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Journal of Anatomy Nov 2005Normal and abnormal jaw growth and tooth eruption are topics of great importance for several dental and medical disciplines. Thus far, clinical studies on these topics... (Review)
Review
Normal and abnormal jaw growth and tooth eruption are topics of great importance for several dental and medical disciplines. Thus far, clinical studies on these topics have used two-dimensional (2D) radiographic techniques. The purpose of the present study was to analyse normal mandibular growth and tooth eruption in three dimensions based on computer tomography (CT) scans, extending the principles of mandibular growth analysis proposed by Björk in 1969 from two to three dimensions. As longitudinal CT data from normal children are not available (for ethical reasons), CT data from children with Apert syndrome were employed, because it has been shown that the mandible in Apert syndrome is unaffected by the malformation, and these children often have several craniofacial CT scans performed during childhood for planning of cranial and midface surgery and for follow-up after surgery. A total of 49 datasets from ten children with Apert syndrome were available for study. The number of datasets from each individual ranged from three to seven. The first CT scan in each of the ten series was carried out before 1 year of age, and the ages for the 49 scans ranged from 1 week to 14.5 years. The mandible and the teeth were segmented and iso-surfaces generated. Landmarks were placed on the surface of the mandible, along the mandibular canals, the inner contour of the cortical plate at the lower border of the symphysis menti, and on the teeth. Superimposition of the mandibles in the longitudinal series was performed using the symphysis menti and the mandibular canals as suggested by Björk. The study supported the findings of stability of the symphysis menti and the mandibular canals as seen in profile view previously reported by Björk & Skieller in 1983. However, the mandibular canals were, actually, relocated laterally during growth. Furthermore, the position of tooth buds remained relatively stable inside the jaw until root formation started. Eruption paths of canines and premolars were vertical, whereas molars erupted in a lingual direction. The 3D method would seem to offer new insight into jaw growth and tooth eruption, but further studies are needed.
Topics: Acrocephalosyndactylia; Adolescent; Bicuspid; Child; Child, Preschool; Cuspid; Female; Humans; Imaging, Three-Dimensional; Infant; Longitudinal Studies; Male; Mandible; Molar; Tomography, X-Ray Computed; Tooth Eruption
PubMed: 16313399
DOI: 10.1111/j.1469-7580.2005.00479.x -
Current Medicinal Chemistry 2008Basic Helix-loop-Helix (bHLH) factors play a significant role in both development and disease. bHLH factors function as protein dimers where two bHLH factors compose an... (Review)
Review
Basic Helix-loop-Helix (bHLH) factors play a significant role in both development and disease. bHLH factors function as protein dimers where two bHLH factors compose an active transcriptional complex. In various species, the bHLH factor Twist has been shown to play critical roles in diverse developmental systems such as mesoderm formation, neurogenesis, myogenesis, and neural crest cell migration and differentiation. Pathologically, Twist1 is a master regulator of epithelial-to-mesenchymal transition (EMT) and is causative of the autosomal-dominant human disease Saethre Chotzen Syndrome (SCS). Given the wide spectrum of Twist1 expression in the developing embryo and the diverse roles it plays within these forming tissues, the question of how Twist1 fills some of these specific roles has been largely unanswered. Recent work has shown that Twist's biological function can be regulated by its partner choice within a given cell. Our work has identified a phosphoregulatory circuit where phosphorylation of key residues within the bHLH domain alters partner affinities for Twist1; and more recently, we show that the DNA binding affinity of the complexes that do form is affected in a cis-element dependent manner. Such perturbations are complex as they not only affect direct transcriptional programs of Twist1, but they indirectly affect the transcriptional outcomes of any bHLH factor that can dimerize with Twist1. Thus, the resulting lineage-restricted cell fate defects are a combination of loss-of-function and gain-of-function events. Relating the observed phenotypes of defective Twist function with this complex regulatory mechanism will add insight into our understanding of the critical functions of this complex transcription factor.
