Predictors of Bone Cavity Volume Reduction Rate Following Marsupialization of Jaw Cysts.

BACKGROUND: Marsupialization is a minimally invasive treatment for large jaw cysts, but the rate of bone cavity volume reduction and factors influencing this rate remain poorly defined. PURPOSE: To estimate bone cavity volume reduction and identify factors associated with reduction after marsupialization of jaw cysts. STUDY DESIGN, SETTING, SAMPLE: This retrospective cohort study included patients treated with marsupialization for histopathologically confirmed odontogenic jaw cysts (initial diameter ≥3.5 cm) between January 2020 and December 2024 at Qujing Central Hospital of Yunnan Province, with baseline and follow-up cone-beam computed tomography scans and minimum 3-month follow up. Exclusion criteria included syndromic cysts, any previous surgical treatment, incomplete imaging data, poor image quality, and loss to follow up. PREDICTOR/EXPOSURE/INDEPENDENT VARIABLE: Predictors included demographics (age, sex), cyst characteristics (histological type, anatomical location, and initial volume), and decompression time. MAIN OUTCOME VARIABLE(S): The primary outcome was bone cavity volume reduction rate (%), calculated as [(V0 - Vt)/V0 × 100], where V0 is the initial cavity volume and Vt is the cavity volume at final follow up. COVARIATES: Not applicable. ANALYSES: Analyses included Pearson correlation, independent t-tests, one-way analysis of variance, and multiple linear regression. Statistical significance was set at P < .05. RESULTS: Among 270 subjects (mean age 31.5 ± 12.0 years; 60.4% [163] male), the mean total reduction rate was 64.12 ± 10.78% over a mean decompression period of 9.29 ± 3.41 months (mean monthly reduction: 6.9%/month, calculated descriptively as total reduction divided by decompression time). Multiple linear regression identified decompression time (b = 2.43, P < .001), maxillary location (b = 2.78, P < .001), younger age (b = -0.30, P < .001), and female sex (b = -2.29, P = .002) as independent predictors. Cyst type and initial volume showed limited independent predictive value after adjustment. The model explained 73.5% of the variance (R2 = 0.735). CONCLUSIONS AND RELEVANCE: Decompression time is the most statistically significant modifiable predictor of bone cavity volume reduction following marsupialization. Serial volumetric assessment should guide clinical decisions. The mean monthly reduction rate of approximately 6.9%/month provides a descriptive benchmark for patient counseling.