Application of Computer-Aided Designing and Rapid Prototyping Technologies in Reconstruction of Blowout Fractures of the Orbital Floor.

INTRODUCTION: Traumatology of the maxillofacial region represents a wide range of different types of facial skeletal injuries and encompasses numerous treatment methods. Application of computer-aided design (CAD) in combination with rapid prototyping (RP) technologies and three-dimensional computed tomography techniques facilitates surgical therapy planning for efficient treatment. OBJECTIVE: The purpose of this study is to determine the efficiency of individually designed implants of poly-DL-lactide (PDLLA) in the reconstruction of blowout fractures of the orbital floor. METHODS: In the course of a surgical treatment, individually designed implants manufactured by CAD/RP technologies were used. Preoperative analysis and postoperative monitoring were conducted to evaluate the successfulness of orbital floor reconstruction using customized PDLLA implants, based on: presence of diplopia, paresthesia of infraorbital nerve, and presence of enophthalmos. RESULTS: In 6 of the 10 patients, diplopia completely disappeared immediately after surgical procedure. Diplopia gradually disappeared after 1 month in 3 patients, whereas in 1, it remained even after 6 months. In 7 patients, paresthesia disappeared within a month after surgery and in 3 patients within 2 months. Postoperative average Orbital volume (OV) of the injured side (13.333 ±â€Š3.177) was significantly reduced in comparison with preoperative OV (15.847 ±â€Š3.361) after reconstruction of the orbital floor with customized PDLLA implant (P < 0.001). Thus, average OV of corrected orbit was not different compared with the OV of the uninjured orbit (P = 0.981). CONCLUSIONS: Reconstruction of blowout fractures of the orbital floor by an individually designed PDLLA implant combined with virtual preoperative modeling allows easier preoperative preparation and yields satisfactory functional and esthetic outcomes.

Polymethyl methacrylate resin for provisional restoration affects rat macrophage function in in vitro conditions.

PURPOSE: This study evaluated the cytotoxic effects of polymethyl methacrylate resin extracts on rat macrophage viability in in vitro conditions. METHODS: Prepared test specimens were immersed in 5 mL of artificial saliva and incubated for 24, 48, and 72 h at 37°C. The cytotoxicity of the obtained solutions of extracted resins, used as a stock solution (100%) and diluted with Roswell Park Memorial Institute (RPMI) medium to obtain the working solutions (50, 40, 30, 20, 10, and 5%), was evaluated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. RESULTS: No dose-dependent toxic activity in macrophage culture was detected for the three types of extracts obtained after 24, 48, and 72 h of material extraction. The shortest extraction of material was found to be completely non-toxic, and the 20% concentration of this extract obtained caused a significant increase in cell ability to metabolize MTT. Extracts obtained after 72 h of extraction showed the highest cytotoxic potential of 50%, 40% and 30%, and extracts obtained after 48 and 72 h of extraction at concentrations of 5% and 10% had a proliferative effect on the macrophage cell line. CONCLUSION: This study demonstrated that the highest cytotoxic effect was observed in cells exposed to the highest concentrations (50, 40, and 30%) of the extracts that were extracted for 72 h.

[Neurophysiological conception of pain in craniomandibular disfunction].

INTRODUCTION: Ethiopathogenesis of dysfunction and pain in temporomandibular joints has been the subject of passionate discussions between supporters of purely mechanical conception and the ones who are supporters of psyhosomatic conception. THE AIM OF THE STUDY: Relying on neurophysiological data, the authors are trying to reveal the main role of reticular mesencephalical formation in mechanisms which provoke craniomandibular dysfunctions and confront the influence of emotional factors from neocortex and painful stimuli from oral structures. DISCUSSION: From dynamical point of view, not only the morphological aspects of teeth and arcades, but also sensitive-sensorial mechanisms connected to masticatory muscles, periodontal structures and oral structures, should be considered. The ideal bite and perfect morphology of tooth arcades are not enough for reconstitution of correct occlusion, if there are no neuromuscular system, temporomandibular joint, and especially central nervous system. CONCLUSION: The presence of pain is just one of the craniomandibular dysfunction symptoms, but if it is added to the other clinical signs and emotional or affect--provoking factor, it will provoke dysfunctional syndrome.