Posterior Ridge Research Articles

Comparison of Bilateral Pulmonary Arterial Level and Diameter in Transposition of the Great Arteries

In normal anatomy, the left pulmonary artery (LPA) is usually situated higher than the right pulmonary artery (RPA); however, transposition of the great arteries (TGA), the LPA is not always situated higher than the RPA. This study was performed to clarify the relative position of the RPA and the LPA in transposition of the great arteries (TGA) as well as the implications. We reviewed 101 angiograms of patients with TGA (age 4.1 ± 1.2 months). The width of the RPA, the LPA, and the pulmonary trunk (PT) were measured just before their first branch in the frontal view. They were classified into four groups according to the ratio between the RPA and the PT (RPA/PT). The initial courses of the LPA and the RPA were compared and defined according to their height in the frontal view, and the preferential flow (or not) to the RPA was recorded. The equation of hydrodynamics was applied to evaluate the bifurcation angle. Both PAs were the same size in all cases. Forty-eight patients (47.5 %) had a RPA/PT diameter ratio < 0.49. The LPA coursed higher than the RPA in the majority of cases (81 [80.2 %]); in a minority of cases the LPA and RPA were at the same level (6 [5.9 %]); and in some cases the RPA coursed higher than the LPA (14 [13.9 %]). Patients with a high degree of PA hypoplasia tended to have both PAs at the same level or a higher-positioned RPA. Autopsy (1 of 3 cases) showed a posterior ridge against the bronchus in the higher RPA. Hydrodynamic calculation showed that the greater the angle between the RPA/PT, the greater the preferential flow. Preferential flow to the RPA in TGA did not necessarily result in LPA hypoplasia before its first branch. Higher RPA position relative to the LPA was associated with greater flow in it against the posterior bronchus. This situation was more prevalent in patients with severe PA hypoplasia.

The isometry of two different paths for remnant-preserving posterior cruciate ligament reconstruction

It is reported that the length of the posterior cruciate ligament (PCL) fibres increases as the knee flexes, and the magnitude of the length change reaches up to 9.8mm throughout the range of motion, which exceeds the range of failure strain. Therefore, we postulated that a compensatory mechanism must be recruited to overcome this large strain in order to maintain physiologic function as a key component of joint kinematics. Our main objective was to compare the length change pattern for the linear distance between the femoral and tibial tunnels with the length change patterns derived from a real isometer test of different curvatures. We utilized ten intact cadaveric knees and created a vertical femoral tunnel (5mm medial to the roof of the intercondylar notch and 5mm proximal from the articular margin) and lateral tibial tunnels (5mm proximal to the posterior bony ridge on the lateral side of the PCL fibre) and performed a 3D-CT scan at 0º, 30º, 60º, 90º, and 120º. The distances between the femoral and tibial tunnels were calculated from the 3D coordinates. Real isometry was checked both (1) over the PCL and (2) under the PCL using an isometer with an accuracy of 0.1mm. The path over the PCL had the longest intra-articular length, followed by the path under the PCL, and the lengths measured by CT, respectively. The path over the PCL had a more curved path compared with the path under the PCL and the lengths measured by CT. The lengths measured by CT showed significantly larger excursion than the real isometer test. The path over the PCL showed the least excursion through the range of motion, followed by the path under the PCL, and the lengths measured by CT, respectively. Our findings suggested that a more curved PCL path has better isometry because the curvature of the PCL compensates for the length change between 0º and 60º flexion. In remnant preservation PCL reconstruction, the passage of graft over the PCL would have increased intra-articular length and better isometry compared with straight under the PCL path. Basic science study.

