Type Of Eruption Research Articles

Magnetotelluric evidence for the deep causes of different eruptive styles of Changbaishan Tianchi and Longgang volcanoes

Longgang Volcano (LGV) and Changbaishan Tianchi Volcano (CTV) share a common magmatic source at mantle depths. However, the two volcanoes have produced completely different types of eruptions. By performing 3D inversion of an MT dataset that completely covers the LGV and CTV, we have obtained high-resolution electrical resistivity images. The results reveal that the two volcanoes have distinct magmatic plumbing systems, and this is likely the reason for their different eruptive styles. Results from 3D modeling do not show a magma chamber in the shallow crust beneath LGV, interpreted as the rapid rise of the magma from the mantle is responsible for producing a series of densely distributed volcanic cones in the LGV field. In contrast, there is a magma chamber in the upper crust beneath the CTV, where the fractional crystallization and mixing of magma has occurred. This magma chamber has facilitated multiple centralized eruptions, and thereby has led to the formation of the large CTV volcanic cone. These results indicate that differences in their crustal structures may have controlled the different eruptive activities of the LGV and CTV in CVS, Northeast China.

Case report: Reactive granulomatous dermatitis presenting with inguinal erythematous plaques in a patient administered with pravastatin

An identical group of disorders has been called “interstitial granulomatous dermatitis” and “palisaded neutrophilic and granulomatous dermatitis.” In addition, a drug-induced subset of this condition has been named “interstitial granulomatous drug reaction (IGDR).” More recently, “reactive granulomatous dermatitis (RGD)” has been proposed as an umbrella term encompassing these three disorders. A considerable number of RGD cases are associated with systemic conditions, including autoimmune diseases, such as rheumatoid arthritis and systemic lupus erythematosus, inflammatory bowel disease, and malignancies. IGDR has also been shown to be caused by certain medications. We present a case of a 74-year-old Japanese man showing an asymptomatic, well-demarcated erythema eruption on the bilateral inguinal region extending to the lower abdomen and proximal thigh area. He had hyperlipidemia and had been taking pravastatin for 4 years. A biopsy specimen taken from the erythematous lesion revealed infiltration of lymphocytes and histiocytes in the upper and lower dermis. Interstitial infiltrates of histiocytes and lymphocytes were found as they were dispersed between collagen bundles. Immunostaining showed CD68+ macrophages intermingled with CD4+ and CD8+ T cells. Based on the clinical and histologic findings, the eruption was diagnosed as RGD. Because of the possibility of IGDR, pravastatin was stopped. His eruption completely disappeared within 6 months after the discontinuation. The list of drugs that cause RGD includes angiotensin-converting enzyme inhibitors, antihistamines, β-blockers, antidepressants, anticonvulsants, tocilizumab and ustekinumab. In addition, various statins have been reported to induce drug eruptions. The eruption types are mainly eczematous or lichenoid reactions, with psoriasiform or ichthyosiform reactions occurring rarely. There was only one report documenting that RGD occurred in patients administered rosuvastatin, with annular, violaceous plaques distributed on the extremities, proximal trunk and intertriginous areas. Pravastatin induces lichenoid eruption, but RGD has not been documented. Our case suggests that RGD is underestimated as an adverse effect of statins possibly because of its unusual cutaneous manifestations.

Volcanic jets to commercial jets: synopsis and diagnosis

Aircraft encounters with volcanic ash have caused significant damage over the past 40 years, resulting in particular attention being given to the issue. We analyzed the volcanic ash-aircraft encounter database published by the USGS. We added new volcanic eruptions and parameters such as eruption types, and dry–wet. Then, we applied standard and advanced statistical methods.Over 130 encounters have been documented in the mentioned database, with volcanic ash causing severe abrasions to the windshield, airframe, wings, and engine components. In nine cases, aircraft engines failed. We applied the binary regression analysis and some laboratory melting experiments on volcanic ash. Besides phreatomagmatism, we use the term external water in this work to describe meteoric water that enters volcanic plumes through precipitation or melting ice on ice-capped volcanoes. We demonstrated that engine failure occurs when our regression analyses undergo dry-to-wet conditions. In other words, statistically, there is a positive correlation between wet ash encounters with aircraft and engine failure incidents. Moreover, experiments conducted at 900 °C and under 40 bar pressure showed increased sintering in the dry sample, while melting textures were more prevalent in hydrated samples. We concluded that despite the various eruptive dynamics of volcanic ash, the introduction of external water into the volcanic plumes, probably causing instantaneous hydration of volcanic ash, is a common factor in engine failure incidents. Thus, we have identified the reasons behind engine failures during encounters between aircraft and volcanic ash and the specific damage that can occur depending on the type of eruption involved.

