Removable Devices Research Articles

Treatment of mandibular odontogenic keratocyst by decompression with a customized removable device: A case report and literature review

Keratocystic odontogenic tumor (KCOT) is a rare, bening intraosseous tumor of odontogenic origin with a potential of aggressive and infiltrative behavior. It shows specific histopathological features, and has a high recurrence rate. In this report, we present a case of 17 year old female patient with large-sized KCOT associated with impacted third molar in the mandibular ramus region and its decompression treatment. Decompression was applied by a customized removable appliance to prevent the closing of the cyst cavity. On the 3rd and 6th months of the control radiography, it was seen that the calcification foci began to be seen and erupting the impacted teeth as a result of shrinkage of the lesion volume. After 18 months, there was a normal contrast image on the tomography and the intraoral healing was uneventfully.Keywords: Customized removable aparey, decompression treatment, keratocystic odontogenic tumor.

Dental and Temporomandibular Joint Problems among SCUBA Divers in Jeddah, KSA

The recent increase in the popularity of scuba diving has emphasized the role of the dentist in the prevention and treatment of oralbarotrauma. Barotrauma is a physical injury that results from ambient pressure changes during flying, diving or hyperbaric oxygen therapy [1]. Pressure changes can induce otitis-media, sinusitis, headache or can be manifested as pain to the oral region [2]. Dental barotrauma can happen while ascending; upon surfacing after completing the dive, the diver may report that a tooth broke or has shattered [4]. Divers may also suffer from signs of tempromandibular disorder such as pain in tempromandibular joint (TMJ) and ears, TMJ clicking or crepitus, trismus and impaired TMJ mobility, headache and facial pain [5]. Hence, this article aims to Assessment of dental and TMJ problems in a sample of SCUBA divers in Jeddah Saudi Arabia,Assessment of dental complaints of divers, Assessment of TMJ problems associated with SCUBA diving and relate the previous problems to diving related characteristics such as the duration of practice, the number of dives and the frequency of diving per month. Material and methods: Divers at four dive centers at the Northern coast of Jeddah (Obhur) asked to complete a questionnaire that requested information regarding diving experience and facial pain and dental symptoms experienced during diving. Cross sectional study assessing the prevalence of dental and TMJ problems among divers. The total number was 60 SCUBA divers. Results: most of divers did not complain of sinusitis (75%). More than have of the sample complained of headache (65%). While facial pain was reported by (46.7%) of the sample. More than half did not experience dental pain (65%) while (35%) had dental pain during diving. More than half of the sample did not experience TMJ pain 70% while (30%) reported having TMJ pain during diving. Conclusions: Scuba diving is one of the fastest growing sports in the world. Since Jeddah is the main port of Saudi Arabia, diving has become an occupation as well a popular sport for many people. This attracted our attention to the importance of evaluating the oral problems related to this activity. It is inevitable that the general dental practitioner will have patients who participate in this sport and they should be aware of a number of problems that a diver can experience that are associated with the teeth and related structures. The dental team must educate the diver patient of the infectious potential of the mouthpiece and recommend using only a private one, and encourage maintenance by hygiene procedures after each use, similar to other removable oral devices. The diver should not dive in times of illness. Diving related TMD symptoms should be differentiated from barotitis symptoms.

Prosthetic rehabilitation for a patient treated for embryonal rhabdomyosarcoma

A female patient, now aged 17 years, was diagnosed with rhabdomyosarcoma (RMS) in the right pterygopalatine fossa when she was 3 years old. The RMS was successfully treated by excision, but the subsequent radiation and polychemotherapy resulted in the complete anesthesia of the distribution area of the right trigeminal nerve and loss of vision in the right eye. The patient also experienced pain in the mandibular joints and masticatory muscles. Panoramic radiographs displayed a multiple agenesia of the permanent teeth and underdeveloped apices. Treatment involved the fabrication of a complete maxillary denture. A removable device was fabricated to evaluate her response to an occlusal vertical dimension increase of 6 mm and provide a stable intercuspal position. After wearing the prosthesis for 6 months, the patient reported that she was completely free of symptoms.

