Coronal Cavity Research Articles

Regenerative Endodontic Procedures With Minced Pulp Tissue Graft in Mature Permanent Teeth: A Clinical Study

IntroductionRegenerative endodontic procedures (REPs) using cell-based approaches have emerged as novel treatment modalities. This clinical study aimed to present the outcomes and explore factors influencing REPs with minced pulp tissue (MP) grafts in a mature tooth. MethodsSix healthy male patients aged 20–27 requiring nonsurgical root canal treatment were enrolled in this study. MP tissue obtained from third molars was introduced into the instrumented, disinfected, and blood-filled root canal. The canal was sealed with bioceramic cement, and the coronal access cavity was restored. ResultsFollow-ups for 6 cases ranged from 19 to 42 months. Radiographically, all the teeth showed favorable outcomes. Among the 6 teeth, 2 showed neither intracanal calcification nor recovery in sensibility tests, and one had no intracanal calcification with an inapplicable sensibility test evaluation. In 2 teeth, intracanal calcification was observed in the apical third; however, there was no recovery in the sensibility tests. One tooth exhibited intracanal calcification in the apical third and showed recovery in the sensibility tests. Considering these outcomes and clinical variables, the size of the apical foramen and the composition of the transplanted pulp tissue were identified as tentative influencing factors. ConclusionsThis study on simplified cell-based therapy using autologous MP for pulp/dentin regeneration in adult teeth not only enhances our understanding of REPs but also suggests its potential as an alternative treatment option to conventional endodontic treatment.

Validity of Endometrial Cavity Length on 3D Pelvic Ultrasound before Endometrial Ablation.

This study aimed to compare endometrial cavity length measurements obtained by preoperative three-dimensional (3D) reconstruction of coronal images on pelvic ultrasound with intraoperative endometrial cavity measurements obtained in advance of Minerva endometrial ablation. This was a retrospective cohort study of 41 individuals who underwent a Minerva endometrial ablation between August 1, 2018 and March 15, 2022 at a single academic medical center. Patients were excluded if they had an in-clinic ablation or no ultrasound with 3D uterine volume within 180 days before surgery. Physician sonologists measured the endometrial cavity length using 3D coronal reconstruction of the cavity. Two measurements were obtained by separate physicians who were blinded to intraoperative values. Intraoperative endometrial cavity lengths were obtained from operative reports. A Bland-Altman plot was used to evaluate the agreement of intraoperative and ultrasound measurements. The mean intraoperative endometrial cavity length (50.7 ± 7.8 mm) was greater than the mean endometrial cavity length by 3D coronal reconstruction of pelvic ultrasound (36.1 ± 6.2 mm, P < 0.0001). The average difference between intraoperative and ultrasound measurements of cavity length was 14.6 ± 9.0 mm. The agreement between measurements was poor (Lin's concordance correlation coefficient 0.06). Using a Bland-Altman plot, the limits of agreement (-3.1 to 32 mm) exceeded the a priori acceptable limits of agreement (-10 to 10 mm). Our findings suggest that preoperative coronal endometrial cavity length measurements by ultrasound are not a valid substitute for intraoperative measurements before Minerva ablation.

