Conical Teeth Research Articles

Clinical, genetic, epidemiologic, evolutionary, and functional delineation of TSPEAR-related autosomal recessive ectodermal dysplasia 14.

TSPEAR variants cause autosomal recessive ectodermal dysplasia (ARED) 14. The function of TSPEAR is unknown. The clinical features, the mutation spectrum, and the underlying mechanisms of ARED14 are poorly understood. Combining data from new and previously published individuals established that ARED14 is primarily characterized by dental anomalies such as conical tooth cusps and hypodontia, like those seen in individuals with WNT10A-related odontoonychodermal dysplasia. AlphaFold-predicted structure-based analysis showed that most of the pathogenic TSPEAR missense variants likely destabilize the β-propeller of the protein. Analysis of 100000 Genomes Project (100KGP) data revealed multiple founder TSPEAR variants across different populations. Mutational and recombination clock analyses demonstrated that non-Finnish European founder variants likely originated around the end of the last ice age, a period of major climatic transition. Analysis of gnomAD data showed that the non-Finnish European population TSPEAR gene-carrier rate is ∼1/140, making it one of the commonest AREDs. Phylogenetic and AlphaFold structural analyses showed that TSPEAR is an ortholog of drosophila Closca, an extracellular matrix-dependent signaling regulator. We, therefore, hypothesized that TSPEAR could have a role in enamel knot, a structure that coordinates patterning of developing tooth cusps. Analysis of mouse single-cell RNA sequencing (scRNA-seq) data revealed highly restricted expression of Tspear in clusters representing enamel knots. A tspeara -/-;tspearb -/- double-knockout zebrafish model recapitulated the clinical features of ARED14 and fin regeneration abnormalities of wnt10a knockout fish, thus suggesting interaction between tspear and wnt10a. In summary, we provide insights into the role of TSPEAR in ectodermal development and the evolutionary history, epidemiology, mechanisms, and consequences of its loss of function variants.

IceAgeSafari in Central Europe along the Rhine Valley migration channel – Mid‐Late Pleistocene spotted, brown, stripped hyena palaeobiogeography and evolution

AbstractAt the beginning of the Middle Pleistocene (MIS 21, 800,000 BP), three distinct hyenas remained to appear in Europe with the spotted hyena (Crocuta), brown hyena (Parahyaena) and striped hyena (Hyaena). Each developed in monophyletic lineages, whereas rare brown hyena Parahyaena brunnea mosbachensis (Geib, 1915) and striped hyena Hyaena hyaena prisca De Serres, Dubreuil and Jeanjean, (1828) did not change in their dentition morphology much to their modern forms. Those warm period extinct hyenas did not migrate from Africa over the Rhine Graben migratory channel to Central Europe after the late Mid‐Pleistocene Holsteinian Interglacial (MIS 9). The spotted hyenas took over the niche of European hyenas with their appearance in warm and cold periods. Those used more and more cave entrances as dens between Spain and Siberia. Their more rapid dental change coevolved from the largest “giant hyena” Crocuta brevirostris Boule, (1893) (Early Pleistocene, MIS 40‐20), over Crocuta intermedia De Serres, Dubreuil and Jeanjean, 1828 (Early Mid‐Pleistocene, MIS 19‐12), C. praespelaea Schütt, 1971 (Early Mid‐Pleistocene, MIS 11‐6), to Crocuta crocuta spelaea (Goldfuss, 1823) (Early Mid‐Pleistocene, MIS 5‐3), which is genetically a subspecies to Modern African extant Crocuta crocuta crocuta Erxleben, 1777 (MIS 2‐1). Spotted hyenas developed a perfect thick‐skin cutter M1 by elongation and bone crusher conical P4 teeth. This adaptation to their main thick‐skin big game guilt: elephants, rhinos and hippos.

