Factors Related to 3-Month Mouth Opening Outcomes in Stage II–III Oral Submucous Fibrosis After Integrated Chinese–Western Medicine: Real-World Study

Oral submucous fibrosis can cause progressive limitation of mouth opening, yet reproducible real-world methods for evaluating short-term functional outcomes after integrated Chinese-Western conservative treatment remain limited. This study describes a single-center retrospective workflow for identifying eligible adults with stage II-III disease, extracting treatment exposures and adherence variables from medical records, applying predefined rules to maximum mouth opening (MMO) measurements at baseline and day 90 ± 14, handling missing covariate data, and analyzing factors associated with 3 month outcomes. Consecutive patients treated between January 2021 and December 2024 were screened; 242 met the eligibility criteria. Treatment included local Western medicine injections, Chinese medicine, risk-factor control, and mouth-opening training. The individual 3 month MMO improvement value was calculated as follows: follow-up MMO minus baseline MMO. The primary multivariable model used 3-month MMO as the dependent variable with baseline MMO forced into the model; chained-equation multiple imputation and complete-case and improvement-value sensitivity analyses were performed. Median MMO improvement was 4.9 mm. Stage III disease and longer disease duration were associated with lower 3 month MMO, whereas the number of local injections, Chinese medicine treatment duration, sustained betel-quid cessation, and regular mouth-opening training were associated with higher MMO; sensitivity analyses were consistent. Because treatment exposures were not randomly assigned, associations involving injection number and treatment duration may reflect treatment selection, adherence, baseline severity, and residual confounding and should not be interpreted causally. This workflow provides a reproducible approach for evaluating short-term functional outcomes in routine integrated care.