Ellis-van Creveld syndrome

Mechanisms driving vestibular lamina formation and opening in the mouse

The vestibular lamina (VL) forms as an epithelial outgrowth parallel to the dental lamina (DL) in the oral cavity. During late development, it opens to create a furrow that divides the dental tissue from the cheeks and lips and is known as the vestibule. Defects in this process lead to failure in the separation of the teeth from the lips and cheeks, including the presence of multiple frenula. In this paper, the development of the VL is followed in the mouse, from epithelial placode in the embryo to postnatal opening and vestibule formation. During early outgrowth, differential proliferation controls the curvature of the VL as it extends under the forming incisors. Apoptosis plays a role in thinning the deepest part of the lamina, while terminal differentiation of the epithelium, highlighted by the expression of loricrin and flattening of the nuclei, predates the division of the VL into two to create the vestibule. Development in the mouse is compared to the human VL, with respect to the relationship of the VL to the DL, VL morphology and mechanisms of opening. Overall, this paper provides insight into an understudied part of the oral anatomy, shedding light on how defects could form in this region.

Development of the Vestibular Lamina in Human Embryos: Morphogenesis and Vestibule Formation

The vestibular lamina (VL) is a transient developmental structure that forms the lip furrow, creating a gap between the lips/cheeks and teeth (oral vestibule). Surprisingly, little is known about the development of the VL and its relationship to the adjacent dental lamina (DL), which forms the teeth. In some congenital disorders, such as Ellis-van Creveld (EVC) syndrome, development of the VL is disrupted and multiple supernumerary frenula form, physically linking the lips and teeth. Here, we assess the normal development of the VL in human embryos from 6.5 (CS19) to 13 weeks of development, showing the close relationship between the VL and DL, from initiation to differentiation. In the anterior lower region, the two structures arise from the same epithelial thickening. The VL then undergoes complex morphogenetic changes during development, forming a branched structure that separates to create the vestibule. Changing expression of keratins highlight the differentiation patterns in the VL, with fissure formation linked to the onset of filaggrin. Apoptosis is involved in removal of the central portion of the VL to create a broad furrow between the future cheek and gum. This research forms an essential base to further explore developmental defects in this part of the oral cavity.

Genetic and developmental disorders of the oral mucosa: Epidemiology; molecular mechanisms; diagnostic criteria; management

A large number of disorders may affect the oral cavity, including genetic diseases, infections, cancers, blood diseases, skin diseases, endocrine and metabolic disorders, autoimmune and rheumatologic diseases, local lesions, to name a few. Oral mucosa shows a considerable variation in its normal structure and a wide range of conditions may affect it. Such conditions are often harmless or minor and could be primary or secondary to systemic disease. Several of them are quite rare and, hence, the diagnosis is not easy. Clinically, lesions may appear as ulcers, discoloration of the oral mucosa and alterations in size and configuration of oral anatomy. Genetic disorders have specific manifestations and can be caused by a derangement of one or more components of the tissue. Many of them follow the skin or systemic signs of the underlying genetic disease, but in a few cases oral signs could be the first manifestation of the disorder. Among them genodermatoses are prominent. They are inherited disorders characterized by a multisystem involvement. This review describes chondro-ectodermal dysplasia, dyskeratosis congenita, Ehlers-Danlos syndrome, hereditary benign intraepithelial dyskeratosis, keratosis follicularis, lipoid proteinosis, multiple hamartoma syndrome, pachyonychia congenita, Peutz-Jeghers syndrome, tuberous sclerosis and white sponge nevus. Other genetic disorders not included in the genodermatosis group and reported in the present review are: acanthosis nigricans, angio-osteo-hypertrophic syndrome, encephalotrigeminal angiomatosis, familial adenomatous polyposis, focal dermal hypoplasia, focal palmoplantar and oral mucosa hyperkeratosis syndrome, gingival fibromatosis, Maffucci's syndrome, neurofibromatosis (type 1) and oro-facial-digital syndrome (type 1). Disorders during embryonic development might lead to a wide range of abnormalities in the oral cavity; some of them are quite common but of negligible concern, whereas others are rare but serious, affecting not only the oral mucosa, but also other structures of the oral cavity (ie palate, tongue and gingiva). Fordyce's granules, leukoedema, cysts of the oral mucosa in newborns, retrocuspid papilla, geographic tongue, fissured tongue, median rhomboid glossitis, hairy tongue, lingual varices and lingual thyroid nodule are described. This review may help dentists, dental hygienists, but also general internists and pediatricians to diagnose different disorders of the oral mucosa, to understand the pathogenesis and to schedule a treatment plan.

Oral manifestations of ellis-van creveld syndrome. A rare case report

Ellis-van Creveld syndrome (EVC) or chondroectodermal dysplasia is an autosomal recessive disorder, characterized by dwarfism, polydactyly, hypoplastic fingernails and congenital heart defects, finding in most of the cases orofacial anomalies. We describe a clinical case of a 9 year old male patient diagnosed with EVC who visited our Maxillofacial private consultation at Alcorcon Southern Hospital, presenting typical oral manifestations such as dental agenesis, delayed eruption, hypoplasia of the enamel, dental dysmorphism, taurodontism and supernumerary teeth. EVC syndrome is a rare disease and requires a multidisciplinary approach. Oral features are constant and requires the jointly performance of Odontologist and Maxillofacial surgeon aiming to get an appropriate treatment sequence surgery-orthodontics in order to achieve a suitable functional result to improve the quality of life of these patients.

Key words:Ellis-Van creveld syndrome, chondroectodermal dysplasia, oral manifestations, craniofacial manifestations.

Oral manifestations in Ellis-van Creveld syndrome: a case report

Introduction: Ellis-van Creveld (EVC) syndrome is an uncommon genetic disease that can be diagnosed at any age. Observation: A case of EVC syndrome was reported in a young 3-year-old female patient presenting chondroectodermal dysplasia, polydactyly, congenital heart defects, damage to the oral mucosa and numerous dental alterations (number, form and structure). Oral management consists of teaching oral hygiene and the prophylactic filling of dental cracks. Discussion: EVC is an autosomal recessive disease. Its diagnosis is only based on clinical features and genetic studies. Conclusion: Dentists should be aware of this syndrome to avoid a late diagnosis and to facilitate a multidisciplinary management.