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Subperiosteal implants (SIs) were first developed by Dahl in 1941 for oral rehabilitation in case of severe jaw atrophy. Over time, this technique was abandoned due to the high success rate of endosseous implants. The emergence of patient-specific implants and modern dentistry allowed a revisitation of this 80-year-old concept resulting in a novel “high-tech” SI implant. This study evaluates the clinical outcomes in forty patients after maxillary rehabilitation with an additively manufactured subperiosteal jaw implant (AMSJI®). The oral health impact profile-14 (OHIP-14) and numerical rating (NRS) scale were used to assess patient satisfaction and evaluate oral health. In total, fifteen men (mean age: 64.62 years, SD ± 6.75 years) and twenty-five women (mean age: 65.24 years, SD ± 6.77 years) were included, with a mean follow-up time of 917 days (SD ± 306.89 days) after AMSJI installation. Patients reported a mean OHIP-14 of 4.20 (SD ± 7.10) and a mean overall satisfaction based on the NRS of 52.25 (SD ± 4.00). Prosthetic rehabilitation was achieved in all patients. AMSJI is a valuable treatment option for patients with extreme jaw atrophy. Patients enjoy treatment benefits resulting in high patient satisfaction rates and impact on oral health.

Additively manufactured subperiosteal jaw implants (AMSJI) are patient-specific, 3D-printed, titanium implants that provide an alternative solution for patients with severe maxillary bone atrophy. The aim of this study was to evaluate the bony remodeling of the maxillary crest and supporting bone using AMSJI. Fifteen patients with a Cawood-Howell Class V or greater degree of maxillary atrophy were evaluated using (cone beam) computed tomography scans at set intervals: one month (T1) and twelve months (T2) after definitive masticatory loading of bilateral AMSJI implants in the maxilla. The postoperative images were segmented and superimposed on the preoperative images. Fixed evaluation points were determined in advance, and surface comparison was carried out to calculate and visualize the effects of AMSJITM on the surrounding bone. A total mean negative bone remodeling of 0.26 mm (SD 0.65 mm) was seen over six reference points on the crest. Minor bone loss (mean 0.088 mm resorption, SD 0.29 mm) was seen at the supporting bone at the wings and basal frame. We conclude that reconstruction of the severely atrophic maxilla with the AMSJI results in minimal effect on supporting bone. Reduced stress shielding with a biomechanically tuned subperiosteal implant does not induce radiographically significant crestal bone atrophy. ispartof: JOURNAL OF CLINICAL MEDICINE vol:10 issue:16 ispartof: location:Switzerland status: published

This paper seeks traffic signal control policies which maximise long-run network throughput when demand is within network capacity and also when demand is beyond network capacity. The paper considers smooth versions of two well-known responsive traffic signal control policies: the P 0 policy (see Smith, 1979b, 1980 or Smith et al., 2015) and the maxpressure or MP policy (see Varaiya, 2013a). The paper gives two simple example networks where both of these smooth responsive traffic control policies give rise to decreasing throughput for increasing demands; when these demands are beyond the network capacity. The paper then suggests a simple modification of the two responsive traffic control policies and shows that the two modified policies do maximise the long run throughput of the two signal-controlled networks; both when a steady input demand D is within network capacity and also when a steady demand exceeds network capacity. The modified version of P 0 is as follows: for a certain positive number K, for D ⩽ K use responsive policy P 0 , and for D > K use the green-times generated by P 0 when D = K . Thus in this modification the green-time proportions generated by responsive P 0 are frozen as demand passes through K; and remain fixed for all demands D which exceed K. The paper shows that the above modification when applied to a continuous version of MP also maximises throughput in both networks for all values of the steady demand D. Finally the paper considers a signal controlled network with route choice. It is shown that if routes are chosen by travellers in their own best interests then the continuous version of MP does not always maximise throughput, even if the constant input demand D is within the network capacity, but P 0 does always maximise throughput, even when the constant input demand D is beyond the network capacity.

This study introduces a novel protocol for the placement of zygomatic implants utilizing presurgical planning with 3-dimensional (3D) computed tomography (CT)/cone-beam (CB)CT diagnostic technologies and advanced 3D printing through the development of a specific surgical guide.The protocol relied on large field of view CT/CBCT for an accurate assessment of the maxillary arch to plan zygomatic implant receptor sites. CT/CBCT-derived surgical guides of a novel design were then fabricated using 3D printing technology. An exact replica of the entire maxilla and zygomatic bone was then fabricated in actual scale model size to allow for a simulation of the operation using replicas of implants to be used during the surgical intervention. Guidance was also provided for the sinus fenestration as part of the surgical template. Four patients received a total of 10 zygomatic implants all placed by the same surgeon.Preoperative positions of the zygomatic implants were compared with the postoperative implant positions by merging the pre- and postoperative CT scan datasets. The degree of accuracy of the superimposition was measured utilizing sophisticated software. Apical, coronal, and angular deviations were determined for each implant. Deviations from the computerized project to the actual implant positions ranged from 2 mm to 3 mm with angular deviations ranging between 1.88 and 4.55 degrees.Placement of zygomatic implants requires surgical experience due to close proximity of vital anatomical structures. This study used methods of superimposition that illustrated satisfactory correspondence between inserted implants and the virtual plan. No adjacent vital anatomical structures were damaged. The novel surgical guide design afforded the surgeon visual control of the drilling protocol. Positioning the guide in close proximity to the entry point of the zygomatic body aided control of the drills up to the vicinity of the exit point, significantly limiting problems associated with angular deviation. Reducing errors and complications is essential for zygomatic implants to remain a viable treatment alternative, and further research on a guided approach to their placement is encouraged.

