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Postural assessments of the lumbar spine lack valuable information about its properties. The purpose of this study was to assess neutral zone (NZ) characteristics via in vivo lumbar spine passive stiffness and relate NZ characteristics to standing lumbar lordosis. A comparison was made between those that develop low back pain during prolonged standing (pain developers) and those that do not (nonpain developers). Twenty-two participants with known pain status stood on level ground, and median lumbar lordosis angle was calculated. Participants were then placed in a near-frictionless jig to characterize their passive stiffness curve and location of their NZ. Overall, both pain developers and nonpain developers stood with a lumbar lordosis angle that was more extended than their NZ boundary. Pain developers stood slightly more extended (in comparison to nonpain developers) and had a lower moment corresponding to the location of their extension NZ boundary. Overall, in comparison to nonpain developers, pain developers displayed a lower moment corresponding to the location of their extension NZ boundary which could correspond to greater laxity in the lumbar spine. This may indicate why pain developers have a tendency to stand further beyond their NZ with greater muscle co-contraction. [ABSTRACT FROM AUTHOR]

Abstract: A classifier may be limited by its conditional misclassification rates more than its overall misclassification rate. In the case that one or more of the conditional misclassification rates are high, a neutral zone may be introduced to decrease and possibly balance the misclassification rates. In this paper, a neutral zone is incorporated into a three‐class classifier with its region determined by controlling conditional misclassification rates. The neutral zone classifier is illustrated with a text mining application that classifies written comments associated with student evaluations of teaching.

Introduction: Providing complete denture therapy to patients with atrophic residual alveolar ridges is challenging, because these patients suffer ongoing resorption of the denture foundation; regardless of contemporary treatment options, physiologically optimal denture contours and appropriate denture tooth arrangement should be achieved to maximize prosthesis stability, comfort and function for patients. One of the methods used to achieve the stability is the neutral zone technique. Aim: It is in this zone that the natural dentitions lie and this is where the artificial teeth should be positioned. This article describes a preview of faciolingual positioning of denture teeth along with a novel approach of recording the neutral zone. Conclusion: The neutral zone is the area where the displacing forces of the lips, cheeks and tongue are in balance. Physiologic recording of the neutral zone aids in stability to the prosthesis.

This paper gives an overview of the operating characteristics of the railway interline power flow controller (RIPFC) regarding the capability of transferring active power between two sections of an electrified railway line separated by a neutral zone and proposes its use for compensating the power factor at the substation instead of regulating the voltage level at the neutral zone. The basic analysis is based on simplified steady-state models for the energy supply architecture, while detailed time-domain simulations are used for more realistic tests. The paper mainly focus on active power balancing between two neighbouring substations and the global losses in the system. Other functionalities of the RIPFC system are also analysed, like reactive power compensation at the substations. The paper presents the main operating principles of the system, shows results for some representative scenarios (generic and reduced) and discusses the results. The most relevant conclusions are related to substation active power balancing and peak shaving, power factor compensation in the substation, voltage stability at the neutral zone and system power losses. [ABSTRACT FROM AUTHOR]

Abstract Background Analyse and discuss the immediate stability of the cervical spine after anterior cervical discectomy and fusion using a door-shaped titanium plate and compare it with the traditional titanium plate, to provide biomechanical evidence for the rationality and effectiveness of the door-shaped titanium plate in clinical applications. Methods Ten adult goat C4/5 vertebral bodies were obtained, and models were prepared using denture base resin. Biomechanical experiments were performed on the specimens before internal fixation. MTS was used to conduct non-destructive biomechanical loading tests in six directions, including flexion, extension, left–right bending, and left–right torsion, recording the range of motion (ROM) and neutral zone (NZ) of each specimen. The specimens were then randomly divided into two groups: the study group was fixed with a door-shaped titanium plate, and the control group was fixed with a traditional titanium plate. ROM and NZ in each direction were measured again. After measurements, both groups were subjected to 0.5 Hz torsion loading with a torque of 2 N m for a total of 3000 cycles, followed by measuring ROM and NZ in six directions once more. Results Compared to before fixation, ROM and NZ in both groups significantly decreased in all six directions after fixation, with statistical significance (P 0.05); after 3000 torsional loads, both internal fixation groups showed increased ROM and NZ compared to after fixation but to a lower extent, and no screw or titanium plate loosening was observed. Compared to before fixation, the differences were still statistically significant (P 0.05). Conclusion The door-shaped titanium plate exhibits mechanical properties similar to the traditional titanium plate in all directions, and its smaller size and simpler surgical operation can be used for anterior cervical endoscopic surgery, reducing surgical trauma. It is clinically feasible and deserves further research and promotion.

