Entrance Of Canal Research Articles

Speech perception outcomes in hearing-impaired individuals with microphone & receiver in the ear (M&RIE) hearing aids.

The Microphone and Receiver in the ear (M&RIE) hearing aid is designed to consider the pinna cues by placing an additional microphone along with a standard receiver at the entrance of the ear canal. There is a need to clinically validate the technology using speech identification measures, as a literature shortage exists. The objective of the study was to evaluate speech identification and quality rating with hearing aids fitted with standard and M&RIE receivers. Twenty individuals (mean ± SD age being 34.10 ± 11.9years) with mild-to-moderately severe sensorineural hearing loss were divided into two groups: naïve and experienced. Their speech identification obtained using the receiver in the ear hearing aid compatible with standard and M&RIE receivers were compared. The study assessed speech identification in quiet using ten sentences, calculated SNR-50 using the Spearman-Karber equation, and used an 11-point scale for self-perceived quality rating. The study analyzed data using SPSS and found no significant difference between naive and experienced hearing aid users in quiet and SNR-50 conditions (p > 0.05). However, naive users rated higher in clarity, naturalness, pleasantness, and overall impression of standard receiver settings. Across different receiver settings, both naïve and experienced groups revealed better speech identification with the M&RIE receiver for both SIS (p < 0.05) and SNR-50 (p < 0.05) measures. The study found that placing a third microphone in the ear canal improves speech identification and quality rating in both naïve and experienced users, with pinna and ear canal resonance playing a crucial role in prescribing hearing aid gain.

3D finite element modeling of earplug-induced occlusion effect in the human ear

Poor utilization of earplugs among military personnel may be due to discomfort caused by the occlusion effect (OE). The OE occurs when an earplug occludes the ear canal, thereby changing bone conduction (BC) hearing and amplifying physiological noises from the wearer. There is a need to understand and reduce the OE in the human ear. A 3D finite element model of the human ear including a 3-chambered spiral cochlea was employed to simulate the OE caused by foam and aerogel earplugs. 90 dB sound pressure was applied at the ear canal entrance and BC sound was applied as vibration of the canal bony wall. The model reported the ear canal pressure and the displacements of the stapes footplate and cochlear basilar membrane with and without earplugs. Without BC stimulation, the foam earplug showed a greater pressure attenuation than the aerogel earplug. However, the foam earplug results were more affected by BC stimulation, with a maximum sound pressure increase of 34 dB, compared to the 21.0 dB increase with the aerogel earplug. The aerogel earplug's lower OE demonstrates its promise as an earplug material. Future work with this model will examine BC sound transmission in the cochlea.

Comparative Effectiveness of Different Er:YAG Laser-Activated Irrigation Systems on Removing Calcium Hydroxide from Simulated Internal Root Resorption Cavities at Different Root Levels.

Objective: To investigate the effectiveness of Er:YAG laser-activated irrigation (LAI) with a short pulse duration for removing calcium hydroxide (CH) from simulated internal root resorption (IRR) cavities at three root levels. Background: Pulse duration is an important parameter during LAI, which ensures the efficiency of irradiation and the corresponding activation process. Short pulses in the range of a few microseconds enable rapid expansion and successive implosion of irrigants, resulting in distinct fluid movement. There have been few reports on CH removal efficacy from IRR cavities of different LAI systems, including those using short pulse duration. Methods: IRR cavities (1.6 mm diameter) were created at the apical, middle, and coronal root levels in 60 mandibular premolars and filled with a radiopaque CH paste. Samples were assigned to the following irrigation groups (n = 12, each): (1) LAI(P)-F, a prototype laser device that operates with short pulse duration (Morita Manufacturing) with a flat tip; (2) LAI(EA)-F, the ErwinAdverl laser device (Morita Manufacturing) with a flat tip; (3) LAI(EA)-T, the ErwinAdverl laser device with a tapered tip; (4) PIPS-T, the Lightwalker laser device (Fotona) with a tapered tip; and (5) SI, the syringe irrigation group. The laser tips were fixed at the canal entrance. The remaining CH volume and surface area were assessed in IRR cavities using micro-computed tomography and scanning electron microscopy, respectively. Data were statistically analyzed utilizing one-way analysis of variance and Tukey's test at 5% significance level. Results: The LAI(P)-F and PIPS-T groups exhibited the highest CH removal rates at three different levels (p < 0.05). The LAI(EA)-F group had a significantly better efficacy of CH removal compared with the LAI(EA)-T group at the middle level (p < 0.05). Conclusion: The LAI(P)-F and PIPS-T groups demonstrated superior efficiency in removing CH from simulated IRR cavities.

