Mesodermal Components Research Articles

Isl Identifies the Extraembryonic Mesodermal/Allantois Progenitors and is Required for Placenta Morphogenesis and Vasculature Formation.

The placenta links feto-maternal circulation for exchanges of nutrients, gases, and metabolic wastes between the fetus and mother, being essential for pregnancy process and maintenance. The allantois and mesodermal components of amnion, chorion, and yolk sac are derived from extraembryonic mesoderm (Ex-Mes), however, the mechanisms contributing to distinct components of the placenta and regulation the interactions between allantois and epithelium during chorioallantoic fusion and labyrinth formation remains unclear. Isl1 is expressed in progenitors of the Ex-Mes and allantois the Isl1 mut mouse line is analyzed to investigate contribution of Isl1+ Ex-Mes / allantoic progenitors to cells of the allantois and placenta. This study shows that Isl1 identifies the Ex-Mes progenitors for endothelial and vascular smooth muscle cells, and most of the mesenchymal cells of the placenta and umbilical cord. Deletion of Isl1 causes defects in allantois growth, chorioallantoic fusion, and placenta vessel morphogenesis. RNA-seq and CUT&Tag analyses revealed that Isl1 promotes allantoic endothelial, inhibits mesenchymal cell differentiation, and allantoic signals regulated by Isl1 mediating the inductive interactions between the allantois and chorion critical for chorionic epithelium differentiation, villous formation, and labyrinth angiogenesis. This study above reveals that Isl1 plays roles in regulating multiple genetic and epigenetic pathways of vascular morphogenesis, provides the insight into the mechanisms for placental formation, highlighting the necessity of Isl1 for placenta formation/pregnant maintenance.

An unusual location of newborn huge dermoid cyst: a case report and literature review

BackgroundDermoid cysts are benign germ cell tumors with ectodermal and mesodermal components. It is a slow-growing lesion that commonly arises in the midline of the head and neck. The last location represented 7%, and the periorbital region was the most frequently arising area. True lateral neck dermoid cysts are rare. We present an unusual location of a dermoid cyst in a newborn.Case presentationWe report an unusual location of a 10-day newborn giant dermoid cyst with multiple implantation sites, namely the shoulder, scapula, cervical, temporal, and occipital scalp. Successful surgical resection was achieved, and the patient was discharged after the removal of the stitches.ConclusionDermoid cysts are unusual neoplasms with rare diagnoses at birth, but often in childhood. Concomitant implantation locations on the shoulder, neck, temporal, and occipital scalps are rare.

First observations of ovary regeneration in an amphipod, Ampelisca eschrichtii Krøyer, 1842.

BackgroundFemales of the gammaridean amphipod Ampelisca eschrichtii with signs of regenerating, previously atrophied ovaries were recovered from the northeastern shelf of Sakhalin Island (Okhotsk Sea, Russia). Ovarian regeneration was previously unknown for any amphipod species. A. eschrichtii have a predominantly 2-year life cycle (from embryo to adult death) and reproduce once between late winter or early spring at the age of 2 years. Occasionally, females survive to a third year. An adaptive value of extended survival among these females is likely to require that they are also reproductive.MethodsHistological sections from a second-year female with ovarian atrophy, a female with normal ovaries, a third-year female with ovarian regeneration, as well as testes of an immature and a sexually mature male were compared to determine the sources of cells of the germinal and somatic lines necessary for ovarian regeneration.ResultsOvarian regeneration in the third-year female began with the formation of a new germinal zone from germ cells preserved in the atrophied ovaries and eosinophilic cells of the previously starving second-year female. Eosinophilic cells form the mesodermal component of the germinal zone. A mass of these cells appeared in the second-year female that had atrophied ovaries and in large numbers on the intestine wall of the third-year female with regenerating ovaries. These eosinophilic cells appear to migrate into the regenerating ovaries.ConclusionsAll germ cells of the second-year female are not lost during ovarian atrophy and can be involved in subsequent ovarian regeneration. Eosinophilic cells involved in ovarian regeneration are of mesodermal origin. The eosinophilic cell morphologies are similar to those of quiescence cells (cells in a reversible state that do not divide but retain the ability to re-enter cell division and participate in regeneration). These histological data thus indicate that eosinophilic and germ cells of third-year females can participate in the regeneration of the ovaries to reproduce a second brood. The precursors of these third-year females (a small number the second-year females with an asynchronous [summer] breeding period and ovaries that have atrophied due to seasonal starvation) appear to possess sources of somatic and germ cells that are sufficient for ovarian regeneration and that may be adaptations to starvation stress.

