Arcrekonstrukciós és orthognath műtétek tervezési lehetőségei háromdimenziós képalkotói módszerekkel

We summarize up-to-date planning technics of orthognathic and reconstructive surgery operation which appeared with three-dimensional imaging, using literature data and some clinical examples. In many cases, orthognathic and reconstructive operations mean the only treatment of facial deformity caused by tumour, traumatic injury or congenital anomaly. In this field, radiology plays an important role not only in the diagnosis but also in the planning of the treatment. With the appearance of cone-beam computed tomography (CBCT), the previously used two-dimensional cephalometric analysis on lateral cephalogram was changed for three-dimensional cephalometric measurements. The first step of the adaptation was the lateral and frontal x-ray images generated from the CBCT database and later the volume rendered surface and segmentation technics provided the moving of the facial bones in three dimensions which meant virtual surgical planning. With the development of CAD/CAM technic and the three-dimensional printing, many opportunities became available, such as preoperative bending splints and plates and printed surgical model for the tangible planning. The progress of imaging facilitated the individual, accurate, and reliable planning which significantly determines the success of the treatment

MRI compatibility of orthodontic brackets and wires: systematic review article

Abstract Background Before the magnetic resonance imaging (MRI) examination fixed orthodontic devices, such as brackets and wires, cause challenges not only for the orthodontist but also for the radiologist. Essentially, the MRI-safe scan of the fixed orthodontic tools requires a proper guideline in clinical practice. Therefore, this systematic review aimed to examine all aspects of MRI-safe scan, including artifact, thermal, and debonding effects, to identify any existing gaps in knowledge in this regard and develop an evidence-based protocol. Methods The Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) statement was used in this study. The clinical question in “PIO” format was: “Does MRI examination influence the temperature of the orthodontic devices, the size of artifacts, and the debonding force in patients who have fixed orthodontic bracket and/or wire?” The search process was carried out in PubMed, PubMed Central, Scopus, and Google Scholar databases. The search resulted in 1310 articles. After selection according to the eligibility criteria, 18 studies were analyzed by two reviewers. The risk of bias was determined using the Quality In Prognosis Studies tool. Results Out of the eligible 18 studies, 10 articles examined the heating effect, 6 were about the debonding effect, and 11 measured the size of artifact regarding brackets and wires. Considering the quality assessment, the overall levels of evidence were high and medium. The published studies showed that heating and debonding effects during MRI exposure were not hazardous for patients. As some wires revealed higher temperature changes, it is suggested to remove the wire or insert a spacer between the appliances and the oral mucosa. Based on the material, ceramic and plastic brackets caused no relevant artifact and were MRI-safe. Stainless steel brackets and wires resulted in susceptibility artifacts in the orofacial region and could cause distortion in the frontal lobe, orbits, and pituitary gland. The retainer wires showed no relevant artifact. Conclusions In conclusion, the thermal and debonding effects of the fixed orthodontic brackets and wires were irrelevant or resoluble; however, the size of the artifacts was clinically relevant and determined most significantly the feasibility of fixed brackets and wires in MRI examination

Landmark-based midsagittal plane analysis in patients with facial symmetry and asymmetry based on CBCT analysis tomography

Purpose Reconstruction of the facial midplane is relevant in anthropometry, orthodontics, maxillofacial surgery, and the accurate measurement of symmetry deviation is relevant in many fields of medicine especially when planning surgical treatment. In the literature, three different means of midplane generation have been published; however, there is currently no consensus regarding the approach to use. Morphometric methods are used to determine the true midsagittal plane (MSP), but its use in clinical practice is difficult. Aregression plane based on N-ANS-PNS landmarks reportedly approximates the morphometric MSP. As these points are vulnerable, we investigated which combination of landmarks can be substituted in symmetric and asymmetric faces. Patients and methods Thirty symmetric and 30asymmetric faces were analyzed on cone-beam computed tomography scans. A total of 50 regression planes were generated based on three unpaired landmarks and 35 regression planes were generated based the midpoints of paired landmarks. The Na-ANS-PNS plane was used as reference plane, and the mean angle between it and each generated MSP was calculated. The differences from the reference plane were compared by t-test between the groups. Results In the symmetric group, 86% of angles deviated by <5 degrees using unpaired points, whereby 74% of angles deviated by <5 degrees for paired points. Between the two groups 50% of planes from midline points, and 77% of planes from paired points were significantly different. All planes deviated more in the asymmetric group. Conclusions The N-ANS-PNS reference plane can be substituted with the following combinations: ANS-G-Ba, ANS-G-S, ANS-S-De, PNS-G-Ba, PNS-S-Ba, PNS-ANS-G, and PNS-N-Ba

The humerus is the best place for bone lengthening

The aim of this study was to examine the effectiveness of lengthening the humerus in children and young adults. Between 1984 and 2005, the Orthopaedic Department of Semmelweis University elongated 11 humeri (ten patients) for reasons of congenital hypoplasia (four cases), osteomyelitis (three cases), epiphyseolysis, growth plate closure after irradiation and obstetrical paralysis (one case each). The study cohort consisted of five females and five males, with an average age at the time of surgery of 17.8 years (range: 12–31 years). In every case, the lengthening was performed with a unilateral Wagner fixator. The lengthening protocol was 1 mm distraction daily (callotasis) after a 7-day latency period. The fixator was removed after total bone healing. Plate fixation or bone transplantation was not used. The average rate of lengthening was 6.2 cm (4.5–10.5 cm), and the achieved lengthening was 27% (range: 16–44%). The average healing index was 32 day/cm. One patient who suffered from temporary radial paresis, and temporary flexion contracture of the elbow was regarded as a complication following placement of the fixator. Based on our results, humeral shortening can effectively be treated with the unilateral Wagner fixator. The main difference between the original Wagner method and our approach is that we were able to leave the fixator in the humerus until total bony reconstruction so there was no need for plate fixation or bone transplantation