Identifying a Case of an Atenolol-induced Papulosquamous Eruption

While beta-adrenergic blocking agents (beta blockers) are generally safe, their incidence of medication-induced cutaneous eruptions remain under-recognized in the primary care setting. The adverse dermatologic effects of these medications may arise in the days to years following drug initiation, contributing to its delayed diagnosis and management. Here we report a case of a papulosquamous drug eruption in an older adult due to atenolol. We also discuss pertinent morphologic findings, diagnostic methods, management, and how to distinguish this type of eruption from other papulosquamous disorders.

Nova 1670 (CK Vulpeculae) was a merger of a red giant with a helium white dwarf

Context. Nova 1670 is a historical transient bearing strong similarities to a recently recognized type of stellar eruption known as the red nova, which is thought to be powered by stellar mergers. The remnant of the transient, CK Vul, is observable today mainly through cool circumstellar gas and dust, and recombining plasma, but we have no direct view on the stellar object. Aims. Within the merger hypothesis, we aim to infer the most likely configuration of the progenitor system that resulted in Nova 1670. Methods. We collected the literature data on the physical properties of the outburst and the remnant (including their energetics), and on the chemical composition of the circumstellar material (including elemental and isotopic abundances). These data, which result from optical and submillimeter observations of the circumstellar gas of CK Vul, are summarized here. We performed simple simulations to analyze the form and the level of mixing within the material associated with the merger. We identified products of nuclear burning, among which we find ashes of hydrogen burning in the CNO cycles and in the MgAl chain, as well as signs of partial helium burning. Results. Based primarily on the luminosity and chemical composition of the remnant, we find that the progenitor primary had to be an evolutionarily advanced red giant branch star of a mass of 1–2 M⊙. The secondary was either a very similar giant, or –more likely– a helium white dwarf. While the eruption event was mainly powered by accretion, we estimate that about 12% of total energy is likely to have come from helium burning activated during the merger. The coalescence of a first-ascent giant with a helium white dwarf created a star with a rather unique internal structure and composition, which resemble those of early R-type carbon stars. Conclusions. Nova 1670 is the result of a merger between a helium white dwarf and a first-ascent red giant and is likely now evolving to become an early R-type carbon star.

Altered Passive Eruption among Patients Visiting Dental Outpatient Department in a Tertiary Care Center: A Descriptive Cross-sectional Study.

The eruption of teeth is considered to be a continuous phenomenon. Two types of eruption are possible namely, active and passive eruption. Failure in passive eruption (by the apical movement of gingiva from the enamel surface) generally results in a clinical condition known as altered passive eruption. It can result in the shortened crown height of a tooth and an esthetically unpleasant situation i.e., excessive gingival display or gummy smile. The main motto of this study was to find out the prevalence of altered passive eruption and associated gingival biotypes in adult patients visiting for dental treatment in tertiary centers along with strategically placed outreach centers. A descriptive cross-sectional study was done in the Department of Dentistry, Dhulikhel Hospital, and four outreach centers of the same hospital. The study was conducted from October 2022 to April 2023 after obtaining the ethical approval. Convenience sampling was done. Point estimate and 95% Confidence Interval were calculated. Among 165 patients, the prevalence of altered passive eruption was 21 (12.72%) (7.62-17.78 at 95% Confidence Interval). Furthermore, among 21 patients, the altered passive eruption was seen in the thick biotype patients in 16 (76.19%) and thin biotype patients in 5 (23.81%). The prevalence of altered passive eruption appeared to be equivalent when compared with the previous studies.