This paper gives an overview of the operating characteristics of the railway interline power flow controller (RIPFC) regarding the capability of transferring active power between two sections of an electrified railway line separated by a neutral zone and proposes its use for compensating the power factor at the substation instead of regulating the voltage level at the neutral zone. The basic analysis is based on simplified steady-state models for the energy supply architecture, while detailed time-domain simulations are used for more realistic tests. The paper mainly focus on active power balancing between two neighbouring substations and the global losses in the system. Other functionalities of the RIPFC system are also analysed, like reactive power compensation at the substations. The paper presents the main operating principles of the system, shows results for some representative scenarios (generic and reduced) and discusses the results. The most relevant conclusions are related to substation active power balancing and peak shaving, power factor compensation in the substation, voltage stability at the neutral zone and system power losses.

Background: Analyse and discuss the immediate stability of the cervical spine after anterior cervical discectomy and fusion using a door-shaped titanium plate and compare it with the traditional titanium plate, to provide biomechanical evidence for the rationality and effectiveness of the door-shaped titanium plate in clinical applications. Methods: Ten adult goat C4/5 vertebral bodies were obtained, and models were prepared using denture base resin. Biomechanical experiments were performed on the specimens before internal fixation. MTS was used to conduct non-destructive biomechanical loading tests in six directions, including flexion, extension, left–right bending, and left–right torsion, recording the range of motion (ROM) and neutral zone (NZ) of each specimen. The specimens were then randomly divided into two groups: the study group was fixed with a door-shaped titanium plate, and the control group was fixed with a traditional titanium plate. ROM and NZ in each direction were measured again. After measurements, both groups were subjected to 0.5 Hz torsion loading with a torque of 2 N m for a total of 3000 cycles, followed by measuring ROM and NZ in six directions once more. Results: Compared to before fixation, ROM and NZ in both groups significantly decreased in all six directions after fixation, with statistical significance (P < 0.05); after fixation, the study group showed slightly lower values for various mechanical reference parameters compared to the control group, with no statistical significance (P > 0.05); after 3000 torsional loads, both internal fixation groups showed increased ROM and NZ compared to after fixation but to a lower extent, and no screw or titanium plate loosening was observed. Compared to before fixation, the differences were still statistically significant (P < 0.05), with the study group having slightly lower ROM and NZ values in all directions compared to the control group, with no statistical significance (P > 0.05). Conclusion: The door-shaped titanium plate exhibits mechanical properties similar to the traditional titanium plate in all directions, and its smaller size and simpler surgical operation can be used for anterior cervical endoscopic surgery, reducing surgical trauma. It is clinically feasible and deserves further research and promotion. [ABSTRACT FROM AUTHOR]

A classifier may be limited by its conditional misclassification rates more than its overall misclassification rate. In the case that one or more of the conditional misclassification rates are high, a neutral zone may be introduced to decrease and possibly balance the misclassification rates. In this paper, a neutral zone is incorporated into a three‐class classifier with its region determined by controlling conditional misclassification rates. The neutral zone classifier is illustrated with a text mining application that classifies written comments associated with student evaluations of teaching. [ABSTRACT FROM AUTHOR]

Copyright of Railway Signalling & Communication Engineering is the property of Railway Signalling & Communication Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Purpose: Management of Anderson and D'Alonzo type II odontoid fractures continues to be controversial despite extensive research and increasing prevalence. To the authors' knowledge, the three odontoid ligaments, the alar ligament, the vertical portion of the cruciate ligament, and the transverse ligament, have not been biomechanically examined in type II odontoid fracture in spite of their potential significance in management. Therefore, this study aims to explore the intersegmental rotations of the craniovertebral junction following Anderson and D'Alonzo type II odontoid fracture and various combinations of ligament ruptures. Methods: A validated C0-C7 cervical spine finite element model was employed to address the research objectives. The model was subjected to flexion-extension, lateral bending, and axial rotation under eight distinct injury conditions apart from the intact state. Prescribed rotations were applied to the top of the cranium while the C7 inferior surface was fixed. Rotation-moment data were retrieved from the model. Results: Type II odontoid fracture caused mixed forms of instability considering flexion-extension. In lateral bending, the fracture alone did not have a significant effect, whereas the disruption of ligaments led to moderate rotation increments. Notably, in axial rotation, the fracture was the most crucial factor for stability. Conclusions: Overall, type II odontoid fracture was found to be the main destabilizing element. Nonetheless, the vertical cruciate and the transverse ligament played a modest role in stabilization. The alar ligament provided minimal or no stability. Furthermore, instances were observed where both the vertical cruciate and the transverse ligament were necessary to prevent more instability. [ABSTRACT FROM AUTHOR]