Mass Cycle and Dynamics of a Virtual Quiescent Prominence

The mass cycle of solar prominences or filaments is still not completely understood. Researchers agree that these dense structures form by coronal in situ condensations and plasma siphoning from the underlying chromosphere. In the evaporation–condensation model siphoning arises due to evaporation of chromospheric plasma from localized footpoint heating, but this is challenging to justify observationally. Here, we simulate the reconnection–condensation model at extreme resolutions down to 20.8 km within a three-dimensional (3D) magnetohydrodynamic coronal volume. We form a draining, quiescent prominence and associated coronal rain simultaneously. We show that thermal instability—acting as a trigger for local condensation formation—by itself drives siphoning flows from the low corona without the need of any localized heating. In addition, for the first time, we demonstrate through a statistical analysis along more than 1000 magnetic field lines that cold condensations give rise to siphoning flows within magnetic threads. This siphoning arises from the strong pressure gradient along field lines induced by thermal instability. No correlation is found between siphoning flows and the prominence mass, making thermal instability the main in situ mass-collection mechanism. Our simulated prominence drains by gliding along strongly sheared, asymmetric, dipped magnetic arcades, and develops natural vertical fine structure in an otherwise horizontal magnetic field due to the magnetic Rayleigh–Taylor instability. By synthesising our data, our model shows remarkable agreement with observations of quiescent prominences such as its dark coronal cavity in extreme-ultraviolet emission channels, fine-scale vertical structure, and reconnection outflows, which, for the first time, have been self-consistently obtained as the prominence evolves.

Observations of the Formation and Disappearance of a Funnel Prominence

We present an observational study of the formation and disappearance of a funnel prominence. Before the funnel prominence formed, cool materials from the top of a preexisting polar crown prominence flowed along saddle-shaped coronal loops to their base, forming a smaller prominence. Meanwhile, the saddle-shaped coronal loops gradually rose, and U-shaped coronal loops, termed prominence horns, began to appear along with a coronal cavity. Afterward, a cool column emerged from the chromosphere, rose vertically into the corona, and then moved laterally to be transported into the U-shaped coronal loops. The formed prominence slid into the chromosphere, while the U-shaped coronal loops and the coronal cavity became more pronounced. As cool materials accumulated at the base of the U-shaped coronal loops, these loops underwent a significant descent and a V-shaped structure appeared at the base of the cool materials, indicating that the U-shaped coronal loops may be dragged down to sag. Subsequently, cool materials from the V-shaped structure continued to flow almost vertically toward the chromosphere, forming the funnel prominence. The vertical downflows might be produced by magnetic reconnection within or between the sagging field lines. Due to persistent vertical downflows, the U-shaped coronal loops were lifted up and prominence materials followed along inclined coronal loops toward the chromosphere, causing the funnel prominence to disappear. Our observations suggest that chromospheric plasma transported into a coronal cavity and then drained out via vertical downflows can form a funnel prominence.

Comparative Study of the Expansive Behaviour of Different Internal Bleaching Agents

Internal bleaching is a conservative treatment applied to a darkened endodontically treated tooth to restore its original colour, either as a single treatment or as a treatment prior to a subsequent prosthetic phase. The aim of this study was to objectively measure and compare using an experimental model the expansive capacity of four bleaching groups: carbamide peroxide 37% (CP 37%), hydrogen peroxide 30% (HP 30%), HP 30% mixed with sodium perborate (SP) and SP mixed with distilled water. A total of 150 lower incisors (n = 30 in each group) were prepared for the Walking Bleach technique and a glass tube with oil was introduced into the coronal access cavity to measure the expansive capacity through oil displacement, due to the reaction that occurs when bleaching agents interact with dental tissues. The results after 10 days were analysed with the Games–Howell post hoc test to compare the samples. Significant higher expansion was observed with HP 30% (p &lt; 0.05) and lower expansion with SP (p &lt; 0.05) compared to the other groups. No significant differences were observed between CP 37% (p &gt; 0.05) and HP 30% + SP (p &gt; 0.05). This provides significant and observable information on the behaviour of each bleaching group and its evolution after 10 days.

Comparative Evaluation of Modified Kvaal’s Formula and Coronal Pulp Cavity Index in the Pune Population – A Cone-beam Computed Tomography-based Retrospective Study

ABSTRACT Introduction: The uniqueness of the human dentition serves its wide acceptance in the identification of individual in forensic science. Aim and Objectives: To estimate the accuracy of age by using modified Kvaal’s formula and coronal pulp cavity index (CPCI) and compare the standard error and establish the technique among the Pune population. Materials and Methods: Four hundred cone-beam computed tomography (CBCT) scans were randomly selected with satisfying the established criteria. The second premolar was included in the study and the maximum length of tooth, root, and pulp was measured using modified Kvaal’s method and CPCI by using Planmeca CBCT machine with Romexis-three-dimensional imaging software. Results: The results were analyzed using the Chi-square test and ANOVA. Modified Kvaal’s formula was found to be the better followed by CPCI in the estimation of age among Indians with lesser error in prior. Conclusion: Modified Kvaal’s formula is precise, noninvasive, and most reliable biomarker for age estimation than tooth-coronal index.

