Eruption Pattern Research Articles

Understanding multi-vent Plinian eruptions at Mt. Tongariro Volcanic Complex, New Zealand

The andesitic Tongariro Volcanic Complex in the Central North Island of New Zealand comprises tens of vents along an actively extending graben. Past work has hypothesised that multiple vents may operate during a single explosive eruption episode, providing an unprecedented hazard challenge for this region. The stratigraphic record suggests an irregular clustering of eruption episodes over time, including an unusual ≤ 200-year-long period from ~11.3–11.1 ka when several large explosive eruptions occurred. We carried out new field mapping, stratigraphy, and sedimentology of the resulting pyroclastic deposits to identify seven episodes during this period, locating the vent sites and calculating their climactic dynamic properties. Five of the episodes involved two or more vent locations that produced separate sub-Plinian/Plinian eruption columns. Eruption columns ranged between 16 and 24 km high and erupted volumes of 0.05 to 0.76 km3, indicating magnitudes of 4 to 5. Each of these episodes show north-to-south “unzipping” of the Tongariro Graben, with episodes beginning in northerly vents, before being joined by vents south of these. This included two scenarios; northern edifice vents followed by central edifice ones or central edifice vents followed by southern ones. In both cases, the northerly vents generally display the greatest peak eruption magnitudes and the steadiest eruptions. By contrast, the southernmost vents formed along a fault-controlled fissure-like system. These produced unsteady plumes and pyroclastic density currents. The northward widening tectonic graben structure thus influences the pattern and style of these Plinian-style eruptions. This study highlights a real possibility for an extreme hazard scenario involving successive large-scale eruptions at volcanic systems in slowly rifting environments and sheds new light on the volcano-tectonic interaction in such settings.

Cavity treatment in primary molars and malocclusion: quasi-randomised clinical trial.

BackgroundAn innovative caries treatment protocol for primary teeth, termed Ultra-Conservative Treatment (UCT), restores small cavities through the Atraumatic Restorative Treatment (ART) protocol and cleans medium to large open cavities with toothbrush and fluoride toothpaste. However, UCT-treated primary molars were found to exfoliate earlier than amalgam (CRT) and ART-restored cavities, which may lead to unacceptable loss of space for normal eruption of permanent successors. The null-hypothesis tested was that there is no difference between the three treatment protocols and the intra-arch distances, and index of orthodontic treatment need (IOTN) after 4 years.MethodsDental casts were taken at baseline (T0) and four (T4) years. The space of the premolars (D + E space), arch perimeter, anterior and total arch depth were measured using a morphometric computer programme. The presence and level of malocclusion were assessed according to the IOTN index. Dependent variables were all intra-arch distances and the IOTN while the independent variable was treatment protocol (CRT, ART and UCT). Data were analysed using linear and logistic regression.ResultsThe sample consisted of 867 pairs of casts of 272 initial 6–7-year-olds. No difference was observed between the UCT protocol and the two restorative protocols for the intra-arch variables in both maxilla and mandible over the 4 year period. There was no difference between the UCT and the CRT and ART protocols regarding the occurrence of orthodontic treatment need (malocclusion). In conclusion, the UCT treatment protocol does not differ significantly from the traditional amalgam (CRT) and ART restorative protocols with respect to intra-arch distances and malocclusion. The earlier exfoliation of UCT-treated primary molars does not lead to a worsening of the eruption pattern of permanent successors.

The Effect of First Permanent Tooth Eruption on Dental Arch Dimension

Background: Crowding is one of the most prevalent types of malocclusion as well as a major problem in clinical orthodontics. It is essential to know the cause of crowding in order to achieve a better treatment. Objectives: A longitudinal analysis of arch dimension changes in late primary and early mixed dentition periods in children was designed and investigated the effect of eruption of precedence on the arch size in the samples under study. Methods: This longitudinal study was carried out on 32 children aged 5.5 - 6.5 years who had no erupted permanent dentition. Impression was taken and the arch perimeter, depth and width as well as tooth size were measured by a digital calliper and a brass wire on casts. After eruption of the first permanent tooth, the second impression was taken; the above-mentioned parameters were measured on the second casts. Data were analysed by ANOVA test. Results: Four pattern of eruption of precedence were as follows: maxillary 1st molar, mandibular incisors, Mandibular 1st molars and simultaneous eruption of maxillary and mandibular 1st molars. With eruption of mandibular central incisors, inter canine width and overjet increased by 0.81 and 0.27 mm, respectively. The mandibular arch perimeter increased by 2.25 mm with simultaneous eruption of maxillary and mandibular permanent first molars. The maxillary arch perimeter increased by 1.25 mm and 1.50 mm with eruption of maxillary first molars and simultaneous eruption of maxillary permanent first molars, respectively. Conclusions: Eruption precedence had a significant effect on changing mandibular inter canine width, maxillary arch perimeter, mandibular arch perimeter and overjet.

