Anterior Elements Research Articles

Sequence of chondrocranial development in the oriental fire bellied toad Bombina orientalis.

The vertebrate head as a major novelty is directly linked to the evolutionary success of the vertebrates. Sequential information on the embryonic pattern of cartilaginous head development are scarce, but important for the understanding of its evolution. In this study, we use the oriental fire bellied toad, Bombina orientalis, a basal anuran to investigate the sequence and timing of larval cartilaginous development of the head skeleton from the appearance of mesenchymal Anlagen in post-neurulation stages until the premetamorphic larvae. We use different methodological approaches like classic histology, clearing and staining, and antibody staining to examine the larval skeletal morphology. Our results show that in contrast to other vertebrates, the ceratohyals are the first centers of chondrification. They are followed by the palatoquadrate and the basihyal. The latter later fuses to the ceratohyal and the branchial basket. Anterior elements like Meckel's cartilage and the rostralia are delayed in development and alter the ancestral anterior posterior pattern observed in other vertebrates. The ceratobranchials I-IV, components of the branchial basket, follow this strict anterior-posterior pattern of chondrification as reported in other amphibians. Chondrification of different skeletal elements follows a distinct pattern and the larval skeleton is nearly fully developed at Gosner Stage 28. We provide baseline data on the pattern and timing of early cartilage development in a basal anuran species, which may serve as guidance for further experimental studies in this species as well as an important basis for the understanding of the evolutionary changes in head development among amphibians and vertebrates.

A New Species of Trichogenes (Siluriformes, Trichomycteridae), with a Discussion on the Homologies of the Anterior Orbital Bones in Trichomycterids and Other Loricarioids

A new species of the rare genus Trichogenes is reported on the basis of specimens without locality and other associated data. The obvious distinctiveness, taxonomic relevance, and phylogenetic importance of the new taxon justify its description with material at hand. Trichogenes beagle, new species, differs from all congeners by the presence of tricuspidate teeth on its jaws; by the distribution of opercular odontodes along a wide area of the margin of the opercle; by the pale integumentary pigmentation, composed of few scattered small spots on dorsum and flanks, but lacking large spots near the base of the anal fin; and by the absence of differential concentration of dark chromatophores along the base of the dorsal fin. The new species differs further from each of its two congeners, T. longipinnis and T. claviger, by various additional traits of internal and external morphology and pigmentation. Trichogenes beagle seems to be the closest relative of T. claviger, the two species sharing a number of putatively derived traits not present in T. longipinnis, such as the presence of a large anterodorsal clawlike process on the neural arches of the anterior four free vertebrae. The three species now included in Trichogenes share all synapomorphies previously proposed for the genus, thus strongly supporting generic monophyly. The enigmatic disc-shaped orbital bone in T. beagle and congeners is homologous to a topologically equivalent rodlike structure in other trichomycterids. New comparative information corroborates the hypothesis that the bone is a neomorphic structure, here called the barbular bone. Previous proposals of its homology with the antorbital or supraorbital are refuted. Ontogenetic data demonstrate that the anterior element of the infraorbital series in trichomycterids is a fusion between the lacrimal and antorbital, as postulated—but previously poorly demonstrated—for other catfishes. The structure of the opercle in the new species is intermediate between the highly derived morphology in most trichomycterids and the plesiomorphic condition in other loricarioids, helping to understand the evolution of the opercle of trichomycterids. New information on T. claviger is reported on the basis of additional material.

Design and feasibility of a flexible, on-body, high impedance coil receive array for a 1.5 T MR-linac