Magma intrusion process during pre-magmatic period (2010−2013) of Sinabung volcano as revealed by seismicity of volcano-tectonic and hybrid earthquakes

Sinabung volcano in Indonesia reactivated, with a series of phreatic eruptions, in August and September 2010. These eruptions were followed by various types of magmatic eruption at the summit, including lava dome growth, pyroclastic density currents, lava flow, and vulcanian eruptions, starting in December 2013. Prior to the magmatic eruptions, Sinabung exhibited two sequences of phreatic eruption and an increase in the seismicity of volcanic earthquakes. This study clarifies the progress of magma intrusion during the pre-magmatic period based on the hypocenter distribution, waveform similarity, seismic moment, rupture length, and stress drop for volcano-tectonic (VT) and hybrid earthquakes. It was found that the hypocenters of VT earthquakes are distributed north and northwest of the summit at a depth range of 1–10 km below sea level. Deep seismicity (4–10 km) alternated with shallow seismicity (2–4 km). The last shallow seismicity, from July to mid-December 2013, was different from previous seismicity in terms of higher intensity, as determined from the seismic moment, a temporary increase in the rupture length, and the migration of hypocenters towards the summit. The seismicity of VT earthquakes was altered by a swarm of hybrid earthquakes in mid-December. The hybrid earthquakes were smaller, in terms of seismic moment (mostly <3 × 1010 Nm), than the VT earthquakes. Their hypocenters were concentrated in the shallowest depth range (−0.5 to 1.5 km below sea level) directly below the summit, their source process was repeatable (they could be grouped into six earthquake families), their dominant peak was in a low-frequency range (2.5–4.5 Hz), and they had a relatively low stress drop (<0.15 MPa). This suggests that the swarm of hybrid earthquakes was induced by a frequent repeated fracture of fluid-filled cracks due to the intrusion of magma up to directly below the summit. The transition of the earthquake family and the change in its source parameters, namely an increase in the stress drop prior to the appearance of a lava dome and then a slight decrease, may reflect a gradual change in internal pressure in the hypocentral zone through the magma intrusion process.

FUNCTIONAL CROWN LENGTHENING AS A PRE-RESTORATIVE PROCEDURE IN THE AESTHETIC ZONE

Introduction: Crown lengthening is a surgical procedure to increase the height of the clinical crown for aesthetic and restorative purposes, or combination. The indications include treatment of subgingival caries and altered passive eruption. Functional crown lengthening for restorative purposes in the esthetic zone should consider the concept of biologic width and the ideal proportion of the dentogingival complex. Case: A 39-year-old male patient was referred from the Department of Conservative Dentistry, RSGM UGM Prof. Soedomo to expose the maxillary anterior teeth crowns for full crown and veneer restorations. Clinical examination showed 11, 12, and 12 post root canal treatment with 3-4 mm remaining crowns. Teeth 13, 21, 22, and 23 appear short, excessive gingival display of 3 mm, with a diagnosis of altered passive eruption type 1B. Treatment: Functional crown lengthening was performed by gingivectomy followed by flap elevation, ostectomy, and osteoplasty. A fenestration was found at the apical of 22 and treated with regenerative procedure. Full crowns and veneers insertion was done 3 months after surgery. Crown lengthening as a pre-restorative procedure is a multidisciplinary treatment that considers the need for restoration by re-establishing the biologic width, to prevent inflammation and bone loss. In addition, adequate post- surgical tissue healing time prior to restoration is necessary to avoid gingival margin rebound and to assure long-term success of the restoration. Conclusionn : Functional crown lengthening as a pre-restorative procedure in the esthetic zone can gives satisfactory and stable results, with careful examination and correct surgical procedure.

Banding in the Margins of Basaltic Dykes Indicates Pulsatory Propagation During Emplacement

AbstractBasaltic fissure eruptions, which are the most common type of eruption on Earth, are fed by dykes which mediate magma transport through the crust. Dyke propagation processes are important because they determine the geometry of the transport pathway and the nature of any geophysical signals associated with magma ascent. Here, we investigate small‐scale (mm–cm wide) banding features at the margins of dykes in the Teno Massif (Tenerife, Spain) and the Columbia River Basalt Province (CRBP) (USA). Similar marginal bands have been reported for dykes in numerous localities around the world. Dyke margins record valuable information about propagation because they are the first material to solidify against the host rock at the propagating dyke tip. We find that the marginal bands are defined by cyclic variations in phenocryst concentration and vesicularity, and we infer that these cyclic variations in texture are a product of cyclic variations in magma flow rates and pressures within the dyke tip. This indicates that dyke emplacement occurs in pulses, with propagation repeatedly hindered by the rapid cooling and solidification of magma in the narrow dyke tip. Using a 1D conduction model, we estimate the time taken for each band to cool and solidify, which provides a timescale of several minutes to tens of minutes for the pulses. The occurrence of similar bands in various volcanic settings suggests that pulsatory propagation is a common, if not ubiquitous, process associated with dyke emplacement.

