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Dentistry Journal Apr 2023Collagen is the building block for the extracellular matrix in bone, teeth and other fibrous tissues. Osteogenesis imperfecta (OI), or brittle bone disease, is a... (Review)
Review
Collagen is the building block for the extracellular matrix in bone, teeth and other fibrous tissues. Osteogenesis imperfecta (OI), or brittle bone disease, is a heritable disorder that results from defective collagen synthesis or metabolism, resulting in bone fragility. The dental manifestation of OI is dentinogenesis imperfecta (DI), a genetic disorder that affects dentin structure and clinical appearance, with a characteristic feature of greyish-brown discolouration. The aim of this study was to conduct a systematic review to identify and/or define any ultrastructural changes in dentinal collagen in DI. Established databases were searched: Cochrane Library, OVID Embase, OVID Medline and PubMed/Medline. Search strategies included: Collagen Ultrastructure, DI and OI. Inclusion criteria were studies written in English, published after 1990, that examined human dental collagen of teeth affected by DI. A Cochrane data extraction form was modified and used for data collection. The final dataset included seventeen studies published from 1993 to 2021. The most prevalent findings on collagen in DI teeth were increased coarse collagen fibres and decreased fibre quantity. Additional findings included changes to fibre orientation (i.e., random to parallel) and differences to the fibre organisation (i.e., regular to irregular). Ultrastructural defects and anomalies included uncoiled collagen fibres and increased D-banding periodicity. Studies in collagen structure in DI reported changes to the surface topography, quantity, organisation and orientation of the fibres. Moreover, ultrastructural defects such as the packing/coiling and D-banding of the fibrils, as well as differences in the presence of other collagens are also noted. Taken together, this study provides an understanding of the changes in collagen and its impact on clinical translation, paving the way for innovative treatments in dental treatment.
PubMed: 37185473
DOI: 10.3390/dj11040095 -
Orphanet Journal of Rare Diseases Aug 2018Dentinogenesis imperfecta (DGI) is a heritable disorder of dentin. Genetic analyses have found two subgroups in this disorder: DGI type I, a syndromic form associated...
BACKGROUND
Dentinogenesis imperfecta (DGI) is a heritable disorder of dentin. Genetic analyses have found two subgroups in this disorder: DGI type I, a syndromic form associated with osteogenesis imperfecta (OI), and DGI type II, a non-syndromic form. The differential diagnosis between types I and II is often challenging. Thus, the present cross-sectional study had two aims: to (i) investigate the prevalence and incidence of DGI type II among Swedish children and adolescents and (ii) search out undiagnosed cases of DGI type I by documenting the prevalence of clinical symptoms of OI in these individuals. We invited all public and private specialist pediatric dental clinics (n = 47) in 21 counties of Sweden to participate in the study. We then continuously followed up all reported cases during 2014-2017 in order to identify all children and adolescents presenting with DGI type II. Using a structured questionnaire and an examination protocol, pediatric dentists interviewed and examined patients regarding medical aspects such as bruising, prolonged bleeding, spraining, fractures, hearing impairment, and family history of osteoporosis and OI. Joint hypermobility and sclerae were assessed. The clinical oral examination, which included a radiographic examination when indicated, emphasized dental variables associated with OI.
RESULTS
The prevalence of DGI type II was estimated to be 0.0022% (95% CI, 0.0016-0.0029%) or 1 in 45,455 individuals. Dental agenesis occurred in 9% of our group. Other findings included tooth retention (17%), pulpal obliteration (100%), and generalized joint hypermobility (30%). Clinical and radiographic findings raised a suspicion of undiagnosed OI in one individual, a 2-year-old boy; he was later diagnosed with OI type IV.
CONCLUSIONS
These results show a significantly lower prevalence of DGI type II than previously reported and point to the importance of excluding OI in children with DGI.
Topics: Adolescent; Adult; Child; Child, Preschool; Connective Tissue; Cross-Sectional Studies; Dentin Dysplasia; Dentinogenesis Imperfecta; Extracellular Matrix Proteins; Female; Genetic Diseases, Inborn; Humans; Incidence; Infant; Male; Osteogenesis Imperfecta; Phosphoproteins; Sialoglycoproteins; Surveys and Questionnaires; Sweden; Young Adult
PubMed: 30134932
DOI: 10.1186/s13023-018-0887-2 -
Journal of Oral Biosciences Mar 2020The Bone Morphogenetic Proteins (BMPs) direct tooth development and still express in the adult tooth. We hypothesized that inhibition of BMP function would therefore...