Amelogenesis Imperfecta, Hypoplastic Type With Congenitally Missing Mandibular Permanent Lateral Incisors- A Case Report

Amelogenesis imperfecta (AI) is a group of hereditary disorders characterised by quantitative or qualitative tooth enamel abnormalities without systemic symptoms. Hereditary enamel dysplasia, Hereditary brown enamel, and Hereditary brown opalescent teeth are different names for the same abnormality, which is exclusively ectodermal because the mesodermal components of the teeth are normal. The AI trait can be inherited in one of three ways: autosomal dominant, autosomal recessive, or X-linked. Genes encoding enamel matrix proteins, such as enamelin and ameloblastin, tuftelin, MMP-20, and kallikrein -4 are implicated in autosomal variants.

Regional Odontodysplasia

Odontodysplasia is a rare nonhereditary developmental anomaly of dental hard tissue with unknown etiology, arising from both ectodermal and mesodermal components. Hitchin in 1934 first described it as a localized arrest of tooth development generally affecting one quadrant of the jaw. When it just affects one quadrant, it is referred to as “regional odontodysplasia,” but when it crosses the midline and affects more than one quadrant, it is referred to as “generalised odontodysplasia.” In this two case series, various types of odontodysplasia have been described, one of which is confined to a single quadrant and the other crossing the midline. The cases of odontodysplasia can only be treated by multidisciplinary approach and restorative and prosthetic rehabilitation and regular follow-up require for improving the quality of life of patients.

Congenital central corneal dermoid: A rare entity.

To understand the pathogenesis of a central corneal dermoid (CD) in a 12-day-old child, a comparison of CD specimen was done with limbal dermoid (LD) and cadaveric corneal (CC) specimens by immuno-histochemical staining. The child underwent penetrating keratoplasty for visual rehabilitation. The corneal tissue was sent for histo-pathological and immunochemistry evaluation. The corneal specimen obtained was compared the origin of central CD with LD and CC based on their antigenic expression profile. Clinically over a period of 75 months post operatively the child maintained a clear graft. Hematoxylin and Eosin staining of LD had a typical morphology including stratified keratinized epithelium, hair shaft with pilo sebaceous glands, eccrine sweat glands, lymphocytes, and blood vessels. Immuno-histochemical staining showed positive stain for Cytokeratin 3 epithelial marker in the epithelium of CC, LD, and CD. Smooth muscle maker (SMA) was identified in LD and CD but not in the CC as it is devoid of blood vessels. Limbal stem cell maker (P63) was detected only in LD. Vimentin, a mesenchymal stem cell marker stained positively in all three tissues of CC, LD, and CD. Corneal dermoid showed positive staining for mesodermal tissue components compared to both ectodermal and mesodermal components in limbal dermoid suggesting possibly a different origin of corneal dermoid.

The Relationship Between the Size and Ectodermal or Mesodermal Components in Laparoscopic Mature Cystic Teratoma Excisions

Overin matür kistik teratomu (MKT) ikinci ve üçüncü dekattaki kadınların en sık görülen over tümörüdür. Hemen tamamı benign olan bu tümörlerin rüptür, torsiyon ve malignite gibi çeşitli komplikasyonları vardır. Her üç germ yaprağından da köken alabilen bu tümörlerde kemik, kıkırdak, diş gibi farklı germ yapraklarına ait dokular izlenebilir. Bu çalışmanın amacı laparoskopik MKT eksizyonu yaptığımız hastaların tümör içeriklerindeki doku farklılıklarını gözlemek ve bu dokuların MKT kist büyüklüğü ile olan ilişkisini araştırmaktır. Retrospektif olarak planlanan bu çalışmaya 01.01.2006 – 31.12.2018 tarihleri arasında bir üniversite hastanesinde laparoskopik MKT eksizyonu uygulanan hastalar alındı. Hastaların demografik özellikleri, MKT çapı, bilateralite oranı, lobülasyon, içeriğindeki kıl, diş, kemik dokusu varlığı ayrıntılı olarak incelendi. Çalışmaya 236 hasta alındı. 222 hastaya laparoskopik MKT kist eksizyonu uygulanmıştı. 14 hastada ise diğer laparoskopik operasyonlar sonrasında patoloji spesimeninde matür kistik teratom saptanmıştı. Bilateralite oranı %15,2 idi. 4-5 cm çapında 58, 5-6 cm çapında 78, 6-7 cm çapında 82, 7 cm’den büyük 54 MKT saptandı. MKT’un çapı arttıkça içerisinde kıl, diş veya kemik doku bulunma veya lobule olma ihtimali belirgin olarak artıyordu. İstatistiksel olarak bakıldığında özellikle 7 cm den büyük kistlerde her üç dokuyu da içerme ve lobülasyon olasılığı en yüksek anlam düzeyine ulaşıyordu. Sonuç olarak laparoskopik MKT eksizyonu yapılan olgularda kist boyutu ile içerdiği farklı germ yapraklarına ait doku komponentleri ve lobülasyon durumu doğru orantılıdır. Bu durum özellikle 7 cm ve üstü matür kistik teratomlarda daha belirgindir.