This article focuses on the high-speed train with unknown speed delays; a spatial adaptive iterative learning control (SAILC) algorithm is designed to solve the displacement-speed trajectory tracking problem by using the spatial differential operator to transform the train temporal dynamic model into a spatial model. First, parametric adaptive control is used to reduce the influence of system uncertainties. Second, a Lyapunov-Krasovskii-like spatial composite energy function (SCEF) is established, the stability of the designed controller and the convergence of the tracking error are demonstrated by verifying the differential negative definiteness and boundedness of the function. In addition, the train speed needs to be maintained within a certain range due to the speed loss when it passes through the neutral zone and overspeed protection. Therefore, the state-constrained mechanism is implanted into the train control algorithm to ensure that the train operates within the speed limits. Finally, the proposed SAILC algorithm is compared with proportional-integral-derivative (PID) and iterative learning control (ILC) algorithm; the results of the numerical simulations prove the effectiveness of the proposed method. After 20 iterations, the maximum absolute error of SAILC is 0.05 m/s, which is 4.7% of PID and 10.7% of ILC. It meets the requirements of Automatic Train Operation (ATO) that the tracking error should not be greater than 1% of the train operating speed. [ABSTRACT FROM AUTHOR]

Introduction: Providing complete denture therapy to patients with atrophic residual alveolar ridges is challenging, because these patients suffer ongoing resorption of the denture foundation; regardless of contemporary treatment options, physiologically optimal denture contours and appropriate denture tooth arrangement should be achieved to maximize prosthesis stability, comfort and function for patients. One of the methods used to achieve the stability is the neutral zone technique. Aim: It is in this zone that the natural dentitions lie and this is where the artificial teeth should be positioned. This article describes a preview of faciolingual positioning of denture teeth along with a novel approach of recording the neutral zone. Conclusion: The neutral zone is the area where the displacing forces of the lips, cheeks and tongue are in balance. Physiologic recording of the neutral zone aids in stability to the prosthesis. [ABSTRACT FROM AUTHOR]

This article intends to explain the legal regime of the Kuwaiti-Saudi Divided Zone, also called the Neutral Zone, in accordance with the Kuwait-Saudi Arabia Agreement to Partition the Neutral Zone signed in 1965, the Treaty Between Kuwait and Saudi Arabia Concerning the Submerged Area Adjacent to the Divided Zone signed in 2000, the Treaty Supplements to the Agreement to Partition and Treaty Concerning the Submerged Area signed in 2019, and the 2019 Memo of Understanding. Additionally, this article addresses the concerns raised by many Kuwaiti scholars, writers, and policymakers regarding the legitimacy and constitutionality of the divided zone system. Moreover, this article emphasizes the importance of the agreed-upon regime based on the principles of sovereignty and cooperation for advancing the interests of both parties at present and in the future. Finally, this article aims to shed light on some potential issues of conflict. [ABSTRACT FROM AUTHOR]

This paper examines religious segregation in Desakota communities, especially in Cihampelas District, West Bandung Regency, West Java, Indonesia. The method used in this paper is a qualitative method through collecting data from literature review, observation, and interviews. The results of the research show that segregation of religious areas has taken place in this place from 1970 until now. The identity of religious organizations is essential for community members to determine where they will live and the social treatment they will receive. Conflicts and clashes became commonplace in the sacred pattern of the community in the Cihampelas District in the 1990s. Therefore, the social and economic changes that have occurred in society have changed many things, including the way of the religion of the people. In addition, there were significant changes in religious and religious patterns in the people in this region; before the 1990s, their sacred designs tended to be exclusive; meanwhile, after the 1990s, until now, the religious and religious patterns of society were more inclusive or characteristic types. This change in spiritual practice has created a neutral sacred zone with community members who are pluralist in faith in that area.

We present the case of a 65-year-old man with maxillary and mandibular complete dentures prepared using neutral zone technique after undergoing mandibulotomy due to tonsil cancer 10 years ago. The patient had a short edentulous period; hence, there was minimal absorption of the alveolar ridge and no abnormality in the motor function of the tongue. However, the retromolar pad was located inside the hamular notch, and the posterior alveolar ridge was relatively turned inward. If the artificial teeth would have been aligned conventionally, the functional space of the tongue would have been invaded, which would have moved the tongue posteriorly thereby reducing the stability of the denture. Therefore, applying the concept of the neutral zone can be a good reference point in such cases. The neutral zone was registered using tissue conditioner, and tooth alignment was performed by making a silicone putty index. The biggest advantage of using neutral zone concept is denture stability. In this case, the neutral zone technique was applied to obtain the lingual alignment limit of the posterior teeth to avoid invasion of the tongue space by the left posterior part of the mandible. Particularly, in case of a patient in which denture stability is difficult to obtain due to absorption of the alveolar ridge, it is believed that better results can be obtained using neutral zone technique. [ABSTRACT FROM AUTHOR]

