Volume and Structure of Maxillofacial Trauma Before, During, and After COVID-19 Restrictions: A Multicentre Interrupted Time-Series and Period-Comparative Analysis of 3954 Patients.

Background and Objectives: COVID-19 restrictions altered population mobility and healthcare use. Most reports describe changes in facial-trauma counts; fewer characterise how injury composition changed or separate policy-associated changes from the secular trend. We examined the volume and structure of maxillofacial trauma around the March 2020 restrictions and the January 2022 easing of restrictions. Materials and Methods: A retrospective study of 3954 patients treated for confirmed facial fractures between 2018 and 2023 at three Slovak tertiary centres. The primary outcome was the monthly count of treated cases (case volume, not incidence, as no catchment denominator was available), modelled by segmented negative binomial regression with level and slope terms at two a priori interruptions and harmonic seasonality. Centre-month panel, centre-specific, and leave-one-centre-out models addressed between-centre heterogeneity. Structural outcomes were modelled by segmented binomial regression at the patient level, adjusting for centre, mechanism, sex, and age. Results: The restrictions were followed by a non-significant reduction in monthly case volume (count ratio 0.84, 95% confidence interval CI 0.67-1.04), and the easing was followed by an increase in the pooled series (1.50, 95% CI 1.22-1.86). This increase was strongly heterogeneous between centres (p < 0.001), was confined to one centre (1.86, 95% CI 1.42-2.43), and was compatible with no change once that centre was excluded (1.15, 95% CI 0.88-1.50). The non-mandibular fracture share fell at the onset of restrictions (odds ratio 0.54, 95% CI 0.38-0.77) and returned thereafter; the post-easing estimate was inconclusive. Electric-scooter injuries rose on a secular trend, with no level shift at either interruption. Conservative management increased at the easing and persisted after adjustment for case mix and centre (aOR 1.44, 95% CI 1.22-1.70). Conclusions: These periods were associated with changes in maxillofacial trauma composition, most consistently a shift toward conservative management. The post-easing volume rise was centre-specific, not a national rebound.