The lack of radiation-attenuating tuning capacitors in high impedance coils (HICs) make HICs an interesting building block of receive arrays for MRI-guided radiotherapy (MRIgRT). Additionally, their flexibility and limited channel coupling allow for low-density support materials, which are likely to be more radiation transparent (radiolucent). In this work, we introduce the use of HICs in receive arrays for MRIgRT treatments. We discuss the design and show the dosimetric feasibility of a HIC receive array that has a high channel count and aims to improve the imaging performance of the 1.5 T MR-linac. Our on-body design comprises an anterior and posterior element, which each feature a channel layout (32 channels total). The anterior element is flexible, while the posterior element is rigid to support the patient. Mockups consisting of support materials and conductors were built, irradiated, and optimized to minimize impact on the surface dose (7% of the dose maximum) and dose at depth (0.8% under a single conductor and 1.4% under a conductor crossing). Anatomical motion and the use of multiple beam angles will ensure that these slight dose changes at depth are clinically insignificant. Subsequently, several functional, single-channel HIC imaging prototypes and a 5-channel array were built to assess the performance in terms of signal-to-noise ratio (SNR). The performance was compared to the clinical MR-linac array and showed that the 5-channel imaging prototype outperformed the clinical array in terms of SNR and channel coupling. Imaging performance was not affected by the radiation beam. In conclusion, the use of HICs allowed for the design of our flexible, on-body receive array for MRIgRT. The design was shown to be dosimetrically feasible and improved the SNR. Future research with a full array will need to show the gain in parallel imaging performance and thus acceleration.

Estrogen promotes the onset and development of idiopathic scoliosis via disproportionate endochondral ossification of the anterior and posterior column in a bipedal rat model

This study aimed to verify the effects of estrogen on the onset and development of adolescent idiopathic scoliosis and the mechanisms associated with these effects by constructing a pubescent bipedal rat model. Experiments were conducted to investigate whether scoliosis progression was prevented by a Triptorelin treatment. One hundred twenty bipedal rats were divided into female, OVX (ovariectomy), OVX + E2, Triptorelin, sham, and male groups. According to a spinal radiographic analysis, the scoliosis rates and curve severity of the female and OVX + E2 groups were higher than those in the OVX, Triptorelin, and male groups. The measurements obtained from the sagittal plane of thoracic vertebrae CT confirmed a relatively slower growth of the anterior elements and a faster growth of the posterior elements between T11 and T13 in the female and OVX + E2 groups than in the OVX and Triptorelin groups. Histomorphometry and immunohistochemistry revealed a significantly longer hypertrophic zone of the vertebral cartilage growth plates that expressed more type X collagen and less type II collagen in the OVX and Triptorelin groups than in the female and OVX + E2 groups. Ki67 immunostaining confirmed an increase in the proliferation of vertebral growth plate chondrocytes in the OVX group compared with the female and OVX + E2 groups. In conclusion, estrogen obviously increased the incidence of scoliosis and curve severity in pubescent bipedal rats. The underlying mechanism may be a loss of coupling of the endochondral ossification between the anterior and posterior columns. Triptorelin decreased the incidence of scoliosis and curve magnitudes in bipedal female rats.

The Crankshaft Phenomenon.

The crankshaft phenomenon, a progressive rotational and angular spinal deformity that can occur after posterior spinal surgery, has been reported in pediatric patients with idiopathic, congenital, and neuromuscular scoliosis. In the skeletally immature patient, the crankshaft phenomenon is thought to occur secondary to continued growth of the anterior elements of the spine after solid posterior spinal fusion. The condition has also been reported in the setting of newer, so-called growth-friendly posterior distraction-based spinal instrumentation. The clinical evidence of crankshaft phenomenon is often subtle, whereas radiographic findings are usually more apparent. However, objective measurement of radiographic signs may be complicated by instrumentation and postoperative changes. Treatment options for patients with the crankshaft phenomenon are limited; in those with problematic deformity and/or risk of progression, additional surgery may be indicated.

Stand-Alone Anterior Cervical Decompression and Fusion in Three Levels with Peek Cages: A Possible Satisfactory Alternative

Anterior cervical decompression and fusion (ACDF) remains the gold standard for subaxial degeneration of anterior elements. By multilevel stenosis corpectomy or instrumentation with screws and plate are supported. Their potential complications, though, should be reckoned. The use of polyetheretherketone (PEEK) cages packed with demineralized bone matrix (DBM) alone can provide good fusion rates and clinical improvement even in cases of three levels degeneration. The purpose of this paper is to present retrospectively the outcomes of 15 patients with cervical stenosis in three levels treated with cage implantation reviewing the relevant literature, too.