An exploratory study on differences in cumulative plantar tissue stress between healing and non-healing plantar neuropathic diabetic foot ulcers

BackgroundMechanical stress is important in causing and healing plantar diabetic foot ulcers, but almost always studied as peak pressure only. Measuring cumulative plantar tissue stress combines plantar pressure and ambulatory activity, and better defines the load on ulcers. Our aim was to explore differences in cumulative plantar tissue stress between people with healing and non-healing plantar diabetic foot ulcers. MethodsWe analyzed a subgroup of 31 patients from a randomized clinical trial, treated with a removable offloading device for their plantar diabetic forefoot ulcer. We measured in-device dynamic plantar pressure and daily stride count to calculate cumulative plantar tissue stress at the ulcer location and associated this with ulcer healing and ulcer surface area reduction at four weeks (Student's t and chi-square test for significance, Cohen's d for effect size). FindingsIn 12 weeks, 68% (n = 21) of the ulcers healed and 32% (n = 10) did not. No statistically significant differences were found for cumulative plantar tissue stress, plantar pressure or ambulatory activity between people with healed and not-healed ulcers. Cumulative plantar tissue stress was 25% lower for people with healed ulcers (155 vs. 207 MPa·s/day; P = 0.71; Effect size: d = 0.29). Post-hoc analyses in the 27 patients who self-reported to be adherent to wearing the device showed that cumulative plantar tissue stress was 49% lower for those who reached ≥75% ulcer surface area reduction at four weeks (140 vs. 275 MPa·s/day; P = 0.09; d = 0.76); smaller differences and effect sizes were found for peak pressure (24%), peak pressure-time integral (30%) and ambulatory activity (26%); (P-value range: 0.14–0.97; Cohen's d range: 0.14–0.70). InterpretationMeasuring cumulative plantar tissue stress may provide insight beyond that obtained from plantar pressure or ambulatory activity alone, with regard to diabetic foot ulcer healing using removable offloading devices. These explorative findings provide baseline data for further studies on this relevant topic.

Multidisciplinary treatment of complex skeletal class III malocclusion

Introduction. Skeletal malocclusions, especially those with a prominent vertical component, always present a challenge for the interdisciplinary approach to their treatment planning. The aim of this report is to present a patient with a complex skeletal deformity in all three directions (vertical, sagittal and transverse). Case report. A twenty-four year old female patient with a skeletal Class III malocclusion, open bite and laterognathia, was firstly treated by orthodontic fixed appliances, whereas the dental decompensation of dentoalveolar structures was carried out and adjusted to their bone structures, thus enabling an adequate and sufficient reposition of the jaw. A surgical correction included bi-maxillary osteotomy due to pronounced vertical cephalometric parameters, necessitating a posterior maxillary intrusion and mandibular repositioning. In that manner, the relapse was prevented and a long-term stable result obtained. In the retention period, the patient wore removable bi-maxillary retention devices. Conclusion. The combined orthodontic-surgical treatment provided the Class I occlusion with aesthetic and functionally satisfactory results which were envisioned by the treatment plan.

Bond Strength to Primary Teeth Dentin Following Disinfection with 2% Chlorhexidine

The aim of the study is to evaluate morphological changes in upper airways in patients undergoing therapy with removable functional orthopedic devices used in the treatment of the II skeletal classes by mandibular retraction.

Career Focus: Film Falsies.

Dental technician Gary Archer makes removable prosthodontic devices for hollywood movies. he shares some of the tricks of the trade with PDJ managing editor Amy Brewerton.

Design and manufacturing of patient-specific orthodontic appliances by computer-aided engineering techniques.

Orthodontic treatments are usually performed using fixed brackets or removable oral appliances, which are traditionally made from alginate impressions and wax registrations. Among removable devices, eruption guidance appliances are used for early orthodontic treatments in order to intercept and prevent malocclusion problems. Commercially available eruption guidance appliances, however, are symmetric devices produced using a few standard sizes. For this reason, they are not able to meet all the specific patient's needs since the actual dental anatomies present various geometries and asymmetric conditions. In this article, a computer-aided design-based methodology for the design and manufacturing of a patient-specific eruption guidance appliances is presented. The proposed approach is based on the digitalization of several steps of the overall process: from the digital reconstruction of patients' anatomies to the manufacturing of customized appliances. A finite element model has been developed to evaluate the temporomandibular joint disks stress level caused by using symmetric eruption guidance appliances with different teeth misalignment conditions. The developed model can then be used to guide the design of a patient-specific appliance with the aim at reducing the patient discomfort. At this purpose, two different customization levels are proposed in order to face both arches and single tooth misalignment issues. A low-cost manufacturing process, based on an additive manufacturing technique, is finally presented and discussed.

Anterior mandibular rehabilitation causing chronic obstructive sialadenitis: ?A series of sialo-CBCT cases and literature review.