Does Body Mass Index affect Tooth Eruption Sequence? A Study among 6-7 Years Old Schoolchildren in Chennai, India.

ABSTRACTBackgroundChanges in eruption pattern cause malocclusion and crowding, which lead to poor oral hygiene as well as periodontal disorders. Hence, it is important for the dentist to know the exact tooth eruption sequence to educate the parents. Tooth eruption sequence we follow is based on the Western population.AimAs Indian population differs from the Western population in ethnicity, racially, and dietary habits, etc., an attempt was undertaken to compare eruption sequence of Indian children in accordance with the Western population and also to correlate whether body mass index (BMI) affects tooth eruption.Materials and methodsBody mass index and eruption status of permanent mandibular central incisors and first molars were recorded among 529 schoolchildren in Chennai. Eruption status was examined with the help of mouth mirrors and illumination under natural light. The recorded data were entered into Microsoft Excel 2007 and were analyzed using Chi-square test, z test, and Spearman's correlation test. Level of significance was set as 0.05.ResultsEruption values attained from our study were not consistent with the eruption values reported by Logan and Kronfeld. The present study showed that girls have early tooth eruption than boys. Our findings showed negative correlation with respect to BMI and eruption sequence of 31 (r = −0.133), 41 (r = −0.140), 36 (r = −0.08), and 46 (r = −0.076).ConclusionEruption values reported by Logan and Kronfeld are inappropriate for Indian population. It is also found that obese children had delayed tooth eruption when compared with underweight children who had early tooth eruption.How to cite this articleAnu V, Brindha JR, Carol PT, et al. Does Body Mass Index affect Tooth Eruption Sequence? A Study among 6–7 Years Old Schoolchildren in Chennai, India. Int J Clin Pediatr Dent 2020;13(3):261–263.

A severe case of toxic epidermal necrolysis which started with AGEP-like features: Does a new clinical type of drug eruption?

Acute generalized exanthematous pustulosis (AGEP) and toxic epidermal necrolysis (TEN) are adverse cutaneous reactions. Despite the fact that these 2 cutaneous reactions differ in presentation, prognosis, pathologic features, and treatment, overlap can exist between them, creating a diagnostic challenge. It has rarely been reported that AGEP overlaps or mimics TEN, while TEN which starting by multiple pustules like AGEP has not been reported. The present study reports a rare case of a 14-year-old male patient with the clinical manifestations of multiple purulent bullae caused by amoxycillin ingestion. On 3. day dermatological examination revealed flaccid bullae and epidermal splitting with positive Nikolsky’s sign on right pectoral area, erosions on oral and anogenital mucosa. Histopathologic examination showed a massive inflammatory infiltration and epidermal necrosis indicated Steven Johnson syndrome. Later on added systemic symptoms with haemodynamic, respiratory imbalance and the patient was exitus. The case is discussed to reveal whether a new clinical pattern of drug eruption has been identified. We describe a patient with TEN who presented initially with clinical features of acute generalized exanthematous pustulosis (AGEP). To the best of our knowledge, one report drug eruption with purulent bulla and epidermal necrolysis has previously been documented, and therefore the present study is the second case report of its kind. Because the initial presentation of such adverse drug reactions may vary, diagnosis is difficult and dermatologists must careful the possibility of mimics among adverse cutaneous reactions.

Studija o nicanju trajnih zuba kod dece uzrasta od pet do deset godina koja su posetila Stomatološki fakultet u gradu Mangalore u Indiji

Teeth are biological markers of maturity, and their eruption into the oral cavity is an essential milestone in an individual's life. Multiple factors have been considered to play a role in the pattern of tooth eruption, including dental caries, fluorides and congenital conditions such as Down's syndrome. The aim of the paper was to determine the time of eruption of permanent teeth amongst children aged between five and ten years, visiting the Dental College in Mangalore. A survey was conducted among children aged between 5 to 10 years visiting A.B. Shetty Memorial Institute of Dental Sciences Deralakatte, Mangalore. Each child included in the study was screened by clinical examination for the erupted and erupting permanent teeth. A parent/guardian accompanying a child was interviewed and their data were recorded. The study revealed that the first tooth to erupt was the left mandibular first molar, with a mean age of eruption at 6.4 years. A slight early eruption of teeth was noticed in the left side of the jaw compared to the right side in the present study. The first permanent tooth to erupt in the oral cavity is the left mandibular first molar and there is a slight delay in the eruption of the maxillary lateral incisor in the study population.