The Femoral Insertion of the Anterior Cruciate Ligament: Discrepancy Between Macroscopic and Histological Observations

To observe the femoral anterior cruciate ligament (ACL) insertion macroscopically, histologically, and immunohistologically. We used 20 embalmed cadaveric knees (mean age, 69.8 ± 5.3 years) for this study. The femoral ACL insertion was observed macroscopically, and areas were measured with digital calipers. The morphology of the ACL insertion was subsequently observed, and the areas were measured histologically and immunohistologically (stained for types I and III collagen). Finally, the macroscopic and microscopic measurements were compared. Macroscopically, in 16 knees, the proximal ACL fibers spread in a fanlike manner on the medial aspect of the lateral femoral condyle and the femoral insertion was oval. The lengths of the long and short axes of the insertion were 17.7 ± 2.7 mm and 4.6 ± 0.7 mm, respectively. Microscopically, the insertion was located just behind the lateral intercondylar ridge (resident's ridge) and could be divided into the direct and indirect insertions. The direct insertion was 5.3 ± 1.1 mm wide and did not continue to the posterior cartilage. The indirect insertion was located behind the direct insertion, and the posterior ACL fiber stained for type I collagen blended into the posterior cartilage on immunohistologic observations. Another bony ridge was found at the posterior margin of the direct insertion. The widths of the direct insertion were similar between microscopic and macroscopic measurements. The femoral ACL insertion observed macroscopically corresponded to the direct insertion observed microscopically. The posterior portion behind the lateral intercondylar posterior ridge was the indirect insertion microscopically and appeared membrane-like macroscopically. Findings from observation of the lateral intercondylar posterior ridge during arthroscopy and consideration of the distance from the posterior cartilage border may contribute to surgeons' decisions about femoral tunnel placement during anatomic ACL reconstruction.

Photoelastic Analysis of the Distribution of Stress in Different Systems of Overdentures on Osseous-Integrated Implants

The aim of this study was to evaluate the distribution of generated stress around implants and adjacent bone tissue using different implant-retained overdenture designs through photoelastic analysis. Over an edentulous human mandible, achieved from a human model, 2 or 4 microunit analog abutments were embedded (Master; Conexao Systems Prosthodontics, São Paulo, Brazil), settled in the interforaminal region. Three models of photoelastic resin (Araltec Chemicals Ltda, Hunstman, Guarulhos, São Paulo, Brazil), with 2 or 4 incorporated implants and microunit abutments, were obtained from molds using silicone for duplication. Inclusion, finishing, and polishing procedures were applied on the frameworks. This study was based on 3 different mechanisms of implant-retained mandibular overdentures: O'ring (GI), bar-clip (GII) (both with 2 implants), and their association (GIII) (with 4 implants). After the adaptation of each overdenture system on the photoelastic models, 100-N alternate occlusal loads were applied on back-side and front-side regions. The photoelastic analysis was made with the aid of a plain polariscope linked to a digital camera, Sony Cybershot α100, which allowed visualization of the fringes and registration of images on digital photographs. The results demonstrated higher tension concentrated over the GIII, with a flat distribution of stress to the posterior ridge and overload on the posterior implants. GI showed the smaller stress level, and GII, intermediate level; there was distribution of stress to the posterior ridge in these 2 groups. The use of bar attachment proved to be a better alternative, because it showed a moderate level of tension with a more uniform stress distribution and possessed higher retention than did the ball system.

Microscopical study of the crop and oesophagus of the carnivorous opisthobranch Philinopsis depicta (Cephalaspidea: Aglajidae)

A histochemical and ultrastructural study of the crop and oesophagus was carried out for the first time in Aglajidae. In Philinopsis depicta, the hind region of the crop contains two large folds creating a channel between them, lined by a ciliated epithelium. This ciliated groove continues through the posterior oesophagus. In addition to these larger folds, both crop and posterior oesophagus present many smaller longitudinal ridges lined by a nonciliated epithelium formed by cells bearing microvilli embedded in a layer of extracellular material. Lysosomes and mitochondria are common in the supranuclear region of these cells, and in the basal region hemidesmosomes are frequent. Epithelial secretory cells contain many large vesicles with a low electron-density content rich in acid polysaccharides, but without detectable amounts of protein. The basal region of the secretory cells comprises the nucleus and several Golgi stacks formed by many flat cisternae with low electron-density content. Secretory cells were not observed in the ciliated epithelium of the channel between the two large folds. The connective tissue of the crop and posterior oesophagus contains many large vacuolar cells with a thin layer of cytoplasm around the single vacuole that occupies about 90% or more of the cell volume. Tubular invaginations of the cell membrane are frequent in these cells and some also contain large vesicles that can open to the central vacuole, suggesting an intense transport activity across the cytoplasm. These vacuolar cells could be related to the calcium cells reported in the connective tissue of other gastropods. Ultrastructural and histochemical studies of the organs of the digestive system in carnivorous and herbivorous cephalaspideans can lead to the discovery of important unknown features, like the vacuolar cells, which might be useful to establish correlations with molecular phylogenetic data or food sources.