Application of virtual reality and haptics system Simodont in Chinese dental education: A scoping review.

Virtual reality (VR) and haptic simulation technology have been increasingly implemented in dental training. Since the first haptic VR dental simulator (Simodont) was introduced 10 years ago, it has been applied in more than 40 universities in mainland China. This scoping review aimed to review literature, showcasing the teaching reform of dental virtual simulation in mainland China to global dental education peers. This scoping review was conducted using the PRISMA extension for scoping review guidelines. Seven electronic databases were searched, and two reviewers independently performed the selection and characterization of the studies. The final scoping review included 12 studies. Four studies focused on the G. V. Black class II cavity, three on manual dexterity skills training, two on full metal crown preparation, one on pulpal access and coronal cavity preparation, one on flipped classroom teaching, and one on 'doctor-patient communication' skills. The most critical scenarios, self-assessment, working posture, curriculum setting, training and cost are analysed and discussed. Haptic simulation technology is a valuable complementary tool to the phantom head in dental education. The combined utilization of these two training devices has been superior to either in isolation. However, there is a lack of research on the sequencing of the two systems, as well as the appropriate distribution of curriculum between them. It is necessary for educators to organize or engage in experience sharing, collaboration and knowledge dissemination. These actions are essential for promoting effective teaching within dental educational institutions.

Two-horn quiescent prominence observed in Hα and Mg II h&amp;k lines with THEMIS and IRIS

Context. Prominences are large magnetic structures in the corona filled by cool plasma with fast evolving fine structure. Aims. We aim to better understand the plasma conditions in the fine structure of a quiescent prominence including two transient horns observed at the bottom of the cavity using the high resolution Interface Region Imaging Spectrograph (IRIS) and the MulTi-Raies (MTR) spectrograph of the Télescope Heliographique pour l’Etude du Magnétisme et des Instabilités Solaires (THEMIS) in the Canary Islands. Methods. We analysed the spectra obtained in Hα by THEMIS and Mg II by IRIS and compare them with a grid of 23 940 1D radiative transfer models which include a prominence-to-corona transition region (PCTR). The full observed profiles of Mg II in each pixel are fitted completely by synthesised profiles with ×RMS (Cross RMS; an improved version of the rolling root mean square (rRMS) method). When the RMS is below a certain threshold value, we recover the plasma conditions from the parameters of the model best fitting the observed line profile. This criterion is met in two regions (the horns and edge of the prominence) where the line profiles can generally be described as single peaked. Results. The 1D models suggest that two different kinds of model atmospheres correspond to these two regions. The region at the edge is found to be fitted mainly with isothermal and isobaric models, while the other area (the horns) is seen to be fitted with models with a PCTR that have optical thicknesses of less than 5. In the prominence edge, the theoretical relationship between the integrated intensities in Hα and Mg II is verified and corresponds to low emission measure values. In these regions the electron density is around 1010 cm−3, while it is one order of magnitude less in the horn regions around 109 cm−3. Conclusions. In the horns, we find some profiles are best fitted with models with high mean temperatures. This suggests that the hot PCTR found in the horns could be interpreted as prominence plasma in condensation phase at the bottom of the coronal cavity.

Fracture Resistance of Endodontically Treated Premolars with Different Access Preparations and Coronal Cavity Designs – An In Vitro Study

Fracture Resistance of Endodontically Treated Premolars with Different Access Preparations and Coronal Cavity Designs – An In Vitro Study

Original Research: Oral Health Concerns of Female Breast Cancer Survivors on Adjuvant Endocrine Therapy.

