CBCT Imaging of Paranasal Sinuses and Variations

Paranasal sinuses located in the bones surrounding the nasal cavity are called maxillary, ethmoid, frontal and sphenoid sinuses. In relation with their location, these sinuses contribute to the development of the facial structures, jaws and upper airway. During the developmental process of the paranasal sinuses, anatomic variations can occur in consequence of intra and extramural migration of the ethmoid air cells, overpneumatization or hypoplasia of the sinuses and bulging of the neurovascular structures to the sinuses. Some of these anatomic variations may affect the drainage pathways, pave the way for chronic infections and cause difficulties when performing paranasal sinuses surgery. Therefore, the aim of this chapter was to examine the paranasal sinus anatomic variations with cone beam computed tomography (CBCT)

Nonlinear robust control of tendon–driven robot manipulators

This work addresses the position tracking control problem for tendon–driven robotic mechanisms in the presence of parametric uncertainty and additive external disturbances. Specifically, a full state feedback nonlinear robust controller is proposed to tackle the link position tracking problem for tendon–driven robot manipulators with uncertain dynamical system parameters. A robust backstepping approach has been utilized to achieve uniformly ultimately bounded tracking performance despite the lack of exact knowledge of the dynamical parameters and presence of additive but bounded disturbance terms. Stability of the overall system is proven via Lyapunov based arguments. Simulation studies performed on a two link planar robot manipulator driven by a six tendon mechanism are presented to illustrate the effectiveness and viability of the proposed approach.Scientific and Technological Research Council of Turkey (112E561

KKTC toplumunda fenestrasyon ve dehisens prevalansının konik ışınlı bilgisayarlı tomografi ile değerlendirilmesi

Amaç: Bu çalışmanın amacı, bir grup KKTC popülasyonunda, Konik Işınlı Bilgisayarlı Tomografi (KIBT) kullanılarak fenestrasyon ve dehisens prevalansının belirlenmesi ve fenestrasyonların lokalizasyonlarına göre sınıflandırılmasıdır.Gereç ve Yöntemler: 100 hastanın KIBT görüntüleri restrospektif olarak incelenmiş ve çalışmamıza dahil edilmiştir. Çalışmamızda toplamda 2619 diş ve 4153 kök değerlendirilmiştir. Kök fenestrasyonları 6 alt tipte değerlendirilmiştir. Dişlerde dehisens varlığı da ayrıca kaydedilmiştir.Bulgular: Değerlendirilen dişlerin % 10.1’inde fenestrasyon ve dehisens bulunduğu gözlenmiştir. En fazla fenestrasyon ve dehisense rastlanan dişler sırası ile maksiller 1. molar, mandibular ve maksiller kanin dişlerdir. En az etkilenin dişler ise mandibular molar dişler olarak tespit edilmiştir. Fenestrasyon tiplerinden Tip I, IV ve VI hepsi 1 vaka hariç maksillada görülmüştür. Tip IV fenestrasyon, % 1.47 görülme oranı ile fenestrasyon tipleri arasında en sık görülen tiptir. En az görülen fenestrasyon tipi ise % 0.2 ile Tip III olarak bulunmuştur. Toplamda incelenen köklerin % 4.3’ünde fenestrasyona, 2.3’ünde ise dehisense rastlanmıştır.Sonuç: Popülasyonumuzda özellikle maksillada fenestrasyon ve dehisens prevalansı yüksek bulunmuştur. Maksillada yapılacak olan endodontik, ortodontik ve cerrahi operasyonlarda bunun göz önünde bulundurularak şüpheli durumlarda bölgenin anatomik yapısının doğru bir şekilde belirlenmesi için KIBT’nin kullanımı yararlıdır.ANAHTAR KELİMELER Fenestrasyon, Dehisens, KIB

Assessment of paranasal sinus parameters according to ancient skulls’ gender and age by using cone-beam computed tomography

Background: The aim of this study was to determine whether paranasal sinus dimensions and volume can be useful to identify gender and age estimation for ancient skulls using cone-beam computed tomography (CBCT) images.  Materials and methods: CBCT scans of 32 ancient skulls of approximately 1000 years of age were included in this retrospective study. The gender and age estimation of the skulls were made by an independent anthropologist, which was considered as the gold standard. Paranasal sinuses’ dimensions (width and height) and volumes of each sinus were measured from the CBCT data set that was linked to the three-dimensional rendering software (Anatomage, Invivo 5.2). All measurements were performed by an independent observer. Intra-observer analysis was made. Mann-Whitney and Kruskal-Wallis tests were used to compare paranasal sinus parameters in terms of age estimation and gender (p < 0.05).  Results: The results demonstrated no statistically significant difference between measurements (p < 0.05). The measurements were found to be highly reprodu- cible. The mean volumes of frontal and sphenoid sinus were found to be higher in males. The distance from anterior-posterior wall of sphenoid sinus in axial sec- tions is larger in males (p > 0.05). The frontal sinus width and volume increased statistically with age above 60 years of age (p > 0.05).  Conclusions: The paranasal volume and dimensions’ measurements from CBCT data can be a promising technique to determine gender and age of ancient skulls because of its lower voxel sizes and higher resolution.