Anticipatory optimal network control is defined as the problem of determining the set of control actions that minimizes a network-wide objective function. This not only takes into account local consequences on the propagation of flows, but also the global network-wide routing behavior of the users. Such an objective function is, in general, defined in a centralized setting, as knowledge regarding the whole network is needed to correctly compute it. Reaching a level of centralization sufficient to attain network-wide control objectives is however rarely realistic in practice. Multiple authorities are influencing different portions the network, separated either hierarchically or geographically. The distributed nature of networks and traffic directly influences the complexity of the anticipatory control problem. This is our motivation for this work, in which we introduce a decomposition mechanism for the global anticipatory network traffic control problem, based on dynamic clustering of traffic controllers. Rather than solving the full centralized problem, or blindly performing a full controller-wise decomposition, this technique allows recognizing when and which controllers should be grouped in clusters, and when, instead, these can be optimized separately. The practical relevance with respect to our motivation is that our approach allows identification of those network traffic conditions in which multiple actors need to actively coordinate their actions, or when unilateral action suffices for still approximating global optimality. This clustering procedure is based on well-known algebraic and statistical tools that exploit the network’s sensitivity to control and its structure to deduce coupling behavior. We devise several case studies in order to assess our newly introduced procedure’s performances, in comparison with fully decomposed and fully centralized anticipatory optimal network control, and show that our approach is able to outperform both centralized and decomposed procedures.

The quality of information on a network is crucial for different transportation planning and management applications. Problems focusing on where to strategically extract this information can be broadly subdivided into observability problems, which rely on the topological properties of the network, and flow-estimation problems, where (prior) information on observed flows is needed to identify optimal sensor locations. This paper contributes mainly to the first category: more specifically, it presents a new methodology and an intuitive metric able to quantify the quality of a solution in case of partial observability, i.e. when not all flow variables are observed or can be uniquely determined from the observed flows. This methodology is based on existing approaches that can efficiently find solutions for full observability (i.e., the set of sensors needed to make the system fully determined), and exploits only the algebraic relations between link, route and origin–destination flow variables to quantify the information contained in any arbitrary subset of these variables. The new metric allows, through its adoption within simple search algorithms, to efficiently select sensor locations when the number of available sensors is limited by, for example, budget constraints and is less than the number needed to guarantee full observability. The chosen positions aim at selecting those locations that contain the largest information content on the whole network. This is an important contribution in this field, since even in small sized networks the solution for full observability requires an exceedingly large amount of sensors. The assessment of partial observability solutions, based on explicit route enumeration, allows one to categorize families of full observability solutions, and shows that these contain different information potential. This way, it is possible to rank solutions requiring a lower number of sensors while containing the same information content. We tested this new methodology both on toy networks, in order to analyse the properties of the metric and illustrate its logic, and to explain and test heuristic search algorithms for optimal sensor positioning on a real-sized network. Analysis of partial observability solutions shows that the basic search algorithms succeed in finding the links that contain the largest deal of information in a network.

The structural evolution of the Al Qarqaf Arch (Libya) and the southern sector of the Ghadames Basin were reconstructed by the integration of remote sensing analysis, 2D seismic lines, well log data and geological maps. The Al Qarqaf Arch (Libya) is a wide, gentle warping of pre-Cambrian and Palaeozoic rocks that forms the southern boundary of the Ghadames Basin, a large Palaeozoic intracratonic basin of the Saharan Platform. Surface and subsurface analyses revealed the presence of different phases of intracratonic deformations, related to the Al Qarqaf Arch uplift and Ghadames Basin development. Extensional tectonic phases prevailed in the study area up until the Devonian, while compressional folding and structural inversion affected the region during Late Carboniferous and Mesozoic, indicating that compressional horizontal stresses affected the plate interior, giving rise to intraplate tectonics. Three major unconformities (Intra-Silurian, Silurian–Devonian transition and Upper Carboniferous unconformities) outline these tectonic events related to the upwarping of the arch and the downwarping of the basin.