Amelogenesis Imperfecta – Case Series and Management

Amelogenesis imperfecta (AI) incorporates an assemblage of hereditary diseases that involve the defective formation or calcification of enamel. Also known by varied names such as Hereditary enamel dysplasia, Hereditary brown enamel, Hereditary brown opalescent teeth, this defect is entirely ectodermal, since mesodermal components are unaffected. AI is typically characterized by generalized enamel defects in both primary and permanent dentition. The AI trait can be transmitted by either autosomal dominant, autosomal recessive, or X-linked modes of inheritance.AI has a marked impact on aesthetics, function and psychology of the patient. Early intervention and dental rehabilitation should be carried out with strong emphasis on the preventive care and strict follow up schedule. Key words: Amelogenesis imperfecta, developmental anomaly, Dental Rehabilitation

Mouse models of human craniofacials spliceosomopathies: Are they neurocristopathies?

Splicing, the removal of introns from pre‐messenger RNA is an essential step for expression of most genes in multicellular organisms and for expanding the number of proteins coded by genomes. Recently, exome sequencing revealed that mutations in splicing factors and small nuclear ribonucleoprotein particles (snRNPs) which form core components of the spliceosome, are responsible for craniofacial malformations. Our group used in situ hybridization to examine expression of three core components of the spliceosome: Eftud2 – mutated in patients with mandibulofacial dysostosis, Guion‐Almeida type (MFDGA); SnrpB – responsible for Cerebrocostomandibular Syndrome (CMS); and Sf3b4 which is responsible for Nager syndrome. Herein, we report expression of Eftud2, Sf3b4 and SnrpB during craniofacial development. In addition, we used CRISPR/Cas9 to generate mice with deletion (Eftud2 del) and conditional mutation of exon 2 of Eftud2 (Eftud2 flox). At embryonic days (E) 7.5 and 8.5, Eftud2 was highly expressed in ectodermal and mesodermal components of the future craniofacial region, by E9.5 expression was also found in the body wall and developing heart. Eftud2 del heterozygous mice were viable and fertile, though these embryos showed reduced levels of Eftud2 mRNA and protein. In contrast, Eftud2 del homozygous mutant embryos arrest at E3.5 and failed to grow and hatch ex vivo. To examine the requirement for Eftud2 in neural crest cells, the Wnt1‐Cre2 transgenic line was used to delete exon 2 of Eftud2 specifically in that lineage. Eftud2 flox homozygous mutant embryos carrying the Wnt1‐Cre2 transgene displayed hypoplasia of the midbrain and pharyngeal arches starting at E9.5. By E11.5, most embryos also had an open neural tube and all embryos showed exencephaly at E14.5. Cartilage preparations revealed an absence of cartilage in the head, reduction/or absence of Meckel's cartilage, and abnormal inner ear development. Since deletion of exon 2 is predicted to generate a truncated protein with partial function, our data suggest that normal levels of Eftud2 is crucial in neural crest cells for normal craniofacial development. Future studies are focused on elucidating the molecular and transcriptional basis of MFDM using this mouse model.Support or Funding InformationCanadian Institute of Health Research (MOP#142452)This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

EFTUD2, The Gene Responsible For Mandibulofacial Dysostosis With Microcephaly (MFDM), Is Required For Implantation And Craniofacial Development In Mouse