Localized reentry within the left atrial appendage: arrhythmogenic role in patients undergoing ablation of persistent atrial fibrillation

Left atrial appendage (LAA) is implicated in maintenance of atrial fibrillation (AF) and atrial tachycardia (AT) associated with persistent AF (PsAF) ablation, although little is known about the incidence and mechanism of LAA AT. The purpose of this study was to characterize LAA ATs associated with PsAF ablation. In 74 consecutive patients undergoing stepwise PsAF ablation, 142 ATs were encountered during index and repeat procedures. Out of 78 focal-source ATs diagnosed by activation and entrainment mapping, 15 (19%) arose from the base of LAA. Using a 20-pole catheter, high-density maps were constructed (n = 10; age 57 ± 6 years) to characterize the mechanism of LAA-AT. The LAA orifice was divided into the posterior ridge and anterior-superior and inferior segments to characterize the location of AT. Fifteen patients with LAA AT had symptomatic PsAF for 17 ± 15 months before ablation. LAA AT (cycle length [CL] 283 ± 30 ms) occurred during the index procedure in four and after 9 ± 7 months in 11 patients. We could map 89% ± 8% AT CLs locally with favorable entrainment from within the LAA, which is suggestive of localized reentry with centrifugal atrial activation. ATs were localized to inferior segment (n = 4), anterior-superior segment (n = 5), and posterior ridge (n = 6) with 1:1 conduction to the atria. Ablation targeting long fractionated or mid-diastolic electrogram within the LAA resulted in tachycardia termination. Postablation, selective contrast radiography demonstrated atrial synchronous LAA contraction in all but one patient. At 18 ± 7 months, 13/15 (87%) patients remained in sinus rhythm without antiarrhythmic drugs. LAA is an important source of localized reentrant AT in patients with PsAF at index and repeat ablation procedures. Ablation targeting the site with long fractionated or mid-diastolic LAA electrogram is highly effective in acute and medium-term elimination of the arrhythmia.