Abstract Background Today, the use of virtual reality (VR) technology as an educational tool in dental education has expanded considerably. This study was aimed to evaluate the effectiveness of using VR technology in teaching neutral zone and teeth arrangement. Methods This randomized trial was conducted at Kermanshah University of Medical Sciences, Iran in 2019. The study sample consisted of 50 six-year dental students who were randomly divided into experimental (n = 25) and control (n = 25) groups. Students’ performance in both groups was assessed using tests. A questionnaire was used to assess the usability of VR technology and students’ satisfaction with it. Results All faculty members confirmed the usability of VR technology in dental education. The majority of students (76%) were highly satisfied with the use of this technology in their learning process. The mean score of students was significantly higher in the experimental group (16.92 ± 1.12) than in the control group (16.14 ± 1.18). Conclusion In general, it can be argued that VR technology is useful and effective in the teaching–learning process. Therefore, its use in medical and dental schools can play an effective role in creating a dynamic, attractive, and successful learning environment.

Residual ridge resorption leads to diminished retention, support, and stability of the prosthesis due to decrease in the denture supporting areas, decreased denture space, and increased leverage due to increase inter-ridge distance. The prosthetic rehabilitation of the severely resorbed ridges needs modification for the fabrication of a stable prosthesis. This clinical report describes the prosthetic management of resorbed ridges using modified impression technique, neutral zone technique, external impressions, and fabrication of a hollow denture using three-dimensional glycerin spacer to enhance the retention and stability of the prosthesis.

The progress of Russian–Japanese negotiations in 1903–1904 is covered; the positions of the parties are analyzed; , the reasons for the intransigence of the Japanese side in the negotiations on the conclusion of a new agreement are examined; and the reaction in the ruling spheres of Russia to the amendments of the Japanese government to the Russian text of the agreement and the nature of Russian–Korean relations on the eve of the Russo–Japanese War are studied. The author focuses on Japan's responsibility for starting the war, showing Japan's aggressive policy in Korea. The essence of the Japanese proposals, tantamount to a demand from the Russian government for the formal recognition of Japan's protectorate over Korea, is analyzed; attempts by Japanese representatives in Seoul to intimidate the Korean Emperor Gojong and impose an agreement on the appointment of a Japanese resident in Seoul to manage domestic and foreign policy to ensure the "moral right" to establish its undivided dominance on the Korean Peninsula and the request of the Korean emperor for the protection and patronage of Russia are shown, the position of the Russian side during the negotiations, based on the preference to continue negotiations with Japan to avoid an armed clash, its perception and evaluation are studied. The article is based on newly discovered archival materials and published sources. Their study indicates that Russian diplomacy showed great pliability, seeking to delay the aggravation of a military conflict. By the final period of the negotiations, the Russian side had agreed to meet Japan halfway on almost all points concerning the Korean issue, seeking only to preserve the mutual obligation to respect the independence, territorial integrity, and inviolability of the Korean Empire. [ABSTRACT FROM AUTHOR]

Copyright of University of Sharjah Journal for Humanities & Social Sciences is the property of University of Sharjah - Scientific Publishing Unit and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Resorbed and flabby ridges is the most common finding in patients for long span edentulism and long span denture wearers. Residual Ridge Resorption is a major consequence of tooth loss and denture wearing. It results in increase inter-arch distance, horizontal discrepancy between edentulous ridges, occurrence of flabby tissues in denture bearing areas which results in denture soreness, loss of retention, stability and support. Prosthodontic management of such patients becomes very difficult. So, fabrication of dentures over such abused tissues becomes challenging for the prosthodontist. A denture or a prosthesis mainly depends on the accuracy of impression. Therefore, it is very important for the clinician to select an appropriate impression technique. This case series describes various materials and methods in managing compromised ridges prosthodontically. [ABSTRACT FROM AUTHOR]