Fixateur externe antérieur avec préhension dans les fractures et luxations du bassin

In the treatment of unstable pelvic ring fractures, external fixators have the limitation of not adequately stabilizing the injured posterior elements. This article presents a novel and simple technique of temporary external fixation of the pelvic ring, able to produce compression of both the anterior and posterior pelvic elements. A curved flexible carbon-fiber rod is used, pre-tensioned before attachment to supra-acetabular Schanz screws. Although more extensive clinical experience is required, favorable preliminary results in a series of 13 patients with unstable pelvic fracture were encouraging: the aim of closing the posterior and anterior elements of the pelvic ring was achieved in all cases treated with this technique, and 12 patients survived. Radiological results were excellent in 3 cases and good in 9 cases. No major complications, such as secondary displacement, vertical re-displacement or deep infection, were observed. Mean operative time was 25minutes, compatible with emergency management.

Anterior pre-tensioned external fixator for pelvic fractures and dislocations. Initial clinical series

In the treatment of unstable pelvic ring fractures, external fixators have the limitation of not adequately stabilizing the injured posterior elements. This article presents a novel and simple technique of temporary external fixation of the pelvic ring, able to produce compression of both the anterior and posterior pelvic elements. A curved flexible carbon-fiber rod is used, pre-tensioned before attachment to supra-acetabular Schanz screws. Although more extensive clinical experience is required, favorable preliminary results in a series of 13 patients with unstable pelvic fracture were encouraging: the aim of closing the posterior and anterior elements of the pelvic ring was achieved in all cases treated with this technique, and 12 patients survived. Radiological results were excellent in 3 cases and good in 9 cases. No major complications, such as secondary displacement, vertical re-displacement or deep infection, were observed. Mean operative time was 25min, compatible with emergency management.

Initiation of cyp26a1 Expression in the Zebrafish Anterior Neural Plate by a Novel Cis-Acting Element.

Early patterning of the vertebrate neural plate involves a complex hierarchy of inductive interactions orchestrated by signalling molecules and their antagonists. The morphogen retinoic acid, together with the Cyp26 enzymes which degrade it, play a central role in this process. The cyp26a1 gene expressed in the anterior neural plate thus contributes to the fine modulation of the rostrocaudal retinoic acid gradient. Despite this important role of cyp26a1 in early brain formation, the mechanisms that control its expression in the anterior neural plate are totally unknown. Here, we present the isolation of a 310-base-pair DNA element adjacent to cyp26a1 promoter, displaying enhancer activity restricted to the anterior neural plate of the zebrafish gastrula. We show that unlike that of cyp26a1, expression driven by this cyp26a1 anterior neural plate element (cANE) is independent of retinoic acid. Through deletion analysis, we identify a 12-nucleotide motif essential for cANE activity. A consensus bipartite binding site for SoxB:Oct transcription factors overlaps with this motif. Mutational analysis suggests that SoxB binding is essential for its activity. We discuss the contribution of this study to the elucidation of the regulatory hierarchy involved in early neural plate patterning.

Preliminary Experience with Pedicle-Lengthening Osteotomy for the Treatment of Lumbar Spinal Stenosis

