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Susa W Herring - One of the best experts on this subject based on the ideXlab platform.
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the periosteum of the Zygomatic Arch vascularization and growth
Anatomical Record-advances in Integrative Anatomy and Evolutionary Biology, 2016Co-Authors: Susa W Herring, Pannee OchareoAbstract:In addition to conveying the forces of attaching muscles and ligaments to the Zygomatic and temporal bones, the Arch periosteum is responsible for lateral apposition and medial resorption during the growth period. In this contribution, we describe the vasculature of the Zygomatic Arch in young pigs (Sus scrofa dom.) in order to understand the relationship of osseous and periosteal vessels to each other, to surrounding tissues, and to patterns of modeling. Subjects 2–6 weeks of age were perfused with vascular fill; some also received the vital bone label calcein. Whole mounts were prepared of the decalcified bony Arch and of its lateral periosteum. Undecalcified Arches were plastic-embedded and thick-sectioned. Additional observations on cell replication were made using material from a previous study. The osseous and periosteal vascular supplies were largely independent, joined only by a fine network at the tissue interface. Osseous vessels entered the medial side of the Arch through clusters of nutrient foramina. The intraosseous branching pattern resembled the direction of appositional growth, which in turn describes the disposition of bony trabeculae in older pigs. In contrast, vessels arrived at the periosteum via muscles and ligaments and thus its perfusion may partially depend on functional activity. The open weave of periosteal vessels bore little similarity to bone Architecture, especially for the temporal bone, but the appositional lateral periosteum showed indications of angiogenesis, whereas the thinner, resorptive periosteum on the medial side featured composite, possibly fusing vessels at the bone surface. Anat Rec, 299:1661–1670, 2016. © 2016 Wiley Periodicals, Inc.
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ontogeny of bone strain the Zygomatic Arch in pigs
The Journal of Experimental Biology, 2005Co-Authors: Susa W Herring, Sco C Pederse, Xiaofeng HuangAbstract:SUMMARY At the time of weaning, infant animals have little experience with hard food, and thus their skulls are not likely to be epigenetically adapted for the loads imposed by mastication. We examined bone strain in the Zygomatic Arch of 4-week-old weanling piglets. Functional strains in piglets differed from those previously reported for older pigs in that the squamosal bone was not bent in the horizontal plane and the principal tensile strain on the Zygomatic bone did not correspond to the direction of masseter muscle pull. Strain patterns were more variable in piglets than in older pigs. In older pigs, masticatory strains can be reproduced by stimulating the masseter muscles. When the piglet masseter was stimulated, strain patterns were more similar to those of older pigs, but shear strain magnitudes were the largest yet recorded from mammalian skull bones, up to 4000 μϵ. To put these findings in the context of skeletal adaptation, 45 dry skulls, including some animals from the strain study, were measured. Reduced major axis regressions indicated that the infant Arch was rounder in cross section and straighter than that of older animals. With growth, the Arch became dorsoventrally higher, while mediolateral thickness decreased in the squamosal bone. Overall, these changes should make strain more predictable, explaining the lower variability in older animals. Other factors likely to be important in causing unique strain regimes in piglets include (1) unfamiliarity with hard food, (2) greater importance of muscles other than the same-side masseter and (3) greater proximity of molariform teeth to the Arch. Collectively, these data indicate that the skeleton is not pre-adapted for specific functional loads.
