DELINEAMENTO: QUANDO A TÉCNICA DOS TRÊS PONTOS NÃO É SATISFATÓRIA - PRÓTESE PARCIAL REMOVÍVEL *

WHEN THE THREE-POINT DELINEATION METHOD IS NOT SATISFACTORY. There are some cases in which the three-point method is not satisfactory for determining the insertion path. • When the removable prosthesis has intracoronal retainers, the insertion path must follow these; here, a Kennedy Class III with two attachments, the insertion plane must necessarily respect them. Note that the two attachments are parallel to each other and to the guide plane of the last molar. In the three-point technique, the attachments would not coincide. • In cases where we only have anterior teeth, from canine to canine, especially in lower cases with conical teeth, that is, smaller than normal, the three-point technique would present a false prosthetic equatorial line and a retentive area that does not actually exist. Here we have a Kennedy Class I, limitation 33/43 with small teeth, due to wear caused by bruxism, with significant bone loss. The three-point technique in this case would present a false prosthetic equatorial guide line. Because with the three-point technique we would have to determine an anterior point, on the incisal edge, between the central incisors, and two virtual points in the posterior region. The determined equatorial line would be false, due to wear of the anterior teeth, consequently the virtual points as well, since they are determined using the existing teeth as a reference. Using the Applegate technique or trial and error, we immediately see the vestibular surface of the canines. Tooth 43 has a satisfactory retentive area, and tooth 33 is divergent. In tooth 43, observe the point of light, indicating a retentive area. Tooth 33, in turn, is completely divergent, making it necessary to create retention, a subtle addition of composite resin on the vestibular surface, or a crescent-shaped wear near the cervical area, which are the grooves or diples. Here we have a Kennedy Class I, limitation 33/42 with excessive vestibularization, where its surface diverges clearly in relation to the posterior points, therefore the equatorial guide line would also be false, by the trial and error technique, the plane is determined by the vestibular of the supporting elements, we will have a postero-anterior insertion plane, it is not the most favorable, but due to the vestibularization it is the most indicated, note that we have retentive areas on both sides, and equivalents The same occurs in this Kennedy Class I, limitation 13/23 In excessively vestibularized anterior teeth, upper or lower, the Roach technique is not satisfactory; Cases with extruded teeth also require attention, as the point is no longer in its original position; In addition to extruded teeth, teeth with large inclinations; • Teeth with occlusal wear are not reliable for reference in the three-point technique; in this case, we would have to use the distal surface of the first molar. Since the Roach technique prioritizes the occlusal surfaces. The Roach three-point method does not take into account the retentions that occur in the soft tissues. When retentive regions of the residual ridge, the location of the prosthesis base, present areas of interference to insertion and removal, this technique is also not applicable. In the Applegate method, or the trial and error method, also known as the convenience method, all areas of the model related to the prosthesis are analyzed. Both hard and soft tissue surfaces are studied in their parallelism, up to the choice of the insertion path that presents the least degree of interference to the placement and removal of the prosthesis, without compromising stability and retention. Several insertion paths are possible for the same case, obtained from different inclinations of the platform. These can be: straight, anteroposterior, or posteroanterior. We should always select the one that minimizes interference from the teeth and ridge. The delineation technique: • three-point method • bisector method • or trial and error method It is the professional's choice.................the important thing is to determine the insertion plane, which facilitates its placement and removal and provides retention, stability, and the necessary support for the wearer's comfort. Contact Renata Blümer +55 19 99955 3001 #removablepartialdenture