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Over the recent years, Artificial Intelligence (AI) has been progressing rapidly with its ability to mimic human cognitive functions. The potential applications of AI technology in diagnosis, treatment planning, and prognosis prediction have been demonstrated in various studies. The present scoping review aimed to provide an overview of AI and Machine Learning (ML) algorithms and their applications in orthognathic surgery. A comprehensive search was conducted in databases including PubMed, Embase, Scopus, Web of Science and OVID Medline until November 2021. This scoping review was conducted following the PRISMA-ScR guidelines. After applying the inclusion and exclusion criteria, a total of 19 studies were included for final review. AI has profoundly impacted the diagnosis and prediction of orthognathic surgeries with a clinically acceptable accuracy range. Furthermore, AI reduces the work burden of the clinician by eliminating the tedious registration procedures, thereby helping in efficient and automated planning. However, focussing on the research gaps, there is a need to foster the AI models/algorithms to contemporize their efficiency in clinical decision making, diagnosis and surgical planning in future studies.

Objectives To estimate the pooled prevalence estimates of the malocclusion among child and adolescent population of India. Contents A comprehensive electronic search was carried to find studies related to assessing malocclusion in Indian children and adolescent population. Indices and classifications considered for pooled analysis were Dental Aesthetic Index, Index of Orthodontic Treatment Needs, Angles classification and terminal plane relationship of primary secondary molars. An eligibility criterion was prepared and quality assessment was done for all the eligible studies. Initial search produced 1090 titles. After removal of duplicates, 850 records were left for further screening. Eighty one articles were found eligible for full text reading. Finally 60 studies were included in this meta-analysis. Pooled prevalence was used to estimate overall effect, with 95% confidence intervals (CI). Statistical difference between the two genders was calculated using chi square test. Summary and outlook The high prevalence of malocclusion is a public health problem around the world. The current status of burden of malocclusion among Indian children and adolescents is not known. Results of this pooled analysis showed that prevalence of malocclusion among Indian children and adolescents has increased since the last national oral health survey. Prevalence of malocclusion ranged from 28.4% (CI 25.02, 31.9) to 66.7% (CI 50.7, 81.06) depending on the type of index or classification used for recording. Boys recorded higher cumulative prevalence than girls. These findings can be utilized by oral health policy makers to draft measures required for reducing this burden of malocclusion.

Background/Aims Giant cell arteritis (GCA) is a medical emergency presenting with a new-onset headache. Delay in treatment can cause permanent vision loss and other complications. It responds quickly to oral and parenteral steroids. Temporal artery biopsy (TAB) is the gold standard. However, it is not easily available in a timely manner and can produce normal results due to skip lesions and if done after starting steroids. In contrast, ultrasound (USS) is a useful non-invasive alternative. The aims of this audit were to study our current practice against the NICE guidelines/BSR pathway on GCA management, to evaluate the impact of USS on diagnosis and management of GCA and the use of tocilizumab and steroid-sparing synthetic DMARDs. Methods This is a retrospective, audit study on patients with a new diagnosis of suspected GCA referred to the Cardiff and Vale Health Board from January 2017 to February 2020. 105 patients who had a USS doppler test were identified, 51 were excluded due to various reasons, ultimately data on 54 patients were analysed. Results 50 patients (93%) were >50 years old; female: male was 4:1.5. 44 (81%) were primary care referrals. 50 (93%) were seen by a rheumatologist within 48 hours. 11 had visual symptoms, all had an ophthalmology review, two had ischemic changes suggestive of GCA. Pre-USS, 21/54 (39%) were classed as likely GCA. Post-USS, 19/54 (35%) were confirmed GCA, two were refuted. Only 3/54 showed signs of GCA on USS (sensitivity: 15.79%). TAB was done in five patients (sensitivity: 20%), 1/5 showed GCA, all had negative USS. The low sensitivity of USS and TAB is likely to be due to steroid exposure, as all patients were on steroids at time of USS and three had the biopsy 2 weeks post-steroid use. 19 patients continued on steroids for GCA. At 12 months follow-up, 2/19 had discontinued steroids, only 4/17 were on prednisolone >10mg. None of the patients in our cohort required tocilizumab or other steroid-sparing agents. Conclusion Temporal artery USS is useful in aiding the GCA diagnosis and reduces the need for TAB, especially in patients with low clinical probability of GCA. Clinical assessment, USS and ophthalmology review together can avoid unnecessary exposure to long-term steroids. It is reassuring that the majority of patients with a low GCA probability had a normal USS. This helped in avoiding steroid use and/or to stop steroids quickly in those who had already started steroids. A local pathway for management of patients referred as suspected GCA is being established in the department. Teaching sessions for non-rheumatologists involving BSR Guidelines on GCA might help reduce unnecessary referrals and improve standard of care. We aim to study the reasons for the low utilisation of tocilizumab and other steroid-sparing agents. Disclosure J. Yau: None. M. Saleh: None. A. Negi: None.

