Purpose Three-dimensional (3D) analysis and planning are powerful tools in craniofacial and reconstructive surgery. The elements include 1) analysis, 2) planning, 3) virtual surgery, 4) 3D printouts ...of guides or implants, and 5) verification of actual to planned results. The purpose of this article is to review different applications of 3D planning in craniomaxillofacial surgery. Materials and Methods Case examples involving 3D analysis and planning were reviewed. Common threads pertaining to all types of reconstruction are highlighted and contrasted with unique aspects specific to new applications in craniomaxillofacial surgery. Results Six examples of 3D planning are described: 1) cranial reconstruction, 2) craniosynostosis, 3) midface advancement, 4) mandibular distraction, 5) mandibular reconstruction, and 6) orthognathic surgery. Conclusions Planning in craniomaxillofacial surgery is useful and has applicability across different procedures and reconstructions. Three-dimensional planning and virtual surgery enhance efficiency, accuracy, creativity, and reproducibility in craniomaxillofacial surgery.
Current Concepts in Orthognathic Surgery Naran, Sanjay; Steinbacher, Derek M; Taylor, Jesse A
Plastic and reconstructive surgery (1963),
06/2018, Letnik:
141, Številka:
6
Journal Article
Recenzirano
After studying this article, the participant should be able to: 1. Identify skeletal differences that are treated with orthognathic surgery; describe the goals of orthognathic surgery; and understand ...modern virtual surgical planning of orthognathic movement of the mandible, maxilla, and chin. 2. Appreciate the surgical principles of maxilla- versus mandible-first surgery, and orthognathic surgery before orthodontic correction; and understand when an osseous genioplasty may be beneficial, and the potency of this bony movement. 3. Appreciate the utility of fat grafting as an adjunct to orthognathic bony movements, and demonstrate understanding of the utility of orthognathic surgery in the treatment of obstructive sleep apnea. 4. Be aware of associated complications and be able to critically assess outcomes following orthognathic surgery.
This CME article outlines the goals of orthognathic surgery, highlighting advances in the field and current controversies. The principles of the sequencing of osteotomies are discussed and literature is reviewed that may assist in decision-making as to maxilla-first versus mandible-first surgery. The emergence of "surgery first," in which surgery precedes orthodontics, is discussed and important parameters for patient candidacy for such a procedure are provided. The emerging standard of virtual surgical planning is described, and a video is provided that walks the reader through a planning session. Soft-tissue considerations are highlighted, especially in the context of osseous genioplasty and fat grafting to the face. The utility of orthognathic surgery in the treatment of obstructive sleep apnea is discussed. The reader is provided with the most current data on complications following orthognathic surgery and advice on avoiding such pitfalls. Finally, outcome assessment focusing on the most current trend of patient-reported satisfaction and the psychological impact of orthognathic surgery are discussed.
Three-dimensional analysis and planning is a powerful tool in plastic and reconstructive surgery, enabling improved diagnosis, patient education and communication, and intraoperative transfer to ...achieve the best possible results. Three-dimensional planning can increase efficiency and accuracy, and entails five core components: (1) analysis, (2) planning, (3) virtual surgery, (4) three-dimensional printing, and (5) comparison of planned to actual results. The purpose of this article is to provide an overview of three-dimensional virtual planning and to provide a framework for applying these systems to clinical practice.
Therapeutic, V.
Purpose Virtual surgical planning (VSP) can promote efficiency, but the ability to transfer the proposed plan to the actual result has not been adequately studied. The purpose of this study was to ...morphometrically compare the virtually preplanned scenario with the postoperative 3-dimensional (3D) anatomic result. Materials and Methods A retrospective review of 10 patients who underwent mandibular reconstruction using a free fibula flap and VSP were evaluated. Pre- and postoperative Digital Imaging and Communications in Medicine files were imported into Mimics 10.01 software (Materialise, Leuven, Belgium) for surgical planning. Preoperative VSP and 1-week postoperative computed tomographic (CT) scans were evaluated to assess surgical accuracy using VSP. The pre- and postoperative morphometric measurements were compared using the Student t test. Results Twenty CT scans from 10 patients (mean age, 56.9 ± 20.2 yr) who underwent partial mandibular resection were analyzed. The dimensions of the fibula segments after osteotomy showed no difference from the preoperative VSP (mean difference in fibula height, 1.2 mm; mean difference in width, 0.9 mm; mean difference in length, 1.3 mm). The postoperative anterior and posterior mandibular angles differed from the VSP by 12.4° and −12.5°, respectively. The condylar distance and inclination showed a discrepancy of only 1.7 mm and 4.6°, respectively, between VSP and postoperative CT scans. Conclusions VSP confers reproducible precision and accuracy for free fibular mandibular reconstruction. The benefit was most striking for large reconstructions requiring multiple fibular segments. Future directions include assessing the use of external registration devices to enhance surgical accuracy and to follow patients longitudinally to monitor the long-term benefit of VSP.