Haploinsufficiency of EFTUD2 is associated with MFDM (mandibulofacial dysostosis with microcephaly), but the etiology of this syndrome remains unknown. Our goal is to determine the tissue and temporal specific expression and requirement for Eftud2 during craniofacial development. We used RT‐PCR and in situ hybridization to examine expression of Eftud2 during embryogenesis. Using CRISPR/Cas9 we designed guide RNAs to generate mice with deletion (Eftud2 del) and conditional mutation of exon 2 of Eftud2 (Eftud2 flox). At embryonic day (E) 7.5 and 8.5 of mouse development, Eftud2 was highly expressed in both ectodermal and mesodermal components of the developing head and craniofacial region, by E9.5 Eftud2 was more broadly expressed, in the body wall and developing heart. Eftud2 del heterozygous mice and embryos were viable and fertile and showed a 38% and a 30% reduction of Eftud2 mRNA and protein expression, respectively. Before the onset of organogenesis, Eftud2 del heterozygous embryos had reduced number of somites when compared to their wild type litter mates, indicating a delay in development. Noticeably, RNA sequencing revealed that Eftud2 was the only transcript significantly affected in these heterozygous mice. Eftud2 del homozygous mutant embryos did not implant and failed to grow and hatch ex vivo. Next, we used the Wnt1‐Cre2 transgenic line to delete exon 2 of Eftud2 specifically in the neural crest cells. Eftud2 flox heterozygous embryos carrying the Wnt‐Cre2 transgene were normal. However, Eftud2 flox homozygous mutant embryos that also carry the Wnt1‐Cre2 transgene displayed hypoplasia of the midbrain and pharyngeal arches starting as early as E9.5. By E11.5, most of these embryos showed an open neural tube, all embryos showed exencephaly at E14.5. Cartilage preparations revealed an absence of cartilage in the head, reduced/or absence of Meckel's cartilage, and abnormal inner ear development. Crosses with the Rosa26R mice reporter line, revealed reduced neural crest cell migration into the pharyngeal region at E10.5. Since the mutation designed is predicted to generate a truncated protein with partial function, our data suggest that normal levels of Eftud2 is crucial during embryogenesis. Future studies are focused on determining the molecular and transcriptional basis of MFDM using this mouse model.Support or Funding InformationCanadian Institutes of Health ResearchThis abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Clinical significance of long non-coding RNA HOTTIP in early-stage non-small-cell lung cancer

BackgroundHOTTIP, a long non-coding RNA located in the HOXA cluster, plays a role in the patterning of tissues with mesodermal components, including the lung. Overexpression of HOXA genes, including HOTTIP, has been associated with a more aggressive phenotype in several cancers. However, the prognostic impact of HOTTIP has not yet been explored in non-small-cell lung cancer (NSCLC). We have correlated HOTTIP expression with time to relapse (TTR) and overall survival (OS) in early-stage NSCLC patients.MethodsNinety-nine early-stage NSCLC patients who underwent surgical resection in our center from June 2007 to November 2013 were included in the study. Mean age was 66; 77.8% were males; 73.7% had stage I disease; and 55.5% had adenocarcinoma. A validation data set comprised stage I-II patients from The Cancer Genome Atlas (TCGA) Research Network.ResultsHOTTIP was expressed in all tumor samples and was overexpressed in squamous cell carcinoma (p = 0.007) and in smokers (p = 0.018). Patients with high levels of HOTTIP had shorter TTR (78.3 vs 58 months; p = 0.048) and shorter OS (81.2 vs 61 months; p = 0.023) than those with low levels. In the multivariate analysis, HOTTIP emerged as an independent prognostic marker for TTR (OR: 2.05, 95%CI: 1–4.2; p = 0.05), and for OS (OR: 2.31, 95%CI: 1.04–5.1; p = 0.04). HOTTIP was validated as a prognostic marker for OS in the TCGA adenocarcinoma cohort (p = 0.025). Moreover, we identified a 1203-mRNA and a 61-miRNA signature that correlated with HOTTIP expression.ConclusionsThe lncRNA HOTTIP can be considered a prognostic biomarker in early-stage NSCLC.