Introduction Lumbar spinal stenosis (LSS) is defined as a reduction in the diameter of the spinal canal and/or neural foramina which leads to significant disability, particularly in the elderly. The most frequent cause of LSS is a degenerative disease, including narrowing and bulging of the intervertebral disk, hypertrophy of the facet joints, thickening and buckling of the ligamentum flavum, and/ or degenerative spondylolisthesis. A variety of nonoperative measures have been advocated for treating LSS, including physical therapy, spinal injections, and medications. Open lumbar laminectomy is the primary surgical therapy for LSS. This procedure is a moderately invasive operation and is most commonly performed under general anesthesia. Unfortunately, open laminectomy may pose an unacceptable risk to some older, medically compromised individuals with LSS besides the risk of a future iatrogenic instability. A new procedure for LSS uses bilateral pedicle-lengthening osteotomies to expand the dimensions of the spinal canal and neural foramen. This percutaneous procedure lengthens the lumbar pedicles through an expanding osteotomy at the junction of the pedicles and the vertebral body. The small gap produced by the pedicle-lengthening device moves the anterior elements away from the posterior elements, resulting in expansion of the spinal canal and neural foramen. The objective of this study was to define the postoperative outcomes and complications of pedicle-lengthening osteotomies for symptomatic LSS. Methods A cohort of 10 patients with symptomatic LSS was treated by pedicle-lengthening osteotomy procedures at 1 or 2 levels. All patients had symptoms of neurogenic claudication or radiculopathy secondary to LSS and had not improved after a minimum 6-month course of nonoperative treatment. Clinical outcomes were measured using the Oswestry Disability Index (ODI), 12-Item Short-Form Health Survey (SF-12), and a visual analog scale (VAS). Results The pedicle-lengthening osteotomies were performed through percutaneous approaches with minimal blood loss in all cases. There were no operative complications. Clinically, significant improvement was observed in the mean values of each of the outcome scales. Most of the patients demonstrated bridging bone on the 6-month postoperative CT scans at the osteotomy site, consistent with healing of the osteotomy. Most of the patients demonstrated an increase in the mean cross-sectional area of the spinal canals on the 6-month CT scans as compared with the preoperative CT scans. Conclusions The pedicle-lengthening osteotomy is a new mini invasive technique for correcting lumbar spinal canal stenosis. This approach has some theoretical advantages because it can be performed percutaneously, thus reducing the surgical morbidity associated with a traditional open laminectomy. In addition, the pedicle-lengthening osteotomy procedure removes no normal spinal structures. Longer-term follow-up will be required to define the durability of the treatment effect with this procedure besides the benefits and risks of the pedicle-lengthening osteotomy procedure in relation to other LSS therapies.

Modification of readings along oblique principal meridians to fit regular corneal surfaces

Anterior astigmatic corneal surface elements may have their continuity disturbed by environmental factors. Powers detected along principal meridians define matrices whose natures distinguish the continuity of surface elements. This work aims to adapt the matrix nature of data to fit closely, uniquely and holistically with the matrix nature in a sample of data for smooth astigmatic corneas that have powers along rectangular meridians. Matrices from continuous surfaces approximate matrices with outliers from irregular surfaces explicitly. Only approximations that minimize the Frobenius norm of the residual matrices are selected. Data from smooth astigmatic corneal surfaces, in an augmented sample, may now produce more reliable analyses.

Hypofractionated Stereotactic Body Radiotherapy in Spinal Metastasis — With or Without Epidural Extension

AimsTo evaluate clinical outcome and the effect of malignant epidural compression (MEC) in the treatment of spine metastasis with stereotactic body radiotherapy (SBRT). Materials and methodsSeventy-six lesions in 52 patients with spinal metastasis received SBRT during the period July 2010 to December 2012. MEC was detected in 20 patients (38.4%) and was separately contoured. The median dose prescribed to involved vertebra (planning target volume) was 24 Gy (range 24–27 Gy) in a median of three fractions (range 1–3). Uninvolved elements were prescribed 21 Gy in three fractions. In 59 lesions (77.6%), the entire vertebra was treated and in 17 lesions (22.4%) only the anterior elements were treated. All patients were treated with volumetric modulated arc therapy with image guidance on a Novalis Tx linear accelerator with the ExacTrac system. Dosimetric and clinical outcomes were compared in patients with or without MEC. ResultsAt a median follow-up of 8.48 months (range 3–40 months), 1 year local control and overall survival was 94 and 68%, respectively. In patients with or without epidural extension, the median dose to the gross tumour volume (GTV; 95%) was 23.48 Gy (range 13.70–25.75) and 22.99 Gy (range 13.55–26.84), the median spinal cord Dmax was 17.36 Gy (range 8.47–21.63) and 15.71 Gy (range 8.39–23.33). The median GTV epidural (D95%) was 21.16 Gy (range 15.43–23.92). Complete pain relief was seen in 90% of patients with MEC and 93.75% without MEC (P = NS) and neurological improvement was seen in 60% of patients in both groups of patients. ConclusionIt is feasible to deliver a high dose of radiation (∼90% of the prescription dose) to the epidural component with volumetric modulated arc therapy SBRT and image guidance. It yielded high rates of pain control and local control in patients with spine metastases with or without MEC.