Background Context: Intervertebral disc degeneration represents one of multiple potential trigger factors for reduced passive spinal mobility and back pain. The effects of age-related degenerative intervertebral disc changes on spinal flexibility were however mainly investigated for the lumbar spine in the past, while intervertebral disc degeneration is also highly prevalent in the thoracic spine.Purpose: To evaluate the effect of the degeneration grade on the range of motion and neutral zone of the thoracic spine.Study Design: Experimental study including combined radiological grading of intervertebral disc degeneration and biomechanical testing of 95 human thoracic functional spinal units (min. n=4 per level from T1-T2 to T11-T12) from 33 donors (15 female / 18 male, mean age 56 years, age range 37-80 years).Methods: Degeneration grades of the intervertebral discs were assessed using the validated x-ray grading scheme of Liebsch et al. (0=no, 1=mild, 2=moderate, 3=severe degeneration). Motion segments were loaded with pure moments in flexion/extension, lateral bending, and axial rotation to determine range of motion and neutral zone at 5 Nm.Results: All tested specimens exhibited degeneration grades between zero and two. Range of motion significantly decreased for grades one and two compared with grade zero in any motion direction (p<.05), showing the strongest decrease in extension comparing grade two with grade zero (-42%), while no significant differences were detected between grades one and two. Similar trends were found for the neutral zone with the strongest decrease in extension also comparing grade two with grade zero (-47%). Donor age did not significantly affect the range of motion, whereas the range of motion was significantly reduced in specimens from male donors due to the significantly higher degeneration grade in this study.Conclusions: Even mild intervertebral disc degeneration reduces the range of motion and neutral zone of the thoracic spine in any motion plane, whereas progressing degeneration does not further affect its flexibility. This is in contrast to the lumbar spine, where a more gradual decrease of flexibility was found in prior studies, which might be explained by differences between thoracic and lumbar intervertebral disc morphologies.Clinical Significance: Thoracic intervertebral disc degeneration should be considered as one of multiple potential causal factors in patients showing reduced passive mobility and middle back pain. [ABSTRACT FROM AUTHOR]

Copyright of Railway Signalling & Communication Engineering is the property of Railway Signalling & Communication Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of University of Sharjah Journal for Humanities & Social Sciences is the property of University of Sharjah - Scientific Publishing Unit and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Residual ridge resorption leads to diminished retention, support, and stability of the prosthesis due to decrease in the denture supporting areas, decreased denture space, and increased leverage due to increase inter-ridge distance. The prosthetic rehabilitation of the severely resorbed ridges needs modification for the fabrication of a stable prosthesis. This clinical report describes the prosthetic management of resorbed ridges using modified impression technique, neutral zone technique, external impressions, and fabrication of a hollow denture using three-dimensional glycerin spacer to enhance the retention and stability of the prosthesis. [ABSTRACT FROM AUTHOR]

Lack of adequate retention, support, and stability in the complete denture can be attributed to a poor fit or incorrect shape of the polished surfaces. This article presents a case using the neutral zone technique effectively with the fabrication of computer‐aided design and computer‐aided manufacturing (CAD‐CAM) record bases in an edentulous patient with severely resorbed alveolar ridges and discusses the overall treatment steps and clinical implications of this technique. A stable neutral zone and an accurate jaw relation were recorded using CAD‐CAM record bases and stability of complete denture was optimized by arranging denture teeth and reforming polishing surfaces in the neutral zone. A new complete denture was fabricated for a patient with atrophic alveolar ridges by a technique utilizing the neutral zone with CAD‐CAM record bases. [ABSTRACT FROM AUTHOR]

Background: Today, the use of virtual reality (VR) technology as an educational tool in dental education has expanded considerably. This study was aimed to evaluate the effectiveness of using VR technology in teaching neutral zone and teeth arrangement. Methods: This randomized trial was conducted at Kermanshah University of Medical Sciences, Iran in 2019. The study sample consisted of 50 six-year dental students who were randomly divided into experimental (n = 25) and control (n = 25) groups. Students' performance in both groups was assessed using tests. A questionnaire was used to assess the usability of VR technology and students' satisfaction with it. Results: All faculty members confirmed the usability of VR technology in dental education. The majority of students (76%) were highly satisfied with the use of this technology in their learning process. The mean score of students was significantly higher in the experimental group (16.92 ± 1.12) than in the control group (16.14 ± 1.18). Conclusion: In general, it can be argued that VR technology is useful and effective in the teaching–learning process. Therefore, its use in medical and dental schools can play an effective role in creating a dynamic, attractive, and successful learning environment. [ABSTRACT FROM AUTHOR]