Morphometric and morphological evaluation of the nasolacrimal groove in 150 dry bones in the Anatolian population.

In this study, we aimed to evaluate the anatomical features of the nasolacrimal groove in detail by providing a morphological classification based on morphometric evaluations of the nasolacrimal groove. A total of 150 sagittal dry bones in the Department of Anatomy, Faculty of Medicine, Istanbul University were evaluated. The length and the width at different points of the nasolacrimal canal were calculated. According to the widths of the nasolacrimal canal ten different morphological types were revealed. The length of the canal was found as mean 13.62 ± 2.42mm on the right and 12.44 ± 2.68mm on the left side. The entrance, the base, the upper and the lower thirds of nasolacrimal canal were 6.22 ± 1.19mm, 7.95 ± 1.85mm, 5.85 ± 1.06mm, 6.60 ± 1.54mm, on the right and 6.08 ± 1.16mm, 7.24 ± 1.64mm, 5.45 ± 1.29mm, 6.23 ± 1.48mm, on the left side, respectively. The width of the entrance of the nasolacrimal canal was the narrowest width compared to the base, upper and lower thirds in 7/10 types of 71/150 cranial bones. This comprehensive morphological classification of the nasolacrimal groove sheds new light on its complex variations. We support that the finding of this study has the potential to improve the precision of diagnostic assessments and guide specific therapeutic interventions for patients with lacrimal drainage disorders.

Dolichoectasia of the ophthalmic artery: a case report on the treatment strategy in endovascular therapy and literature review

BackgroundDolichoectasia is a rare arterial condition characterized by the dilatation, tortuosity, and elongation of cerebral blood vessels. The vertebrobasilar artery and internal carotid artery are the common sites of dolichoectasia. However, dolichoectasia of the branch arteries, such as the ophthalmic artery (OA), is extremely rare. To the best of our knowledge, this is the first case of ophthalmic dolichoectasia that was successfully treated with endovascular internal coil trapping.Case presentationA 54-year-old female patient presented with transient left ophthalmalgia and visual disturbance. Magnetic resonance imaging revealed a dilated and elongated left OA compressing the optic nerve at the entrance of the optic canal. However, a previous image that was taken 17 years back revealed that the OA was normal, which suggested the change in dolichoectasia was acquired. Cerebral angiography showed that the dilated and tortuous OA was running from the ophthalmic segment of the left internal carotid artery into the orbit. The symptoms could have been attributed to the direct compression of the dolichoectatic OA in the optic canal. A sufficient anastomosis between the central retinal artery and the middle meningeal artery was identified on external carotid angiography with balloon occlusion of the internal carotid artery. Endovascular treatment with internal trapping of the OA was performed due to ophthalmic symptom progression. Internal coil trapping of the OA was performed at the short segment between the OA bifurcation and the entrance of the optic canal. As expected, the central retinal artery was supplied via the middle meningeal artery after the treatment. The transient visual disturbance was immediately resolved. Ophthalmalgia worsened temporarily after the treatment. However, it completely resolved after several days of oral corticosteroid therapy. Postoperative angiography showed that the origin of the OA was occluded and that the OA in the optic canal was shrunk. The flow of the central retinal arteries via the middle meningeal artery was preserved.ConclusionsOA dolichoectasia is rare, and its pathogenesis and long-term visual prognosis are still unknown. However, endovascular therapy can improve symptom by releasing the pressure site in the optic canal.