Experiment and Simulation Research on Rock Damage Mechanism in Tooth Indentation

In the oil and gas drilling industry, cemented carbide teeth are one of the most widely used rock-breaking elements. In order to reveal the rock damage mechanism of tooth indentation, a series of tooth indentation experiments were conducted in this study, and an indentation simulation was also conducted as a supplement to the experiment. In the experiment, a new method to observe the inner damage status of the rock was put forward, i.e., utilizing the splitting action of the teeth to avoid unexpected rock damage that may affect the actual experiment results. The load-displacement curves and the damage status of the rock revealed that the wedge tooth was more efficient in fracturing and damaging the rock because the load requirement of the wedge tooth was lower, the narrow tooth crown generated larger specific stress in the rock; that rock-breaking advantage of the wedge tooth resulted from the occurrence of the compacted core and the tension stress generated by the core. According to the simulation results, the plastic strain in the intermediate area between the wedge teeth appeared more concentrated and increased faster, and the rock material beneath the wedge teeth was removed earlier than beneath the conical teeth, indicating that wedge teeth, disposed with proper spacing, can break rock more effectively than the conical teeth. The experiment and simulation results in this paper have proved the advantages of the wedge tooth in rock fracturing and damaging, which will provide technical support for the design and development for the drill bits applied in oil and gas drilling.

The clinical and genetic findings in a Chinese family with Axenfeld-Rieger syndrome

ObjeciveTo describe the clinical and genetic findings of an Axenfeld-Rieger syndrome (ARS) family with a new PITX2 splicing mutation. MethodsA Chinese ARS family with five affected individuals was recruited. Exome sequencing was performed on the proband and the variant (C.253-9C > A) in PITX2 gene was detected as a pathogenic mutation. Sanger sequencing was performed for verification and cosegregation analysis. Real-time polymerase chain reaction (RT- PCR) and Western blotting were performed to verify the expression of the pathogenic gene. ResultsAll the patients showed abnormalities in the anterior segment of both eyes including posterior embryotoxon, corectopia, iris dysplasia, and iridocorneal tissue adhesions. In addition, they all presented systemic features, including maxillary hypoplasia, underbite, hypodontia, conical teeth. Only III-7 showed obvious umbilical skin. In the PITX2 family, we identified a novel heterozygous splicing mutation (C.253-9C > A) which was confirmed by Sanger sequencing to be completely cosegregated with the ARS phenotype. Real-time quantitative PCR and Western results showed that PITX2 mRNA and protein expression were significantly lower in patients compared with unrelated normal controls. ConclusionIn the ARS pedigree, we summarized the variable phenotype, described a novel PITX2 splicing mutation which expand the genetic spectrum of ARS. We further confirmed the possibility of development of ARS induced by this PITX2 gene deficiency.

Systematic Review and Cranial Osteology of Petersius with Redescription of P. conserialis (Teleostei: Alestidae) from the Rufiji and Ruvu Rivers of Tanzania

We review the systematics of the monotypic alestid genus Petersius and provide a taxonomic redescription of P. conserialis from eastern Tanzania. Morphological investigation includes direct observation and examination of radiographed and µCT-scanned data from type and non-type specimens. We delimit the taxon's geographic distribution along the lowland regions of the Rufiji and Ruvu river basins in Tanzania and provide information on ecology, sexual dimorphism, and ontogenetic variation. Petersius is herein diagnosed by the possession of a unique cuspidation patterning of the inner-row premaxillary dentition and a distinctively shaped anterodorsal margin of the supraoccipital crest. It shares with some species of Phenacogrammus a sigmoid-shaped process on the dorsal margin of the second infraorbital, a feature lacking in other alestid taxa. Additional features of potential utility for ongoing investigation of relationships among alestid genera include the possession of contralateral premaxillae separated by the anteromedial process of the mesethmoid and without interdigitations connecting the medial surfaces of the premaxillae; four, occasionally five or six, small outer-row premaxillary teeth implanted alternately with those of the inner row; a dentary lacking a pair of conical inner-row teeth proximal to the symphysis; a dorsal posttemporal fossa that is smaller than the ventral fossa; a median third posttemporal fossa located entirely within the epioccipital; a truncate dorsomedial cranial fontanel; and a complete circumorbital series forming an uninterrupted ring around the orbit in adult specimens.