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three dimensional loading and growth of the Zygomatic Arch
The Journal of Experimental Biology, 2000Co-Authors: Katherine L Rafferty, Susa W Herring, Flavia ArteseAbstract:Despite a number of previous biomechanical studies on the Zygomatic Arch, unanswered questions remain about its three-dimensional loading and growth. Using young miniature swine, we have for the first time recorded strains from both the medial and lateral aspects of the squamosal bone during mastication and masseter muscle stimulation. Strains from the Zygomatic bone flange and Zygomatic Arch growth data were also obtained from the same animals. A second study on a younger group of animals examined the growth of the Zygomatic flange following partial removal of the masseter. Strain data indicated that the squamosal bone is bent out-of-plane and that this pattern of loading is quite different from that of the adjacent Zygomatic bone, which experiences much lower strains with little evidence of out-of-plane bending. Surprisingly, strains were higher in the Zygomatic flange during contralateral chews and contralateral masseter stimulations than during ipsilateral chews/stimulations. These strains proved to arise from movement of the condyle, explaining why partial removal of the masseter had little effect on the growth of the flange. Other growth results indicated an approximately threefold greater rate of subperiosteal deposition on the lateral surface of the squamosal bone than on the Zygomatic bone. This difference in growth rate is attributed to the presence of sutures that contribute to the lateral displacement of the Zygomatic bone but not the squamosal bone. This explanation does not exclude the possibility that the rapid apposition on the lateral squamosal surface is regulated by the high surface strains that result from out-of-plane bending.
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stereological analysis of bone Architecture in the pig Zygomatic Arch
Anatomical Record-advances in Integrative Anatomy and Evolutionary Biology, 1997Co-Authors: Shengyi Teng, Susa W Herring, I W Choi, Joh M RensbergeAbstract:An understanding of stress distribution within bones requires three-dimensional information on bone strain and bone material properties. Material properties can be relatively easily obtained by mechanical (Turner and Burr, 1993) or ultrasonic (Ashman et al., 1984; Dechow et al., 1993) techniques for locations that are predominantly cortical. Trabecular bone is more difficult to assess, because the dimensions of the test samples strongly influence measured properties (Linde et al., 1992) and because failure at sample ends biases the overall results (Odgaard et al., 1989). These problems can be overcome if the sample of trabecular bone is large enough to allow strain to be measured specifically from the central section (Ashman et al., 1987; Odgaard et al., 1989; Teng and Herring, 1996). Unfortunately, there are many cancellous areas in the irregularly shaped flat bones of the craniofacial skeleton that are too small for an adequate sample. Moreover, the orientation of the trabeculae can vary greatly between adjacent areas, suggesting that regional differences, which cannot be assessed experimentally, may be of great significance in the overall Architecture of the bones. In such cases the best available technique is textural analysis of bone structure using stereological methods (Cowin, 1985; Goldstein, 1992). Such an analysis of the mandibular condyle of the pig (Teng and Herring, 1995) provided an accurate prediction of actual mechanical properties (Teng and Herring, 1996). One location where analysis of trabecular Architecture may help to elucidate loading is the Zygomatic Arch, a construct of two flat bones (Zygomatic and squamosal) that are primarily cancellous in growing animals. In addition to providing the origin of the large masseter muscle, the Arch mechanically links the tooth-bearing maxilla to the jaw joint and braincase. Loading in the Arch is far from simple. A recent in vivo study of strain in the Zygomatic Arch of the pig (Herring et al., 1996) revealed the surprising finding that the lateral surfaces of the two component bones are deformed to different degrees and in different directions. Specifically, strain magnitudes were substantially higher in the squamosal bone than in the Zygomatic, and the axes of the principal strains were rotated approximately 50°. Reasons for this striking variation are not clear. The two bones of the Arch may be loaded differently. Specifically, the squamosal bone, but not the Zygomatic bone, may be bent out-of-plane such that its lateral surface becomes more convex. Because strain gauges can be installed only on the lateral surface it is difficult to assess out-of-plane bending. Another possibility is that a relatively less dense and more anisotropic Architecture of the squamosal bone was responsible for increased and reoriented strain even in the face of the same applied load. The present study on trabecular Architecture was undertaken to investigate these possibilities.
