Evaluation of jaw cyst shrinkage in the posterior mandible after decompression therapy with cone beam computed tomography: 3D volumetric analysis evaluation of jaw cyst shrinkage in the posterior mandible after decompression therapy with cone beam computed tomography: 3D volumetric analysis

SAYDAM B. 2024. Evaluation of Jaw Cyst Shrinkage in the Posterior Mandible after Decompression Therapy with Cone Beam Computed Tomography: 3D Volumetric Analysis. Yeditepe University Institute of Health Sciences, Department of Oral and Maxillofacial Surgery, Doctorate Thesis, Istanbul. The aim of this study was to evaluate volume reduction after decompression therapy in cyst patients and assess the correlation between several parameters with volume reduction and bone healing and formation using Cone-Beam Computed Tomography (CBCT). For the sampling, the CBCT images of the patients with the diagnosis 'cyst' between the years 2011 and 2023 were retrieved from the archives of the Department of Dentomaxillofacial Radiology at Yeditepe University, the Faculty of Dentistry. Three hundred and sixty-five scans were reviewed initially. All scans were taken using the same imaging device (i-CAT Imaging Science International, Inc. Hatfield, PA, USA). Based on inclusion and exclusion criteria and G power analysis carried out based on the published study of U. Consolo et al., 12 patients were considered eligible for the study. The software Mimics 20.0 (Materialize Medical, Leuven, Belgium) was used to measure the volume of the cystic lesion. The CT digital imaging and communication in medicine (DICOM) datasets were imported into the program and sliced in the axial, coronal, and sagittal planes. The cross-section of the lesion was delineated on CT images, and the delineated images were then integrated to reconstruct three-dimensional structures prior to volumetric analysis. Then the program automatically calculated the cyst volumes. Among 12 patients (8 keratocyts and 4 dentigerous cysts), it was determined that all patients had a decrease in cyst volumes after treatment (p<0,05). Patients were classified according to gender, age, initial volume of the lesion, duration, presence of involved teeth, cortical bone expansion, cortical bone perforation, smoking, drain localization, drain type, extraction and pathological diagnosis. Considering all these parameters, it was found that there was no correlation or statistically significant difference between these parameters and volume reduction of cystic lesions (p>0,05). In conclusion, CBCT plays an important role in detecting and evaluating cystic lesion shrinkage after decompression therapy and to determine the right time for enucleation. In addition, the results obtained in the study revealed that decompression treatment was effective in causing changes in the procedures and behaviors of the cyst and reducing the complications that may arise during and after the treatment. Keywords: Cyst, Odontogenic Cyst, Decompression, CBCT