64 Conical teeth? Think outside the box!

BackgroundEctodermal dysplasias (ED) are inherited disorders involving congenital abnormalities of different ectodermal structures, the most prominent presentation being adontia/hypodontiaIn this article, we present a brief overview of several pediatric cases of ED with a short review of the odontological manifestations.2. Case reportsWe report several cases of children consulting in the pediatric department for abnormal teeth, with or without systemic manifestations.The clinical examination of these patients revealed insufficient and abnormal dentition, with rare beveled teeth and thin and rare hair, as well as eyelashes and eyebrows.Also, parents reported episodes of hyperthermia without sweating from an early age.Dental radiography confirmed the diagnosis of ectodermal dysplasia.3. DiscussionEctodermal dysplasias (EDs) are a group of various inherited disorders involving abnormal congenital development of at least two ectodermal structures (hair, nails, teeth, and sweat glands). The management of these rare disabling conditions is still mainly symptomatic. The traditional removable prosthesis can be an option to replace missing teeth. However, implants provide the best long-term results and prognosis. In particular, dental implants are commonly used in oral reconstruction of ED patients, but long-term data on bone augmentation and bone resorption, aesthetic outcomes, and implant success are needed.4. ConclusionEDs are a myriad of heterogeneous conditions encompassing several inherited embryopathies affecting teeth and other ectoderm-derived structures in utero.Diagnosis is essentially clinical, confirmed by radiology and genetics which can specify the causal mutation; treatment is mainly conservative.

Butyrumichthys henricii gen. et sp. nov.: a new stromateiform fish from the lower Eocene Fur Formation, Denmark

ABSTRACT A new genus and species of stromateiform fish, Butyrumichthys henricii gen. et sp. nov., from the Eocene Fur Formation of Denmark is described. The description is based on six well-preserved, almost complete articulated skeletons plus a well-preserved head. All the specimens originate from the carbonate concretion horizons of the Fur Formation. The fossils were investigated also through element-mapping of strontium and phosphorus using a micro-XRF spectrometer in order to expose and enhance the skeletal anatomy. Butyrumichthys gen. nov. exhibits a unique combination of characters that support its recognition as a new stromateoiform genus, including jaws with uniserially arranged, small conical teeth, preopercle with at least 15 prominent spines, 37–38 (17–18 + 20) vertebrae, dorsal fin with 5–6 weak spines and 27–28 soft rays, and anal fin with two spines and 19–20 soft rays. The new fossil stromateoid described herein shows several morphological similarities to certain species of the genus Schedophilus Cocco, 1839, especially S. pemarco (Poll, 1959) and S. medusophagus (Cocco, 1839), and is tentatively referred to the family Centrolophidae. The exceptionally preserved fossil fishes of the Fur Formation increase our knowledge of the diversity of Paleogene marine teleosts, also providing some of the earliest occurrences of modern lineages based on articulated skeletal remains, including that of the stromateiforms.

A long-snouted and long-necked polycotylid plesiosaur from the Late Cretaceous of North America

SummaryPlesiosaurs are a group of Mesozoic marine diapsids. Most derived plesiosaurs fall into one of two typical body forms: those with proportionately small heads, short snouts, and elongated necks, and those with large heads, elongated snouts, and short necks. Serpentisuchops pfisterae is a polycotylid plesiosaur from the Upper Cretaceous Pierre Shale that presents the trait combination of both an elongate snout and elongate neck (consisting of 32 vertebrae). Phylogenetic analysis places Serpentisuchops within the Polycotylinae, indicating that its long snout is an ancestral trait, while its long neck is secondarily derived and convergent with that of ancestral plesiosaurs, contemporaneous elasmosaurids, and some more basal members of the Polycotylidae. The conical, recurved, and narrow teeth are consistent with a piscivorous diet. The tall and anteroposteriorly broad cervical neural spines indicate large epaxial muscles, suggesting that Serpentisuchops used both its neck and snout in fast lateral strikes aimed at proportionately small prey.