Morphometric Analysis of Greater Palatine Canal by Computed Tomography

Aim: The greater palatine canal connects to the oral cavity through the greater palatine foramen. Preoperatively identifying the morphology of the greater palatine canal and greater palatine foramen is very important to avoid possible complications during surgery. This study aimed to evaluate the greater palatine canal and surrounding anatomical structures using computed tomography. Material and Methods: Images from 100 patients (35 female and 65 male) who had previously undergone computed tomography for various reasons were evaluated. The study data were divided into three age groups, &amp;lt;20 years, 20-60 years, and &amp;gt;60 years. Morphological parameters measured in this study included; diameter measurement from the widest part of the canal, length of the canal, beginning diameter of the canal, the ends diameter of the canal, localization of the canal entrance with respect to the third molar tooth, distance of the canal entrance to palatine suture. The values obtained from the measurements were compared in terms of age group, gender, and side. Results: The mean length of the canalis palatinus major was 15.19±4.38 mm. The diameter of the widest part of the canal and the end of the canal, and the distance between the canal entrance and the sutura palatina increased with age, but these increases were not statistically significant. Conclusion: Proper administration of anesthesia through the greater palatine foramen in maxillofacial surgeries and related applications requires a detailed understanding of the anatomy of the greater palatine canal, and the results of the present study will contribute to the understanding of this anatomy.

Development of the ear insertion-type noise dosimeter with hearing protection

This study developed the ear insertion-type noise dosimeter with an earpiece. This dosimeter is composed of features two microphones, one located at the ear canal entrance, and the other positioned inside the ear canal. The dosimeter calculates LAeq and LApeak at one-second intervals. The device logs data from both the inside and outside microphones for up to 8 hours, and the recorded data can be conveniently accessed and displayed on a smartphone. The difference between the inside LAeq and the outside LAeq indicates the exposed level attenuated by the earpiece. The ear insertion-type noise dosimeter was evaluated in a free field by using an acoustic measurement manikin (KEMAR; GRAS Inc, Denmark). Results obtained in this study showed that the differences between the LAeq in the free field and that at the entrance of the ear canal were found to be slightly amplified by the pinna effect. Also, the LAeqs measured at the microphone that positioned inside the ear canal was consistently 3.2 dB lower on average than that recorded by KEMAR's microphone. These findings suggest that the LAeq on the eardrum can be estimated by using the LAeq measured by the inside microphone. Additionally, the sound attenuation value can be calculated by comparing the values obtained from the outside microphones with those from the inside microphones.

Influence of pulse energy, tip design and insertion depth during Er:YAG‐activated irrigation on cleaning efficacy in simulated severely curved complex root canal systems in vitro