Topics: Acrocephalosyndactylia; Animals; Basic Helix-Loop-Helix Transcription Factors; DNA; Dimerization; Epithelial Cells; Extremities; Gene Expression Regulation, Developmental; Helix-Loop-Helix Motifs; Humans; Mesoderm; Mice; Molecular Sequence Data; Nuclear Proteins; Phenotype; Phosphorylation; Sequence Homology, Amino Acid; Twist-Related Protein 1
PubMed: 18855684
DOI: 10.2174/092986708785908987 -
Indian Journal of Dermatology,... 2010
Topics: Acrocephalosyndactylia; Female; Humans; Infant; Isotretinoin; Male; Young Adult
PubMed: 21079334
DOI: 10.4103/0378-6323.72479 -
Revue Medicale de Liege Oct 2021Apert syndrome, or acrocephalosyndactilia type I, is a rare genetic disorder caused by mutations in the FGFR2 gene and characterized by craniosynostosis, craniofacial...
Apert syndrome, or acrocephalosyndactilia type I, is a rare genetic disorder caused by mutations in the FGFR2 gene and characterized by craniosynostosis, craniofacial dysmorphia and symmetrical syndactyly of the hands and feet. The estimated prevalence of this syndrome is 10 to 15.5 cases per 1,000,000 live births. This syndrome presents significant clinical variability and its early diagnosis is essential. We report an isolated case of Apert syndrome, diagnosed during follow-up of a biamniotic bichorium twin pregnancy.
Topics: Acrocephalosyndactylia; Craniosynostoses; Female; Humans; Mutation; Pregnancy; Receptor, Fibroblast Growth Factor, Type 2; Syndactyly
PubMed: 34632738
DOI: No ID Found -
Romanian Journal of Morphology and... 2017Apert syndrome - acrocephalosyndactyly - is a rare autosomal dominant disorder representing 1:65 000 cases of living newborns. Characteristic malformations of the Apert...
Apert syndrome - acrocephalosyndactyly - is a rare autosomal dominant disorder representing 1:65 000 cases of living newborns. Characteristic malformations of the Apert syndrome are early craniostenosis, microviscerocranium and II-V finger syndactyly of hand and toes with proximal phalanx of the bilateral thumb "in delta". It is difficult to determine prenatal diagnosis in the second quarter, when examining the morphology of fetal signs; the dysmorphism signs appeared in the third pregnancy quarter. We present here the case of a newborn with Apert syndrome that was born prematurely in our Clinic after a monitored pregnancy, where there was issued a suspicion of cranio-facial dysmorphism, malposition and malformation of the feet and hands in the third quarter of prenatal pregnancy. The diagnosis of Apert syndrome was placed on clinical signs, laboratory and genetic tests. The clinical outcome of the baby in the maternity was favorable, the therapeutic management being established by a multidisciplinary team. Immediate complications were due to the case of prematurity: respiratory distress syndrome and the characteristics of the syndrome: micrognathia and naso-facial dysmorphism, syndactyly, bilateral foot metatarsus adductus.
Topics: Acrocephalosyndactylia; Female; Humans; Infant, Newborn; Pregnancy; Reticulocytosis; Syndactyly
PubMed: 28523332
DOI: No ID Found -
The Laryngoscope Apr 2021To characterize tracheal cartilage morphology in mouse models of fibroblast growth factor receptor (Fgfr2)-related craniosynostosis syndromes. To establish relationships...
OBJECTIVES
To characterize tracheal cartilage morphology in mouse models of fibroblast growth factor receptor (Fgfr2)-related craniosynostosis syndromes. To establish relationships between specific Fgfr2 mutations and tracheal cartilaginous sleeve (TCS) phenotypes in these mouse models.
METHODS
Postnatal day 0 knock-in mouse lines with disease-specific genetic variations in the Fgfr2 gene (Fgfr2 , Fgfr2 , Fgfr2 , Fgfr2 , and Fgfr2 ) as well as line-specific controls were utilized. Tracheal cartilage morphology as measured by gross analyses, microcomputed tomography (μCT), and histopathology were compared using Chi-squared and single-factor analysis of variance statistical tests.