Endovascular treatment of femoro-popliteal artery stenosis/obstruction using a repositionable self-expanding nitinol stent: a preliminary study

Introduction. The aim of this study was to report our preliminary results regarding the use of the repositionable self-expanding nitinol stent in a cohort of patients with femoro-popliteal artery occlusion/stenosis. Material and methods. The study groups consisted a total of 8 patients (10 extremities) between 47 and 70 years of age who presented with typical symptoms of intermittent claudication and/or critical limb ischaemia (Fontaine stage II–IV) and underwent primary elective superficial femoral artery percutaneous transluminal angioplasty and/or stenting using a Jaguar repositionable self-expanding nitinol stent in the dates of 2013–2015. Information for patency at 6th month after the stenting procedure was obtained. Results. The mean operation time was 38.56 ± 26.40 minutes. No patients had procedure-related stent fracture, distal thromboembolism, haematoma, femoral pseudoaneurysm or stent occlusion. At 6-month follow-up, at least one categorical improvement was observed in 7 patients (87.5% of intent-to-treat population). Conclusions. The Jaguar self-expanding nitinol stent has several technical advantages, and its use was associated with a low risk of complications. Further study is warranted to establish its superiority in providing good long-term patency

Nerve conduction studies in the early diagnosis of amyotrophic lateral sclerosis and the importance of split-hand phenomenon

Aim: The heterogeneity of the Amyotrophic Lateral Sclerosis (ALS) clinical phenotypes leads to difficulties in early diagnosis. The ‘split hand’ sign is defined as the thenar muscles that are more prominently affected by hypothenar. In this study, the results of the initial nerve conduction study of the patients were compared with those of the controls in order to increase the findings supporting early diagnosis. Material and Method: Seventy-five patients who were diagnosed with ALS in our clinic were included in the study. The initial ENMG findings of the patients were compared with those of 70 healthy controls: Distal motor latency (DML), the compound muscle action potential (CMAP) amplitude, velocity in the motor conduction of median, ulnar, peroneal and tibial nerves; distal latency, amplitude, velocity in sensorial conduction were evaluated. Ulnar/median DML and ulnar/median CMAP amplitude ratios were examined. Results: In ALS group, DMLs of the median, ulnar, peroneal, and tibial nerves were significantly longer, and CMAP amplitudes were significantly smaller than those of the controls. The sensory conductions of the median, ulnar, and sural nerves were not statistically different between the groups. The ulnar/median DML ratio of the patients was lower than the ratio of controls (0.73/0.80;p=0.003); while the ulnar/median CMAP amplitude ratio was greater (1.40/1.11; p=0.002). Conclusion: Prolonged DML and reduced amplitudes were observed in the motor nerve conduction of ALS patients in the early period. The results of the present study also support the presence of split-hand phenomenon even in early period of limb-onset ALS (both upper and lower). These findings suggest that nerve conduction studies and electrophysiologically detected split-hand sign are important clues for the early diagnosis of ALS in case of heterogeneous clinical phenotype

Kikuchi Fujimato Disease

Kikuchi Fujimato disease (KFD) also know as histiocytic necrotizing lymphadenitis (HNL) is a benign, self limiting disease, which commonly affects young women under 30 years of age. Most of the cases resolve in a six month period. Laboratory and clinical findings of KFD show similarities with tuberculosis lymphadenitis, mailgn lymphoma, other malign and benign diseases. The diagnosis is established on the basis of histology of lymph node excisional biopsy. The differentiation of KFD from Sistemik Lupus Eritematosus (SLE) can sometimes be problematic because both can show similar clinical and histological features. KFD and SLE can be seen together. Forty two years-old female patient diagnosed with KFD was discussed in light of current literature

Clinically applicable artificial intelligence system for dental diagnosis with CBCT

Abstract In this study, a novel AI system based on deep learning methods was evaluated to determine its real-time performance of CBCT imaging diagnosis of anatomical landmarks, pathologies, clinical effectiveness, and safety when used by dentists in a clinical setting. The system consists of 5 modules: ROI-localization-module (segmentation of teeth and jaws), tooth-localization and numeration-module, periodontitis-module, caries-localization-module, and periapical-lesion-localization-module. These modules use CNN based on state-of-the-art architectures. In total, 1346 CBCT scans were used to train the modules. After annotation and model development, the AI system was tested for diagnostic capabilities of the Diagnocat AI system. 24 dentists participated in the clinical evaluation of the system. 30 CBCT scans were examined by two groups of dentists, where one group was aided by Diagnocat and the other was unaided. The results for the overall sensitivity and specificity for aided and unaided groups were calculated as an aggregate of all conditions. The sensitivity values for aided and unaided groups were 0.8537 and 0.7672 while specificity was 0.9672 and 0.9616 respectively. There was a statistically significant difference between the groups (p = 0.032). This study showed that the proposed AI system significantly improved the diagnostic capabilities of dentists