AbstractAimTo investigate the influence of pulse energy, tip geometry and tip position in simulated 3D‐printed root canals with multiple side canals at different levels in all directions on the cleaning performance of laser‐activated irrigation (LAI) compared to sonic activation (EDDY) and conventional needle irrigation (NI).Methodology3D‐printed root canal models (25/.06, length 20 mm, curvature 60°, radius 5 mm) with side canals (diameter 0.2 mm) at 2, 5 and 8 mm from the apex were filled with coloured biofilm‐mimicking hydrogel. LAI (Morita AdvErL Evo, Kyoto, Japan) was performed with six settings (n = 20; pulse‐energy, pulses per second [PPS], tip position): LAI1 (50 mJ, 25 PPS, P400FL, canal entrance [CE]), LAI2 (same as LAI1, but insertion depth 9 mm before the apical endpoint [AE] [corresponding to 1 mm above the first lateral canals]), LAI3 (80 mJ, 25 PPS, P400FL, 9 mm before AE), LAI4 (same as LAI 3, but at CE) for 3 × 20 s each, LAI5 (50 mJ, 25 PPS, P400FL 2 × 20 s, CE &amp; R200T (30 mJ, 25 PPS, 1 × 20 s, 9 mm before AE), LAI6 (30 mJ, 25 PPS, R200T, 9 mm before AE, 3 × 20 s). A continuous irrigation (3 mL/20 s) using distilled water accompanied the irrigation cycles. NI and EDDY (3 × 20 s each; 3 mL/20 s irrigation, insertion AE minus 1 mm, amplitude 4 mm) served as control groups. Biofilm‐mimicking hydrogel removal (ImageJ, NIH) was assessed for the entire system, the central canal and the lateral canals using standardized photographs with a microscope (Expert DN, Müller‐Optronic) and statistically analysed was performed using Kruskal–Wallis and Dunn tests (p = .05). Irrigant extrusion beyond the foramina was also recorded.ResultsLAI2 (99.08%; interquartile range [IQR]: 96.85–100.00) and LAI3 (97.50%; 96.24–100.00) achieved the significantly best and LAI6 (80.08%; 73.41–84.69) the significantly worst removal of hydrogel from the entire root canal system amongst all LAI configurations (p &lt; .05). There were no significant differences between LAI6, EDDY (72.89%; 67.49–76.22) and manual irrigation (54.39%; 51.01–56.94) (p &gt; .05). R200T laser tip caused significantly more often irrigant extrusion than all other techniques (p &lt; .05).ConclusionTip design, energy settings, and the positioning of the laser tip below the canal entrance caused an improvement in cleaning performance of the LAI. However, the small R200T tip created significantly more procedural errors (irrigant extrusion) due to higher concentrated energy.

Experimental and finite element analysis of the generation mechanism of high impulse noise overpressure (caused by a recoilless weapon) at the bottom of the ear

The intense impulse noise may damage the soldiers’ hearing organs during a weapon's firing. It is essential to find out the generation mechanism of the overpressure at the bottom of the ear. The experiments of measuring the overpressure at the bottom of the ear were conducted through a rotating human head model at a recoilless weapon firing platform. The results showed that the overpressure peak at the bottom of the ear decreases with the increasing incident angle. A simulation of the test condition was developed based on the plane shock wave method. The finite element model was verified reasonably compared to the test results. The Friedlander wave propagating to the ear canal was implemented at different incident angles. The generation of the overpressure at the bottom of the ear was analyzed. According to the pressure nephograms, the impulse noise stagnated at the bottom of the ear, so the overpressure was the total pressure of impulse noise. Two parts of impulse noise entered the canal successively due to the influence of the pinna. The overpressure and Mach number at the entrance of the ear canal both decreased with increasing incident angles, resulting in impulse noise superimposed at the bottom of the ear. Investigating the generation of overpressure at the bottom of the ear under varying incident angles may have important reference value for analyzing and preventing auditory organ damage caused by impulse noise.

Cleaning Efficiency of Different Irrigation Techniques in Simulated Severely Curved Complex Root Canal Systems

IntroductionTo compare the biofilm-mimicking hydrogel removal efficiency of laser-activated irrigation (LAI) with five other irrigation techniques in simulated curved root canals with lateral canals. MethodsThree-dimensional–printed root canal models (60°-curvature, radius 5 mm; dimension 25/.06) with a total length of 20 mm and lateral canals in all directions at 2, 5, and 8 mm (diameter 0.2 mm) from the apex were filled with a colored biofilm-mimicking hydrogel. The following protocols (each 3 × 20 seconds continuous irrigation with distilled water 3 ml/20 seconds; n = 20) were carried out: conventional needle irrigation; manual agitation ([MA], gutta-percha point 25/.06); EndoActivator (=sonically-activated irrigation EndoActivator, 25/.04); EDDY (=sonically-activated irrigation EDDY [SAI-E]; 25/.04); ultrasonically-activated irrigation and LAI (Erbium-doped Yttrium Aluminum Garnet laser; P400FL tip at canal entrance; 25 pps, 50 mJ, 300 μs). Standardized photos were taken with a microscope and the removal of the hydrogel was determined as a percentage for the entire system, the main canal and the lateral canals. Statistical analysis was performed using analysis of variance and Scheffé test (P = .05). ResultsLAI (89.3% ± 5.9%) showed the greatest hydrogel removal followed by SAI-E (65.5% ± 3.3%) and ultrasonically-activated irrigation (59.1% ± 4.7%), with significant differences between these groups (P < .05). Needle irrigation, MA, and sonically-activated irrigation EndoActivator performed equally (P > .05) and obtained the significantly lowest values (P < .05). LAI and SAI-E showed the significantly best hydrogel removal from the main canal (P < .05). At all three levels, LAI removed significantly more hydrogel from the lateral canals than all other techniques (P < .05). ConclusionsLAI was superior to other techniques in both the entire system and the lateral canals in removing the hydrogel. SAI-E achieved comparable results in the main canal.