Regenerative Endodontics: A Paradigm Shift in Clinical Endodontics.

ABSTRACTPreserving the natural dentition in its normal form and function is one of the major goals of endodontic treatment. Re-establishing the lost vitality and development of root maturation in immature permanent teeth with pulp necrosis/apical periodontitis is quiet challenging clinically. The very basis of regenerative endodontics relies on the concept of tissue engineering using stem cells, biomimetic scaffold, and bioactive growth factors to regenerate the pulp tissue damaged by microbial infection, injury, or developmental defects. In clinical endodontics, this approach is referred to as a “paradigm shift.” Even though repair instead of true regeneration is achieved with current protocols, it is hoped that further research in the area of stem-cell-based tissue engineering will allow for true regeneration and improved treatment outcomes. The aim of this review is to discuss about the various aspects of regenerative endodontics, current clinical protocols, and the future of pulp regeneration techniques.

Pediatric Ameloblastic Fibroma: A Case Report

To highlight the potential difficulties in diagnosing neoplastic lesion of the head and neck in children within autism spectrum. Ameloblastic fibromas are a variation of odontogenic tumors that are located in the posterior mandible in 70% of cases. The tumors may be either unilocular or multilocular when observed radiographically. Ameloblastic fibromas tend to have well-defined, scalloped margins radiographically but may also be corticated. In close to 75% of all cases, an impacted tooth is associated with the lesion. Although not confined to patients who are in their first or second decades of life, ameloblastic fibromas most often arise in this population. A 9-year-old male diagnosed with autism presented with tenderness in the left mandible. The parents were able to elucidate the child's problem as tingling rather than pain. The patient was referred for histopathological diagnosis and treatment. After evaluation and biopsy, the lesion was identified as a pediatric ameloblastic fibroma. He subsequently underwent the conservative approach of marsupialization and curettage without complication. Six-month follow-up revealed no evidence of recurrence and normal eruption patterns of the succedaneous teeth in the affected area. In this specific case, the conservative approach to treatment appears to have been appropriate. This may not be the appropriate course for every case; as such, each case will have an individualized approach. Earlier recognition with careful inspection can reduce potential complications. We might be missing early diagnosis of ameloblastic fibroma and other significant orofacial neoplasms in patients who are nonverbal or nondescriptive such as those with autism. Moreover, careful inspection of radiographic and clinical signs cannot be overemphasized.

Orthodontic treatment of a severe combined anterior and posterior open bite case, involving ankylosis and eruption disturbances in late adolescence

Treatment of a combined anterior and posterior open bite case is a demanding orthodontic procedure that requires, in many cases, a multidisciplinary approach. Disturbances in the time or pattern of permanent teeth eruption can often cause or aggravate these clinical conditions, that once established can affect the occlusion, the mastication, the speech, and the oral health quality of life index of such a patient. This article describes the orthodontic treatment of a teenager with severe anterior and posterior open bite, a unilateral posterior crossbite and serious mastication problems. Proper diagnosis, treatment planning, and mechanotherapy used, resulted in excellent orthodontic outcome, greatly improving all aspects of the patient’s initial concerns and the clinician’s goals.

INFANTILE OSTEOPETROSIS ASSOCIATED WITH MANDIBULAR OSTEOMYELITIS: A CASE REPORT

A 7-year-old male patient was referred to an oral medicine service for assessment of mandibular osteomyelitis after deciduous molars extraction. In the anamnesis, infantile osteopetrosis was reported. Intraoral examination revealed an exposed bone area with the presence of suppuration located in the region of previous extraction. Panoramic radiography showed changes in the pattern of eruption and a poorly delimited radiolucent area in left mandibular alveolar region, suggestive of chronic osteomyelitis. A bone debridement was performed which resulted in healing of the alveolar mucosa. However, 9 months later, the patient returned with recurrence of the infectious process and the presence of extraoral fistulas on the left side. As a treatment for mandibular osteomyelitis secondary to osteopetrosis, the patient underwent surgical procedures first for bone debridement in the left mandible and then, for marginal segmental resection of the mandible and placement of a titanium plate. The patient shows no signs of recurrence of the infectious process. Support: FAPEMIG.