Reviews of Current Literature

Lozada JL, Goodacre C, Al-ardah AJ, Garbadea A. Lateral and crestal bone planing antrostomy: a simplified surgical procedure to reduce the incidence of membrane perforation during maxillary sinus augmentation procedures. J Prosthet Dent. 2011;105:147–153.This clinical report of 2 patients presents a variation to conventional surgical techniques for opening the maxillary sinus antrum via lateral and crestal approaches. This procedure, described as a lateral/crestal bone planing antrostomy (LBPA, CBPA) involves the use of specially designed rotary instruments that plane away the bone in thin layers. This technique has the potential to reduce the perforation rate of the maxillary sinus membrane during the access process. The authors provide a good review of conventional lateral wall and crestal access techniques and discussion concerning the most common surgical complication of sinus membrane perforation. Two clinical case reports (one LBPA and one CBPA) with detailed stepwise procedural details are presented using bone planing. Excellent color photographs enhance the reader's ability to understand the surgical process.These case reports provide an interesting alternative to existing techniques, however controlled clinical studies with randomized designs are needed before a definitive conclusion can be drawn concerning wide spread acceptance of the technique.James L. RutkowskiEditor-in-Chief, Journal of Oral ImplantologyChairman, Clarion Research GroupFellow AAIDDiplomat ABOI/IDSilverstein LH, Kurtzman D, Shatz PC. Principles of Hard Tissue Regeneration and Implant Therapy: A Complete Step-by-Step Guide. Newton, Pa: Aegis Communications.This textbook is a comprehensive step-by-step manual available to teach surgical hard tissue regeneration for implant dentistry including: socket grafting, ridge augmentation, and maxillary subantral augmentation using either a Caldwel-Luc or crestal approach. The authors describe each procedure in detail with 7 layered animation type visual technology illustrations. One such procedure illustrated describes how to split a posterior ridge for facial expansion and an anterior ridge labially. Instructions are provided on “how-to-do” mono cortical ridge grafting with either the ramus or symphysis as the donor site. Multiple grafting techniques are covered.Readers are shown all steps for each procedure, from administering local anesthetic, to the specific surgical blades, blade angles, sites, and parameters of where the incisions should be made. All surgical procedural steps are explained in detail with corresponding illustrations. Each procedure details the description of suturing; which needles, threads, surgical knots, and specific techniques to use. Specific postoperative instruction sheets are provided that can be copied and given to the patient.The text was refereed and has received CERP accreditation. After successful completion of the test located at the back of the book and proper submission of the CE form, the clinician will receive three hours of Continuing Education credit.This textbook provides a thorough step-by-step outline for multiple hard tissue regeneration procedures as they apply to implant dentistry and should be a well-used reference by all clinicians. This is a must-have text for the Implant Dentist's library.James L. RutkowskiEditor-in-Chief, Journal of Oral ImplantologyChairman, Clarion Research GroupFellow AAIDDiplomat ABOI/ID

Erratum: Uncertainty quantification in chemical systems

There was an error in the implementation of the Bayesian inference algorithms used in our earlier work 1. As a result, the true posterior density corresponding to the data in Figure 1 of the paper differs from the density shown in Figure 4. Similarly, the degree of mixing evident in Figure 2 and the marginal PDFs in Figure 3 are incorrect. The marginal bivariate true posterior distribution still exhibits a strong correlation between the two parameters ln A and ln E. However there is a slight curvature of the resulting posterior ridge in the (ln A, ln E) plane. Moreover, the mean parameter values are different, resulting in a somewhat better fit to the data, and the extent of the posterior is larger than that in Figure 4, resulting in higher uncertainty in (ln A, ln E) than that observed in Figure 3. The key point of the paper, however, is unchanged. Given a posterior exhibiting a high degree of correlation among (ln A, ln E), the paper demonstrates the use of local polynomial chaos methods for propagation of parametric uncertainty in associated chemical ignition computations, illustrating the structure of the uncertain solution, and its dependence on the particular dependence relationship between the two parameters.

Maxillary anterior and mandibular posterior residual ridge resorption in patients wearing a mandibular implant-retained overdenture

The mandibular implant-retained overdenture could improve masticatory function compared to the conventional complete denture. However, increased forces exerted by the overdenture could increase residual ridge resorption of the maxillary anterior and mandibular posterior areas. The aim of this study was to compare the effect of the mandibular implant-retained overdenture using two or four dental implants, or the conventional complete denture on resorption of the residual ridge of the maxillary anterior and mandibular posterior areas over a period of 10 years. In total, 120 patients, 30 patients treated with an overdenture on two implants (two-implant group), 30 patients with an overdenture on four implants (four-implant group) and 60 patients treated with a conventional full denture (conventional group), participated in this study. On panoramic radiographs, made before and 10 years after treatment, proportional area measurements were applied to determine changes in bone height. After 10 years, a statistically significant amount of bone resorption had occurred in the anterior maxilla in the two-implant group and in the four-implant group. A significant amount of bone resorption had occurred in the posterior mandible in all three groups. There were no statistically significant differences between the groups in both areas. Patients presented large individual differences. It is concluded that patients rehabilitated with implant-retained mandibular overdentures are not subjected to more residual ridge resorption in the anterior maxilla when compared to patients wearing a conventional full denture. Regarding the mandibular posterior residual ridge, resorption was irrespective of wearing an implant-retained mandibular overdenture or a conventional mandibular denture.

