ABSTRACT

We aimed to use cone-beam computed tomography (CBCT) as an alternative to conventional impression techniques in intraoral maxillectomy defects and to assess the volumetric accuracy of the obturator bulb sections placed in the defect area of obturator prosthesis fabricated using stereolithography.

The artificial defects created in human cadaver maxilla (n=9) were scanned with CBCT. Total slices were captured and stored as digital imaging and communications in medicine (DICOM) images Thereafter, the images were imported and processed with Mimics Software (Mimics Innovation Suite, Materialize, Leuven, Belgium). From the DICOM images, 3D volumetric data of craniofacial hard and soft tissue were then segmented. Thereafter, the hard tissue and soft tissue data were imported into 3-MATIC software module where in virtual models were created and obturator bulb models were designed for maxillary defects considering defect surface borders. The production of obturator bulbs was conducted using a stereolithography device after 3D volumetric images were converted to stl. file format. A physical model of the defect was obtained using an A-type silicon impression material that represents the origins of the borders of the defects. The water displacement technique was used to measure silicon and resin bulb volumes. Data were sent to Minitab Release 15 statistical software program. One-way ANOVA was used to compare volumetric measurements obtained using the two techniques. Statistical significance was set at p<0.05.

Although volumetric measurements obtained using CBCT images were lower than those obtained using silicon impression measurements, this difference was statistically insignificant (p>0.05).

The production of obturator bulbs that fit into maxillary defects using 3D models created from CBCT images seems to be an achievable task.

Keywords: 3D printer, cone-beam computed tomography (CBCT), maxillectomy, obturator, stereolithography