Frequency and clinico-topographic distribution patterns of pruritic papular eruption in HIV patients in a Nigerian Tertiary Hospital

Frequency and clinico-topographic distribution patterns of pruritic papular eruption in HIV patients in a Nigerian Tertiary Hospital

The apex of amphicyonid hypercarnivory: solving the riddle of Agnotherium antiquum Kaup, 1833 (Mammalia, Carnivora)

ABSTRACTSince its first description, only a single undisputed specimen, an isolated, highly abraded m1, was known from the enigmatic amphicyonid Agnotherium antiquum Kaup, 1833. Here, we describe the second specimen of A. antiquum from the type locality of Eppelsheim (early late Miocene, MN 9/10 of Germany), unearthed 184 years after the first description of A. antiquum. The specimen consists of a partial left juvenile mandible with dp3, m1 in eruption, i3, canine, p4, and a highly reduced m2 still in crypt. The p1–3 and m3 are completely reduced, as are the metaconids of m1 and m2. We confirm previous assignments of late Miocene specimens from the localities of Charmoille, Switzerland, and Pedregueras 2A, Spain, to A. antiquum, whereas a maxilla from Bled Douarah, Tunisia, can only tentatively be assigned to the species. We confirm that the monotypic genus Agnotherium is a thaumastocyonine amphicyonid, discuss other supposed thaumastocyonine specimens, and briefly review the evolutionary history of the subfamily. Agnotherium was a 275 kg, extremely powerful, strictly carnivorous ambush hunter that represents the apex of amphicyonid evolution toward carnivory. Its tooth eruption pattern resembles recent Ursus more than recent Canis, but it shows a considerable delay of eruption timing like in the ursid Agriotherium. Agnotherium antiquum is one of six carnivoran species from the Eppelsheim Formation that is heavier than 200 kg. The co-occurrence of Agnotherium (or its relatives Tomocyon and Thaumastocyon), Machairodus, and a smaller saber-toothed carnivoran is typical for early late Miocene faunas of Europe and tentatively North Africa.

Notes on…

  Dr Sarah Caddy of the BSAVA Scientific Committee provides some advice to practitioners on estimating the age of kittens from their teeth to help with determining the timing of neutering. The online version includes an article 'The time and pattern of eruption of the permanent teeth of the cat' which is kindly made available to BSAVA members courtesy of the American Association for Laboratory Animal Science. This article is useful as it enables veterinarians to accurately determine how old cat are based on their dentition. This is important for determining a suitable age to neuter cats, as well as being useful for import/export purposes and evaluating suitability of various drugs.

Distinct Histopathologic Patterns of Finger Eruptions in Dermatomyositis Based on Myositis-Specific Autoantibody Profiles

This histologic analysis of cutaneous manifestations of dermatomyositis examines whether skin eruptions can be histopathologically classified into myositis-specific autoantibodies-associated groups.

Schultz’s rule in domesticated mammals

Schultz’s rule predicts early eruption of replacement teeth (incisors, canines, and premolars) relative to molars as growth slows and life history events take place over a greater span of time. Here, we investigate if the opposite trend might occur during the domestication process as a consequence of an accelerated life-history and driven by increased energetic needs. We provide new data on tooth eruption in four mammalian species and their domesticated forms: wolf and dog, polecat and ferret, bezoar and goat, wild boar and pig. Our results show some variation in eruption sequences between wild and domestic forms, but none that is consistent and reliably distinct from intraspecific variation. There may be variation in the absolute timing of dental eruption, but despite well documented changes across life history variables, which distinguish wild from domestic forms, eruption sequences remained constant in each wild and domestic version of the species we examined. A conserved eruption sequence is in accordance with many earlier studies, which found no evidence for Schultz’s rule in some wild clades of mammals. Phylogenetic conservation and functional factors likely play an important role in constraining patterns of growth and tooth eruption in these mammals. Furthermore, we suggest that the domestication processes started too recently for fundamental changes of tooth eruption sequences to occur.

Calibration of life history traits with epiphyseal closure, dental eruption and bone histology in captive and wild red deer.

The study of skeletochronology and bone tissue as a record of information on ontogenetic stages and events is widely used for improving the knowledge about life histories (LHs) of extinct and extant vertebrates. Compared with dinosaurs and extant reptiles, mammalian bone histology has received little attention. Here, we calibrate for the first time bone and dental age with histological bone characteristics and LH stages in ontogenetic series of red deer. We rely on known LHs of different aged individuals of captive Cervus elaphus hippelaphus from Austria to correlate epiphyseal closure, dental eruption pattern, bone growth marks and bone tissue patterns in femora and tibiae, and of wild Cervus elaphus hispanicus from Spain. Our data show that females (of both subspecies) attain skeletal maturity earlier than males. At this moment, epiphyseal closure (in femora and tibiae) and dental eruption are complete and long bones start to deposit an external fundamental system. The results also show that the attainment of reproductive maturity in red deer occurs slightly before skeletal maturity.