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rigid fixation and strain patterns in the pig Zygomatic Arch and suture
Journal of Oral and Maxillofacial Surgery, 1997Co-Authors: Joh A Freema, Shengyi Teng, Susa W HerringAbstract:Abstract Purpose: In orthognathic surgery, rigid fixation is routinely used to hold together bone fragments that may experience heavy forces from attached masticatory muscles. Internal fixation plates are assumed to hold bony parts rigidly, but the mobility at such sites subjected to normal masticatory function has not been measured. The purpose of this study was to investigate in vivo the degree to which a linear plate immobilizes separated bones, specifically sutures. Materials and Methods: Three female miniature pigs (Sus scrofa) had 1.3-mm Synthes titanium plates placed across the suture in the Zygomatic Arch. Foil strain gauges were used to record load deformation in the Zygomatic and squamosal (temporal) bones and across the vertical and horizontal parts of the suture. Strain was recorded in vivo during mastication and in anesthetized pigs with electrical stimulation of masticatory muscles. Results: Strain at the suture was not reduced from normal levels. The plate induced increases in strain within the bones, but the changes were slight. Conclusion: The results indicate that linear “rigid fixation” does not immobilize sutures.
Kiseok Koh - One of the best experts on this subject based on the ideXlab platform.
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topographic relationship between the Zygomatic Arch and coronoid process of the mandible
Korean Journal of Physical Anthropology, 2010Co-Authors: Wuchul Song, Yong Woo Kim, Hee Ji Kim, Kiseok KohAbstract:Illustrations in almost all textbooks and atlases of anatomy normally show that the Zygomatic Arch (ZA) and coronoid process (CP) of the mandible overlap vertically. Their topographic relationship is important for plastic surgeons in various situations, such as restorations of ZA fractures. The present study investigated the topographic relationship between the ZA and CP of the mandible in three-dimensional models of Korean human cadavers. The topographic relationship was classified into three types: overlapped, tangential, and separate. The overlapped type was the most common, but the three types showed similar incidences in three-dimensional models. There were no lateral or sex differences according to the three types. The incidence of both sides showing the same type was 70.1%. In conclusion, the predominance of illustrations in almost all textbooks and atlases showing the overlapped type is misleading, since the other two types - where the CP of the mandible does not overlap the ZA - are almost as common.
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topographic anatomy of the Zygomatic Arch and temporal fossa a cadaveric study
Journal of Plastic Reconstructive and Aesthetic Surgery, 2009Co-Authors: W C Song, Hee Ji Kim, Hyungo Choi, Soonheum Kim, Kiseok KohAbstract:The Zygomatic Arch (ZA) is a long, slender and laterally protruding structure of the face that is vulnerable to fracture by various types of trauma. Knowledge of the topographic anatomy of the ZA and temporal fossa is important for appropriate management of ZA problems. Thirty-seven male and 33 female cadavers were investigated in this study. Skin, subcutaneous tissue, fascia and periosteum were completely removed from around the ZA. Several depths and distances were measured based on three landmarks on the ZA: the anterior, middle and posterior portions of its superior margin. The thickness of the ZA was relatively constant in the three portions. The distance from the internal surface of the ZA to the surface of the temporalis muscle was similar in the anterior and middle portions, at about 8mm, and slightly lesser in the posterior portion. The distance from the external surface of the ZA to the temporal bone was the greatest at the anterior portion, and there was a large difference between the anterior and middle portions. The temporalis muscle was the thickest in the anterior portion and the thinnest in the posterior portion. This study suggests that the maximum distance from the internal surface of the ZA to the surface of the temporalis muscle is 8mm, and this should be considered when performing reduction malarplasty on the ZA.
Joachim E Zolle - One of the best experts on this subject based on the ideXlab platform.