Study Design: An in vitro biomechanics investigation exposing porcine functional spinal units (FSUs) to sudden impact loading although in a flexed, neutral, or extended posture.Objective: To investigate the combined effect of impact severity and postural deviation on intervertebral joint mechanics.Summary Of Background Data: To date, no in vitro studies have been conducted to explore lumbar tissue injury potential and altered mechanical properties from exposure to impact forces. Typically, after a motor vehicle collision, the cause of a reported acute onset of low back pain is difficult to identify, with potential soft tissue strain injury sites including the intervertebral disc, facet joint and highly innervated facet joint capsule ligament.Methods: Seventy-two porcine functional spinal units (36 C34, 36 C56), consisting of 2 adjacent vertebrae, ligaments, and the intervening intervertebral disc were included in the study. Each specimen was randomized to 1 of 3 experimental posture conditions (neutral, flexed, or extended) and assigned to 1 of 3 impact severities representing motor vehicle accident accelerations (4 g, 8 g, and 11 g). Before impact (pre) and after impact (post) flexion-extension and anterior-posterior shear neutral zone testing was completed.Results: A significant two-way interaction was observed between pre-post and impact severity for flexion-extension neutral zone length and stiffness and anterior-posterior shear neutral zone length and stiffness. This was a result of increasedneutral zone range and decreased neutral zone stiffness pre-post for the highest impact severity (11 g), regardless of posture.Conclusion: Functional spinal units exposed to the highest severity impact (11 g) had significant neutral zone changes, with increases in joint laxity in flexion-extension and anterior-posterior shear and decreased stiffness, suggesting that soft tissue injury may have occurred. Despite observed main effects of impact severity, no influence of posture was observed.Level of Evidence: N/A. [ABSTRACT FROM AUTHOR]

The vast majority of previous experimental studies on the thoracic spine were performed without the entire rib cage, while significant contributive aspects regarding stability and motion behavior were shown in several other studies. The aim of this literature review was to pool and increase evidence on the effect of the rib cage on human thoracic spinal biomechanical characteristics by collating and interrelating previous experimental findings in order to support interpretations of in vitro and in silico studies disregarding the rib cage to create comparability and reproducibility for all studies including the rib cage and provide combined comparative data for future biomechanical studies on the thoracic spine. After a systematic literature search corresponding to PRISMA guidelines, eleven studies were included and quantitatively evaluated in this review. The combined data exhibited that the rib cage increases the thoracic spinal stability in all motion planes, primarily in axial rotation and predominantly in the upper thorax half, reducing thoracic spinal range of motion, neutral zone, and intradiscal pressure, while increasing thoracic spinal neutral and elastic zone stiffness, compression resistance, and, in a neutral position, the intradiscal pressure. In particular, the costosternal connection was found to be the primary stabilizer and an essential determinant for the kinematics of the overall thoracic spine, while the costotransverse and costovertebral joints predominantly reinforce the stability of the single thoracic spinal segments but do not alter thoracic spinal kinematics. Neutral zone and neutral zone stiffness were more affected by rib cage removal than the range of motion and elastic zone stiffness, thus also representing the essential parameters for destabilization of the thoracic spine. As a result, the rib cage and thoracic spine form a biomechanical entity that should not be separated. Therefore, usage of entire human non-degenerated thoracic spine and rib cage specimens together with pure moment application and sagittal curvature determination is recommended for future in vitro testing in order to ensure comparability, reproducibility, and quasi-physiological validity.

Mandibular ridge resorption is a biomechanical and a complex disease that brings about chronic, progressive, cumulative and irreversible changes in bone structure resulting in severe impairment in fit and function of prosthesis. Some common hormonal, neurological, metabolic disorders can affect the adaptability of denture which can be diagnosed by a trained prosthodontist with proper history taking and clinical examination. If a denture stays inside or outside of the neutral zone, it will be unstable during functional & physiological activities such as talking, swallowing and mastication. Neutral zone technique is a long being used for the management of severely resorbed mandibular ridge. Various materials can used in recording neutral zone which have their own advantages and disadvantages. This technique serves as an alternative approach for the construction of mandibular complete denture. This technique is most effective for denture where there is a highly atrophic ridge, neuromuscular incoordination and history of denture instability. This clinical report describes in detail the fabrication of a complete denture in a patient with poorly formed mandibular ridge using neutral zone technique with addition of cast metal in mandibular denture for extra stability. [ABSTRACT FROM AUTHOR]

Introduction. Rational goals for denture construction are basically directed at the restoration of esthetics and masticatory function and the healthy preservation of the remaining natural tissues The three dimensional volume of complete dentures optimally occupies an edentulous space that is substantial, in the light of the progressive changes that accompany edentulism and functional dynamics. The paper discusses current knowledge of neutral zone in complete denture treatment.

Background/Aim: The purpose of this literature review and case report was to highlight the oral symptoms and the pathophysiology of Myasthenia Gravis (MG). MG is an autoimmune, antibody-mediated neuromuscular disorder. It is characterized by fluctuating fatigability and weakness affecting ocular, bulbar and (proximal) limb skeletal muscles.

The technique of neutral zone is useful. It is the convergence of many concepts and ideas into a feasible and functional method. The technique aims to build a denture in accordance with the underlying oral structures that are formed by muscle function. It acts as an alternative technique in case of highly atrophic ridges. With a history of denture instability, it is most successful. This paper seeks to provide information with an enclosure of a patient input study to use the technique.