Residents' journal review

Residents' journal review

Reduced body size of insular black-tailed deer is caused by slowed development.

Adult body size correlates strongly with fitness, but mean body sizes frequently differ among conspecific populations. Ultimate, fitness-based explanations for these deviations in animals typically focus on community-level or physiological processes (e.g., competition, thermoregulation). However, proximate mechanisms underlying adaptive body size adjustments remain poorly understood. Adjustments in adult body size may result from shifts in growth-related life-history traits, such as the length of time to achieve adult body size (i.e., growth period) and how quickly the body increases in size (i.e., growth rate). Since insular populations often demonstrate dramatic shifts in adult body size, island populations represent a natural experiment by which to test the proximate mechanisms of size change. Here, using dental eruption patterns, we show that a dwarfed population of black-tailed deer (Odocoileus hemionus columbianus) experiences significant heterochronic shifts relative to mainland conspecifics. Namely, juvenile development slowed, such that teeth erupted ≥ 1year later, but cranial growth suggested no concurrent adjustments in skeletal growth period. Thus, slowed growth rate, shown here with teeth, combined with unchanged growth period resulted in dwarfism, consistent with ultimate predictions for insular, resource-limited populations. Therefore, selection on body size may act on life-history traits that influence body size, rather than acting on body size directly.

Unexpected evolutionary patterns of dental ontogenetic traits in cetartiodactyl mammals.

Studying ontogeny in both extant and extinct species can unravel the mechanisms underlying mammal diversification and specialization. Among mammalian clades, Cetartiodactyla encompass species with a wide range of adaptations, and ontogenetic evidence could clarify longstanding debates on the origins of modern specialized families. Here, we study the evolution of dental eruption patterns in early diverging cetartiodactyls to assess the ecological and biological significance of this character and shed new light on phylogenetic issues. After investigation of the ontogenetic dental series of 63 extinct genera, our parsimony reconstructions of eruption state evolution suggest that the eruption of molars before permanent premolars represents a plesiomorphic condition within Cetartiodactyla. This result substantially differs from a previous study based on modern species only. As a result, the presence of this pattern in most ruminants might represent an ancestral condition contributing to their specialized herbivory, rather than an original adaptation. In contrast, the late eruption of molars in hippopotamoids is more likely related to biological aspects, such as increases in body mass and slower pace of life. Our study mainly shows that eruption sequences reliably characterize higher level cetartiodactyl taxa and could represent a new source of phylogenetic characters, especially to disentangle the origin of hippopotamoids and cetaceans.

Usefulness of Cutaneous Provocation Tests to Study Drugs Responsible for Cutaneous Adverse Drug Reactions

Cutaneous adverse drug reactions, particularly immune-mediated idiosyncratic reactions, are a very challenging area of Dermatology. For confirming the culprit drug, after a complete history of drug exposure with its chronologic relation with the eruption and characterization of the pattern of the drug eruption, skin provocation tests can be performed after resolution of the acute phase. Patch tests are indicated in the study of non-immediate T cell–mediated drug eruptions (maculopapular exanthema, drug reaction with eosinophilia and systemic symptoms (DRESS), Stevens–Johnson syndrome (SJS)/toxic epidermal necrolysis (TEN), acute generalized exanthematous pustulosis, fixed drug eruption, and drug photoallergy). It is recommended to test with pure drugs usually at 10% pet commercialized as patch test allergens, but in most cases, drugs have to be prepared in house, whenever possible in a final dilution at 10% pet. Methods are similar to patch testing in allergic contact dermatitis except in fixed drug eruptions where duplicate tests are needed; one of them applied for 24 h on a residual lesion. Patch tests are safe and highly specific when performed according to the recommendations, but sensitivity is highest in exanthemas, DRESS, and fixed drug eruptions and particularly for abacavir, carbamazepine, aminopenicillins and other antibiotics, diltiazem, and tetrazepam. Allopurinol is never positive, and reactivity is low in SJS/TEN. Therefore, a negative patch test cannot exclude a possible culprit, but a positive patch test is almost always relevant. Patch tests with drugs are also useful for evaluating cross-reactions and studying effector mechanism involved in the cutaneous adverse reaction.