Using a one-dimensional finite-element approximation of Webster's horn equation to estimate individual ear canal acoustic transfer from input impedances

Knowledge of the sound pressure transfer to the eardrum is important. The transfer is highly influenced by the shape of the ear canal and its acoustic properties, such as the acoustic impedance at the eardrum. Invasive procedures to measure the sound pressure at the eardrum are usually elaborate or costly. We propose a numerical method to estimate the transfer impedance of the ear canal given only input impedance measurements at the ear canal entrance, by using one-dimensional first-order finite elements and Nelder-Mead optimization algorithm. Estimations on the area function of the ear canal and the acoustic impedance at the eardrum are achieved. Results are validated through numerical simulations on ten different ear canal geometries and three different acoustic impedances at the eardrum, using synthetically generated data from three-dimensional finite element simulations.

3D Finite Element Model of Human Ear with 3-Chamber Spiral Cochlea for Blast Wave Transmission from the Ear Canal to Cochlea

Blast-induced auditory trauma is a common injury in military service members and veterans that leads to hearing loss. While the inner ear response to blast exposure is difficult to characterize experimentally, computational models have advanced to predict blast wave transmission from the ear canal to the cochlea; however, published models have either straight or spiral cochlea with fluid-filled two chambers. In this paper, we report the recently developed 3D finite element (FE) model of the human ear mimicking the anatomical structure of the 3-chambered cochlea. The model consists of the ear canal, middle ear, and two and a half turns of the cochlea with three chambers separated by the Reissner's membrane (RM) and the basilar membrane (BM). The blast overpressure measured from human temporal bone experiments was applied at the ear canal entrance and the Fluent/Mechanical coupled fluid-structure interaction analysis was conducted in ANSYS software. The FE model-derived results include the pressure in the canal near the tympanic membrane (TM) and the intracochlear pressure at scala vestibuli, the TM displacement, and the stapes footplate (SFP) displacement, which were compared with experimentally measured data in human temporal bones. The validated model was used to predict the biomechanical response of the ear to blast overpressure: distributions of the maximum strain and stress within the TM, the BM displacement variation from the base to apex, and the energy flux or total energy entering the cochlea. The comparison of intracochlear pressure and BM displacement with those from the FE model of 2-chambered cochlea indicated that the 3-chamber cochlea model with the RM and scala media chamber improved our understanding of cochlea mechanics. This most comprehensive FE model of the human ear has shown its capability to predict the middle ear and cochlea responses to blast overpressure which will advance our understanding of auditory blast injury.

Solitary trichoepithelioma of the external ear canal: A rare case report

Trichoepithelioma is a benign tumor originating from hair follicles. Histopathological examination is crucial in the diagnosis as it can be confused with basal cell carcinoma clinically. A 23-year-old female patient presented to our clinic with complaints of a mass at the entrance of the left external auditory canal, decreased hearing, and occasional ear bleeding for five years, starting after pregnancy. Physical examination revealed a purple-gray mass completely covering the left external auditory meatus. The histopathological examination of the mass, which was surgically excised, was reported as trichoepithelioma. In this article, clinical findings, diagnosis, and surgical treatment process of a case of trichoepithelioma, which is rarely observed in the external auditory canal, were presented in light of current literature.