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intraoperative ultrasound control of Zygomatic Arch fractures does additional imaging improve reduction quality
Journal of Oral and Maxillofacial Surgery, 2019Co-Authors: Johannes Ulle, Matthias Zirk, Matthias Kreppel, Volke Maus, Joachim E ZolleAbstract:Purpose Intraoperative navigation to assess anatomic reduction is the general trend in maxillofacial trauma surgery. The aim of this study was to evaluate the closed reduction outcome of isolated Zygomatic Arch fractures using ultrasound compared with palpation control. Materials and Methods In this case-and-control study, the authors identified consecutively treated patients who underwent closed reduction of isolated Zygomatic Arch fractures using the Volkmann reposition hook with intraoperative ultrasound. Controls were patients with the same diagnosis and surgical procedure without ultrasound imaging. Pre- and postoperative radiographic datasets were geometrically analyzed. The outcome variables postoperative cortical step, persistent postoperative displacement, and overall grade of reduction were compared in the 2 study groups. Subgroups of fracture patterns were classified as M-shaped or variable. Statistical analysis was performed using t test for continuous variables and 2-sided χ2 test for categorical variables, with a P value less than .05 defined as significant. Results Sixteen cases with intraoperative ultrasound and 60 controls were identified from the institution's database. The angle of postoperative displacement was significantly decreased in the ultrasound group for all fractures (2.4° vs 5.3°; P = .004) and the variable fracture type (1.6° vs 8.1°; P = .005). Overall grade of reduction was improved in the ultrasound group for all fractures (P = .03) but with no difference solely for M-shaped fractures (P = .37). Conclusions Although reduction control using palpation and probing using the Volkmann hook showed satisfactory results for M-shaped fractures, additional intraoperative ultrasound imaging showed promise for increasing success rates for the variable type of Zygomatic Arch fracture.
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radiomorphometric analysis of isolated Zygomatic Arch fractures a comparison of classifications and reduction outcomes
Journal of Cranio-maxillofacial Surgery, 2018Co-Authors: Johannes Ulle, Matthias Zirk, Matthias Kreppel, Volke Maus, Elisa Zirk, Andrea Grandoch, Joachim E ZolleAbstract:Abstract Purpose Although different proposals have been made to categorize isolated Zygomatic Arch fractures (ZAF), an investigation about fracture type and clinical outcome has not been published. In this study, we analyzed the geometric fracture morphology in isolated ZAF and provide a survey of reduction outcomes in accordance with 4 independent classifications. Materials and methods Geometric measurements were performed in radiologic images of 94 patients with isolated ZAF, which were consecutively treated by closed reduction over transbuccal approach. Fracture types were allocated to the classifications of Rowe and Williams, Honig and Merten, Yamamoto et al., and Ozyazgan et al. The odds of achieving a satisfactory outcome were calculated for all categories. Results Wide preoperative dislocation angles of more than 22° presented in M-type fractures (77.1%) more frequently compared to 2 fragments without the M-shape (33.3%) and one fragment (14.8%, p B V (both 85.4%, p Conclusion The classifications of Honig and Merten, Yamamoto et al., and Ozyazgan were quite applicable, and subgroups showed significant increments in reduction outcome. Our analysis emphasizes that the differentiation of two clinical relevant groups, M-shaped and variable Arch fractures, is feasible to manage and efficient to determine the odds of reduction outcome.
Chan Hum Park - One of the best experts on this subject based on the ideXlab platform.
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Aqua splint suture technique in isolated Zygomatic Arch fractures
European Archives of Oto-Rhino-Laryngology, 2014Co-Authors: Chan Hum ParkAbstract:Various methods have been used to treat Zygomatic Arch fractures, but no optimal modality exists for reducing these fractures and supporting the depressed bone fragments without causing esthetic problems and discomfort for life. We developed a novel aqua splint and suture technique for stabilizing isolated Zygomatic Arch fractures. The objective of this study is to evaluate the effect of novel aqua splint and suture technique in isolated Zygomatic Arch fractures. Patients with isolated Zygomatic Arch fractures were treated by a single surgeon in a single center from January 2000 through December 2012. Classic Gillies approach without external fixation was performed from January 2000 to December 2003, while the novel technique has been performed since 2004. 67 consecutive patients were included (Classic method, n = 32 and Novel method, n = 35). An informed consent was obtained from all patients. The novel aqua splint and suture technique was performed by the following fashion: first, we evaluated intraoperatively the bony alignment by ultrasonography and then, reduced the depressed fracture surgically using the Gillies approach. Thereafter, to stabilize the fracture and obtain the smooth facial figure, we made an aqua splint that fit the facial contour and placed monofilament nonabsorbable sutures around the fractured Zygomatic Arch. The novel aqua splint and suture technique showed significantly correlated with better cosmetic and functional results. In conclusion, the aqua splint suture technique is very simple, quick, safe, and effective for stabilizing repositioned Zygomatic Arch fractures. The aqua splint suture technique can be a good alternative procedure in isolated Zygomatic Arch fractures.