Dental Morphologies in Gartersnakes (Thamnophis) and Their Connection to Dietary Preferences

We examined morphological variation in tooth structure in four populations of garter snakes (genus Thamnophis) with diverse feeding habits and tested the hypothesis that morphological homoplasy evolved in the malacophagous predators Thamnophis ordinoides and Thamnophis elegans terrestris. Although long, slender teeth are typical in Neotropical colubrid snake species that prey on slugs and snails, this morphological feature did not occur in T. ordinoides and T. e. terrestris relative to closely related garter snakes (the diet generalist Thamnophis elegans elegans and piscivore Thamnophis couchii). However, we did find pronounced posterior ridges located on the posterior maxillary teeth in the two slug predators but not in the generalist feeders. The evolutionary origin and functional advantage of these ridges has yet to be identified. The fish specialist T. couchii has many morphological features characteristic of adaptations for piscivory, such as long, sharper teeth and elongated mandible bones.

Pectoral anatomy of Tribodus limae (Elasmobranchii: Hybodontiformes) from the Lower Cretaceous of northeastern Brazil

ABSTRACT New, undescribed material of the hybodont shark Tribodus limae, from the Lower Cretaceous of northeastern Brazil, provides new information on the pectoral endoskeleton in this taxon. This allows for a revision of its pectoral morphology, which may be broadly applicable to other Hybodontoidei. Four new specimens of Tribodus with well-preserved pectoral girdles are described, including the first complete, three-dimensionally preserved hybodont scapulocoracoid and partial pectoral fin. These specimens permit examination of the posterior surface of the scapulocor-acoid, not visible in previously described hybodonts. Overall pectoral morphology of Tribodus is similar to that of other hybodontiforms and neoselachians. However, the new material shows that the pectoral articulation in Tribodus comprises an oblique posterior ridge on the scapulocoracoid, unlike previous reconstructions of pectoral anatomy in Tribodus and other hybodonts based on two-dimensionally preserved specimens. However, other elasmobranchs, including many neoselachians, Orthacanthus, and ctenacanths, also have an oblique posterior articulation, indicating that this feature may be primitive for elasmobranchs. The pectoral articulation of Tribodus differs noticeably from that of Cladoselache and similar Paleozoic chondrichthyans, which have an elongated, laterally positioned articular process, and from the outgroup (osteichthyans, acanthodians and placoderms). Tribodus also differs from the Paleozoic hybodontiform Ony-choselache in which the articular region comprises a laterally positioned glenoid fossa and posterior condyle. Tribodus has an additional diazonal foramen not found in other hybodonts. Other pectoral features of Tribodus are in agreement with previous phylogenetic hypotheses, supporting the position of Tribodus within Hybodontoidei.

Early Implant Placement in Bilateral Sinus Floor Augmentation Using Iliac Bone Block Grafts in Severe Maxillary Atrophy: A Clinical, Histological, and Radiographic Case Report

Effectively restoring a grossly atrophic maxilla can be difficult for the implant surgeon. The placement of dental implants in patients who are edentulous in the posterior maxilla can present difficulties because of deficient posterior alveolar ridge and increased pneumatization of the maxillary sinus, resulting in a minimal hard tissue bed. Implant placement requires adequate quality and quantity of bone, especially in the posterior maxilla. Insufficient bone height and width in this area of the maxilla, because of expansion of the maxillary sinus and atrophic reduction of the alveolar ridge, represents a contraindication for conventional insertion of dental implants. The reconstruction of edentulous patients with adequate bone volume and density by the use of bone graft and, subsequently, the placement of dental implants has become a viable treatment option with high predictability. It is commonly shared that autologous bone graft is the gold standard grafting method in the augmentation of Higmoro antrum and in any kinds of guided bone regeneration. In this article, the authors report a case of severe maxillary atrophy that is augmented by block bone graft harvested from iliac crest. An early placement of implants is possible due to the quick healing of the site, as proven by histologic examinations.