Retrosigmoid versus Retrolabyrinthine Posterior Petrosal Route to the Petroclival Area: Quantitative Assessment of Endoscope-Assisted Approaches and Correlations with Morphometric Features

Using a cadaveric model, we compared endoscope-assisted retrosigmoid (EAR) and endoscope-assisted retrolabyrinthine posterior petrosal (EARPP) approaches towards the petroclival area, regarding surgical exposure and instrument maneuverability, also verifying how some petroclival morphometric parameters correlate with these variables. In five cadaver heads, EAR approach was performed on one side and EARPP on the other (10 approaches). Under endoscopic view, neuronavigation coordinates were acquired to compute areas of exposure (petroclival and pontomedullary) and maneuverability at Dorello's canal entrance to run the comparison. Correlations of these variables with petroclival angle and clival depth were also analyzed. EAR and EARPP showed equivalence regarding surgical exposure (petroclival: 365.85 ± 133.12 mm2 and 320.62 ± 103.44 mm2, respectively, P= 0.69; pontomedullary: 255.83 ± 88.26 mm2 and 229.80 ± 74.39 mm2, respectively, P= 0.83), but EAR afforded greater maneuverability at Dorello's canal (1155.88 ± 134.35 mm2, P= 0.03). The petroclival angle and clival depth showed different strong correlations with maneuverability depending upon the route, but not with surgical exposure in both approaches. Endoscopic techniques can spare the need for additional steps of greater morbidity when approaching the petroclival area in both routes. A simpler and faster approach as EAR was favored over EARPP in this standardized quantitative assessment. The petroclival angle and clival depth may interfere with maneuverability, but not with surgical exposure in both endoscope-assisted approaches.

Proliferative necrotizing otitis externa in two young cats

In this paper, proliferative necrotizing otitis externa is described in two young cats. The lesions were characterized by proliferative, erosive to ulcerative dermatitis with necrosis affecting the medial aspect of the pinna, the entrance of the ear canal and the periaural skin of both ears. The lesions developed rapidly and were covered by adherent crusts. Histopathology of the lesions was characterized by severe epidermal hyperplasia, with parakeratotic hyperkeratosis, scattered apoptotic keratinocytes in the epidermis and superficial hair follicle epithelium, and serocellular crusts. In both cases, regression of the lesions appeared after systemic and topical immunomodulatory therapy.

Dentin Thickness of the Danger Zone in the Mesial Roots of the Mandibular Molars: A Cone Beam Computed Tomography Analysis

Mandibular first molars appear to be the most commonly tooth subjected to a root canal treatment, therefore a better understanding of the anatomy critical zones for resistance of this teeth may decrease the treatment's failure rate. So, this study was conducted to evaluate the dentin thickness of the danger zone in mesial roots of mandibular first molars using cone beam computed tomography in an Iranian population. In this cross-sectional study, 210 Cone Beam Computed Tomography acquisition of the mandibular first molars were collected from a radiology center in Qazvin. The dentin thickness of the mesial roots (mesiobuccal and mesiolingual canals) was measured from the furcation to 5 mm below. The relationship between the dentin thickness in the danger zone and parameters, like age, gender, placement side, root length, the curvature of the canal, canal type, presence of middle mesial canal, and distance between the orifices of the mesial canals was investigated. Frequency, mean and standard deviation for variables were calculated, and data analysis was done by SPSS using simple and multiple linear regression and Pearson correlation coefficient. Also, two-sample t-test was used to compare mesiobuccal and mesiolingual on two sides. The significant level was also considered at (p < 0.05). The average minimum thickness of danger zone dentin was found to be 0.885 ± 0.259 mm in the mesiobuccal canal and 0.906 ± 0.206 mm in the mesiolingualcanal. Also, the minimum thickness of dentin in the mesiobuccal and mesiolingual canals in the range of 0 to 1 mm from the furcation was more than in other areas. There was no significant relationship between the minimum dentin thickness of the danger zone with gender, placement side, root length, canal type, and mesial canal entrance distance. But with increasing age, the thickness of dentin in the danger zone in the mesiolingualcanal increased significantly (p = 0.008). It was also observed that with the increase in the curvature of the canal, the thickness of the dentin in the danger zone in the mesiobuccal canal decreased (moderately curved (p = 0.008), severely curved (p = 0.046)). In addition, the thickness of the dentin in the mesiobuccal and mesiolingual canal was less in the samples with the middle mesial canal (p = 0.047, 0.044). Less dentin thickness in the danger zone in the mesial roots of mesiolingual mandibular first molars was seen in younger patients in mesiolingual canal, with a greater degree of canal curvature in the mesiobuccal canal and teeth with a middle mesial canal. Therefore, it is suggested that large taper instruments should be used with more precision to prevent complications.

