Patterns of Dental Interventions Across Tooth Position, Age, and Sex: A Retrospective Real-World Clinical Study

Background/Objectives: The lateral symmetry of dental disease and treatment patterns reflects underlying biological, behavioral, and systemic factors. Although clinical experience suggests asymmetric treatment frequencies, large-scale quantitative evidence remains limited. This study aimed to analyze the symmetry and asymmetry of dental interventions—encompassing restorations, extractions, endodontic treatments, and prosthetic procedures—in relation to tooth position, jaw, patient sex, and age group. Methods: A retrospective analysis was conducted on 30,063 dental intervention records from 2738 patients treated at a single private practice between 1999 and 2025. Tooth identification was based on FDI two-digit notation. Chi-square goodness-of-fit tests were applied to assess left–right and upper–lower symmetry, stratified by sex, age group, and tooth position. Bonferroni correction was applied to account for multiple comparisons (adjusted α = 0.0033). Results: Overall left–right symmetry was maintained across the full dataset (χ2 = 0.17, p = 0.682). After Bonferroni correction, only the right-side excess at the first premolar position remained statistically robust (p = 0.002), driven predominantly by the lower jaw (tooth 44 vs. 34; p = 0.011). The upper jaw received significantly more interventions than the lower jaw (56.3% vs. 43.7%, p < 0.001). Additional asymmetries observed at the uncorrected threshold—in the lower jaw (p = 0.026), in the 18–30 age group (p = 0.009), and a sex × jaw interaction (p = 0.047)—did not survive correction. Conclusions: Dental treatment patterns are predominantly symmetric at the population level. The most robust site-specific finding was a right-side excess of first premolar interventions, particularly in the lower jaw. These results may inform targeted preventive strategies and population-level oral health planning, with caution warranted in generalizing findings beyond the single-practice setting.