Management of Biomechanical Complication of Implant-Supported Restoration of a Patient With Combination Syndrome: A Case Report

Combination syndrome (CS) is a pathologic condition of the stomatognathic system characterized by an edentulous maxilla with an atrophic anterior ridge, maxillary papillary hyperplasia, hypertrophic maxillary tuberosities, super-erupted mandibular anterior teeth, as well as atrophic mandibular posterior ridges. This condition can present a challenging situation to the clinician who needs to assemble evidence from all aspects of dentistry to formulate an appropriate treatment plan. One of the possible treatment choices for the fully edentulous patient with a CS is a full-arch implant-supported reconstruction for both maxilla and mandible. The purpose of this study is to illustrate and discuss a biomechanical complication-fractured maxillary meso bar in a patient with CS, and to present a description of how this complex case was corrected and successfully completed. The analysis of implant-supported and implant-retained full arch restorations in edentulous patients with CS is presented and treatment recommendations are given. A necessity of individualized approach for every implant reconstruction case, especially complicated with a CS, is suggested.

Widening a narrow posterior mandibular alveolus following extirpation of a large cyst: a case treated with a titanium mesh-plate type distractor

Vertical alveolar augmentation by distraction osteogenesis has become a standard pretreatment of dental implants due to the main benefit of lack of donor site complications, and many reports have shown its benefit with various types of alveolar distractors. However, autogenous bone transplantation and/or guided bone regeneration techniques are still the standard treatment for correcting a narrow alveolar ridge because of few commercially available distractors for alveolar widening. In this article, we treated a case by a mesh-plate type of alveolar widening distractor for a narrow posterior mandibular alveolar ridge after extirpation of a large jaw cyst.

Screwless Fixed Detachable Partial Overdenture Treatment for Atrophic Partial Edentulism of the Anterior Maxilla

This is a case report of the restoration of a partially edentulous atrophic anterior maxilla and atrophic mandibular posterior ridges. This case report demonstrates one method for successful treatment of partial edentulism at No. 7 to 10, where interlock attachments on natural cuspids and mini dental implants support an acrylic-based screwless fixed detachable partial denture to provide lip support and masticatory function in the anterior maxilla. The presenting qualities of this case were similar to combination syndrome.

Bipolar Order

The Drosophila wing has proven valuable in understanding planar cell polarity (PCP), the phenomenon that dictates the packing geometry and polarity of cells in a polarized epithelium. Each cell of the dorsal wing epithelium produces a single hair, and the Frizzled (Fz) PCP pathway aligns all the hairs along the proximodistal (PD) wing axis. Doyle et al. report that mutations that disrupt Fz PCP signaling also caused defects in the alignment of wing ridges. In the posterior wing compartment, ridges are oriented along the PD axis, but in the anterior compartment they are oriented along the anteroposterior (AP) axis, thus making hairs and ridges aligned in the posterior compartment but orthogonal in the anterior compartment. To address the question of how a single PCP pathway could generate two different patterns in the same polarized epithelium, the group focused on Spiny legs (Sple) and Prickle (Pk), two different protein isoforms encoded by the pk gene. Through loss- and gain-of-function genetic experiments, the authors found that disrupting PCP signaling early in wing development [up to 18 hours after pupal formation (APF)] did not affect hair polarity but did affect posterior ridge orientation and that disrupting late PCP signaling (more than 18 hours APF) affected hair polarity all over the wing but only altered ridge orientation in the anterior compartment. The authors propose a model in which the early Sple-dependent phase of PCP patterning establishes a cell-packing pattern that orients all ridges along the PD axis; during the late Pk-dependent phase of PCP, hair polarity is established and the anterior compartment ridges are reoriented. The differential use of two closely related isoforms of a PCP pathway component enables the system to function biphasically. K. Doyle, J. Hogan, M. Lester, S. Collier, The Frizzled Planar Cell Polarity signaling pathway controls Drosophila wing topography. Dev. Biol. 317 , 354-367 (2008). [PubMed]