Abstract WP163: Relationship Between Three-dimensional Arterial Tortuosity And Difficulty Of Guide Catheter Access During Endovascular Reperfusion Therapy

Introduction: Few studies have investigated the tortuosity of great vessels only in the longitudinal direction during endovascular reperfusion therapy. This study evaluated the tortuosity of the great vessels in the perpendicular and longitudinal directions by using novel reference line and how it affects procedural difficulty. Methods: We retrospectively reviewed the medical records of 294 patients with large vessel occlusion. Features of the anatomy of the ipsilateral great vessels were investigated by preintervention CT angiography. The reference line used to evaluate tortuosity was defined as a line from the origin of each ipsilateral great vessel to the entrance of the external auditory canal (AE-line). Coronal and sagittal angles were calculated using the AE-line and the most curved point of each ipsilateral great vessel. The right side of the reference line was negative and the left side was positive, and similarly, the ventral side of the reference line was negative and the dorsal side of the reference line was positive. Patients were divided into three groups with a threshold of -20° and 20° based on sagittal and coronal angles on the both sides, and finally into nine groups. (Figure) Reference group was set to Group 5. Procedural difficulty was determined by whether or not the internal carotid artery could be accessed within 10 min. Results: On the left side, compared with the reference group, the odds ratio [OR] (95% confidence interval [CI]) for the procedural difficulty in the Group 9 was 9.020 (2.85-28.5; p&lt;0.001). On the right side, the ORs (95% CI) for the procedural difficulty in the Group 2, Group 3, and Group 9 were 21.700 (2.200-215.000; p=0.008), 29.000 (1.770-475.000; p=0.018), and 65.200 (8.010-532.000; p&lt;0.001), respectively. Conclusion: There was a strong correlation between difficulty in guide catheter placement in the internal carotid artery and three-dimensional tortuosity when using the AE-line as a reference.

Influence of Coronal Flaring on the Shaping Ability of Two Heat-Treated Nickel-Titanium Endodontic Files: A Micro-Computed Tomographic Study.

Nickel-titanium (NiTi) usage is associated in endodontics with some complications including canal transportation. Centering ability of a NiTi file is the ability to stay centered in the root canal system during instrumentation. Any undesirable deviation from the natural canal path is indicated as canal transportation. A possible strategy to improve the centering ability of NiTi instruments is the pre-enlargement of the coronal third of the root canal to minimize coronal interferences. This procedure is known as coronal flaring. The aim of this study was to perform a micro-computed tomographic (micro-CT) evaluation of the effect of coronal flaring on canal transportation and centering ability of two heat treated nickel-titanium rotary instruments, 2Shape (Micro Mega, Besançon, France) and HyFlex CM (Coltène Whaledent, Altstätten, Switzerland). Thirty extracted mandibular molars with two independent mesial canals were selected and randomly instrumented (n = 15 canals) with One Flare (Micro Mega, Besançon, France) before HyFlex CM, HyFlex CM (without coronal flaring), One Flare before 2Shape and 2Shape (without coronal flaring). One Flare (Micro Mega, Besançon, France) was introduced 4 mm below the canal entrance for canals prepared with coronal flaring. HyFlex CM and 2Shape were used accordingly to manufacturers’ instructions. New files were used for each canal. During and after instrumentation, irrigation procedures were performed. Micro-CT images were obtained pre- and post-preparation to measure and record root canal transportation and centralization. They were reconstructed from root apex to canal orifices, generating approximately 1000 sections per specimen. The anatomical thirds were determined by dividing the number of cross-sectional slices by three. Root canal transportation and centralization were determined by Gambil method, and the mean values were analyzed by repeated measures analysis of variance followed by multiple comparisons of Bonferroni to compare the different instrumentations procedures and the root thirds (p < 0.05). As for root canal transportation, 2Shape reported significantly higher values compared to HyFlex CM in the cervical region independently from the coronal flaring. In the apical region, 2Shape caused significantly minor canal transportation when used with coronal flaring with compared with the absence of coronal flaring. Regarding the centralization, HyFlex CM showed higher values than 2Shape in the cervical, independently from coronal flaring. In the apical region, 2Shape with coronal flaring exhibited significant major centering ratio, compared with not. Within the limitations of this study, coronal flaring reduced canal transportation and improved centralization of the 2Shape files in the apical section while it had no significant influence on shaping ability of the HyFlex CM instruments. Coronal flaring could represent a valid strategy to improve the shaping ability of NiTi files knowing that its benefit could be influenced by the shaping file used.

