Planos bioscópicos de interés protésico y su influencia en la altura coronal

Abstract

lntroduction: The exact determination of the occlusal plane is necessary to construct proper prosthetic restorations involving posterior areas. The goal of our study is to determine which part of the posterior edge of the tragus enables the tracing of the prosthetic plane which is most parallel to the occlusal plane as well as the influence that this selection has on the height of the clinical crowns. Material and method: 40 lateral tele-radiographs were taken on 40 subjects (17 women, 23 men). Previously, on each participant three radiological markers had been placed on the tragus and one on the base of the wing of the nose. The parallelism between the lines traced from each tragus marker and the nose base marker plane (upper part, mid part and lower part of the tragus), and changes on the height of the clinical crown of the first upper molar were then determined. Results: The most parallel plane to the occlusal plane was the Camper plane traced through the lower part of the tragus, followed by that traced through the mid part and lastly by the one traced throughout the upper part of the tragus. Differences among procedures were statistically significant. The clinical crown height of the first upper molar was 1.53 mm shorter when based on the mid part of the tragus as a reference and 2.93 mm shorter when taking as a reference the upper part of the tragus. These differences were also signifficant. Conclusions: Camper plane traced through the lower part of the tragus is the most parallel to the occlusal plane and it creates a longer clinical crown of the first upper molar than those obtained by using the camper planes traced through the mid and upper part of the tragus, in a statistically signifficant way.