Intrathoracic fibrolipoma resected using complete thoracoscopic surgery: a case report

BackgroundOther than adipocytes, lipomas may contain mesodermal components such as varying proportions of fibrous tissues and blood vessels. Fibrolipoma is an uncommon variant of lipoma and comprises a high proportion of fibrous components. An intrathoracic fibrolipoma is extremely rare; to the best of our knowledge, only three such cases have been reported till date.Case presentationA 51-year-old female presented with a left intrathoracic mass, which was confirmed to be a lipomatous tumor using computed tomography. A pedunculated tumor originating from the parietal pleura was resected using complete thoracoscopic surgery. Pathological examination indicated a diagnosis of fibrolipoma. Intrathoracic fibrolipomas are extremely rare; this is one of the first reported cases of successfully resecting an intrathoracic fibrolipoma using complete thoracoscopic surgery.ConclusionsThe tumor was asymptomatic and relatively small when detected during a medical checkup. This enabled the successful resection of the tumor via complete thoracoscopic surgery. Although fibrolipomas are histologically benign, careful observation and follow-up are essential owing to the possibility of recurrence.

1284P - HOXA-related long non-coding RNAs impact prognosis in early stage NSCLC patients

Background: HOX genes, grouped in four clusters in humans (HOXA-D), encode for transcription factors that are master regulators of embryonic development and oncogenesis. HOXA cluster, located in chromosome 7, play a critical role in the patterning of tissues with mesodermal components such as lungs. Long non-coding RNAs (lncRNAs) are especially abundant in the HOXA cluster (HOXA10-AS, HOXAS2, HOXAS3, HOXA11-AS, HOTAIRM1 and HOTTIP). We aimed to evaluate the prognostic role of HOXA-related lncRNAs in early stage non-small cell lung cancer (NSCLC). Methods: 100 early stage NSCLC patients resected in our center from June 2007 to November 2013 were studied. Patient characteristics: median age, 65 (32-84); 78% males; 74% stage I; 56% ADK; 23% received adjuvant treatment. With a mean follow-up of 28.7 months, 31% relapsed. As validation data set 200 NSCLC patients from TCGA Research Network were used (RNAseq data). Only stage I-II TCGA samples without prior malignancy or synchronous cancer that not received neoadjuvant treatment were included. Statistical analysis was performed using R and TANRIC. Results: HOTTIP and HOXA11AS impacted prognosis in our cohort of patients. HOTTIP was expressed in all samples and patients with high levels of HOTTIP had shorter TTR (78.3 vs 58 months; p = 0.048) and shorter OS (81.2 vs 61 months; p = 0.023). HOTTIP was overexpressed in SCC (p = 0.007) and in smokers (p = 0.018). HOXA11AS was expressed only in 9% of patients but the patients expressing HOXA11AS had shorter TTR (73.5 vs 32 months; p = 0.002). In the multivariate analysis HOXA11AS emerged as an independent prognostic marker for TTR (OR: 3.13, 95%CI: 1.3-7.3; p = 0.009), while HOTTIP (OR: 2.357, 95%CI: 1.1-5.2; p = 0.036) and age>65 (p = 0.022) for OS. In the validation data set HOXA11AS was validated as prognostic marker (p = 0.019). HOXA11AS expression correlated positively with development genes HOXA11, HOXA13, HOXA10, HOXA9, HOXA3, FOXD1, ZIC5 and miR-196b (HOXA cluster miRNA) and negatively with surfactant metabolism genes SFTPB and NAPSA or let-7a(p < 0.001). Interestingly, the high expression was associated to patients harboring RTN1 mutations (p < 0.0001). Conclusions: HOXA11AS expression in early stage NSCLC patients is a high-risk relapse marker. Legal entity responsible for the study: University of Barcelona, Barcelona, Spain Funding: None Disclosure: All authors have declared no conflicts of interest. Keywords: HOTTIP, NSCLC, lncRNA, HOXA11AS

Mature cystic teratoma with neurogenic components and struma ovarii: a rare case report and review of the literature

Mature cystic teratoma of the ovary is a common germ cell tumor among women. Teratomas are more frequently seen in younger women. In teratoma, all three germ cell layers are present, and hence any type of histological tissue can develop. As regards the type of tissue present, it may be mature or immature. In monodermal teratoma, one of the tissues may predominate, such as thyroid tissue in struma ovarii and neuroectodermal tissue in carcinoid tumor. Here, we present a case report in which a young woman presented with ovarian mass diagnosed histopathologically as mature ovarian teratoma having mostly neurologic elements such as glial tissue, melanotic cells, choroid plexus, and struma ovarii, and along with that fat and respiratory epithelium were also identified. Ovarian teratoma is composed of derivatives of three germ cell layers, but in some cases monodermal component such as struma ovarii can be seen with neurogenic components and mesodermal components.