The aim of this study was to assess and present, using sialo-cone beam computed tomography (sialo-CBCT) examination, cases of submandibular gland (SM) chronic obstructive sialadenitis (COS) caused by dental rehabilitation. Clinical and radiographic data of all patients referred for SM sialo-CBCT imaging in the Oral and Maxillofacial Imaging Unit with recurrent SM swelling between January 2012 and July 2015 were reviewed. Cases with suggested iatrogenic cause were selected and described. A literature review of similar cases was also performed. Seventy-one patients with salivary gland (SG) swelling were referred for SM sialo-CBCT. Of these, 16 had implant-supported fixed partial prostheses and seven had full mandibular overdentures. In five patients, COS was diagnosed and a causal relationship between their dental rehabilitation and symptoms was suggested. A literature search revealed 11 cases of SM COS secondary to anterior mandibular rehabilitation. Clinicians rehabilitating the anterior edentulous mandibular region should be aware that both fixed and removable devices may block the orifices of the SM, causing COS.

Propagation Model with Varying Population Size of Removable Memory Device Virus

Removable memory device (RMD) is one of main way for propagating computer virus. In this paper, a dynamic propagation model of RMD-virus with varying population size is discussed. Unlike other computer virus propagation models, the proposed model mainly considers the RMD-virus propagation between host and RMD, which is embodied by introducing the RMD state and new propagation rate. Furthermore, to control the RMD-virus, three threshold parameters are obtained. The simulation results show that the proposed model can serve as a basis for understanding and simulating RMD-virus.

Use of maxillofacial laboratory materials to construct a tissue-equivalent head phantom with removable titanium implantable devices for use in verification of the dose of intensity-modulated radiotherapy

The dose of radiotherapy is often verified by measuring the dose of radiation at specific points within a phantom. The presence of high-density implant materials such as titanium, however, may cause complications both during calculation and delivery of the dose. Numerous studies have reported photon/electron backscatter and alteration of the dose by high-density implants, but we know of no evidence of a dosimetry phantom that incorporates high density implants or fixtures. The aim of the study was to design and manufacture a tissue-equivalent head phantom for use in verification of the dose in radiotherapy using a combination of traditional laboratory materials and techniques and 3-dimensional technology that can incorporate titanium maxillofacial devices. Digital designs were used together with Mimics® 18.0 (Materialise NV) and FreeForm® software. DICOM data were downloaded and manipulated into the final pieces of the phantom mould. Three-dimensional digital objects were converted into STL files and exported for additional stereolithography. Phantoms were constructed in four stages: material testing and selection, design of a 3-dimensional mould, manufacture of implants, and final fabrication of the phantom using traditional laboratory techniques. Three tissue-equivalent materials were found and used to successfully manufacture a suitable phantom with interchangeable sections that contained three versions of titanium maxillofacial implants. Maxillofacial and other materials can be used to successfully construct a head phantom with interchangeable titanium implant sections for use in verification of doses of radiotherapy.

A software agent enabled biometric security algorithm for secure file access in consumer storage devices

In order to resist unauthorized access, consumer storage devices are typically protected using a low entropy password. However, storage devices are not fully protected against an adversary because the adversary can utilize an off-line dictionary attack to find the correct password and/or run an existing algorithm for resetting the existing password. In addition, a password protected device may also be stolen or misplaced allowing an adversary to easily retrieve all the stored confidential information from a removable storage device. In order to protect the consumer's confidential information that has been stored, this paper proposes a mutual authentication and key negotiation protocol that can be used to protect the confidential information in the device. The functionality of the protocol enables the storage device to be secure against relevant security attacks. A formal security analysis using Burrows-Abadi- Needham (BAN) logic is presented to verify the presented algorithm. In addition, a performance analysis of the proposed protocol reveals a significantly reduced communication overhead compared to the relevant literature.

可撤式舌機能訓練装置により摂食嚥下障害が改善した 1 例

可撤式舌機能訓練装置により摂食嚥下障害が改善した 1 例

Design of Removable Guardrail System Based on ZigBee Network

In order to solve the problem that tidal phenomena will lead to severe traffic jam, this paper designs a Removable Guardrail System based on ZigBee network (RGSZ). This system includes the user terminal device and the removable guardrail device. The user terminal selects CC2530 which supports ZigBee protocol as wireless transmission module. It sends moving instructions from user terminal to nearest guardrail device. The removable guardrail device selects MSP430 as the controller to receive moving instructions from user terminal, then driver chip will drive stepping motor to move. At the same time CC2530 sends moving instructions to next guardrail device through ZigBee, making all guardrail devices moving together. By remote controlling removable guardrails to change the width of the road on both sides, this system makes road more humanized and improves the traffic jam greatly. The result of experiment tests indicates that: the system has the characteristics of runs stably, high precision and safe information transmission.