A new species of the congrid eel genus Bathycongrus (Order Anguilliformes) from eastern Taiwan

A new species of the congrid eel genus Bathycongrus is described on the basis of three specimens collected from the deep waters of eastern Taiwan. Bathycongrus melanostomus sp. nov., belongs to the few vertebrae species complex and is distinct in having a short and broad snout; a much reduced caudal fin; abdomen, mouth cavity and gill chamber blackish; small conical blunt teeth on vomer forming an elongate patch; total vertebrae 133-135, and total lateral-line pores 108-109.

On the presence of Xiphactinus (Teleostei, Ichthyodectiformes) in the Coniacian-Campanian marine deposits of the Piedritas site, Coahuila, northern Mexico

The discovery of the first Mexican fossil specimen belonging to the species Xiphactinus audax is reported here. This specimen was recovered in the Coniacian-Campanian marine deposits of the Austin Group at the Piedritas site, within the homonymous ejido, Municipality of Ocampo, north of Coahuila. Although the specimen is strongly fragmentary, partially preserved by impressions or molds of the bones, and only shows parts of the head, the opercular series, and the pectoral fins, this has enough anatomical features that allow its specific taxonomic determination. Among these diagnostic features, this fossil has a well-developed ethmopalatine bone, a well-developed supraoccipital crest, a maxilla anteriorly higher than the rest of the bone, and a very robust palatine articular head. Particularly, this fossil exhibits two distinctive features of the genus Xiphactinus, a row of conical teeth, irregularly sized and distributed in the maxilla and dentary bones, as well as a pectoral radius 1 extremely developed and at least 2.5 times wider than the subsequent ray. At the same time, its teeth are smooth and have no sharp edges or carenae, which allows its specific identification. The present discovery complements the geographical distribution of Xiphactinus confirming its wide longitudinal distribution throughout America.

Osteological description of Indian lepidophagous catfish Pachypterus khavalchor (Siluriformes: Horabagridae) from the Western Ghats of India

The present study provides a comprehensive osteological description of Pachypterus khavalchor from the family Horabagridae. Nine individuals of P. khavalchor representing both males and females collected from the type locality were cleared and double-stained to provide a description of osteological characteristics. The presence of an almost straight dorsal roof to the cranium, a long and protruding premaxilla with numerous rows of tiny, villiform teeth, a spoon-like lower jaw with villiform teeth projecting outward, and five long and ossified ceratobranchials, with the 5th ceratobranchial containing a set of 80 to 90 conical teeth, sheds light on the ecomorphological adaptation in P. khavalchor that may have led to the evolution of lepidophagy. Furthermore, a slight difference in the structure of the complex hypurapophysis was observed between males and females. The information on the osteology of the Khavalchor catfish forms a baseline for taxonomic research of the entire Horabagridae family comprising four genera with ten species distributed in Asia.

Ectodermal dysplasia: A retrospective evaluation of the clinical findings of forty-four cases in the 0-16 years age

Aim: The aim of this study was to review the craniofacial anomaly results of children diagnosed with ectodermal dysplasia (ED) and to identify the oral requirements of ED cases. Methodology: The data of this study were obtained by taking clinical examinations and radiographs on forty-four (44) children (22 females and 22 males), 0-16 years aged, who were admitted to the Dicle University, Faculty of Dentistry due to dental problems and were diagnosed with ED. The number of affected siblings was ascertained, and systemic findings were evaluated. Malformations in the hair, nails, nose, skin, lips, and teeth were clinically examined. Results: The most common clinical findings were sparse hair, dry skin, sweating problems, respiratory difficulty, saddle nose, a history of fever, hearing loss, and deformation in the nails. In the intraoral and radiological examinations, findings were evaluated of conical teeth, protuberant lips, prosthetic rehabilitation, impacted teeth, and abnormal root resorption. The rates of ED in the siblings of the ED cases were determined as 39.2% in the siblings of male cases and 37.9% in the siblings of female cases. Conclusion: The frequency rates of the anomalies seen in ED obtained in this study can be considered important as a guide for further studies of individuals with ED. When multiple missing teeth and conical teeth are encountered, the dental practitioner should investigate whether or not there are other symptoms of ED, and it must not be forgotten that the dentist may be the first step in the diagnosis of this genetic irregularity. How to cite this article: Akleyin E, Sarıyıldız Osmanoğulları C, Yavuz İ, Adıgüzel Ö. Ectodermal dysplasia: A retrospective evaluation of the clinical findings of forty-four cases in the 0-16 years age. Int Dent Res 2022;12(1):21-6. https://doi.org/10.5577/intdentres.2021.vol11.no1.4 Linguistic Revision: The English in this manuscript has been checked by at least two professional editors, both native speakers of English.