Oral complications from cancer treatments are among the adverse effects breast cancer survivors can face. Yet such complications are often overlooked in cancer survivorship care. Many breast cancer survivors are receiving adjuvant endocrine therapy, but there is limited understanding of potential oral complications from this therapy. This study aimed to compare aspects of oral health in female breast cancer survivors who were taking adjuvant endocrine therapy with those of survivors not taking such therapy. National Health and Nutrition Examination Survey data collected from January 2009 through March 2020 were used for the analysis. Female adults ages 20 years and older who had been diagnosed with breast cancer were included. Linear regression and χ 2 analyses were conducted to examine aspects of oral health, using IBM SPSS Complex Samples software, version 27. In our sample of 423 female breast cancer survivors, 7.1% were taking tamoxifen, 7.8% were taking anastrozole, 4.3% were taking letrozole, and 2.9% were taking exemestane. Compared with the survivors not taking such therapy, a greater proportion of those taking it had decayed teeth, gum disease/problems, and were recommended for imminent dental care after oral health examination by dentists. The survivors who were not taking adjuvant endocrine therapy had more coronal cavities. Data analysis showed that female breast cancer survivors taking adjuvant endocrine therapy appear more likely to have oral health issues than those not taking such therapy. Improved awareness of these issues is critical. Assessment and management guidelines to address these oral health issues are needed by health care providers.

Rotational Flows in Solar Coronal Flux Rope Cavities

We present a 2.5D magnetohydrodynamic simulation of a systematically rotating prominence inside its coronal cavity using the open-source MPI-AMRVAC code. Our simulation starts from a nonadiabatic, gravitationally stratified corona, permeated with a sheared arcade magnetic structure. The flux rope (FR) is formed through converging and shearing footpoints driving, simultaneously applying randomized heating at the bottom. The latter induces a left–right asymmetry of temperature and density distributions with respect to the polarity inversion line. This asymmetry drives flows along the loops before the FR formation, which gets converted to net rotational motions upon reconnection of the field lines. As the thermal instability within the FR develops, angular momentum conservation about its axis leads to a systematic rotation of both hot coronal and cold condensed plasma. The initial rotational velocity exceeds 60 km s−1. The synthesized images confirm the simultaneous rotations of the coronal plasma seen in 211 and 193 Å and condensations seen in 304 Å. Furthermore, the formation of the dark cavity is evident in 211 and 193 Å images. Our numerical experiment is inspired by observations of so-called giant solar prominence tornadoes and reveals that asymmetric FR formation can be crucial in triggering rotational motions. We reproduce observed spinning motions inside the coronal cavity, augmenting our understanding of the complex dynamics of rotating prominences.

Estimated Age Calculation with Tooth Coronal Index (TCI) Method Using Orthopanthomography in Malang City Population

Age estimation is an important aspect in forensics because it plays a role in determining individual identity. In cases of forensic identification of bodies that are difficult to identify visually or in poor condition, radiography is the choice of non-invasive method that can be used for age estimation, one of which is panoramic radiography. The Tooth Coronal Index (TCI) method is one method that can be used to identify a person's biological age through panoramic radiography. The purpose of this study was to compare the chronological age with the biological age obtained from the measurement of the TCI method on the mandibular premolars using panoramic radiography in the Malang City population. TCI measurement was done by measuring the height of the pulp chamber (Coronal Height) and the height of the crown of the tooth (Coronal Pulp Cavity Height) vertically from the Cemento Enamel Junction (CEJ) on the mandibular premolars. Then the value is entered in the regression equation that has been determined to obtain an estimate of biological age. Then, the results of the estimated biological age are compared with their chronological age. At last, the difference between biological and chronological age is calculated to determine the approximate age. The mean difference between chronological age and biological age was ± 1.32 years and there is no significant difference between the biological age and the chronological age (p value 0.11). TCI method on the mandibular premolars using panoramic radiography can be used to estimate age in Malang City Population.

