Decompression Fails to Achieve Clinically Meaningful Volumetric Reduction in Glandular Odontogenic Cysts.

BACKGROUND

Glandular odontogenic cysts (GOCs) are rare, aggressive lesions, and the effect of decompression on their volume has not been systematically studied.

PURPOSE: This study quantified the volumetric response of GOCs to decompression and assessed the volume change over time.

STUDY DESIGN, SETTING, AND SAMPLE: A retrospective case series included subjects diagnosed with GOCs between January 2012 and March 2020 at Al-Azhar University, Egypt, and Qassim University, Saudi Arabia. Cases lacking complete radiographs or follow-up were excluded.

PREDICTOR VARIABLES: Not applicable.

OUTCOME VARIABLES: The primary outcome was the therapeutic effect of decompression, measured as absolute volumetric changes (cc3) and percentage reduction relative to baseline. Volumes were measured on CT scans at before decompression, 3 months postdecompression, and the end of postdecompression. Reduction rates per month (cc3/month) were also calculated to assess the rate of volumetric response over time.

COVARIATES: They included age, sex, lesion site and side, clinical and radiographic features, decompression period, and follow-up period.

STATISTICAL ANALYSIS: Descriptive statistics, including mean ± standard deviation, median (interquartile range [IQR]), ranges, and percentages, were used. No inferential analyses were performed due to the study nature, and P values were not applicable.

RESULTS

The 5 subjects (3 males, 2 females) had a mean age of 26.8 ± 11 years. Most lesions were unilocular and located in the mandible. Initial mean lesion volume was 252.4 ± 22.7 cc3. At 3 months, volumes decreased slightly to 247.9 ± 22.7 cc3 and, at the end of decompression period, to 243.8 ± 22.7 cc3. The mean absolute reduction was 8.6 ± 5.2 cc3 (3.4%), with median reduction of 7.5 cc3 (IQR: 9.1 cc3). Monthly reduction rates ranged from 0.4 to 2.8 cc3/month, and monthly rate of reduction ranged from 0.2 to 1.1% (mean ± standard deviation: 0.5 ± 0.4%; median: 0.4%, IQR: 0.4). Median decompression period was 8 months (range: 6 to 9 months). No recurrences were observed during long-term follow-up (median: 9 years, IQR: 3, range: 7 to 13 years).

CONCLUSION

Unlike other odontogenic cysts, GOCs show minimal and inconsistent volumetric reduction following decompression. Extending the decompression period does not reliably enhance shrinkage, highlighting the limited effect of decompression.