The pseudotympanum in the Gymnotiformes (Teleostei, Ostariophysi, Otophysi): homology and evolution of a previously unexplored system in Neotropical electric fishes

The pseudotympanum, a reduction of the hypaxialis muscle in the body wall lateral to the anterior portion of the swim bladder, is unique to some members of the Otophysi, the largest clade of primarily freshwater fishes. Prior studies documented the presence of the pseudotympanum in a number of groups within the Characiformes, to a lesser extent in subunits of the Siluriformes, and in a few taxa of the Cypriniformes, but with only one record of the aperture in the Gymnotiformes – the Neotropical electric fishes. Surveys across the five families and c. two-thirds of the genera in the Gymnotiformes revealed the occurrence of a pseudotympanum in all examined taxa. Pronounced variation in the expanse and details of the morphology of the opening and its relationship to the anterior elements of the axial skeleton was documented amongst Neotropical electric fish. Details of pseudotympanal morphology in the different families of the Gymnotiformes are described and the variation evaluated within the context of the two alternative hypotheses of higher-level phylogenetic relationships within the order. © 2015 The Linnean Society of London

Radio Medico Norway, video consultation

In the treatment of unstable pelvic ring fractures, external fixators have the limitation of not adequately stabilizing the injured posterior elements. This article presents a novel and simple technique of temporary external fixation of the pelvic ring, able to produce compression of both the anterior and posterior pelvic elements. A curved flexible carbon-fiber rod is used, pre-tensioned before attachment to supra-acetabular Schanz screws. Although more extensive clinical experience is required, favorable preliminary results in a series of 13 patients with unstable pelvic fracture were encouraging: the aim of closing the posterior and anterior elements of the pelvic ring was achieved in all cases treated with this technique, and 12 patients survived. Radiological results were excellent in 3 cases and good in 9 cases. No major complications, such as secondary displacement, vertical re-displacement or deep infection, were observed. Mean operative time was 25 minutes, compatible with emergency management.

AO spine classification system for thoracolumbar fractures

The classification of a certain pathology––be it located at the spine or at another anatomical region of the human body, and be it traumatic or a disease––is a fundamental medical act in terms of developing a common language for the understanding of this pathology and as an attempt to standardize treatment and to measure outcome. Classifications should be as simple as possible and consistently reproducible and have a rational treatment implication. There may be a basic classification for the daily clinical use and a more detailed sub-classification for more sophisticated scientific evaluations. This “philosophy” has been tried to be applied in the original AO Spine thoracolumbar fracture classification, and before it has been published [1] many different attempts have been made to develop this common language mentioned above. After almost 20 years in use without a rigid validation process and, nevertheless, gradually becoming the most applied classification in spinal trauma circles, the authors of the article in this issue [2] felt they had to adapt and to revise this classification. Classifications are exposed to the dynamics of medical progress and change in the knowledge in terms of diagnostic tools, treatment options, outcome expectation and a certain fashion from which also surgeons and physicians may not be excluded. The new presented revision follows in principle the known concept of the original classification by recognizing the intact or injured, so-called posterior ligament complex/tension banding system as the key differentiating factor for the severity of injury: The A-type injuries with an intact posterior tension banding system on one side, and The B- and C-type injuries with a disrupted posterior tension banding system, the latter in addition to the disruption of the anterior elements. The C-injuries are now characterized by “displacement”, whereas before they were the result of an inability to resist torsional forces. Whether the concept of displacements is a better injury denominator, we will see in the practical application, however, we should be reminded that fractures may have a displacement in the process of injury and may present themselves in a reduced position when prone, although highly unstable. However, the concept of the C-injuries is not fully applied in the subtype C1 lesions, which do not go together with a displacement. The C1 lesions were originally classified within the B-3 lesions. The subtypes C2 and C3 are in the a-p view (see Fig. 3 of reference 2) clearly combined with a rotational displacement, a morphological criteria, which led in the original classification to the interpretation of the inability of a spinal segment to withstand torsional forces. In the A-types we have now four subtypes instead of three as a result of classifying incomplete and complete burst fractures in separate subtypes. This is a breach with the original “three division” concept in analogy to the AO Classification of the long bones. I recommend to study this revised classification carefully and to try to understand its evolution from the original classification. We want to leave it to the practical application, whether the revision will bring us a step forward for the treatment of those injuries. This per se is an interesting exercise, which I encourage all those who treat thoracolumbar fractures to engage in and bring back a practical feedback to the authors, who should be congratulated for their hard work.