Adipose-derived mesenchymal stem cells are a robust, multipotent cell source. They are easily harvested and exhibit promise in a variety of regenerative applications. The purpose of this study was to ...evaluate the aging impact on adipose-derived mesenchymal stem cells, relating to morphology, senescent properties, growth factor expression, and osteogenesis.
Cells obtained from distinct age groups (infant, adult, and elderly) were cultured. Morphology was examined using microscopy, and cell surface markers were interrogated using flow cytometry. Telomere length was measured using real-time polymerase chain reaction. Expression of pertinent angiogenic and osteogenic growth factors was compared. Osteogenic capability was investigated further by evaluating induction response, and by quantification of mRNA expression of RUNX-2 and osteocalcin.
The same isolating ratio of mesenchymal stem cells was derived from each donor, regardless of age. The infant adipose-derived stem cells exhibited elongated spindle morphology and increased telomere length compared with older cells. Angiogenic factors were more highly expressed by infant cells, whereas osteogenic expression was similar among all ages. Response to osteogenic induction was more profound in infant than in older stem cells, as evidenced by alkaline phosphatase and alizarin red staining, as was bone-related gene expression.
Adipose-derived mesenchymal stem cells are available across all age groups. Infant-derived cells are morphologically spindle-shaped, with long telomeres, and exhibit enhanced angiogenic and osteogenic capabilities compared with older cells. Conversely, all age groups exhibit similar osteogenic paracrine activity, and the authors posit that clinical applicability is conserved during the adult to elderly period.
Anthropogenic nitrogen inputs cause major negative environmental impacts, including emissions of the important greenhouse gas N
O. Despite their importance, shifts in terrestrial N loss pathways ...driven by global change are highly uncertain. Here we present a coupled soil-atmosphere isotope model (IsoTONE) to quantify terrestrial N losses and N
O emission factors from 1850-2020. We find that N inputs from atmospheric deposition caused 51% of anthropogenic N
O emissions from soils in 2020. The mean effective global emission factor for N
O was 4.3 ± 0.3% in 2020 (weighted by N inputs), much higher than the surface area-weighted mean (1.1 ± 0.1%). Climate change and spatial redistribution of fertilisation N inputs have driven an increase in global emission factor over the past century, which accounts for 18% of the anthropogenic soil flux in 2020. Predicted increases in fertilisation in emerging economies will accelerate N
O-driven climate warming in coming decades, unless targeted mitigation measures are introduced.
Changes in baseline (here understood as representative of continental to hemispheric scales) tropospheric O3 concentrations that have occurred at northern mid-latitudes over the past six decades are ...quantified from available measurement records with the goal of providing benchmarks to which retrospective model calculations of the global O3 distribution can be compared. Eleven data sets (ten ground-based and one airborne) including six European (beginning in the 1950's and before), three North American (beginning in 1984) and two Asian (beginning in 1991) are analyzed. When the full time periods of the data records are considered a consistent picture emerges; O3 has increased at all sites in all seasons at approximately 1% yr−1 relative to the site's 2000 yr mixing ratio in each season. For perspective, this rate of increase sustained from 1950 to 2000 corresponds to an approximate doubling. There is little if any evidence for statistically significant differences in average rates of increase among the sites, regardless of varying length of data records. At most sites (most definitively at the European sites) the rate of increase has slowed over the last decade (possibly longer), to the extent that at present O3 is decreasing at some sites in some seasons, particularly in summer. The average rate of increase before 2000 shows significant seasonal differences (1.08 ± 0.09, 0.89 ± 0.10, 0.85 ± 0.11 and 1.21 ± 0.12% yr−1 in spring, summer, autumn and winter, respectively, over North America and Europe).