RESULTS
A greater proportion of rings per trachea were abnormal in Fgfr2 tracheas (63%) than Fgfr2 (17%), Fgfr2 (17%), Fgfr2 (12%), and controls (10%) (P < .001 for each vs. Fgfr2 ). TCS segments were found only in Fgfr2 (100%) and Fgfr2 (72%) tracheas. Cricoid and first-tracheal ring fusion was noted in all Fgfr2 and 94% of Fgfr2 samples. The Fgfr2 and Fgfr2 groups were found to have greater areas and volumes of cartilage than other lines on gross analysis and μCT. Histologic analyses confirmed TCS among the Fgfr2 and Fgfr2 groups, without appreciable differences in cartilage morphology, cell size, or density; no histologic differences were observed among other Fgfr2 lines compared to controls.
CONCLUSION
This study found TCS phenotypes only in the Fgfr2 mouse lines. These lines also had increased tracheal cartilage compared to other mutant lines and controls. These data support further study of the Fgfr2 mouse lines and the investigation of other Fgfr2 variants to better understand their role in tracheal development and TCS formation.
LEVEL OF EVIDENCE
NA Laryngoscope, 131:E1349-E1356, 2021.
Topics: Acanthosis Nigricans; Acrocephalosyndactylia; Animals; Cartilage; Craniofacial Dysostosis; Craniosynostoses; Disease Models, Animal; Ear; Genetic Association Studies; Humans; Mice; Mutation; Phenotype; Receptor, Fibroblast Growth Factor, Type 2; Scalp Dermatoses; Skin Abnormalities; Trachea; Tracheal Diseases; X-Ray Microtomography
PubMed: 32886384
DOI: 10.1002/lary.29060 -
Tidsskrift For Den Norske Laegeforening... May 2004Complex craniofacial synostosis is a group of rare genetic disorders characterized by premature closure of the sutures in the craniofacial skeleton and which to varying... (Review)
Review
BACKGROUND
Complex craniofacial synostosis is a group of rare genetic disorders characterized by premature closure of the sutures in the craniofacial skeleton and which to varying degrees affects the extremities.
MATERIAL AND METHODS
On the basis of relevant literature, we present a review of syndromal craniofacial synostosis.
RESULTS
Phenotypically, the complex craniofacial syndromes have many similarities. Synostosis of the sutures of the cranial vault can result in a variety of skull deformations, depending on the sutures involved, the sequence of premature closure, and the time of closure. Synostosis of the sutures in the skull base and facial skeleton leads to shallow orbits, exophthalmus, hypertelorism, midface retrusion, and prognathia.
INTERPRETATION
Precise diagnosis of complex craniofacial syndromes may be difficult solely on the basis of a clinical examination. However, several of the most common syndromes are caused by mutations in genes that code for fibroblast growth-factor receptors. Children with a suspected complex craniofacial syndrome should be referred to genetic testing.
Topics: Acrocephalosyndactylia; Craniosynostoses; Humans; Infant; Infant, Newborn; Mutation; Phenotype; Receptors, Fibroblast Growth Factor
PubMed: 15131704
DOI: No ID Found -
Journal of Korean Medical Science Apr 2006Pfeiffer Syndrome is as rare as Apert syndrome in the Western population. This condition is very rare in the Asian population and has not been previously reported in... (Review)
Review
Pfeiffer Syndrome is as rare as Apert syndrome in the Western population. This condition is very rare in the Asian population and has not been previously reported in Korea. The authors report with a review of literature the case of a newborn baby with Pfeiffer syndrome, manifested by bicoronal craniosynostosis, broad thumbs, and big toes. The infant also had bilateral syndactyly of the fingers and toes, mild proptosis, choanal hypoplasia and maxillary hypoplasia.