Search for protostellar jets with UWISH2 in the molecular cloud complexes Vulpecula and IRDC G53.2

Abstract Jets and outflows are the early signposts of stellar birth. Using the UKIRT Wide Field Infrared Survey for H2 (UWISH2) at 2.12 μm, 127 outflows are identified in molecular cloud complexes Vulpecula OB1 and IRDC G53.2 covering 12 square degrees of the Galactic plane. Using multi-wavelength datasets, from 1.2 to 70 μm, 79 young stellar objects (YSOs) are proposed as potential driving sources, where, ∼79 % are likely Class 0/I protostars, 17 % are Class II YSOs and the remaining 4 % are Class III YSOs. The outflows are characterized in terms of their length, flux, luminosity and knot-spacing. The identified outflows have a median lobe length of 0.22 pc and 0.17 pc for outflows in Vulpecula OB1 and IRDC G53.2, respectively. Our analysis, from the knot spacing, reveals a typical ejection frequency of ∼1.2 kyr suggesting an intermediate type between the FU-Ori and EX-Ori type of eruptions in both cloud complexes. Furthermore, the physical parameters of the driving sources are obtained by performing radiative transfer modelling to the observed spectral energy distributions (SEDs), which suggest that the outflows are driven by intermediate mass stars. Various observed trends between the outflow properties and the corresponding driving sources, and various interesting outflows and star forming sites, including sites of triggered star formation and protocluster forming clump with clusters of jets, are discussed. The obtained results and the identified jet-bearing protostellar sample will pave the way to understand many aspects of outflows with future high-resolution observations.

Treatment of excessive gingival display using conventional esthetic crown lengthening versus computer guided esthetic crown lengthening: (a randomized clinical trial)

BackgroundSurgical guides have been proposed in an attempt to reach more predictable outcomes for esthetic crown lengthening. The objective of the present study was to evaluate the effectiveness of esthetic crown lengthening using 3D-printed surgical guides in the management of excessive gingival display due to altered passive eruption type 1B.Materials and methodsSixteen patients diagnosed with altered passive eruption type 1B, were divided into two groups. In the control group, the procedure was carried out conventionally, and in the study group, a dual surgical guide was used. The parameters of wound healing (swelling, color, probing depth, bleeding index, and plaque index), pain scores, gingival margin stability, and operating time were assessed at 1 week, 2 weeks, 3 months, and 6 months postoperatively.ResultsThere was no statistically significant difference in terms of wound healing, pain scores, and gingival margin stability between both groups at different time intervals (P = 1), however, there was a statistical difference between both groups in terms of operating time with the study group being significantly lower (P < 0.001).ConclusionDigitally assisted esthetic crown lengthening helps shorten the operating time and reduces the possibility of human errors during the measurements. This will be useful in helping practitioners achieve better results.Practical implicationsThe conventional method remains to be the gold standard. However, shorter operating time and lower margins for errors will help reduce costs as the chair side time is reduced as well as the possibility for a second surgery is lower. This will improve patient satisfaction as well.

Disaster risk analysis of Merapi Volcano eruption in the north slope based on the New Volcanic Risk Ranking (VRR) methods

Merapi Volcano is one of the most active volcanoes in the world and has inconsistent direction and eruption types. In addition, unplanned urbanization and the ever-increasing population on the North Slope of Merapi Volcano can cause population concentration and increasingly complex economic activities in areas exposed to natural hazards. This research aims to determine the hazard, exposure, vulnerability, resilience, and risk of Merapi Volcano eruption on the northern slopes. Risk level analysis uses the New Volcanic Risk Ranking methodology. The New Volcanic Risk Ranking consists of 34 parameters, with hazard having two parameters, exposure having nine parameters, vulnerability having ten, and resilience having thirteen parameters. Because the number of parameters evaluated for each factor is different, normalization is required to 10 so that they have the same weight. The research results show that the eruption threat index on the northern slopes of Merapi Volcano was dominated by high class, with the highest areas in Tlogolele Village (priority in Hamlet 5) and Klakah Village (focus in Hamlet 3 and 4). The high-exposure index within a 5 km radius of the Merapi Volcano crater is Tlogolele Village (priority in Hamlet 5) and Klakah Village (focus in Hamlet 4). The overall vulnerability index on the North Slope is in the medium class. The highest disaster resilience index is in Tlogolele and Klakah Villages. The high-risk level is in Tlogolele Village (priority in Hamlet 5) and Klakah Hamlet (focus in Hamlet 3 and 4).