OBJECTIVES
The Bone Morphogenetic Proteins (BMPs) direct tooth development and still express in the adult tooth. We hypothesized that inhibition of BMP function would therefore disrupt dentinogenesis by differentiated odontoblasts.
METHODS
We generated mice overexpressing the BMP-inhibitory protein Noggin in differentiated odontoblasts and osteocytes under control of a Dmp1 promoter-driven cre transgene. We compared the dentin phenotype in these mice with that in WT littermates and in mice with a Smad4 odontoblast/osteocyte knockout mediated by the same cre and therefore lacking all BMP and Tgfβ signaling in the same tissues.
RESULTS
Three-month-old first molars from both Noggin-expressing and Smad4-deleted mice showed decreased dentin volume with enlarged pulp cavities, and both displayed less organized and mineralized dentinal tubules compared to WT. The Smad4-ablated phenotype was more severe. While dentin sialophosphoprotein (DSPP) and bone sialoprotein (BSP) were decreased in the dentin of both lines, dentin matrix protein 1 (DMP1) was sharply increased in Noggin-expressing teeth.
CONCLUSIONS
The phenotypes we observed in Noggin-overexpressing and Smad4-conditional knockout teeth resemble the phenotype of Dentinogenesis Imperfecta (DGI) type III. Our results show that BMPs regulate post-natal dentinogenesis and that BMP-inhibitory proteins like Noggin play a role in that regulation. The increased severity of the Smad4 phenotype indicates that Tgfβ ligands, in addition to BMPs, play a crucial role in post-developmental dentinogenesis.
Topics: Animals; Carrier Proteins; Dentin; Dentinogenesis; Extracellular Matrix Proteins; Mice; Phosphoproteins; Sialoglycoproteins
PubMed: 31862386
DOI: 10.1016/j.job.2019.11.001 -
Current Genomics Apr 2018During the last decades, a large amount of newly described microduplications and microdeletions associated with intellectual disability (ID) and related neuropsychiatric... (Review)
Review
During the last decades, a large amount of newly described microduplications and microdeletions associated with intellectual disability (ID) and related neuropsychiatric diseases have been discovered. However, due to natural limitations, a significant part of them has not been the focus of multidisciplinary approaches. Here, we address previously undescribed chromosome 4q21.2q21.3 microduplication for gene prioritization, evaluation of cognitive abilities and estimation of genomic mechanisms for brain dysfunction by molecular cytogenetic (cytogenomic) and gene expression (meta-) analyses as well as for neuropsychological assessment. We showed that duplication at 4q21.2q21.3 is associated with moderate ID, cognitive deficits, developmental delay, language impairment, memory and attention problems, facial dysmorphisms, congenital heart defect and dentinogenesis imperfecta. Gene-expression meta-analysis prioritized the following genes: ENOPH1, AFF1, DSPP, SPARCL1, and SPP1. Furthermore, genotype/phenotype correlations allowed the attribution of each gene gain to each phenotypic feature. Neuropsychological testing showed visual-perceptual and fine motor skill deficits, reduced attention span, deficits of the nominative function and problems in processing both visual and aural information. Finally, emerging approaches including molecular cytogenetic, bioinformatic (genome/epigenome meta-analysis) and neuropsychological methods are concluded to be required for comprehensive neurological, genetic and neuropsychological descriptions of new genomic rearrangements/diseases associated with ID.
PubMed: 29606904
DOI: 10.2174/1389202918666170717161426 -
Clinical Oral Investigations Apr 2024Dentinogenesis imperfecta (DI) is an inherited dentin defect and may be isolated or associated with disorders such as osteogenesis imperfecta, odontochondrodysplasia...
OBJECTIVE
Dentinogenesis imperfecta (DI) is an inherited dentin defect and may be isolated or associated with disorders such as osteogenesis imperfecta, odontochondrodysplasia Ehler-Danlos and others. Isolated DI is caused mainly by pathogenic variants in DSPP gene and around 50 different variants have been described in this gene. Herein, we report on 19 patients from two unrelated Egyptian families with isolated DI. Additionally, we focused on genetic counselling of the two families.
