ABSTRACT
To explore the digital manufacturing process of distal extension removable partial denture. From November 2021 to December 2022, 12 patients (7 males and 5 females) with free-ending situation were selected from the Department of Prosthodontics, School of Stomatology, The Fourth Military Medical University. Three-dimensional model of the relationship between alveolar ridge and jaw position was obtained by intraoral scanning technique. After routine design, manufacturing and try-in of metal framework for removable partial denture, the metal framework was located in the mouth and scanned again to obtain the composite model of dentition, alveolar ridge and metal framework. The free-end modified model is obtained by merging the digital model of free-end alveolar ridge with the virtual model with the metal framework. The three-dimensional model of artificial dentition, and base plate was designed on the free-end modified model, and the resin model were made by digital milling technology. The removable partial denture was made by accurately positioning the artificial dentition and base plate, bonding metal framework with injection resin, grinding and polishing the artificial dentition and resin base. Compared with the design data after clinical trial, the results showed that there was an error of 0.4-1.0 mm and an error of 0.03-0.10 mm in the connection between the resin base of artificial dentition and the connecting rod of the in-place bolt and the connection between artificial dentition and resin base. After denturen delivery, only 2 patients needed grinding adjustment in follow-up visit due to tenderness, and the rest patients did not find any discomfort. The digital fabrication process of removable partial denture used in this study can basically solve the problems of digital fabrication of free-end modified model and assembly of artificial dentition with resin base and metal framework.
ABSTRACT
<p><b>OBJECTIVE</b>To evaluate the application of digital surgical technology in reconstruction of orbital frame and assess the treatment outcomes.</p><p><b>METHODS</b>Seven patients with post-traumatic orbital defect were included in this study. Images of the orbit were obtained for each individual through computed tomography (CT). Preoperative design was finished according to rapid prototyping, computer-aided design and computer-aided manufacturing (CAD-CAM) and other digital surgical techniques. Surgical fracture reductions with internal fixation and implant of Medpor were used in operation to reconstruct orbit as well as correct enophthalmos and diplopia.</p><p><b>RESULTS</b>Accurate realignment of the displaced orbital rim was obtained in all the 7 patients, and enophthalmos and diplopia were corrected in 4 and 2 patients, respectively.</p><p><b>CONCLUSIONS</b>Digital techniques provide a precise means for preoperative design and operation implementation during orbital reconstruction. As a result, complications can be reduced, and the patient's facial appearance can be maximally improved.</p>
Subject(s)
Adult , Female , Humans , Male , Middle Aged , Young Adult , Computer-Aided Design , Diplopia , General Surgery , Enophthalmos , General Surgery , Fracture Fixation, Internal , Imaging, Three-Dimensional , Orbit , Diagnostic Imaging , General Surgery , Orbital Fractures , Diagnostic Imaging , General Surgery , Radiography , Plastic Surgery Procedures , Methods , Surgery, Computer-Assisted , Treatment OutcomeABSTRACT
<p><b>OBJECTIVE</b>To develop an effective and feasible method to construct three-dimensional finite element model of the whole edentulous maxilla and cranial skeleton.</p><p><b>METHODS</b>Based on three-dimensional computer aided design model which was constructed by multi-slices helical CT scanning data of a male's head in specialized software, three-dimensional finite element model of edentulous maxillary and cranial skeleton was established; the stresses distribution in maxilla was investigated under occlusal load with computer simulated a complete overdenture.</p><p><b>RESULTS</b>The three-dimensional finite element model of edentulous maxilla and cranial skeleton had favorite similarity in geometry, the distributions of stresses in maxilla and the wall of maxillary sinus could be clearly observed.</p><p><b>CONCLUSIONS</b>The study verifies that this three-dimensional finite element modeling method is feasible and effective.</p>