Does the type of impacted third molar induce the formation of caries on the distal surface of the second molar? A different outcome and interpretation

Introduction: Investigators have different ideas about whether or not the third molars should be extracted as a preventive measure. The aim of this study is to evaluate the relationship of impacted third molar with the frequency of caries on the distal surface of the second molar.&#x0D; Material and Methods: In this prospectively designed study, oral examination and panoramic radiographic images of 438 patients were performed. All of the second and third molars on the mandible are classificated by the eruption levels and angulation degrees. The presence of caries on the distal surface of the second molars was determined with the help of ICDAS-II criteria. Pearson Chi-Square and McNemar test was used to compare categorical variables and both segments.&#x0D; Results: The participants in the study ranged in age from 18 to 62, with a mean age of 28.33± 9.2 years. While a total of 1752 teeth were examined and both segments were evaluated for angulation type and level of eruption. The most frequent angulation type was vertical, and the most frequent eruption level was A. Mesioangulation was the most common type of angulation associated with caries in adjacent teeth.There was a statistically significant variation in the prevalence of caries between the two segments (p

What controls the formation of vulcanian bombs? A case study from the 1 February 2014 eruption of Tungurahua (Ecuador)

Vulcanian eruptions are very common at many volcanoes around the world that erupt intermediate to silicic magmas. This type of eruption generates a wide variability of bombs and blocks preserving information onto the conduit processes that strongly control the dynamics of these events. After 84 years of repose, a new cycle of eruptive activity of Tungurahua volcano (Ecuador) started in October 1999, consisting of recurrent low-to-moderate explosive phases, which included sporadic stronger Strombolian to sub-Plinian pulses, as well as Vulcanian outbursts. The 1 February 2014 eruption was one of the most important Vulcanian events and was characterized by highly energetic explosions resulting from a plug conduit failure that generated a ∼ 9 km-high eruptive column and fallback pyroclastic density currents. Four different types of blocks and bombs were found in the deposits of the pyroclastic density currents: dense fragments (DB), breadcrust bombs (BCB), cauliflower bombs (CFB) and foliated, banded bombs (FB). All the different types of bombs have homogenous andesitic bulk-rock compositions but different, highly evolved matrix glass compositions ranging from rhyolitic for BCB to dacitic for CFB and DB, suggesting the occurrence of contrasting shallow crystallization processes within the conduit. The wide variability of the bombs in terms of patterns of surface cracks, external morphologies, internal density and vesicularity gradients records different conditions of formation from a same magma composition.The combination of morphological measurements, compositional data and textural analysis allow us (i) to infer the pre-eruption physical and rheological state of the conduit plug, (ii) to reconstruct the short-scale lateral and vertical gradients characterizing the plug, and (iii) to clarify the specific mechanism controlling the formation conditions of CFB, still poorly defined in the literature.

Statistical Study of Confined Filament/Prominence Eruptions during Solar Cycle 23

Filament/prominence eruptions can have a significant impact on Earth's upper atmosphere and space environment, and are the primary drivers of what is now called space weather. To distinguish the different types of filament eruptions we statistically examine them during the 23rd Solar cycle. In this study we use 159 filament eruptions using the List of interplanetary (IP) Shocks Observed during Solar Cycle 23 (May 1996 – January 2008) and their Source Information Environmental Satellites (GOES) X-ray plots (see Gopalswamy et al. [Gopalswamy N., H. Xie, P. Mäkelä, S. Akiyama, S. Yashiro et al. (2010) Interplanetary shocks lacking type II radio bursts, Astrophys. J., 710, 1111–1126]). It is found that 69% of the filament eruptions are confined eruptions, while 31% are ejective eruptions. Confined eruptions are 110 and 34 events (21%). They are due to active filaments and 76 events (48%) are due to disappearing filaments. The occurrences of active and disappearing filaments during the increasing phase of solar cycle 23 is found to be 80% while in the decreasing phase they are 13%. We have found that the dominant X-ray flare energy of confined eruptions is that of C class. The most common filaments field extent is located between 5 and 15 degrees. The most common flare duration is between 16 and 40 minutes.