Stress patterns in conical teeth of reptiles and mammals: experimental and finite element analyses

A 3-Dimensional Finite Element Analysis (FEA) of conical teeth of reptiles and some mammals, suggests that under a vertical loading condition along the longer axis of tooth, horizontal tensile stresses are produced. In dental enamel, these stresses are distributed mainly in two horizontal directions, i.e. in X direction and in Z direction. The empirical observation of stresses possibly leading to the vertical failure of the teeth was obtained through Universal Testing Machine (UTM) using recent unicuspid teeth of crocodiles, varanus and canines of pig, cat and dog. The horizontal development of Hunter Schreger Bands (HSBs) has been observed in the enamel of canines of herbivore and carnivore mammals, which seems to be an effective structural strategy to counter splitting of tooth enamel under vertical loading. In contrast, the unicuspid teeth of reptiles lack the HSBs, and are more susceptible to failure. However, as reptilian teeth are continuously replaced, the damage is negligible.

The evolutionary development of the jaws and dentition

The development of the jaws and dentition during half a billion years of evolution is described in broad lines and two theories regarding the origin of the dentition are discussed in detail. It is highly likely our dentition developed from dermal ossification 'denticles' originally protecting, in particular, the head of primitive extinct vertebrates. Simple, at first tubercular, later conical teeth developed into complex tooth and molar forms, especially in mammals. Special attention is given to the development of molar cusps. The process of continuous replacement of the dentition is also discussed in more detail.

Record of Additional Middle Eocene Vertebrate Remains from the Mikir Hills, NE India: Implications on Paleoenvironment and Paleobiogeography

The fossiliferous middle Eocene deposits of Sylhet Limestone of Mikir Hills have yielded vertebrate and invertebrate faunas. The fossil assemblages recorded in this contribution consist of shark, ray, crocodile, conical tooth, broken fragments and echinoderm spines. Ray and crocodile tooth are reporting for the first time from the Mikir Hills. Paleoenvironmental analysis based on the fossil fish assemblage in association with invertebrate (foraminifera) remains and sedimentogical observations suggest a shallow marine environment ranging from open marine, inner neritic to more proximal coastal settings. Also, the presence of common marine elements (similar faunas) from Kutch, Rajasthan, Himachal Pradesh, Assam (India), New Hampshire, Libya, Iraq, Iran, North Western Sahara (Algeria), Tanzania (East Africa), Italy, Germany, Southern North Sea basin (Europe) based on previous published works and the present finding testifies to the connection of the Tethys Sea during Lutetian-Bartonian of middle Eocene.

Prosthodontic Rehabilitation of a Female Child with Ectodermal Dysplasia: A Case Report

Ectodermal Dysplasia (ED) is an X-linked inherited disorder with male predominance. Female patients may show partial expression of Ectodermal Dysplasia. Significant findings include hypodontia, hyposalivation, protuberant lips, conical teeth and loss of vertical dimension. The alveolar ridge fails to develop properly. Thus it presents as a challenge to dental treatment. This paper presents a case of prosthodontic rehabilitation of an 8 years old girl having hypodontia associated with hypohidrotic ectodermal dysplasia with removable partial denture in maxilla after temporary fixed prosthesis and complete denture in mandible to rehabilitate the patient for esthetics and function.

Integrative taxonomy-based discovery of Dussumieria modakandai sp. nov. from India.