MATERIALS AND METHODS
The patients were examined clinically and dentally. Panoramic X-rays were done to some patients. Whole exome sequencing (WES) and Sanger sequencing were used.
RESULTS
WES revealed two new nonsense variants in DSPP gene, c.288T > A (p.Tyr96Ter) and c.255G > A (p.Trp85Ter). Segregation analysis by Sanger sequencing confirmed the presence of the first variant in all affected members of Family 1 while the second variant was confirmed to be de novo in the patient of Family 2.
CONCLUSIONS AND CLINICAL RELEVANCE
Our study extends the number of DSPP pathogenic variants and strengthens the fact that DSPP is the most common DI causative gene irrespective of patients' ethnicity. In addition, we provide insights on genetic counseling issues in patients with inherited DSPP variants taking into consideration the variable religion, culture and laws in our society.
Topics: Humans; Dentinogenesis Imperfecta; Genetic Counseling; Ethnicity; Osteochondrodysplasias; Radiography, Panoramic
PubMed: 38630328
DOI: 10.1007/s00784-024-05636-z -
The Journal of Clinical Pediatric... 2019Dentinogenesis Imperfecta type II (DI2), also known as hereditary opalescent dentin, is one of the most common genetic disorders affecting the structure of dentin, not... (Review)
Review
Dentinogenesis Imperfecta type II (DI2), also known as hereditary opalescent dentin, is one of the most common genetic disorders affecting the structure of dentin, not related with osteogenesis imperfecta, which involves both primary and permanent dentitions. The purpose of this article is to perform a scoping review of the published peer-reviewed literature (1986-2017) on DI2 management in children and to outline the most relevant clinical findings extracted from this review. Forty four articles were included in the present scoping review. According to the extracted data, the following are the most important tasks to be performed in clinical pediatric dentistry: to re-establish the oral mastication, esthetics, and speech, and the development of vertical growth of alveolar bone and facial muscles; to reduce the tendency to develop caries, periapical lesions and pain; to preserve vitality, form, and size of the dentition; to avoid interfering with the eruption process of permanent teeth; to decrease the risk of tooth fractures and occlusion disturbances; to return the facial profile to a more normal appearance; and to prevent or treat possible temporomandibular joint problems. Therefore, Pediatric Dentists should bear in mind that early diagnosis and treatment, together a long-term follow-up of DI2 in children, continue to be the best approaches for achieving enhanced patient psychological well-being and, in consequence, their quality of life.
Topics: Child; Child, Preschool; Dental Care for Children; Dentinogenesis Imperfecta; Dentition, Permanent; Esthetics, Dental; Humans; Quality of Life
PubMed: 30964718
DOI: 10.17796/1053-4625-43.3.1 -
Journal of Oral and Maxillofacial... Mar 2021Dentinogenesis imperfecta (DGI) type II affects both primary and permanent dentitions and has the autosomal mode of inheritance. The affected teeth may appear as amber...
Dentinogenesis imperfecta (DGI) type II affects both primary and permanent dentitions and has the autosomal mode of inheritance. The affected teeth may appear as amber or gray because of chipping of enamel shortly after their eruption. Correct diagnosis and management are highly needed to restore the quality of oral health and to improve esthetics and masticatory functions. We present here a case of systematic and conservative dental approach in the management of a 7-year-old child having Dentinogenesis Imperfecta Type II (DGI Type II) with 1 ½ follow-up.
PubMed: 34083977
DOI: 10.4103/jomfp.JOMFP_172_20 -
Annals of Translational Medicine Nov 2021Dentinogenesis imperfecta (DGI), Shields type-II is an autosomal dominant genetic disease which severely affects the function of the patients' teeth. The dentin...
BACKGROUND
Dentinogenesis imperfecta (DGI), Shields type-II is an autosomal dominant genetic disease which severely affects the function of the patients' teeth. The dentin sialophosphoprotein () gene is considered to be the pathogenic gene of DGI-II. In this study, a DGI-II family with a novel DSPP mutation were collected, functional characteristics of DGI cells and clinical features were analyzed to better understand the genotype-phenotype relationship of this disease.