The role of phreatomagmatism in the formation of complex monogenetic volcanic systems in a low-lying coastal plain

Monogenetic volcanoes are characterised worldwide by a single eruptive phase that is short-lived, with small eruptive volumes that produce a wide range and complexity of landforms. Investigating the evolution in eruptive styles through the active history of a volcano is key to understanding the role of phreatomagmatism in the formation of these complex monogenetic systems. The classification of the complexity of a monogenetic volcanic centre is of great significance to understanding both past volcanoes and the hazards of future volcanoes. Complexity can be defined by the number of volcanic structures created, the presence of multiple types of eruptions, and the number of conduits involved. In this paper we reconstruct the volcanic history of the Waitomokia Volcanic Complex, located in the southern lowlands of the active monogenetic Auckland Volcanic Field (AVF), New Zealand. Activity began with deposition of an initial tuff ring, followed by vent migration and establishment of a maar with a surrounding tuff ring. Four smaller tuff rings developed on the north and northeastern rim of the maar. This was followed by the noteworthy deposition of complex intercalated transitional deposits from at least two tuff rings and magmatic deposits from a scoria cone. Three scoria cones were then built within the maar, followed by minor effusion of short lava flows. Waitomokia highlights the prospect of having a complex system with ten or more landforms being created in different areas active at the same time, with associated eruptive styles and mechanisms. The possibility of a complex eruption, where several styles may occur simultaneously from distinct vents, should be considered in hazard assessment and crisis management plans.

Ectopic Eruption of the Maxillary Permanent First Molar: A Brief Review and Clinical Case Report

The Ectopic Eruption of the Maxillary Permanent First Molar (EEMPFM) is an eruption anomaly, characterized for the maxillary permanent first molar’s impaction in the distal surface of the deciduous second molar. The etiology is related with change of the axial axis of eruption of the permanent first molar associated with missing space in the maxilla. The diagnosis is the combination of clinical and complementary examination. There are two types of Ectopic Eruption: the reversible and the irreversible. The irreversible type requires orthodontics treatment, because it causes root resorption of the deciduous second molar, causing its premature loss. For the treatment, procedures can be used with the aim of promoting distal inclination of the ectopic first molar, using separator elastics, removable or fixed appliances. The aim of this work is to report a clinical case of a patient of 9 years and 6 months old, female gender, who attended the Clinic presenting EEMPFM of the maxillary right permanent first molar. The treatment was a removable appliance composed with an acrylic base plate with clasps and a finger spring activated against a resin button bonded on the mesiobuccal cusp of the maxillary right permanent first molar. The correction of this anomaly was obtained with 35 days of treatment. Therefore, the sequence of procedures from diagnosis to the indication of an adequate treatment method is fundamental to obtain satisfactory results.

Prevalence and characteristics of ectopic eruption of the first permanent molar and predictive factors for clinical outcome

Background: The primary objective of this study was to assess the occurrence, distribution, and features of ectopic first permanent molars (FPMs), as well as to investigate the clinical outcomes associated with ectopic eruption based on the degree of root resorption observed in primary second molars. Methods: This study was performed retrospectively by examining panoramic radiographs of 7070 patients aged 5 to 12 years. The gender and age of the patients, the number, location, and distribution mode of ectopic FPMs, the resorption degree of the distal roots of primary second molars, and the clinical outcome of ectopic eruption were evaluated. Descriptive statistics and chi-square test were performed on the obtained data using SPSS version 22 (SPSS Inc, Chicago, IL, USA). Results: In 144 of 7070 cases, a total of 221 ectopic permanent first molar teeth were detected (2% prevalence). The mean age of the 144 patients was 8.04 years. Ectopic eruption was most common in patients aged 7–8 years (48.63%), which was statistically significant (P&lt;0.05). Ectopic eruptions were more common in females (58.30%) than males (41.70%; P&lt;0.05). Of the ectopic permanent first molars, 78 (35.30%) were in the mandible, and 143 (64.70%) were in the maxilla. The relationship between the degree of resorption and the type of ectopic eruption was statistically significant (P&lt;0.05). Conclusion: The increase in the severity of root resorption in the primary second molars was a significant predictor for the prognosis of ectopic eruption in the present study. Early diagnosis and treatment of ectopic FPMs are of great importance to preventing premature loss of primary second molars resulting in malocclusion.