Mandibular dentures often present greater difficulty in achieving retention, stability, and support than do maxillary dentures, primarily, due to a complex anatomy because of bone architecture and muscle attachments, and consequently, increased number of anatomic limitations. Long-term edentulism as well as prolonged use of ill-fitting dentures result in severe resorption of the alveolar ridges, further, worsening this situation. The present case report describes a similar case of a 90-year-old male patient who reported to the department of prosthodontics seeking replacement of his missing teeth. On examination, the lower denture was ill fitting with a severely resorbed mandibular alveolar ridge. Intraoral examination revealed an Atwood's Class III maxillary edentulous ridge with Class VI edentulous mandibular ridge. Special measures were adopted for the management of the patient through a modified impression technique along with physiologic registration of the neutral zone.

Complete edentulism poses significant challenges to oral function, esthetics, and overall quality of life. The use of complete dentures remains a cornerstone in rehabilitating such patients and restoring masticatory function, phonetics, and facial esthetics. However, to improve patients' function, it is important to restore the stomatognathic system. The rehabilitation process begins with a thorough assessment of the patient's oral health status, including evaluation of the remaining supporting structures and the surrounding soft tissues. Impressions and jaw relation records are meticulously obtained to ensure accurate denture fabrication. Proper denture retention, stability, and occlusion are crucial for successful rehabilitation. Beyond functional aspects, attention to esthetics plays a pivotal role in patient satisfaction and acceptance of complete dentures. Customization of denture teeth in terms of shape, shade, and arrangement is essential to achieve natural-looking smiles and facial harmony. Complete dentures remain a valuable treatment modality for the comprehensive rehabilitation of completely edentulous patients. Through a combination of meticulous treatment planning, advanced techniques, and patient-centered care, we can achieve successful outcomes in restoring oral function and thus improving the overall quality of life for such patients. Thus, this case report outlines a simple, economical, and useful rehabilitation plan for a patient with an edentulous maxillary and mandibular arch with flabby tissue and a resorbed mandibular ridge., Competing Interests: Human subjects: Consent was obtained or waived by all participants in this study. Conflicts of interest: In compliance with the ICMJE uniform disclosure form, all authors declare the following: Payment/services info: All authors have declared that no financial support was received from any organization for the submitted work. Financial relationships: All authors have declared that they have no financial relationships at present or within the previous three years with any organizations that might have an interest in the submitted work. Other relationships: All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work., (Copyright © 2024, Deshmukh et al.)

A flabby ridge is a hyperplastic and movable soft tissue that affects both maxillary and mandibular ridges most commonly the maxillary anterior region. This tissue that supports the denture is dynamic and can be dislodged by masticatory pressures, which affects denture stability and causes a loss of peripheral seal. The mobile tissue may be distorted as a result of forces applied during the impression-making process. For dental practitioners, fabricating dentures on a flabby ridge might be a Herculean endeavor because the dentures may not be stable and may not yield satisfactory outcomes. When treating such patients, practitioners should use extra caution. While treating such circumstances, adjustments to standard impression processes can be helpful. There are several ways to address flabby ridges, such as implant therapy, balanced occlusal load distribution, surgical management, and unique impression techniques. In this case report, a patient with a flabby ridge is treated prosthodontically via an alternative impression approach., Competing Interests: Human subjects: Consent was obtained or waived by all participants in this study. Conflicts of interest: In compliance with the ICMJE uniform disclosure form, all authors declare the following: Payment/services info: All authors have declared that no financial support was received from any organization for the submitted work. Financial relationships: All authors have declared that they have no financial relationships at present or within the previous three years with any organizations that might have an interest in the submitted work. Other relationships: All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work., (Copyright © 2024, Gupta et al.)

The ill-fitting and unstable complete denture prosthesis is the most commonly faced problem by patients with compromised resorbed ridge. The retention, support, and stability of dentures are compromised in severely resorbed ridges, leading to difficulty in mastication and swallowing. The flabby tissue can be managed by using appropriate mucostatic impression techniques, and severely resorbed ridges can be managed by the coordination of a complete denture prosthesis with the neuromuscular function using a neutral zone for the arrangement of artificial teeth. This case report presents a combination of the Hobkirk technique and the neutral zone concept for the rehabilitation of the flabby tissue and severely resorbed alveolar ridge., Competing Interests: Human subjects: Consent was obtained or waived by all participants in this study. Conflicts of interest: In compliance with the ICMJE uniform disclosure form, all authors declare the following: Payment/services info: All authors have declared that no financial support was received from any organization for the submitted work. Financial relationships: All authors have declared that they have no financial relationships at present or within the previous three years with any organizations that might have an interest in the submitted work. Other relationships: All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work., (Copyright © 2024, Chitlange et al.)