Mitochondrial Triglyceride Dysregulation in Optic Nerves Following Indirect Traumatic Optic Neuropathy.

The purpose of this work is to identify mitochondrial optic nerve (ON) lipid alterations associated with sonication-induced traumatic optic neuropathy (TON). Briefly, a mouse model of indirect TON was generated using sound energy concentrated focally at the entrance of the optic canal using a laboratory sonifier (Branson Digital Sonifier 450, Danbury, CT, USA) with a microtip probe. We performed an analysis of a previously generated dataset from high-performance liquid chromatography-electrospray tandem mass spectrometry (LC-MS/MS). We analyzed lipids from isolated mitochondria from the ON at 1 day, 7 days, and 14 days post-sonication compared to non-sonicated controls. Lipid abundance alterations in post-sonicated ON mitochondria were evaluated with 1-way ANOVA (FDR-adjusted significant p-value &lt; 0.01), debiased sparse partial correlation (DSPC) network modeling, and partial least squares-discriminant analysis (PLS-DA). We find temporal alterations in triglyceride metabolism are observed in ON mitochondria of mice following sonication-induced optic neuropathy with notable depletions of TG(18:1/18:2/18:2), TG(18:1/18:1/18:1), and TG(16:0/16:0/18:1). Depletion of mitochondrial triglycerides may mediate ON damage in indirect traumatic optic neuropathy through loss energy substrates for neuronal metabolism.

Numerical Study of Sedimentation and Flow Pattern at the Open Channel Intake

Generally, open channel lateral intake structures are extensively used in the water and environmental projects. The passing flow at side intakes is mostly turbulence containing vertical and horizontal spiral currents causing sediment problems. The flow separation region in the intake channel is critical for sediment and water distribution during the diversion. It denotes a large reduction in the possible breadth of the lateral branch's incoming flow, as well as a place where sediment has collected, obstructing the deviated flow. This study aims to reduce and control sediment problems at the lateral intake by improving the flow pattern at this area using three-dimensional numerical models simulated in CFD, ANSYS Fluent software. The correctness of the three-dimensional numerical model was validated by a previous experimental study that showed good accuracy. Different discharge ratios and a range of shape designs were used to simulate the flow pattern at the intake channel junction. The findings demonstrated that the separation zone measurements minimize as the discharge ratio increases. Based on the changing the intake entrance shape results, cutting the outer boundary of the canal entrance widens the separation area, as well as an additional separation spot as the cutting size grows. In contrast with the internal chamfered angle models of the intake inlet, the separation area dimensions are reduced. The chamfered and rounded inner intake edge model with 30o angle to the main channel flow direction and the length of the chamfered side that normal to the flow direction (c value ) equal to three-quarters of the intake width was noticed to be the best design for lessening separation extent in this study. Thereby, the reduction ratio of the separation area width and length reaches in this case to 90% and 72%, respectively.