Comprehensive Genomic Characterization of Staphylococcus aureus Isolated from Atopic Dermatitis Patients in Japan: Correlations with Disease Severity, Eruption Type, and Anatomical Site.

Atopic dermatitis (AD) shows frequent recurrence. Staphylococcus aureus is the primary microbial component in AD and is associated with disease activity. However, traditional typing methods have failed to characterize virulent AD isolates at the clone level. We conducted a comprehensive genomic characterization of S. aureus strains isolated from the skin of AD patients and healthy donors, comparing the whole-genome sequences of the 261 isolates with anatomical and lesional (AD-A)/nonlesional (AD-NL)/healthy sites, eruption types, clinical scores, virulence, and antimicrobial resistance gene repertoires in Japan. Sequence type (ST) diversity was lost with worsening disease activity; ST188 was the most frequently detected ST in AD-A and had the strongest correlation with AD according to the culture rate and proportion with worsening disease activity. ST188 and ST20 isolates inhabited all skin conditions, with significantly higher proportions in AD skin than in healthy skin. ST8, ST15, and ST5 proportions were equivalent for all skin conditions; ST30 was detected only in healthy skin; and ST12 was detected only in AD skin. ST97 detected in AD-A and healthy skin was clearly branched into two subclades, designated ST97A and ST97H. A comparison of two genomes led to the discovery that only ST97A possessed the complete trp operon, enabling bacterial survival without exogenous tryptophan (Trp) on AD skin, where the Trp level was significantly reduced. Primary STs showing an AD skin inhabitation trend (ST188, ST97A, ST20, and ST12) were all trp operon positive. The predominant clones (ST188 and ST97) possessed almost no enterotoxin genes, no mecA gene, and few other antimicrobial resistance genes, different from the trend observed in Europe/North America. IMPORTANCE While Staphylococcus aureus is a member of the normal human skin flora, its strong association with the onset of atopic dermatitis (AD) has been suggested. However, previous studies failed to assign specific clones relevant to disease activities. Enterotoxins produced by S. aureus have been suggested to aggravate and exacerbate the inflammation of AD skin, but their role remains ambiguous. We conducted a nuanced comprehensive characterization of isolates from AD patients and healthy donors, comparing the whole-genome sequences of the isolates with anatomical and lesional/nonlesional/healthy sites, eruption types, clinical scores, virulence, and antimicrobial resistance gene repertoires in Japan. We demonstrate that specific clones are associated with disease severity and clinical manifestations, and the dominant clones are devoid of enterotoxin genes and antimicrobial resistance genes. These findings undermine the established notion of the pathophysiological function of S. aureus associated with AD and introduce a new concept of S. aureus colonization in AD.

Acne-like Eruptions: Disease Features and Differential Diagnosis

The term “acne-like eruptions” encompasses a variety of skin conditions resembling acne vulgaris. While both acne-like dermatoses and true acne are frequently observed in clinical settings, differentiating between the two might be challenging. Similar to acne, the lesions of acne-like eruptions may exhibit papules, pustules, nodules, and cysts. However, contrary to acne, comedones are uncommon but may still be observed in certain types of acne-like eruptions. Moreover, acne-like eruptions can be differentiated from acne based on their sudden onset, the propensity to occur across all age groups, the monomorphic appearance of lesions, and the distributions extending outside the seborrheic regions. The development of acne-like eruptions cannot be attributed to a single underlying mechanism; nevertheless, various factors such as patient age, infections, occupation, habits, cosmetics, and medications may be involved. The observed lesions may not respond to standard acne therapy, necessitating that treatment strategies are tailored in accordance with the identified causative agents. The following review aims to outline distinct entities of acne-like eruptions and present features that set them apart from true acne. Acne-like eruptions in the adult population, infectious diseases resembling acne, and acne-like eruptions resulting from exposure to chemical and physical agents are addressed in this paper. An understanding of the clinical presentation, pathophysiology, and epidemiology of this group of dermatoses is pivotal for a precise diagnosis and provision of appropriate care.