Indices of Anseriform body shape based on the relative size of major skeletal elements and their relationship to reproductive effort

To assess whether relative clutch mass (RCM) in Anseriformes (wildfowl or waterfowl) is constrained by body shape, principal components (PCs) of size‐adjusted measurements of five major skeletal elements of adult males and females of 60 species of Anseriformes provided indices of body shape. PC1 accounted for 69.8% of the variance and contrasted anterior elements (cranium and sternum) to posterior elements (synsacrum, femur and tibiotarsus). PC1 scores were high in species with a ‘duck‐like’ body shape and low in those with a ‘goose‐like’ body shape. Over the phylogeny of Anseriformes, decreased PC1 scores were associated with feeding on land. PC2 accounted for 18.6% of the variance and contrasted core elements (sternum and synsacrum) with peripheral elements (cranium, femur and tibiotarsus). High PC2 scores were associated with dependence on animal food, particularly in diving species. PC3 accounted for 7.7% of the variance and reflected mainly the relative size of the femur, which was low in diving species. Controlling statistically for phylogenetically independent contrasts in female body shape, there was a significant positive partial correlation between RCM and PC1, suggesting that independent of body size, body shape imposes constraints on reproductive effort in Anseriformes. The results suggest that models of the evolution of reproductive effort in this order, and perhaps in other orders, of birds should control for the effects of body shape.

Anterior decompression and strut graft versus posterior decompression and pedicle screw fixation with vertebroplasty for osteoporotic thoracolumbar vertebral collapse with neurologic deficits

Background contextWith the increase of the elderly population, osteoporotic vertebral fractures have been frequently reported. Surgical intervention is usually recommended in osteoporotic vertebral collapse with neurologic deficits. However, very few reports on surgical interventions exist. PurposeTo compare surgical results of anterior and posterior procedures for treating osteoporotic thoracolumbar vertebral collapse with sustained neurologic deficits. Study designRetrospective comparative study. Patient sampleFifty patients who sustained osteoporotic thoracolumbar vertebral collapse with neurologic deficits were treated either by anterior decompression and strut graft (n=32) or by posterior decompression and pedicle screw fixation with vertebroplasty (n=18). Outcome measuresIncidence of complications, sagittal Cobb angle, spinal canal encroachment, and Japanese Orthopedic Association score. MethodsThe authors retrospectively reviewed the results of a consecutive series of patients undergoing anterior decompression and strut graft or posterior decompression and pedicle screw fixation with vertebroplasty for osteoporotic thoracolumbar vertebral collapse with neurologic deficits. Operative notes, clinical charts, and radiographs were analyzed. ResultsOperative time was similar between the groups, but intraoperative blood loss was significantly lower in the posterior group. All patients showed neurologic recovery. No significant difference was observed in the neurologic improvement, kyphosis correction angle, and loss of correction. Perioperative respiratory complications were found in 11 patients (34%) in the anterior group. In the anterior group, early posterior reinforcement was required in patients with very low bone density below 0.60 g/cm2 and/or in those with three segments of instrumentation for two vertebral collapses. Posterior group patients did not undergo additional surgery. ConclusionsAnterior reconstruction for osteoporotic vertebral collapse is significant because anterior elements, particularly those at the thoracolumbar junction, play a major role in load bearing. However, difficulties arise when anterior reconstruction is performed in cases with very low bone density and in those with multiple vertebral collapse.