Field-aligned and Magnetic Reconnection Flows in a Magnetohydrodynamic Simulation of Prominence-cavity System

Nested ring-shaped line-of-sight (LOS) oriented flows in coronal cavities have been observed in recent years but rarely explained. Using a magnetohydrodynamic simulation of a prominence-cavity system, we investigate the relationship between the simulated field-aligned flows, magnetic reconnection flows, and the LOS-oriented flows observed by the Coronal Multi-Channel Polarimeter. The field-aligned flows are along magnetic field lines toward the dips and driven by the hydrodynamic forces exerted by the prominence condensation. The reconnection flows are driven by the overlying reconnection and tether-cutting reconnection. The velocity of the reconnection flows increases from the quasi-static phase to the fast-rise phase, reaching several kilometers per second, which is similar to the speed of the field-aligned flows. We calculate the synthetic Doppler images by forward modeling and compare them with the observed LOS-oriented flows. The synthetic images show that the LOS-oriented flows of one ring with opposite internal flow driven by the field-aligned flows are identified in the simulation. And the synthetic images integrated along three different LOSs can resemble the observed direction reversal of the LOS-oriented flow in about 20 hr, when the included angle of two adjacent LOSs is about 10°. These results suggest that the observed LOS-oriented flows of one ring with an opposite internal flow may be explained by the LOS integration effect of field-aligned flows along different loops.

Stronger than Ever: Multifilament Fiberglass Posts Boost Maxillary Premolar Fracture Resistance.

This paper investigates the influence of cavity configuration and post-endodontic restoration on the fracture resistance, failure mode and stress distribution of premolars by using a method of fracture failure test and finite elements analysis (FEA) coupled to Weibull analysis (WA). One hundred premolars were divided into one control group (Gcontr) (n = 10) and three experimental groups, according to the post-endodontic restoration (n = 30), G1, restored using composite, G2, restored using single fiber post and G3, restored using multifilament fiberglass posts (m-FGP) without post-space preparation. Each experimental group was divided into three subgroups according to the type of coronal cavity configuration (n = 10): G1O, G2O, and G3O with occlusal (O) cavity configuration; G1MO, G2MO, and G3MO with mesio-occlusal (MO); and G1MOD, G2MOD, and G3MOD with mesio-occluso-distal (MOD). After thermomechanical aging, all the specimens were tested under compression load, and failure mode was determined. FEA and WA supplemented destructive tests. Data were statistically analyzed. Irrespective of residual tooth substance, G1 and G2 exhibited lower fracture resistance than Gcontr (p < 0.05), whereas G3 showed no difference compared to Gcontr (p > 0.05). Regarding the type of restoration, no difference was highlighted between G1O and G2O, G1MO and G2MO, or G1MOD and G2MOD (p > 0.05), whereas G3O, G3MO, and G3MOD exhibit higher fracture resistance (p < 0.05) than G1O and G2O, G1MO and G2MO, and G1MOD and G2MOD, respectively. Regarding cavity configuration: in G1 and G2, G1O and G2O exhibited higher fracture resistance than G1MOD and G2MOD, respectively (p < 0.05). In G3, there was no difference among G3O, G3MO and G3MOD (p > 0.05). No difference was found among the different groups and subgroups regarding the failure mode. After aging, premolars restored with multifilament fiberglass posts demonstrated fracture resistance values comparable to those of an intact tooth, irrespective of the different type of cavity configuration.