The Role of Pressure Offloading on Diabetic Foot Ulcer Healing and Prevention of Recurrence.

An increased plantar pressure is a causative factor in the development of plantar foot ulcers in people with diabetes mellitus, and ulcers are a precursor of lower extremity amputation. In this article, the evidence is reviewed that relieving areas of increased plantar pressure (ie, offloading) can heal plantar foot ulcers and prevent their recurrence. Noninfected, nonischemic neuropathic plantar forefoot ulcers should heal in 6 to 8 weeks with adequate offloading. Recent meta-analyses and systematic reviews show that nonremovable knee-high devices are most effective. This is probably because they eliminate the problem of nonadherence with the use of a removable device. Studies show a large discrepancy between evidence-based recommendations on offloading and what is used in clinical practice. Many clinics continue to use methods that are less effective or have not been proven to be effective, while ignoring evidence-based methods. Strategies are proposed to address this issue, notably the adoption and implementation of recent international guidelines by professional societies and a stronger focus of clinicians on expedited healing. For the prevention of plantar foot ulcer recurrence in high-risk patients, 2 recent trials have shown that the incidence of recurrence can be significantly reduced with custom-made footwear that has a demonstrated pressure-relieving effect through guidance by plantar pressure measurements, under the condition that the footwear is worn. This review helps to inform clinicians about effective offloading treatment for healing plantar foot ulcers and preventing their recurrence.

Can't Stand the Pressure: The Association Between Unprotected Standing, Walking, and Wound Healing in People With Diabetes.

The objective was to report patterns of physical activity and their relationship to wound healing success in patients with diabetic foot ulcers protected with removable or irremovable offloading devices. Forty-nine people with diabetic foot ulcers were randomized to wear either a removable cast walker (RCW) or an irremovable instant total contact cast (iTCC). Primary outcome measures included change in wound size, physical activities including position (ie, sitting, standing, lying) and locomotion (speed, steps, etc). Outcomes parameters were assessed on weekly basis until wound healing or until 12 weeks. A higher proportion of patients healed at 12 weeks in the iTCC group ( P = .038). Significant differences in activity were observed between groups starting at week 4. RCW patients became more active than the iTCC group (75% higher duration of standing, 100% longer duration of walking, and 126% longer unbroken walking bout, P < .05). Overall, there was an inverse association between rate of weekly wound healing and number of steps taken per day ( r < -.33, P < .05) for both groups. RCW patients had a significant inverse correlation between duration of daily standing and weekly rate of healing ( r = -.67, P < .05). Standing duration was the only significant predictor of healing at 12 weeks. The results from this study suggest significant differences in activity patterns between removable and irremovable offloading devices. These patterns appear to start diverging at week 4, which may indicate a decline in adherence to offloading. Results suggest that while walking may delay wound healing, unprotected standing might be an even more unrealized and sinister culprit.

Distributed Intelligent MEMS

In recent years, distributed intelligent microelectromechanical systems (DiMEMSs) have appeared as a new form of distributed embedded systems. DiMEMSs contain thousands or millions of removable autonomous devices, which will collaborate with each other to achieve the final target of the whole system. Programming such systems is becoming an extremely difficult problem. The difficulty is due not only to their inherent nature of distributed collaboration, mobility, large scale, and limited resources of their devices (e.g., in terms of energy, memory, communication, and computation) but also to the requirements of real-time control and tolerance for uncertainties such as inaccurate actuation and unreliable communications. As a result, existing programming languages for traditional distributed and embedded systems are not suitable for DiMEMSs. In this article, we first introduce the origin and characteristics of DiMEMSs and then survey typical implementations of DiMEMSs and related research hotspots. Finally, we propose a real-time programming framework that can be used to design new real-time programming languages for DiMEMSs. The framework is composed of three layers: a real-time programming model layer, a compilation layer, and a runtime system layer. The design challenges and requirements of these layers are investigated. The framework is then discussed in further detail and suggestions for future research are given.