Two-stage, combined, three-level en bloc spondylectomy for a recurrent post-radiation sarcoma of the lumbar spine

En bloc or extralesional resection means resection of the tumor in one piece together with a layer of healthy tissue: the margin is either marginal or wide. The prerequisite for an en bloc or extralesional spondylectomy is a tumor involvement of no more than one side of the posterior structures, so that a corridor can be created through which the spinal cord is released. This article presents a two-stage, combined anterior and posterolateral, three-level en bloc spondylectomy, and local flap wound coverage for a patient with a recurrent post-radiation sarcoma of the lumbar spine and infected wound after intralesional treatment. The patient had radiation therapy for an L4 Hodgkin's lymphoma 5 years before the development of the post-radiation sarcoma. Two-stage, three-level en bloc spondylectomy was done through a combined anterior and posterolateral approach. The resection margins were microscopically negative. Dural tear occurred intraoperatively because of tightly adherent dense scar tissue. Two years after spondylectomy, there was no evidence of tumor or infection recurrence; however, the patient died from her lymphoma. In surgically difficult spinal resections, we recommend the two-stage, combined anterior and posterolateral approach for en bloc spondylectomy. The staged procedure may provide for reduced perioperative complications and mortality, and meticulous dissection in the irradiated area, especially if infected. The combined approach provides for easier and safer dissection of the tumor and the spine from the anterior elements under direct visual control, and wide tumor resection.

Direct restorative treatment of anterior weared teeth after re‐establishment of occlusal vertical dimension: a case report

The loss of posterior teeth resulting in a lack of stability may lead to excessive mandibular load on some points of occlusion of the remaining teeth, causing wear. The rehabilitation of these cases must be carefully planned and the treatment requires a period of adaptation with a new vertical dimension. This case report describes the treatment of a patient with a loss of almost all posterior inferior teeth and a consequential loss of occlusal vertical dimension and accentuated wear of anterior elements. Provisional removable partial dentures were manufactured and the patient used them for a period of adaptation prior to restoration of the anterior teeth. After the patient's adaptation with the new occlusal dimension, anterior restorations were made using a mycrohibrid resin composite with different color aspects for an optimal stratification. The restorations achieved an aesthetic configuration with ideal function as the final result and the occlusion showed a satisfactory stability for a provisional removable partial dentures. This article presents an anterior direct rehabilitation approach not only as an alternative option, but also as viable and less expensive treatment option with an optimally aesthetic and functional result.

An 11-year review of dental injuries associated with maxillofacial fractures in Turin, Italy

The aim of the study was to analyze the incidence, characteristics, and correlations between maxillofacial fractures and dental injuries in patients who were treated at a first-level trauma center in a metropolitan center in northwest Italy in the last 11 years. Between January 1, 2001 and December 31, 2011, 2,110 patients with maxillofacial fractures were admitted. Only dentulous patients with complete clinical records who presented with associated dental injuries were included in this study. Data on the age, gender, mechanism of injury, damaged tooth, type of dental injury, site of facial fractures, and concomitant injuries were recorded. On the whole, 267 patients (13.1%), mainly males aged 20-29 years, presented with 759 dental injuries associated with maxillofacial fractures, especially following motor vehicle accidents. The maxillary teeth, most often the anterior elements with decreasing involvement from the incisors to the molars, were the teeth most frequently damaged overall. The main types of dental trauma in patients with maxillofacial fractures were luxations and dental fractures. Our findings show that patients with mandibular fractures were statistically and significantly associated with dental injury, and the teeth in the upper jaw were the most frequently injured teeth, exhibiting mainly luxations and crown fractures. Confirmation of the predominant impact site in patients with dental injuries associated with maxillofacial fractures comes from the 177 lacerations noted in the chin and lip regions in 267 patients.