Regenerative endodontic therapy in mature teeth with necrotic pulp and apical periodontitis using two disinfection protocols

ObjectiveThis study compared the effect of diode laser (DL) 980 nm and double antibiotic paste (DAP) on response of mature teeth with necrotic pulp and apical periodontitis to regenerative endodontic therapy in a dog model.MethodsPulp necrosis and periapical pathosis were induced in 40 mature double rooted premolars in four 2-year-old mongrel dogs. These teeth were randomly divided according to disinfection protocol into four equal groups (10 teeth each/20 roots), group I: DAP; group II: DL980 nm; group III: positive control (without treatment) and group IV: negative control (untouched teeth). These groups were further subdivided into 2 subgroups (5 teeth each/10 roots) according to evaluation period, subgroup (A): one month and subgroup (B): three months. Revascularization techniques were performed using bleeding induction and application of platelet rich fibrin (PRF). The coronal cavities were sealed with mineral trioxide aggregate (MTA) and glass ionomer cement. The inflammatory response, vital tissue in-growth, new hard tissue formation and bone resorption were assessed. Statistical analysis was done utilizing ANOVA, Tukey’s post hoc and paired t tests.ResultsIn both subgroups, there were no significant differences between DAP and DL980 in terms of inflammatory cell count, vital tissue in-growth, new hard tissue formation and bone resorption (P ≤ 0.05).ConclusionDiode laser 980 nm can alternate DAP as a disinfection method of the root canal during RET for mature necrotic teeth, therefore it may accelerate regenerative endodontic therapy for both the patient and dentist and allows for RET in a single appointment.

Stereoscopic observation of simultaneous longitudinal and transverse oscillations in a single filament driven by two-sided-loop jet

ABSTRACT We report the first observations of simultaneous large-amplitude longitudinal and transverse oscillations of a quiescent filament trigged by a two-sided-loop jet formed by the magnetic reconnection between the filament and an emerging loop in the filament channel, recorded by the Solar Dynamics Observatory and the Solar TErrestrial RElations Observatory. The north arm of the jet firstly pushed the filament mass moving northwardly along the magnetic field lines consisting of the coronal cavity, then some elevated filament mass fell back and started to oscillate longitudinally at the bottom of the cavity (i.e. the magnetic dip). The northernmost part of the filament also showed transverse oscillation simultaneously. The amplitude and period of the longitudinal (transverse) oscillation are 12.96 (2.99) Mm and 1.18 (0.33) h, respectively. By using the method of filament seismology, the radius of curvature of the magnetic dip is about 151 Mm, consistent with that obtained by the 3D reconstruction (166 Mm). Using different physical parameters of the observed longitudinal and transverse oscillations, the magnetic field strength of the filament is estimated to be about 23 and 21 Gauss, respectively. By calculating the energy of the moving filament mass, the minimum energy of the jet is estimated to be about $1.96 \times 10^{28} \operatorname{erg}$. We conclude that the newly formed jet can not only trigger simultaneous longitudinal and transverse oscillations in a single filament, but also can be used as a seismology tool for diagnosing filament information, such as the magnetic structure, magnetic field strength, and magnetic twists.

Comparative Evaluation Of Amount Of Apically Extruded Debris In Endodontic Retreatment Procedures Using Four Different File Systems- An Invitro Study

Objective(s): To compare the amount of apical debris extruded during endodontic retreatment procedures performed using H files, R-Endo Retreatment files, GPR files and ProTaper Universal Retreatment files.&#x0D; Materials and Methods: The conventional coronal access cavity was prepared for 40 extracted Mandibular Premolars. The root canals were prepared with ProTaper Next Rotary files till X1. Obturation was done by combination of Lateral and Vertical Compaction technique. All the samples were later attached to Eppendorf tubes. The samples were then divided into four groups each containing 10 samples on the basis of different retreatment files to be used. After complete removal of root canal filling material, the debris and the root filling material remnants adhered was collected in preattached Eppendorf tubes. For final weight computation and comparison, the weight of empty tube was deducted from the weight of tube accommodating the debris. ANOVA and Tukey test were applied for statistical analysis.&#x0D; Results: The R-Endo retreatment files showed minimum apical extrusion of debris than all the other examined files in the study. The apical extrusion of debris for R Endo min to max was -0.045 to 0.009. However, there was no statistically significant difference in amount of apical extrusion of debris by different files system (p&gt;0.005).&#x0D; Conclusion(s): There was no significant difference between the groups in apical extrusion of debris. Also rotary retreatment files showed lesser apical of debris than Hedstrom hand files. R Endo extruded less debris apically in this study.&#x0D; Keywords: Apical extrusion of debris; Gutta-percha; Retreatment files.