Background Rituximab is an anti-CD-20 used in resistant RA. It functions by reducing the efficacy of B cells which participate in this pro-inflammatory process. The BSR recommend immunoglobulin monitoring when using rituximab to aid rapid detection of hypogammaglobinaemia and address its potential complications which have been suggested by a recent large study in 2018 in the UK. Our objectives included: Are we measuring immunoglobulin (Ig) levels prior to rituximab infusions in all RA patients? Are we measuring Ig levels ‘4-6 months post infusions’ as per BSR guidelines? Is the cumulative dose of rituximab associated with hypogammaglobinaemia? Methods We collected data from departmental records for all the RA patients who were initiated on rituximab between 30/1/15 and 30/1/19. We recorded their basic demographics, pre-infusion immunoglobulin levels and subsequent levels with repeated infusions. All data was anonymised, but some patients had to be excluded from the final analysis due to missing immunoglobulin levels. Results 42 patients were identified via the methodology. 88% of the 42 had Ig’s checked before starting rituximab. Only 38% of 37 patients included in this subsequent analysis had Ig’s checked within the recommended 6 months after their initial rituximab infusion. We also observed a notable average percentage drop in IgG levels after receiving approximately 6g of rituximab therapy, with 2 new patients developing new hypogammaglobinamia after 8g-10g of rituximab. After 10g of rituximab we noted an average percentage drop in rituximab of 26.8%. However, no statistical correlation between hypogammaglobinaemia and infection rates was found. Conclusion Although no correlation between hypogammaglobinaemia and infection rates were found, this study used small numbers from a single centre only. To improve UHW’s monitoring of Ig’s we introduced a performer which aims to help recording of pre and post IgG levels and recording of infections experienced between infusions. We hope this will increase identification of newly developed hypogammaglobinaemia and increase awareness of infection rates, ultimately leading to an improvement in patient care. Disclosures C. Rice None. D. Ghandi-Das None. A. Negi None.

Introduction: The ability to close space efficiently in orthodontic tooth movement is of major clinical importance. Elastomeric chains are extensively used as tooth moving mechanism in orthodontics. The objective of this study was to evaluate the dynamic force delivery and damping behaviour of different brands of elastomeric chains using Dynamic Mechanical Analysis. Materials and Methods: Five types of clear elastomeric chains were taken from the different manufacturers: GAC International (Sunburst TM Power Chain), 3M Unitek (AlastiK TM Power Chain), ROCKY MOUNTAIN ORTHODONTICS (Energy Chain TM ), ORMCO Power Chain and LIBRAL (Rabbit Force). Dynamic Mechanical Analysis was performed at room temperature at eight defined frequencies (0.125, 0.25, 0.5, 1.0, 2.0, 4.0, 8.0, and 16.0 Hz) in immediate succession from lowest to highest. Five variables (Dynamic force, loss Stiffness, Storage Stiffness, Tan Delta and Damping) were analyzed using repeated measures analysis of variance and Post-Hoc test was done to evaluate the difference between the means at different frequencies. Results: Post-hoc tests compared all frequencies for each brand showing significant differences were found among the different types of brands. Significance was set at 0.05. Conclusion: GAC brand had higher dynamic, storage and loss stiffness values. GAC brand shows higher damping values at lower frequencies.

Transactional contention management policies show considerable variation in relative performance with changing workload characteristics. Consequently, incorporation of fixed-policy Transactional Memory (TM) in general purpose computing systems is suboptimal by design and renders such systems susceptible to pathologies. Of particular concern are Hardware TM (HTM) systems where traditional designs have hardwired policies in silicon. Adaptive HTMs hold promise, but pose major challenges in terms of design and verification costs. In this paper, we present the ZEBRA HTM design, which lays down a simple yet high-performance approach to implement adaptive contention management in hardware. Prior work in this area has associated contention with transactional code blocks. However, we discover that by associating contention with data (cache blocks) accessed by transactional code rather than the code block itself, we achieve a neat match in granularity with that of the cache coherence protocol. This leads to a design that is very simple and yet able to track closely or exceed the performance of the best performing policy for a given workload. ZEBRA, therefore, brings together the inherent benefits of traditional eager HTMs-parallel commits-and lazy HTMs-good optimistic concurrency without deadlock avoidance mechanisms-, combining them into a low-complexity design.