Topics: Acrocephalosyndactylia; Female; Humans; Infant, Newborn; Korea; Radiography
PubMed: 16614535
DOI: 10.3346/jkms.2006.21.2.374 -
The Journal of Neuroscience : the... Sep 2022multiple epidermal growth factor-like domains 8 (dMegf8) is a homolog of human encodes a multidomain transmembrane protein which is highly conserved across species....
multiple epidermal growth factor-like domains 8 (dMegf8) is a homolog of human encodes a multidomain transmembrane protein which is highly conserved across species. In humans, mutations cause a rare genetic disorder called Carpenter syndrome, which is frequently associated with abnormal left-right patterning, cardiac defects, and learning disabilities. is also associated with psychiatric disorders. Despite its clinical relevance, remains poorly characterized; and although it is highly conserved, studies on animal models of Megf8 are also very limited. The presence of intellectual disabilities in Carpenter syndrome patients and association of with psychiatric disorders indicate that mutations in cause underlying defects in synaptic structure and functions. In this study, we investigated the role of dMegf8 in glutamatergic synapses of the larval neuromuscular junctions (NMJ) in both males and females. We show that dMegf8 localizes to NMJ synapses and is required for proper synaptic growth. mutant larvae and adults show severe motor coordination deficits. At the NMJ, mutants show altered localization of presynaptic and postsynaptic proteins, defects in synaptic ultrastructure, and neurotransmission. Interestingly, mutants have reduced levels of the Type II BMP receptor Wishful thinking (). displays genetic interactions with () and , and in association with Dnrx and Wit plays an essential role in synapse organization. Our studies provide insights into human MEGF8 functions and potentially into mechanisms that may underlie intellectual disabilities observed in Carpenter syndrome as well as MEGF8-related synaptic structural and/or functional deficits in psychiatric disorders. Carpenter syndrome, known for over a century now, is a genetic disorder linked to mutations in () gene and associated with intellectual disabilities among other symptoms. is also associated with psychiatric disorders. Despite the high genetic conservation and clinical relevance, the functions of remain largely uncharacterized. Patients with intellectual disabilities and psychiatric diseases often have an underlying defect in synaptic structure and function. This work defines the role of the fly homolog of human , , in glutamatergic synapse growth, organization, and function and provide insights into potential functions of in human central synapses and synaptic mechanisms that may underlie psychiatric disorders and intellectual disabilities seen in Carpenter syndrome.
Topics: Acrocephalosyndactylia; Animals; Drosophila; Drosophila Proteins; EGF Family of Proteins; Female; Humans; Intellectual Disability; Male; Membrane Proteins; Mutation; Receptors, Cell Surface; Synapses
PubMed: 35944997
DOI: 10.1523/JNEUROSCI.0442-22.2022 -
Archives of Gynecology and Obstetrics Jul 2022Syndromic craniosynostosis is a rare genetic disease caused by premature fusion of one or multiple cranial sutures combined with malformations of other organs. The aim...
PURPOSE
Syndromic craniosynostosis is a rare genetic disease caused by premature fusion of one or multiple cranial sutures combined with malformations of other organs. The aim of this publication is to investigate sonographic signs of different syndromic craniosynostoses and associated malformations to facilitate a precise and early diagnosis.
METHODS
We identified in the period of 2000-2019 thirteen cases with a prenatal suspected diagnosis of syndromic craniosynostosis at our department. We analyzed the ultrasound findings, MRI scans, genetic results as well as the mode of delivery, and postnatal procedures.
RESULTS
Eight children were diagnosed with Apert Syndrome, two with Saethre Chotzen syndrome, one with Crouzon syndrome, and one with Greig cephalopolysyndactyly syndrome. One child had a mutation p.(Pro253Leu) in the FGFR2 gene. We identified characteristic changes of the head shape as well as typical associated malformations.
CONCLUSION
Second trimester diagnosis of syndromic craniosynostosis is feasible based on the identified sonographic signs. In case of a suspected diagnosis a genetic, neonatal as well as surgical counseling is recommended. We also recommend to offer a fetal MRI. The delivery should be planned in a perinatal center.
Topics: Acrocephalosyndactylia; Child; Craniosynostoses; Diagnosis, Differential; Female; Humans; Infant, Newborn; Magnetic Resonance Imaging; Mutation; Pregnancy
PubMed: 34633507
DOI: 10.1007/s00404-021-06263-9