Traumatic Occlusion in Orthodontics: A Systematic Review and Meta-Analysis of Prevalence, Classification, Treatment Outcomes, and the Evidence-Practice Gap

Background: Trauma from occlusion (TFO) is a frequently under-recognized clinical entity. While narrative reviews exist, no prior systematic review has quantitatively synthesized the prevalence of TFO signs in orthodontic patients, the distribution of the Akerly classification for deep traumatic overbite, the efficacy of orthodontic intrusion, or the outcomes of immediate orthodontic repositioning of traumatized incisors. Furthermore, the knowledge-practice gap among orthodontists regarding trauma management has not been meta-analyzed. Methods: Systematic review and meta-analysis of observational and interventional studies, including cross-sectional studies, randomized controlled trials, and before-after studies. We searched PubMed (n=57), PubMed Central (n=538), the Cochrane Library (n=11: 2 reviews, 9 trials), and Google Scholar (~3,930) up to December 2025. Studies reporting prevalence of TFO signs, Akerly classification distribution, overbite reduction following orthodontic intrusion, success of immediate orthodontic repositioning, or orthodontist knowledge/practice were included. Random-effects meta-analyses were performed using the 'meta' package in R (DerSimonian-Laird estimation for tau-squared). The protocol was not registered due to the exploratory nature of this multi-domain synthesis; however, the methodology strictly adhered to PRISMA 2020 guidelines. Results: Twenty-seven studies (n=8,432 participants) were included. The pooled prevalence of any TFO sign was 34% (95% CI: 27-42%, I-squared = 86%), with wide prediction intervals indicating substantial between-study variability. TFO was variably defined across studies as the presence of at least one of the following: fremitus, increased mobility, occlusal interference, soft tissue trauma, or CR-CO discrepancy. Higher prevalence was observed in Class II malocclusion (46% vs. 22%). Among deep traumatic overbite cases classified using the Akerly system, Type II was most common (52%, 95% CI: 44-60%), followed by Type I (31%) and Type III (17%). Orthodontic intrusion reduced overbite by a mean of 2.8 mm (95% CI: 2.1-3.5, I-squared = 72%); TAD-assisted intrusion produced greater reduction (3.4 mm) than conventional archwires (2.1 mm, p < 0.001). Immediate orthodontic repositioning of traumatized incisors with light forces ([&le;] 50 g) achieved 91% success (95% CI: 84-96%) at 12 months, comparable to splinting (84%), with no statistically significant difference between groups. The orthodontic group required fewer visits and reported better comfort. Meta-analysis of orthodontist knowledge showed correct awareness of specific trauma management protocols was below 40% in most domains, indicating a substantial evidence-practice gap. Conclusion: This first systematic review and meta-analysis on TFO in orthodontics provides preliminary quantitative benchmarks. One-third of orthodontic patients exhibit TFO signs; Akerly Type II is the dominant deep overbite pattern; orthodontic intrusion effectively reduces overbite by approximately 3 mm; immediate light-force repositioning is comparable to splinting in success and superior in efficiency. However, the disconnect between high clinical efficacy (e.g., 91% success of repositioning) and low practitioner awareness (<40%) represents a substantial translational gap in clinical practice. Assessment of publication bias was limited due to the small number of studies in several analyses (<10), precluding reliable funnel plot interpretation.