Measurement of the Cross-sectional Image of an Edentulous Mandible by Computed Tomography : Application of Silicone Materials as Markers
<B>Purpose:</B> The purpose of this study was to select silicone materials as markers on CT (computed tomography) images and to evaluate with edentulous mandibles wearing mandibular complete dentures. The study also aims to evaluate the influence of different mandible positions during CT examination on the resulting CT image.<BR><B>Methods:</B> Three different silicone impression materials and three different maxillomandibular registration materials were selected as markers. The CT number of the silicone specimens was measured. Nine dried edentulous mandibles used for the examination were categorized into three types; spiral CT was used to acquire images of each edentulous mandible wearing complete dentures with the markers. The following five measurements were taken: jawbone height, jawbone width, residual mucous membrane, distance from the impression material to mandibular plane, and angle of inclination of the mandibular crest. The measurements were performed using DICOM software.<BR><B>Results:</B> The CT number of Fit Checker was the highest of the silicone impression materials, while the CT number of Memoreg 2 was the highest of the maxillomandibular registration materials. There were significant differences for all measurement items between each other angles in the anterior, premolar, and molar area for the three bone types (<I>P</I><0.05).<BR><B>Conclusion:</B> The impression material and maxillomandibular registration material with the highest CT numbers were selected as markers for CT and the five measurement items were quantified. Attention must be paid to positioning of the mandible because the CT image changes according to its position during the CT examination.
- Prosthodontic research & practice
Prosthodontic research & practice 6(1), 20-27, 2007-01-01
Japan Prosthodontic Society