Desenvolvimento de um afastador labial para uso em exame termográfico da cavidade bucal

Abstract

The aim of this study, therefore, is to investigate the influence of three lip retractors and three different emissivity values on the temperature measurement of intraoral IT images, as well as to develop, through Additive Manufacturing (AM), a model of mouth retractor to be used in the exam. Intraoral Infreared Thermography (IT) images were taken in 30 volunteers with two conventional retractors, Flex Retractor (FR) and Lateral U-shaped Retractor (UR), and a Flex Retractor Adapted with Styrofoam (FRadapt) to simulate a draft blocking device of breathing. Three acquisitions were performed for each retractor, varying the emissivity value (Ɛ) (0.98, 0.96 and 0.91). For obtaining thermal images, a FLIR thermal camera model T650sc Infrared was used, positioned 40cm from the volunteer and the average temperature of the regions of interest (ROI) of the upper anterior teeth were recorded for later comparison. A retractor was built with a central apparatus, using the digital manufacturing cycle, through computational tools Computer Aided Design (CAD), Computer Aided Engineering (CAE), Computer Aided Manufacturing (CAM) and 3D printing, through Fused Deposition Modeling (FDM) technology using acrylonitrile butadiene styrene (ABS) material. Then, thermal acquisitions were performed in 10 volunteers, comparing the developed device with the UA. Mean temperature values of the same ROIs evaluated on axis 1 were obtained for later comparison. In addition, a questionnaire with different methods of Visual Analog Scale (VAS) was applied to assess the degree of discomfort of the created device. For statistical analysis, two-way ANOVA parametric tests, t test and Friedman's ANOVA test were used. Was observed higher temperature mean values for tooth 12 (30.42ºC), with UA at Ɛ 0.91. The mena temperature values obtained with the UR retractor differed statistically from the other assessed retractors (p<0.05). The temperature values obtained using Ɛ0.91 differed statistically from those obtained using Ɛ0.98 and 0.96 for all types of retractors. The CAE result demonstrated that the device has similar characteristics of resistance to the process and to the type of material. When comparing the temperature values obtained with the retractor developed in the study with the UR, we observed statistically significant difference (p<0.05), with the highest mean temperature obtained for the UR. As for the degree of discomfort, most patients classified it as mild, with no statistically significant difference between the evaluated pain measurement scale methods (p>0.05). Conventional retractors used in the acquisition of thermal images can interfere with the accuracy of the temperature value obtained. The development of a specific retractor for intraoral IT is necessary to acquire reliable data, as AM can facilitate the manufacture of parts that solve clinical problems, in addition to allowing better adaptation of the device to the oral cavity.