A custom-made removable appliance for the decompression of odontogenic cysts fabricated using a digital workflow.

Objectives: This case series aimed to assess the feasibility of a custom-made decompression appliance fabricated using a digital workflow to decompress odontogenic cysts. Additionally, the treated cysts were assessed for volumetric changes.

Methods: A three-dimensional (3D) reconstruction software (CoDiagnostiX version 10.4) was used to obtain the master cast STL (Standard Tessellation Language) file by placing a customized virtual implant to create a recess for the tube of the decompression device. The decompression appliance was planned using Dental Wings Open Software (DWOS). Following rapid prototyping, the tube of the appliance was perforated using round burs. In cases where the appliances were designed to replace teeth, denture teeth were added using the conventional workflow. The appliances were delivered on the day of the cystostomy. Following decompression, cyst enucleation was performed. Cyst volume was assessed by manual segmentation of pre- and post-operative cone-beam computed tomography (CBCT) reconstructions using slice-by-slice boundary drawing with a scissors tool in the 3DSlicer 4.10.2 software. Percentage of volume reduction was calculated as follows: volume reduction/pre-operative volume × 100.

Results: Six odontogenic cysts in six patients (5 male, 1 female; age 40 years, range: 15-49 years) with a pre- and post-operative cyst volume of 5597 ± 3983 mm and 2330 ± 1860 mm respectively (p < 0.05) were treated. Percentage of volume reduction was 58.84 ± 13.22 % following a 6-month-long decompression period.

Conclusions: The digital workflow described in this case series enables the delivery of decompression appliances at the time of cystostomy, thus effectively reducing the volume of odontogenic cysts. The resulting bone formation established a safe zone around the anatomical landmarks; therefore, during enucleation surgery, complications to these landmarks can be avoided.