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the fixation effect of a silk fibroin bacterial cellulose composite plate in segmental defects of the Zygomatic Arch an experimental study
Archives of Otolaryngology-head & Neck Surgery, 2013Co-Authors: Jung Mi Lee, Ji Heui Kim, Ok Joo Lee, Chan Hum ParkAbstract:Importance Bioresorbable fixation systems have been popular for the treatment of facial fractures. However, their mechanical properties are uncertain and complications have been reported. To overcome these problems, we developed a bioresorbable fixation plate using a composite of silk fibroin and bacterial cellulose (SF-BC) with biodegradability and increased biocompatibility. Objective To investigate the regenerative effect of the bioresorbable SF-BC fixation plate on Zygomatic Arch defects in rats. Design In vivo animal study. The SF-BC composite plate had a tensile strength similar to that of a polylactic acid plate and a tight, pore-free microstructure. Bilateral segmental bone defects (2 mm in length) were created in the Zygomatic Arches of adult rats. One side was fixed with the SF-BC composite plate, and the other side was left without fixation. Setting Academic reseArch laboratory. Participants Fifteen adult Sprague-Dawley rats. Interventions Fixation of the Zygomatic Arch defect with the SF-BC composite plate. Main Outcomes and Measures Micro–computed tomography and histological evaluation of bone samples. Results Gross inspection revealed no specific complication. At 1, 2, 4, and 8 postoperative weeks, the Zygomatic Arches were explored by micro–computed tomography and histological examination. Control sides did not heal completely and showed bony degeneration and necrosis during the 8-week follow-up. However, we observed new bone formation in sides treated with the SF-BC composite plate, and bony defects were completely healed within 8 weeks. Conclusions and Relevance The SF-BC composite plate is a potential candidate for a new bioresorbable fixation system. Our composite material could considerably shorten bone regeneration time. Additional study of the control of biodegradability and mechanical properties of SF-BC composite plates and a comparative study with the resorbable plates currently in use should be undertaken.
Jun Hyuk Lee - One of the best experts on this subject based on the ideXlab platform.
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external radiopaque marking of gillies posterior Zygomatic Arch osteotomy in reduction malarplasty
Journal of Cranio-maxillofacial Surgery, 2016Co-Authors: Sae Bi Lee, Jun Hyuk LeeAbstract:Although the Gillies (temporal) approach to reduction malarplasty helps preserve supportive soft tissue and avoid facial scars, the osteotomy site is difficult to gauge when using this blind technique. Our experience with external radiopaque marking of the Zygomatic Arch to guide this process is presented herein. This retrospective review included all patients who underwent reduction malarplasty (as above) at our clinic between August 2013 and September 2015. Procedures entailed L-shaped osteotomy only (no segmental excision) of the Zygomatic body by the intraoral route, and posterior Zygomatic Arch osteotomy by the Gillies approach, guided by external radiopaque markings. Patient characteristics, surgical outcomes, and complications were analyzed to assess the merits of this strategy. Postoperative results were evaluated by both the patients and the surgeon. Most patients expressed satisfaction during the follow-up period (range, 3-27 months). Posterior osteotomies were properly performed as planned, with no major complications (i.e., malunion or nonunion, cheek drooping, or facial nerve injury), although minor complications were recorded in three instances. Use of external radiopaque markings provides guidance during malarplasty by the Gillies approach and may help avoid procedural complications.