Low back pain is a common problem among competitive swimmers, and repeated torso hyperextension is claimed to be an etiological factor. The purpose of this study was to describe the three-dimensional torso configurations in the front crawl stroke and to test the hypothesis that swimmers experience torso hyperextension consistently across the stroke cycles. Nineteen collegiate swimmers underwent 2 measurements: a measurement of the active range of motion in 3 dimensions and a measurement of tethered front crawl stroke at their maximal effort. Torso extension beyond the active range of torso motion was defined as torso hyperextension. The largest torso extension angle exhibited during the stroke cycles was 9 ± 11° and it was recorded at or around 0.02 ± 0.08 s, the instant at which the torso attained the largest twist angle. No participant hyperextended the torso consistently across the stroke cycles and subjects exhibited torso extension angles during tethered front crawl swimming that were much less than their active range of motion. Therefore, our hypothesis was rejected, and the data suggest that repeated torso hyperextension during front crawl strokes should not be claimed to be the major cause of the high incidence of low back pain in swimmers. [ABSTRACT FROM AUTHOR]

Abstract Background Neutral zone (NZ) is a specific area in the oral cavity where muscular opposite forces are null. NZ represents the ideal zone for prosthesis placement. In this study, we compared digital implant planning using conventional technique and using NZ registration through piezography. Methods Sixty‐tree implants were digitally planned. Angular deviation differences between traditional planned and NZ‐planned implants were calculated. In addition, interferences with soft tissues (i.e., tongue and cheeks) were evaluated. Results We observed a significant difference between traditional technique and piezographic approach in terms of implants angulation (p = .003), independent of site. A 4.7% of the planned abutments with traditional technique were placed outside the NZ, causing conflict with soft tissues in the digital model. Conclusions Compared with traditional technique, piezography allows a significantly different exploitation of the nonconflict area, which potentially translates into better management of soft tissues and improved functionality of the implants.

Intervertebral disc (IVD) degeneration is associated with low back pain (LBP) and accompanied by mechanical changes to the spine. Secreted protein acidic and rich in cysteine (SPARC) is a protein that contributes to the functioning and maintenance of the extracellular matrix. SPARC-null mice display accelerated IVD degeneration and pain-associated behaviors. This study examined if SPARC-null mice also display altered spine mechanics as compared to wild-type (WT) mice. Lumbar spines from SPARC-null (n=36) and WT (n=18) mice aged 14-25?months were subjected to cyclic axial tension and compression to determine neutral zone (NZ) length and stiffness. Three separate mechanical tests were completed for each spine to determine the effect of the number of IVDs tested in series (one versus two versus three IVDs). SPARC-null spine NZs were both stiffer (p<0.001) and smaller in length (p<0.001) than WT spines. There was an effect of the number of IVDs tested in series for NZ length but not NZ stiffness when collapsed across condition (SPARC-null and WT). Correlation analysis revealed a weak negative correlation (r=-0.24) between age and NZ length in SPARC-null mice and a weak positive correlation (r=0.30) between age and NZ stiffness in WT mice. In conclusion, SPARC-null mice had stiffer and smaller NZs than WT mice, regardless of the number of IVDs in series being tested. The increased stiffness of these IVDs likely influences mobility at these spinal joints thereby potentially contributing to low back pain. [ABSTRACT FROM AUTHOR]

This article deals with the way urban planning during colonial times affects the mobility of pedestrians today. In Kinshasa, a green belt cuts the oldest part of the city right in two, and this hinders a smooth traffic flow. The belt is what remains of the neutral zone the colonial authorities implemented to separate the European from the African neighborhoods; it consisted of several large walled-off facilities, such as a zoo, a park, and a hospital. In this article, we explore how pedestrians in Kinshasa deal with these obstructions to their mobility. We show that they forge their pedestrian itineraries through walls designed to be impermeable, in particular by shortcutting through a hospital. These alternative itineraries have solidified through time, revealing the effectiveness of their persistent daily walks. As we argue, the pedestrians actively redefine the mobility patterns of their city. [ABSTRACT FROM AUTHOR]

The loose and unstable lower complete denture is one of the most common problems faced by denture wearers. Prosthetic rehabilitation of a patient with severely resorbed ridge is the most challenging therapy a Prosthodontist can undertake. Masticatory function requires a unique coordination with muscles and oral structures. If the denture is placed in a zone where the displacing forces of tongue, lips, cheeks and modulus are balanced, then the denture during function will be retained more effectively. This zone is known as neutral zone.1,2 It is in this zone that the natural teeth lie, and this is where the artificial teeth should also be positioned. This area is achieved by using the neutral zone technique. [ABSTRACT FROM AUTHOR]