Volume reduction of cystic lesions after surgical decompression: a computerised three-dimensional computed tomographic evaluation.

Objectives: This study was performed to evaluate the three-dimensional radiographic variation in mandibular odontogenic cystic lesions after decompression.

Materials And Methods: Pre- and post-decompression computed tomography (CT) evaluations in 20 patients affected by keratocysts (n = 10), dentigerous cysts (n = 9) and ameloblastoma (n = 1) were analysed using software designed for three-dimensional measurement of volumes; the results were correlated with treatment duration, age, sex and histological type.

Results: The mean (range) decompression time was 5.70 (3-12) months. The mean (SD) pre- and post-decompression volumes were 9.50 (7.74) and 4.65 (4.34) cm(3), respectively (P < 0.001), with a mean (SD) reduction of 49.86 % (19.34 %). The volume reduction was positively correlated with the duration of decompression (P < 0.001), whereas no correlations with other variables were found (P = 0.2357). The median monthly reduction in cyst volume was 11.34 % (mean, 13.52 %; range, 4.45-30.43 %) (P < 0.001).

Conclusions: This three-dimensional CT investigation demonstrated the effectiveness of decompression in the treatment of mandibular odontogenic cystic lesions and showed a positive correlation between the duration of treatment and volume reduction.

Clinical Relevance: Decompression treatment, which is simple to perform and generally well-accepted by patients, is a reliable method to considerably reduce the volume of mandibular odontogenic cystic lesions before surgical removal. Extended decompression time seems to improve results of the reduction process.