Researchers have found in a new study that professional tooth cleaning performed one day before surgery was associated with a reduced risk of postoperative pneumonia (PP) in patients with oral squamous cell carcinoma (OSCC).Professional tooth cleaning is a simple, low-cost preoperative oral intervention. Its role in reducing postoperative complications in oral squamous cell carcinoma (OSCC) remains unclear. This retrospective cohort study included 415 oral squamous cell carcinoma patients undergoing radical resection with free flap reconstruction. After propensity score matching, 174 well-matched pairs were analyzed. Patients were divided into a tooth cleaning group (n = 174) and a control group (n = 174). Outcomes included postoperative pneumonia (PP), surgical site infection (SSI), fever, length of stay, and unplanned reoperation were recorded.Results: Preoperative tooth cleaning was significantly associated with lower postoperative pneumonia risk (OR = 0.30). Significant independent risk factors for postoperative pneumonia included tumor location at the floor of the mouth (OR = 4.70), hypertension (OR = 2.93), and longer operative duration (OR = 1.33 per hour). The radiographic severity of periodontitis was not a significant risk factor for postoperative pneumonia. No associations were found between tooth cleaning and other outcomes. Stratified analyses showed significant protective effects in patients aged > 60 years (OR = 0.19), with hypertension (OR = 0.08), periodontitis (OR = 0.07), or surgeries > 5 h (OR = 0.18).Preoperative professional tooth cleaning one day before surgery is associated with a reduced risk of postoperative pneumonia in oral squamous cell carcinoma patients.Reference:Xiao, C., Y. Yang, G. P. Lubamba, C. Li, X. Wang, and Z. Ding. 2026. “ Preoperative Professional Tooth Cleaning as a Preventive Measure for Postoperative Pneumonia in OSCC Patients: A Retrospective Study.” Oral Diseases 1–12. https://doi.org/10.1111/odi.70200.Keywords:Preoperative, Tooth, Cleaning, Reduces, Postoperative, Pneumonia, Risk, Patients, oral, squamous cell carcinoma, Study, Xiao, C., Y. Yang, G. P. Lubamba, C. Li, X. Wang, and Z. Ding.