Odontodysplasia involving single tooth: A rare entity

Odontodysplasia is the developmental anomaly caused due to disturbances in the ectodermal and mesodermal component of the tooth. Although it involves multiple teeth in a quadrant, the involvement of a single tooth germ is very rare. The present report is a case of odontodysplasia involving a single maxillary central incisor.

Comprehensive timeline of mesodermal development in the quail small intestine

To generate the mature intestine, splanchnic mesoderm diversifies into six different tissue layers each with multiple cell types through concurrent and complex morphogenetic events. Hindering the progress of research in the field is the lack of a detailed description of the fundamental morphological changes that constitute development of the intestinal mesoderm. We used immunofluorescence and morphometric analyses of wild-type and Tg(tie1:H2B-eYFP) quail embryos to establish a comprehensive timeline of mesodermal development in the avian intestine. The following landmark features were analyzed from appearance of the intestinal primordium through generation of the definitive structure: radial compartment formation, basement membrane dynamics, mesothelial differentiation, mesenchymal expansion and growth patterns, smooth muscle differentiation, and maturation of the vasculature. In this way, structural relationships between mesodermal components were identified over time. This integrated analysis presents a roadmap for investigators and clinicians to evaluate diverse experimental data obtained at individual stages of intestinal development within the longitudinal context of intestinal morphogenesis.

Development of head and trunk mesoderm in the dogfish, Scyliorhinus torazame: I. Embryology and morphology of the head cavities and related structures

Vertebrate head segmentation has attracted the attention of comparative and evolutionary morphologists for centuries, given its importance for understanding the developmental body plan of vertebrates and its evolutionary origin. In particular, the segmentation of the mesoderm is central to the problem. The shark embryo has provided a canonical morphological scheme of the head, with its epithelialized coelomic cavities (head cavities), which have often been regarded as head somites. To understand the evolutionary significance of the head cavities, the embryonic development of the mesoderm was investigated at the morphological and histological levels in the shark, Scyliorhinus torazame. Unlike somites and some enterocoelic mesodermal components in other vertebrates, the head cavities in S. torazame appeared as irregular cyst(s) in the originally unsegmented mesenchymal head mesoderm, and not via segmentation of an undivided coelom. The mandibular cavity appeared first in the paraxial part of the mandibular mesoderm, followed by the hyoid cavity, and the premandibular cavity was the last to form. The prechordal plate was recognized as a rhomboid roof of the preoral gut, continuous with the rostral notochord, and was divided anteroposteriorly into two parts by the growth of the hypothalamic primordium. Of those, the posterior part was likely to differentiate into the premandibular cavity, and the anterior part disappeared later. The head cavities and somites in the trunk exhibited significant differences, in terms of histological appearance and timing of differentiation. The mandibular cavity developed a rostral process secondarily; its homology to the anterior cavity reported in some elasmobranch embryos is discussed.

Early Diagnosis of Regional Odontodysplasia in an Infant

Regional odontodysplasia is a rare and significant dental malformation. It is a dental alteration of unknown etiology, involving both mesodermal and ectodermal dental components, which present clinical, radiographic, and histologic features. This article reports a clinical case of a 10-month-old child who was diagnosed with regional odontodysplasia in the maxilla, confirmed by radiographic examination, with a follow-up of 5 years. The clinical, radiographic, and histologic features were reviewed.

Regional odontodysplasia—an unusual case occurring along with supernumerary teeth

Regional odontodysplasia (RO) is an unusual developmental anomaly which affects the ectodermal and mesodermal component in a group of contiguous teeth. Supernumerary teeth are those that are found in addition to the normal series of teeth. An interesting case of RO, multiple impacted supernumerary teeth and alveolar swelling in the second quadrant is reported here. Unlike the earlier reported cases, the case was unique in that the roots of the hypoplastic teeth showed continued root formation suggesting for more conservative treatment and no cases of simultaneous occurrence of RO and impacted supernumerary teeth have been reported in the literature.

Literature Review of Amelogenesis Imperfecta with Case Report

Amelogenesis imperfecta (AI) is a diverse collection of inherited diseases that exhibit qualitative or quantitative tooth enamel defects in the absence of systemic manifestations. Also known by varied names, such as hereditary enamel dysplasia, hereditary brown opalescent teeth, this defect is entirely ectodermal, since mesodermal components of the teeth are basically normal. This article details a case of AI along with complete review which presents in his twin siblings with clinical, radiological and histopathological report.