DENTITION IN PATIENTS BEFORE AND AFTER ORTHODONTIC TREATMENT OF MALOCCLUSION CLASS III

Many scientists were engaged in the study of dentition anthropometry in patients before and after orthodontic treatment. The most common orthodontic device for the treatment of malocclusion class III is a regulator of Frenkel type III. We have proposed a new orthodontic device for the treatment of patients with malocclusion class III and premature removal of temporary molars. Aim - to compare changes of dentitions in children aged 6-12 before and after orthodontic treatment of malocclusion class III using the device of own design and regulator of Frenkel type III. Materials and methods. 110 patients at the age of 6-12 years with malocclusion class III were treated with the use of removable orthodontic curative devices. Anthropometry of dentitions was conducted before and after the treatment. Results. After applying the new diagnostic and treatment algorithm, the duration of orthodontic treatment of patients with malocclusion class III reduced by 1.3 times. The children's quality of life have improved after orthodontic treatment. Conclusion. In case of children aged 6-12 years with malocclusion class III associated with premature removal of temporary molars, it is necessary to use the device of our design. This will give the opportunity not only to fix the dento-facial abnormality, but also to restore the functions of chewing, swallowing and speech.

Role and Determinants of Adherence to Off-loading in Diabetic Foot Ulcer Healing: A Prospective Investigation.

Studies indicate that off-loading adherence is low in patients with diabetic foot ulcers (DFUs), which may subsequently delay healing. However, there is little empirical evidence for this relationship or the factors that influence adherence. This prospective, multicenter, international study of 79 (46 from the U.K. and 33 the U.S.) persons with type 2 diabetes and plantar DFUs assessed the association between off-loading adherence and DFU healing over a 6-week period. Additionally, potential demographic, disease, and psychological determinants of adherence were examined. DFUs were off-loaded with a removable device (77% a removable cast walker). Off-loading adherence was assessed objectively by activity monitors. Patient-reported measures included Hospital Anxiety and Depression Scale (HADS), Neuropathy and Foot Ulcer Quality of Life (NeuroQoL) instrument, and Revised Illness Perception Questionnaire (IPQ-R). Off-loading adherence was monitored for 35 ± 10 days, and devices were used during 59 ± 22% of subjects' activity. In multivariate analyses, smaller baseline DFU size, U.K. study site, and better off-loading adherence predicted smaller DFU size at 6 weeks (P < 0.05). Better off-loading adherence was, in turn, predicted by larger and more severe baseline DFUs, more severe neuropathy, and NeuroQoL foot pain (P < 0.05). In contrast, greater NeuroQoL postural instability predicted worse off-loading adherence (P < 0.001). HADS and IPQ-R measures were not significantly associated with off-loading adherence. Off-loading adherence is associated with the amount of DFU healing that occurs, while postural instability is a powerful predictor of nonadherence. Clinicians should take this neuropathic symptom into consideration when selecting an off-loading device, as off-loading-induced postural instability may further contribute to nonadherence.

MATHEMATICAL MODEL AND METHODOLOGY FOR CALCULATION OF MINIMIZATION ON TURNING RADIUS OF TRACTOR UNIT WITH REPLACEABLE SUPPORTING AND MANEUVERING DEVICE

Smooth plowing with the help of reversible plows has replaced an enclosure method of soil treatment. The method may cause a formation of back ridges or open furrows. Due to this fact turnings of a tractor unit with a minimum radius required in order to ensure shuttle movements each time in the furrow of the preceding operating stroke have become a dominant type of turnings. Non-productive shift time is directly dependent on them and it is on the average 10–12 %, and it is up to 40 % in small contour areas with short run. Large non-productive time is connected with the desire to reduce headland width at field edges, and then a turning is made in several stages while using a complicated maneuvering. Therefore, an increase in efficiency of a plowing unit by means of minimization on its turning radius and execution of turning at one stage in the shortest possible time are considered as relevant objectives. In such a case it is necessary to take into account the fact that potential capabilities of universal tractors having established time-proved designs in respect of reduction of turning radius are practically at the end. So it is expedient to solve the matter at the expense of additional removable devices that ensure transformation of tractor wheel formula at the run end in order to reorient its position. Finally high quality plowing ensured by future-oriented reversible plows will be accompanied not only by output increase per shift, but also by decrease in headland width, their compaction and abrasion due to suspension systems and increase in productivity. The developed design having a novelty which proved by an invention patent and representing an additional supporting and maneuvering device significantly minimizes all the above-mentioned disadvantages and does not require any changes in tractor production design. Investigations have been carried on the following topic: “Minimization of turning radius for universal tractors by transformation of wheel formula”. The paper presents a mathematical model, which reflects all the parameters having an effect on a tractor unit with a supporting and maneuvering device and it also considers a longitudinal and transverse stability.