Toward a Unified Explanation for the Three-part Structure of Solar Coronal Mass Ejections

Coronal mass ejections (CMEs) are associated with the eruption of magnetic flux ropes (MFRs), which usually appear as hot channels in active regions and coronal cavities in quiet-Sun regions. CMEs often exhibit a classical three-part structure in the lower corona when imaged with white-light coronagraphs, including a bright front, dark cavity, and bright core. For several decades, the bright core and dark cavity have been regarded as the erupted prominence and MFR, respectively. However, recent studies have clearly demonstrated that both the prominence and hot-channel MFR can be observed as the CME core. The current research presents a three-part CME resulting from the eruption of a coronal prominence cavity on 2010 October 7, with observations from two vantage perspectives, i.e., edge-on from the Earth and face-on from the Solar Terrestrial Relations Observatory (STEREO). Our observations illustrate two important results: (1) for the first time, the erupting coronal cavity is recorded as a channel-like structure in the extreme-ultraviolet passband, analogous to the hot-channel morphology, and is dubbed as the warm channel; and (2) both the prominence and warm-channel MFR (coronal cavity) in the extreme-ultraviolet passbands evolve into the CME core in the white-light coronagraphs of STEREO-A. The results suggest that we are working toward a unified explanation for the three-part structure of CMEs, in which both prominences and MFRs (hot or warm channels) are responsible for the bright core.

Coronal Cavities in CoMP Observations

Abstract Quiescent coronal cavities can provide insight into solar magnetic fields. They are observed in the coronal emission lines in both polarized and unpolarized light. In the total linear polarization fraction (L/I), they often possess a “lagomorphic,” or “rabbit-shaped,” structure that reflects the underlying magnetic field configuration. We studied quiescent coronal cavities observed between 2012 and 2018 by the Coronal Multichannel Polarimeter (CoMP). The majority of cavities in our study had a characteristic lagomorphic structure in linear polarization. We additionally compared cavity widths as observed in intensity with sizes of their linear polarization signatures for 70 cavities and found that both features are strongly correlated. Our results indicate that chances for observing a lagomorphic structure increase greatly with cavity lifetime, suggesting that the visibility depends on the spatial orientation of the cavity. Forward-modeled observations in linear polarization of flux ropes confirmed this assumption. We conclude that observations of the solar coronal cavities in linear polarization are consistent with the theoretical model of flux rope formation and structure.

Age estimation in Western Indian population by Cameriere's and Drusini's methods.

Objectives:The aim of the present study is to determine applicability of Cameriere's and Drusini's methods in Western Indian population.Methodology:Panoramic radiographs of total 300 Gujarati individuals, equally divided into four study groups were studied by two investigators. The pulp/tooth area ratio (AR) were calculated for maxillary and mandibular canines and tooth coronal indexes (TCI) i.e., the ratio between coronal pulp cavity height and crown height were calculated for mandibular premolars and first and second molars. The acquired data were subjected to correlation and regression analysis and also inter and intraobserver reliability was obtained for both the investigators.Results:The ARs and TCIs for all the respective teeth were significantly correlated with the age of the individuals. The individual regression formulae were derived for all the teeth and were then used separately to calculate the age. There was no statistically significant difference between the mean chronological age and mean calculated age for all the teeth.(P > 0.05). The mean absolute errors for all the teeth were <10 years.Conclusion:The findings of this study prove the applicability of Cameriere's and Drusini's age estimation methods for Western Indian population. However, the weak correlation coefficients suggest the need for further studies to get more accurate results.