Introduction: The objective of the study was to evaluate the percentage of force degradation of elastomeric chains, NiTi closed coil spring and stainless steel closed coil spring at different time intervals in different media. Materials and methods: Three types of space closing auxiliaries, such as elastomeric chains, NiTi closed coil springs and stainless steel coil springs immersed in artificial saliva, alcohol-free mouthrinse (Colgate plax) and alcohol-containing mouthrinse (Listerine) at time interval of 1, 4, 7,14, 21 and 28 days were divided into nine groups of 15 each: Group I- 15 polyurethane elastomeric chain immersed inside artificial saliva (Control). Group II-15 polyurethane elastomeric chain immersed inside alcohol-free mouthrinse. Group III- 15 polyurethane elastomeric chain immersed inside alcohol-containing mouthrinse. Group IV-15 stainless steel closed coil springs immersed inside artificial saliva (Control). Group V- 15 stainless steel closed coil springs immersed inside alcohol-free mouthrinse. Group VI-15 stainless steel closed coil springs immersed inside alcohol-containing mouthrinse. Group VII- 15 NiTi closed coil springs immersed inside artificial saliva (Control). Group VIII-15 nickel titanium closed coil springs immersed inside alcohol-free mouthrinse. Group IX- 15 NiTi closed coil springs immersed inside alcohol-containing mouthrinse. The percentage of force degradation was measured with the universal testing machine. Results: The force produced by elastomeric chain, stainless steel closed coil spring and NiTi closed coil spring at seven time intervals in artificial saliva, alcohol-free mouthwash and alcohol-containing mouthwash showed a statistically significant difference (p < 0.001). Conclusion: The force degradation in alcohol-containing mouthwash solution (Listerine) is more as compared to alcohol-free mouthwash solution (Colgate plax) .

Objectives : To test the hypothesis that there is no association between sagittal maxillomandibular relationship and pharyngeal airway passage dimensions. Materials and methods : Lateral cephalograms of 90 subjects were used to measure the upper pharyngeal airway. The subjects were divided into three groups (each group included 30 subjects) according to ANB angle: Class III (ANB < 0.7°); Class I (ANB > 0.7° and < 4.7°); Class II (ANB > 4.7°). All lateral cephalograms were traced manually. Results : The results showed a significant reduction in the upper airway at the level of nasopharynx and oropharynx and the airway showed a tendency to decrease from Class III to Class I and Class I to Class II. Conclusion : Sagittal skeletal pattern had a close association between the pharyngeal airway passage and the dimensions of the pharyngeal airway passage. The dimensions of pharyngeal airway passage were decreased from Class III to Class I and Class I to Class II subjects.

Objective : This study was conducted to evaluate the role of smile in overall facial esthetics. Materials and methods : The sample comprised of photographs taken in natural head position of 100 normal Himachali subjects (50 males, 50 females) and they were divided in 3 age groups: Group I consisiting of 39 subjects aged (15-20) years, Group II consisiting of 35 subjects aged (21-24) years, Group III consisiting of 26 subjects aged (25-29) years. The various parameters were analyzed using the clever ruler software: Upper lip length during rest and smiling, lower lip length during rest and smiling, smile index, buccal corridor, upper lip thickness, lower lip thickness, interlabial gap, incisal display, widest visible maxillary display and intercommissural width. Student t-test and using one- way analysis of variance (ANOVA) were used to compare the mean of different groups. Results : The results showed changes in the maxillary incisal display, interlabial gap and smile index were highly significant from Group I to Group III. There was a decrease of 2.2 mm in maxillary incisal display and 2.0 mm in interlabial gap whereas smile index showed an increase of 0.7 mm with the increasing age. Conclusion : It has been concluded from the study that with the increasing age, the smile gets wider transversely and narrow vertically.

Hardware transactional memory implementations are becoming increasingly available. For instance, the Intel Core i7 4770 implements Restricted Transactional Memory (RTM) support for Intel Transactional Synchronization Extensions (TSX). In this paper, we present a detailed evaluation of RTM performance and energy expenditure. We compare RTM behavior to that of the TinySTM software transactional memory system, first by running micro benchmarks, and then by running the STAMP benchmark suite. We find that which system performs better depends heavily on the workload characteristics. We then conduct a case study of two STAMP applications to assess the impact of programming style on RTM performance and to investigate what kinds of software optimizations can help overcome RTM's hardware limitations.