Antero-laterale Unkoforaminektomie zur Behandlung zervikaler spondylotischer Monoradikulopathie

Thirty seven patients with cervical spondylotic monoradiculopathy treated with antero-lateral uncoforaminectomy were analysed. Spondylotic spur of the level associated with radiculopathy was revealed to be continuous from the uncovertebral joint to the posterior ridge of the vertebral body in 35 patients. Antero-lateral uncoforaminectomy was found to safely remove the continuous type of spur, resulting in decompression of the cord-root-complex, which shifted anteriorly after surgery. As a result, no neurological symptoms were observed in 36 of 37 radiculopathy patients. It could be concluded that the most important factor in relieving neurological manifestations of this disorder is decompression of the cord-root-complex.

Catheter Ablation for Atrial Fibrillation

▪ Abstract Atrial fibrillation is frequently disabling and resistant to antiarrhythmic drugs. Curative treatment by catheter-based ablation has been shown to be feasible either by achieving long linear lesions, mainly in the left atrium, or by targeting the initiating focus, most frequently in the pulmonary veins. This paper reviews the different ablation approaches, their results, potential complications, and relative merits.

Septocutaneous perforators of the peroneal artery relative to the fibula: anatomical basis of the use of pedicled fasciocutaneous flap

There are many studies describing the perforating branches of the peroneal artery but none of them identifies their locations relative to fibula. The aim of this study was to demonstrate the locations of the perforators relative to the fibula and to present a case, treated with an adipofascial flap, based on one of these small arteries. In this study, nine fresh male cadavers' legs injected with colored latex were dissected for demonstration of the longitudinal axis of these perforators. A large incision was made on the lateral part of the leg from the head of the fibula to the ankle. The peroneal perforating vessels were displayed. The posterior margin of the fibula was marked with needles from proximal to distal just above every perforator. The distance between the needle and the perforator was recorded. Their diameters were measured at the level of fascial emergence. There were four to seven perforating vessels; the larger vessels were near the proximal end of the fibula with an average of 1.1 mm and a minimum of 0.8 mm. We found that these branches were not parallel to fibula, but aligned in an oblique projection from posterior to anterior and from distal to proximal because of the course of the intermuscular septum between the soleus and peroneus longus muscles. The lowermost vessel was 1.7 cm away from the posterior margin of the fibula while the uppermost vessel was 0.25 cm away from the posterior ridge of the fibula. Adipofascial or fasciocutaneous flaps, which have important advantages in covering small to medium sized defects, can be based on the perforators of the peroneal artery. But for the centralization of the flap pedicle, the locations of the perforators, which are aligned from the lateral malleolus to the fibular head in oblique direction and from the posterior to the anterior must be taken into consideration. This knowledge is crucial for the flap design and the centralization of the vessels.

New ommatids from the Late Jurassic of western Liaoning, China (Coleoptera: Archostemata)

Abstract A new genus Amblomma gen. nov. of fossil beetles is erected and can be assigned to the family Ommatidae because its two procoxal cavities are contiguous and the articulations of the abdominal ventrites are abutting. The new genus is similar to Zygadenia Handlirsch, 1906 (=Notocupes Ponomarenko, 1964), Tetraphalerus Waterhouse, 1901, Rhobdocupes Ponomarenko, 1966 and Sinocupes Lin, 1976, but can be distinguished from other genera according to the following characters: the second segment of antennae is shorter than the third one in length; the posterior tarsi with the basal segment is obviously shorter than the three following taken together in length; the antennae reach the posterior ridge of prothroax in length, and the sides of the prothroax with serrulate margin. Four new species of the new genus are described and figured: Amblomma psilata gen. et sp. nov., Amblomma rudis gen. et sp. nov., Amblomma epicharis gen. et sp. nov., and Amblomma stabilis gen. et sp. nov. A key to species within this new genus is provided. All the specimens are collected from the Late Jurassic Yixian Formation of western Liaoning and are now housed in the College of Life Science, Capital Normal University, Beijing, China.