practice and long-term prognosis.
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