Hardware Transactional Memory (HTM) exposes parallelism by allowing possibly conflicting sections of code, called transactions, to execute concurrently in multithreaded applications. However, conflicts among concurrent transactions result in wasted computation and expensive rollbacks. Under high contention HTM protocol overheads can, in many cases, amount to several times the useful work done. Blindly scheduling transactions in the presence of contention is therefore clearly suboptimal from a resource utilization standpoint, especially in situations where several scheduling options exist. This paper presents HARP (Hardware Abort Recurrence Predictor), a hardware-only mechanism to avoid speculation when it is likely to fail. Inspired by branch prediction strategies and prior work on contention management and scheduling in HTM, HARP uses past behavior of transactions and locality in conflicting memory references to accurately predict conflicts. The prediction mechanism adapts to variations in workload characteristics and enables better utilization of computational resources. We show that an HTM protocol that integrates HARP exhibits reductions in both wasted execution time and serialization overheads when compared to prior work, leading to a significant increase in throughput (~30%) in both single-application and multi-application scenarios. Adria Armejach's work is supported by the Ministry of Science and Technology of Spain and the European Union under contracts TIN2007-60625 and TIN2008-02055-E. Anurag Negi's work at Chalmers is supported by grants from the Swedish Foundation for Strategic Research (SSF) under the SCHEME project.

When supported in silicon, transactional memory (TM) promises to become a fast, simple and scalable parallel programming paradigm for future shared memory multiprocessor systems. Among the multitude of hardware TM design points and policies that have been studied so far, lazy conflict resolution designs often extract the most concurrency, but their inherent need for lazy versioning requires careful management of speculative updates. In this paper we study how coherent buffering, in private caches for example, as has been proposed in several hardware TM proposals, can lead to inefficiencies. We then show how such inefficiencies can be substantially mitigated by using complete or partial non-coherent buffering of speculative writes in dedicated structures or suitably adapted standard per-core write-buffers. These benefits are particularly noticeable in scenarios involving large coarse grained transactions that may write a lot of non-contended data in addition to actively shared data. We believe our analysis provides important insights into some overlooked aspects of TM behaviour and would prove useful to designers wishing to implement lazy TM schemes in hardware.

Transactional memory (TM) promises to unlock parallelism in software in a safer and easier way than lock-based approaches but the path to deployment is unclear for several reasons. First of all, since TM has not been deployed in any machine yet, experience of using it is limited. While software transactional memory implementations exist, they are too slow to provide useful experience. Existing hardware transactional memory implementations, on the other hand, can provide the efficiency required but they require a significant effort to integrate in cache coherence infrastructures or freeze critical policy parameters. This paper proposes the LV∗ (lazy versioning and eager/lazy conflict resolution) class of hardware transactional memory protocols. This class of protocols has been implemented with ease of deployment in mind. LV∗ can be integrated with low additional complexity in standard snoopy-cache MESI-protocols and can be accommodated in a directory-based cache coherence infrastructure. Since the optimal conflict resolution policy (lazy or eager) depends on transactional characteristics of workloads, LV∗ supports a set of conflict resolution policies that range from LazEr — a family of Lazy versioning Eager conflict resolution protocols — to LL-MESI which provides lazy resolution. We show that LV∗ can be hosted in a MESI protocol through straightforward extensions and that the flexibility in the choice of conflict resolution strategy has a significant impact on performance.

International audience; Transactional memory (TM) promises to unlock parallelism in software in a safer and easier way than lock-based approaches but the path to deployment is unclear for several reasons. First of all, since TM has not been deployed in any machine yet, experience of using it is limited. While software transactional memory implementations exist, they are too slow to provide useful experience. Existing hardware transactional memory implementations, on the other hand, can provide the efficiency required but they require a significant effort to integrate in cache coherence infrastructures or freeze critical policy parameters. This paper proposes the LV* (lazy versioning and eager/lazy conflict resolution) class of hardware transactional memory protocols. This class of protocols has been implemented with ease of deployment in mind. LV* can be integrated with low additional complexity in standard snoopy-cache MESI-protocols and can be accommodated in a directory-based cache coherence infrastructure. Since the optimal conflict resolution policy (lazy or eager) depends on transactional characteristics of workloads, LV* supports a set of conflict resolution policies that range from LazEr – a family of Lazy versioning Eager conflict resolution protocols – to LL-MESI which provides lazy resolution. We show that LV* can be hosted in a MESI protocol through straightforward extensions and that the flexibility in the choice of conflict resolution strategy has a significant impact on performance.