Análise tomográfica da espessura óssea do pilar nasomaxilar e zigomaticomaxilar para fixação de miniplacas

Abstract

The purpose of this study was to evaluate the bone thickness of the nasomaxillary and zygomaticomaxillary buttresses to identify the most favorable region for the installation of miniplates. Bilateral tomographic images of 103 individuals were evaluated, totaling 206 nasomaxillary and zygomaticomaxillary buttresses. Measurements of bone thickness were performed in parasagittal reconstructions at three vertical lines on the nasomaxillary buttress and at four vertical lines on the zygomaticomaxillary buttress, totaling 21 and 28 measurement points respectively. The vertical line measurements for each buttress were compared with each other using the Kruskal-Wallis test. In order to correlate the thicknesses obtained with the patients gender and the right/left sides, the Spearman s correlation coefficient was used. The level of significance adopted was 5%. The nasomaxillary and zygomaticomaxillary buttresses presented statistical differences between the thickness of their respective points (p<0.05). The analysis of the nasomaxillary buttress showed that there was thicker bone following the long axis of the upper canine, with more bone available in the lower points, closer to the root. For the zygomaticomaxillary buttress, bone was thicker closer to a vertical line distally to the distobuccal root of the first molar, with more bone available higher up, closer to the zygoma. In conclusion, the ideal position for the installation of miniplates on the nasomaxillary buttress is on the central plane of the maxillary canine at a distance of 3 mm from to root apex. For the zygomaticomaxillary buttress, it is recommended to install miniplates distally to the distobuccal root of the maxillary first molar, at a distance of 3.5 mm from the lower limit of the infraorbital foramen.