This study is based on integrative taxonomy and reports a new fish species Dussumieria modakandai sp. nov. from India. The new species differs from three valid species within the genus by a combination of characters such as longer maxilla (9.1%-9.9% standard length vs. 8.7% in Dussumieria elopsoides, 6.3%-8.5% in Dussumieria acuta) and one or two rows of small conical teeth on palatine (vs. several rows in D. elopsoides and Dussumieria albulina). It also differs by the absence of longitudinal striae on the posterior side of body scales (vs. presence in D. acuta and D. albulina) and the absence of parasphenoid teeth (vs. presence in D. acuta). The maxilla length of D. modakandai sp. nov. is greater than snout length, which distinguishes it from other congeners. The multivariate analysis of morphometric characters using PCA differentiated the new species from D. elopsoides and D. acuta samples collected in this study. The molecular analysis, based on cytochrome c oxidase I, distinguished the new species from D. acuta, D. albulina and D. elopsoides with a high genetic distance of 13.73%, 12.22% and 12.74%, respectively. The maximum-likelihood phylogenetic tree and automatic barcode gap discovery analysis showed the existence of six putative species in Dussumieria. Even the exhaustive sub-clade formation within species and high intra-species genetic distance in D. acuta (1.59) and D. modakandai (1.95) indicate the possibility of a few more cryptic species. This warrants comprehensive sample collection across the distribution range and integrative taxonomic study of the genus Dussumieria.

Recurrent Fevers in a Boy Toddler with Dysmorphic Features and Hypodontia.

Recurrent Fevers in a Boy Toddler with Dysmorphic Features and Hypodontia.

Phylogeny of Micronesian emperor fishes and evolution of trophic types

Island communities that rely on reef fish are currently faced with declining marine resources due to unsustainable fishing and climate change. Identification of genetic stocks through phylogenetic analyses has become a growing field of study with conservation implications, but genetic information on reef fish in Micronesia is limited. In this study we focus on Lethrinidae, one of the most commonly fished reef fish families in Micronesia. Our main goal was to establish a phylogeny for Lethrinidae based on Micronesian data with the intent to help future conservation efforts and clarify the evolutionary history of trophic types in this family. Thirty-eight Lethrinidae specimens collected across five Micronesian islands were used to build a phylogeny with three mitochondrial and one nuclear gene. The phylogenetic analyses allowed us to clarify the identity and position of 11 commonly harvested species and provided a novel genetic identification for Monotaxis heterodon in Micronesia. Our improved and dated phylogeny supports a new hypothesis for the ancestral trophic type of emperor fishes: “stalkers” with low-bodies and conical teeth. We correlated the radiation of most Lethrinidae species with the radiation of major scleractinian coral lineages in the middle Miocene, highlighting the tight relationships between declining reefs and the survival of emperor fishes.

A Report of Incontinentia Pigmenti in an 11-year-old Girl

Introduction: Incontinentia pigmenti (IP) is a rarely diagnosed x-linked dominant disease affecting tissues of ectodermal and mesodermal origin such as cutaneous tissues, teeth, eyes, hair, and the central nervous system. Dermatologic manifestations are often the first signs observed in patients diagnosed with IP and are present in nearly all the subjects, but they are less harmful and do not require treatment. Oral manifestations in patients diagnosed with IP might affect both the deciduous and permanent teeth, with tooth shape anomalies and hypodontia, delayed tooth eruption, cleft palate, and high arched palate. These oral abnormalities influence feeding, quality of life (QoL), and self-esteem of the patient but can be successfully corrected by oral rehabilitation. Case Presentation: Here, we report the case of a female patient, aged 11 years, presenting with dental manifestations such as hypodontia, conical teeth, delayed tooth eruption, narrow and atrophic dental ridge, and also some non-dental findings of IP. Her dental ‎management included oral hygiene instructions, extraction of all unrestorable primary molars, and composite filling of all primary canines. Conclusions: A removable space maintainer was constructed for the patient, which resulted in favorable esthetic outcomes, proper re-establishment of mastication, and improved self-esteem.