Two recent papers have quantified long‐term ozone (O3) changes observed at northern midlatitude sites that are believed to represent baseline (here understood as representative of continental to ...hemispheric scales) conditions. Three chemistry‐climate models (NCAR CAM‐chem, GFDL‐CM3, and GISS‐E2‐R) have calculated retrospective tropospheric O3 concentrations as part of the Atmospheric Chemistry and Climate Model Intercomparison Project and Coupled Model Intercomparison Project Phase 5 model intercomparisons. We present an approach for quantitative comparisons of model results with measurements for seasonally averaged O3 concentrations. There is considerable qualitative agreement between the measurements and the models, but there are also substantial and consistent quantitative disagreements. Most notably, models (1) overestimate absolute O3 mixing ratios, on average by ~5 to 17 ppbv in the year 2000, (2) capture only ~50% of O3 changes observed over the past five to six decades, and little of observed seasonal differences, and (3) capture ~25 to 45% of the rate of change of the long‐term changes. These disagreements are significant enough to indicate that only limited confidence can be placed on estimates of present‐day radiative forcing of tropospheric O3 derived from modeled historic concentration changes and on predicted future O3 concentrations. Evidently our understanding of tropospheric O3, or the incorporation of chemistry and transport processes into current chemical climate models, is incomplete. Modeled O3 trends approximately parallel estimated trends in anthropogenic emissions of NOx, an important O3 precursor, while measured O3 changes increase more rapidly than these emission estimates.
Key Points
CCM results disagree with measured long‐term changes of O3 concentrations
Reduced confidence implied for estimates of radiative forcing of tropospheric O3
Understanding of tropospheric O3 as it is incorporated into models is incomplete
We present an approach to infer ground‐level nitrogen dioxide (NO2) concentrations by applying local scaling factors from a global three‐dimensional model (GEOS‐Chem) to tropospheric NO2 columns ...retrieved from the Ozone Monitoring Instrument (OMI) onboard the Aura satellite. Seasonal mean OMI surface NO2 derived from the standard tropospheric NO2 data product (Version 1.0.5, Collection 3) varies by more than two orders of magnitude (<0.1–>10 ppbv) over North America. Two ground‐based data sets are used to validate the surface NO2 estimate and indirectly validate the OMI tropospheric NO2 retrieval: photochemical steady‐state (PSS) calculations of NO2 based on in situ NO and O3 measurements, and measurements from a commercial chemiluminescent NO2 analyzer equipped with a molybdenum converter. An interference correction algorithm for the latter is developed using laboratory and field measurements and applied using modeled concentrations of the interfering species. The OMI‐derived surface NO2 mixing ratios are compared with an in situ surface NO2 data obtained from the U.S. Environmental Protection Agency's Air Quality System (AQS) and Environment Canada's National Air Pollution Surveillance (NAPS) network for 2005 after correcting for the interference in the in situ data. The overall agreement of the OMI‐derived surface NO2 with the corrected in situ measurements and PSS‐NO2 is −11–36%. A larger difference in winter/spring than in summer/fall implies a seasonal bias in the OMI NO2 retrieval. The correlation between the OMI‐derived surface NO2 and the ground‐based measurements is significant (correlation coefficient up to 0.86) with a tendency for higher correlations in polluted areas. The satellite‐derived data base of ground level NO2 concentrations could be valuable for assessing exposures of humans and vegetation to NO2, supplementing the capabilities of the ground‐based networks, and evaluating air quality models and the effectiveness of air quality control strategies.
Non-syndromic craniosynostosis (NSC) is a frequent congenital malformation in which one or more cranial sutures fuse prematurely. Mutations causing rare syndromic craniosynostoses in humans and ...engineered mouse models commonly increase signaling of the Wnt, bone morphogenetic protein (BMP), or Ras/ERK pathways, converging on shared nuclear targets that promote bone formation. In contrast, the genetics of NSC is largely unexplored. More than 95% of NSC is sporadic, suggesting a role for de novo mutations. Exome sequencing of 291 parent–offspring trios with midline NSC revealed 15 probands with heterozygous damaging de novo mutations in 12 negative regulators of Wnt, BMP, and Ras/ERK signaling (10.9-fold enrichment, P = 2.4 × 10−11). SMAD6 had 4 de novo and 14 transmitted mutations; no other gene had more than 1. Four familial NSC kindreds had mutations in genes previously implicated in syndromic disease. Collectively, these mutations contribute to 10% of probands. Mutations are predominantly loss-of-function, implicating haploinsufficiency as a frequent mechanism. A common risk variant near BMP2 increased the penetrance of SMAD6 mutations and was overtransmitted to patients with de novo mutations in other genes in these pathways, supporting a frequent two-locus pathogenesis. These findings implicate new genes in NSC and demonstrate related pathophysiology of common non-syndromic and rare syndromic craniosynostoses. These findings have implications for diagnosis, risk of recurrence, and risk of adverse neurodevelopmental outcomes. Finally, the use of pathways identified in rare syndromic disease to find genes accounting for non-syndromic cases may prove broadly relevant to understanding other congenital disorders featuring high locus heterogeneity.
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