METHODS
Clinical data were collected, whole exome sequencing (WES) was conducted, and Sanger sequencing was used to verify the mutation sites. Physical characteristics of the patient's teeth were examined using scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The localization of green fluorescent protein (GFP)-fused wild-type (WT) dentin sialoprotein (DSP) and its variant were evaluated via an immunocytochemistry (ICC) assay. The behaviors of human dental pulp stem cells (hDPSCs) were investigated by flow cytometry, osteogenic differentiation, and quantitative real-time polymerase chain reaction (qRT-PCR).
RESULTS
A novel heterozygous mutation c.53T > G (p. Val18Gly) in was found in this family. The SEM results showed that the participants' teeth had reduced and irregular dentinal tubes. The EDS results showed that the Ca/P ratio of the patients' teeth was significantly higher than that of the control group. The ICC assay showed that the mutant DSP was entrapped in the endoplasmic reticulum (ER), while the WT DSP located mainly in the Golgi apparatus. In comparison with normal cells, the patient's cells exhibited significantly decreased mineralization ability and lower expression levels of and .
CONCLUSIONS
The c.53T > G (p. Val18Gly) variant was shown to present with rare hypoplastic enamel defects. Functional analysis revealed that this novel variant disturbs dentinal characteristics and pulp cell behavior.
PubMed: 34988181
DOI: 10.21037/atm-21-5369 -
Oral Diseases Mar 2019Hereditary dentin disorders include dentinogenesis imperfecta (DGI) and dentin dysplasia (DD), which are autosomal dominant diseases characterized by altered dentin... (Review)
Review
Hereditary dentin disorders include dentinogenesis imperfecta (DGI) and dentin dysplasia (DD), which are autosomal dominant diseases characterized by altered dentin structure such as abnormality in dentin mineralization and the absence of root dentin. Shields classified DGI into three subgroups and DD into two subtypes. Although they are all hereditary dentin diseases, they do not share the same causative genes. To date, the pathogenic genes of DGI type I, which is considered a clinical manifestation of syndrome osteogenesis imperfecta, include COL1A1 and COL1A2. Mutations of the DSPP gene, which encodes the dentin sialophosphoprotein, a major non-collagenous protein, are responsible for three isolated dentinal diseases: DGI-II, DGI-III, and DD-II. However, DD-I appears to be special in that researchers have found three pathogenicity genes-VPS4B, SSUH2, and SMOC2-in three affected families from different countries. It is believed that DD-I is a genetically heterogeneous disease and is distinguished from other types of dentin disorders. This review summarizes the DD-I literature in the context of clinical appearances, radiographic characteristics, and functions of its pathogenic genes and aims to serve clinicians in further understanding and diagnosing this disease.
Topics: ATPases Associated with Diverse Cellular Activities; Caenorhabditis elegans Proteins; Calcium-Binding Proteins; Dentin Dysplasia; Dentinogenesis Imperfecta; Diagnosis, Differential; Endosomal Sorting Complexes Required for Transport; Genetic Heterogeneity; Humans; Phosphoprotein Phosphatases
PubMed: 29575674
DOI: 10.1111/odi.12861 -
Global Medical Genetics Sep 2021Dentin sialophosphoprotein ( ) gene mutations cause autosomal dominantly inherited diseases. gene mutations lead to abnormal expression of DSPP, resulting in a series... (Review)
Review
Dentin sialophosphoprotein ( ) gene mutations cause autosomal dominantly inherited diseases. gene mutations lead to abnormal expression of DSPP, resulting in a series of histological, morphological, and clinical abnormalities. A large number of previous studies demonstrated that DSPP is a dentinal-specific protein, and gene mutations lead to dentin dysplasia and dentinogenesis imperfecta. Recent studies have found that DSPP is also expressed in bone, periodontal tissues, and salivary glands. DSPP is involved in the formation of the periodontium as well as tooth structures. DSPP deficient mice present furcation involvement, cementum, and alveolar bone defect. We speculate that similar periodontal damage may occur in patients with mutations. This article reviewed the effects of gene mutations on periodontal status. However, almost all of the research is about animal study, there is no evidence that mutations cause periodontium defects in patients yet. We need to conduct systematic clinical studies on mutation families in the future to elucidate the effect of gene on human periodontium.
PubMed: 34430959
DOI: 10.1055/s-0041-1726416