Objective: To establish a standardized method for classifying nasal septal mucoperichondrial flap (NSMF) thickness using computed tomography (CT) scans and correlate preoperative measurements with intraoperative findings to improve surgical planning and outcomes.

Methods: A retrospective cohort study. Methods: A private hospital. Methods: A total of 196 adult patients (mean age 31.99 years) who underwent septoplasty between April 2021 and February 2024. Methods: The primary outcomes included the optimal CT thickness cutoff to differentiate NSMF as "thin" or "thick" and its sensitivity and specificity. Secondary outcomes included demographic predictors of intraoperative complications.

Results: Our study determined that a 3.65 mm cutoff in CT scans could differentiate between "thin" and "thick" NSMF with 80.9% sensitivity and 78.5% specificity. The average age of participants was 31.99 years. No gender-based differences were observed in the subjective reporting of nasal thickness during surgery. Logistic regression identified age as a significant predictor for the occurrence of tears during surgery.

Conclusions: The research validates the use of a 3.65 mm CT scan cutoff for preoperative NSMF thickness classification, correlating with surgical findings and demonstrating high accuracy. These findings suggest the potential for CT measurements to become a routine part of preoperative nasal surgery planning, improving outcomes and reducing the risk of complications. Further investigation into direct measurement techniques for septal thickness is recommended to enhance surgical precision.